{"id":281,"date":"2023-06-14T23:30:08","date_gmt":"2023-06-15T03:30:08","guid":{"rendered":"https:\/\/opentextbooks.concordia.ca\/explorations\/chapter\/8\/"},"modified":"2025-07-17T13:20:41","modified_gmt":"2025-07-17T17:20:41","slug":"8","status":"publish","type":"chapter","link":"https:\/\/opentextbooks.concordia.ca\/explorations\/chapter\/8\/","title":{"raw":"Primate Evolution","rendered":"Primate Evolution"},"content":{"raw":"<div class=\"__UNKNOWN__\">\r\n<p class=\"import-Normal\">Jonathan M. G. Perry, Ph.D., Western University of Health Sciences<\/p>\r\n<p class=\"import-Normal\">Stephanie L. Canington, Ph.D., University of Pennsylvania<\/p>\r\n<p class=\"import-Normal\"><em>This chapter is a revision from \"<\/em><a class=\"rId7\" href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/chapter\/__unknown__-10\/\"><em>Chapter 8: Primate Evolution<\/em><\/a><em>\u201d by Jonathan M. G. Perry and Stephanie L. Canington. In <\/em><a class=\"rId8\" href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/\"><em>Explorations: An Open Invitation to Biological Anthropology, first edition<\/em><\/a><em>, edited by Beth Shook, Katie Nelson, Kelsie Aguilera, and Lara Braff, which is licensed under <\/em><a class=\"rId9\" href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\"><em>CC BY-NC 4.0<\/em><\/a><em>. <\/em><\/p>\r\n\r\n<div class=\"textbox textbox--learning-objectives\"><header class=\"textbox__header\">\r\n<h2 class=\"textbox__title\"><span style=\"color: #ffffff;\">Learning Objectives<\/span><\/h2>\r\n<\/header>\r\n<div class=\"textbox__content\">\r\n<ul>\r\n \t<li>Understand the major trends in primate evolution from the origin of primates to the origin of our own species.<\/li>\r\n \t<li>Learn about primate adaptations and how they characterize major primate groups.<\/li>\r\n \t<li>Discuss the kinds of evidence that anthropologists use to find out how extinct primates are related to each other and to living primates.<\/li>\r\n \t<li>Recognize how the changing geography and climate of Earth have influenced where and when primates have thrived or gone extinct.<\/li>\r\n<\/ul>\r\n<\/div>\r\n<\/div>\r\n<p class=\"import-Normal\">The first fifty million years of primate evolution was a series of <strong>[pb_glossary id=\"1683\"]adaptive radiations[\/pb_glossary]<\/strong> leading to the diversification of the earliest lemurs, monkeys, and apes. The primate story begins in the canopy and understory of conifer-dominated forests, with our small, furtive ancestors subsisting at night, beneath the notice of day-active dinosaurs.<\/p>\r\n<p class=\"import-Normal\">From the ancient [pb_glossary id=\"1684\"]<strong>plesiadapiforms<\/strong>[\/pb_glossary] (archaic primates) to the earliest groups of true primates ([pb_glossary id=\"1686\"]<strong>euprimates<\/strong>[\/pb_glossary]) (Bloch and Boyer 2002), the origin of our own order is characterized by the struggle for new food sources and microhabitats in the arboreal setting. Climate change forced major extinctions as the northern continents became increasingly dry, cold, and seasonal and as tropical rainforests gave way to deciduous forests, woodlands, and eventually grasslands. Lemurs, lorises, and tarsiers\u2014once diverse groups containing many species\u2014became rare, except for lemurs in Madagascar, where there were no anthropoid competitors and perhaps few predators. Meanwhile, <strong>[pb_glossary id=\"1685\"]anthropoids[\/pb_glossary]<\/strong> (monkeys and apes) likely emerged in Asia and then dispersed across parts of the northern hemisphere, Africa, and ultimately South America. The movement of continents, shifting sea levels, and changing patterns of rainfall and vegetation contributed to the developing landscape of primate biogeography, morphology, and behavior. Today\u2019s primates provide modest reminders of the past diversity and remarkable adaptations of their extinct relatives. This chapter explores the major trends in primate evolution from the origin of the Order Primates to the beginnings of our own lineage, providing a window into these stories from our ancient past.<\/p>\r\n\r\n<h2 class=\"import-Normal\">Major Hypotheses About Primate Origins<\/h2>\r\n<p class=\"import-Normal\">For many groups of mammals, there is a key feature that led to their success. A good example is powered flight in bats. Primates lack a feature like this (see Chapter 5). Instead, if there is something unique about primates, it is probably a group of features rather than one single thing. Because of this, anthropologists and paleontologists struggle to describe an ecological scenario that could explain the rise and success of our own order. Three major hypotheses have been advanced to consider the origin of primates and to explain what makes our order distinct among mammals (Figure 8.1); these are described below.<\/p>\r\n\r\n\r\n[caption id=\"attachment_278\" align=\"aligncenter\" width=\"634\"]<img class=\"wp-image-256\" src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/03\/8.1.jpg\" alt=\"Primates swinging in tree, eating an insect, and eating fruit.\" width=\"634\" height=\"221\" \/> Figure 8.1: The three major hypotheses are (a) the arboreal hypothesis, (b) the visual predation hypothesis, and (c) the angiosperm-primate coevolution hypothesis. Credit: Primate origin hypotheses original to Explorations: An Open Invitation to Biological Anthropology (2nd ed.) by <a class=\"rId13\" href=\"https:\/\/marynelsonstudio.com\">Mary Nelson<\/a> is under a <a class=\"rId14\" href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/\">CC BY-NC 4.0 License<\/a>.[\/caption]\r\n<h3 class=\"import-Normal\"><strong>Arboreal Hypothesis<\/strong><\/h3>\r\n<p class=\"import-Normal\">In the 1800s, many anthropologists viewed all animals in relation to humans. That is, animals that were more like humans were considered to be more \u201cadvanced\u201d and those lacking humanlike features were considered more \u201cprimitive.\u201d This way of thinking was particularly obvious in studies of primates. A more modern way of referring to members of a group that lack certain evolutionary innovations seen in other members is to call them [pb_glossary id=\"1688\"]<strong>plesiomorphic<\/strong>[\/pb_glossary] (literally \u201canciently shaped\u201d). The state of their morphological features is sometimes referred to as [pb_glossary id=\"1689\"]<strong>ancestral<\/strong><strong> traits<\/strong>[\/pb_glossary].<\/p>\r\n<p class=\"import-Normal\">Thus, when anthropologists sought features that separate primates from other mammals, they focused on features that were least developed in lemurs and lorises, more developed in monkeys, and most developed in apes (Figure 8.2). Frederic Wood Jones, one of the leading anatomist-anthropologists of the early 1900s, is usually credited with the Arboreal Hypothesis of primate origins (Jones 1916). This hypothesis holds that many of the features of primates evolved to improve locomotion in the trees; this way of getting around is referred to as arboreal. For example, the grasping hands and feet of primates are well suited to gripping tree branches of various sizes and our flexible joints are good for reorienting the extremities in many different ways. A mentor of Jones, Grafton Elliot Smith, had suggested that the reduced olfactory system, acute vision, and forward-facing eyes of primates are adaptations for making accurate leaps and bounds through a complex, three-dimensional canopy (Smith 1912). The forward orientation of the eyes in primates causes the visual fields to overlap, enhancing depth perception, especially at close range. Evidence to support this hypothesis includes the facts that many extant primates are arboreal, and the plesiomorphic members of most primate groups are dedicated arborealists. The Arboreal Hypothesis was well accepted by most anthropologists at the time and for decades afterward.<\/p>\r\n\r\n\r\n[caption id=\"\" align=\"aligncenter\" width=\"663\"]<img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image27-2.png\" alt=\"Diagram shows primates descended from Plesiadapiforms.\" width=\"663\" height=\"543\" \/> Figure 8.2: Primate family tree showing major groups. Disconnected lines show uncertainty about relationships. Two lines lead to tarsiers from different possible groups of origin. <a href=\"https:\/\/docs.google.com\/document\/d\/1VUDKMBJYS_jNONjLxT04jQN0_z9Ua50BRN6auGSHUuU\/edit\" target=\"_blank\" rel=\"noopener\">A full text description of this image is available<\/a>. Credit: <a class=\"rId16\" href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/chapter\/__unknown__-10\/\">Primate family tree (Figure 8.2)<\/a> by Jonathan M. G. Perry is under a <a class=\"rId17\" href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/\">CC BY-NC 4.0 License<\/a>.[\/caption]\r\n<h3 class=\"import-Normal\"><strong>Visual Predation Hypothesis<\/strong><\/h3>\r\n<p class=\"import-Normal\">In the late 1960s and early 1970s, Matt Cartmill studied and tested the idea that the characteristic features of primates evolved in the context of arboreal locomotion. Cartmill noted that squirrels climb trees (and even vertical walls) very effectively, even though they lack some of the key adaptations of primates. As members of the Order Rodentia, squirrels also lack the hand and foot anatomy of primates. They have claws instead of flattened nails and their eyes face more laterally than those of primates. Cartmill reasoned that there must be some other explanation for the unique traits of primates. He noted that some nonarboreal animals share at least some of these traits with primates; for example, cats and predatory birds have forward-facing eyes that enable visual field overlap. Cartmill suggested that the unique suite of features in primates is an adaptation to detecting insect prey and guiding the hands (or feet) to catch insects (Cartmill 1972). His hypothesis emphasizes the primary role of vision in prey detection and capture; it is explicitly comparative, relying on form-function relationships in other mammals and nonmammalian vertebrates. According to Cartmill, many of the key features of primates evolved for preying on insects in this special manner (Cartmill 1974).<\/p>\r\n\r\n<h3 class=\"import-Normal\"><strong>Angiosperm-Primate Coevolution Hypothesis<\/strong><\/h3>\r\n<p class=\"import-Normal\">The visual predation hypothesis was unpopular with some anthropologists. One reason for this is that many primates today are not especially predatory. Another is that, whereas primates do seem well adapted to moving around in the smallest, terminal branches of trees, insects are not necessarily easier to find there. A counterargument to the visual predation hypothesis is the angiosperm-primate coevolution hypothesis. Primate ecologist Robert Sussman (Sussman 1991) argued that the few primates that eat mostly insects often catch their prey on the ground rather than in tree branches. Furthermore, predatory primates often use their ears more than their eyes to detect prey. Finally, most early primate fossils show signs of having been omnivorous rather than insectivorous. Instead, he argued, the earliest primates were probably seeking fruit. Fruit (and flowers) of angiosperms (flowering plants) often develop in the terminal branches. Therefore, any mammal trying to access those fruits must possess anatomical traits that allow them to maintain their hold on thin branches and avoid falling while reaching for the fruits. Primates likely evolved their distinctive visual traits and extremities in the Paleocene (approximately 65 million to 54 million years ago) and Eocene (approximately 54 million to 34 million years ago) epochs, just when angiosperms were going through a revolution of their own\u2014the evolution of large, fleshy fruit that would have been attractive to a small arboreal mammal. Sussman argued that, just as primates were evolving anatomical traits that made them more efficient fruit foragers, angiosperms were also evolving fruit that would be more attractive to primates to promote better seed dispersal. This mutually beneficial relationship between the angiosperms and the primates was termed coevolution or more specifically [pb_glossary id=\"1691\"]<strong>diffuse coevolution<\/strong>.[\/pb_glossary]<\/p>\r\n<p class=\"import-Normal\">At about the same time, D. Tab Rasmussen noted several parallel traits in primates and the South American woolly opossum, <em>Caluromys<\/em>. He argued that early primates were probably foraging on both fruits and insects (Rasmussen 1990). As is true of <em>Caluromys<\/em> today, early primates probably foraged for fruits in the terminal branches of angiosperms, and they probably used their visual sense to aid in catching insects. Insects are also attracted to fruit (and flowers), so these insects represent a convenient opportunity for a primarily fruit-eating primate to gather protein. This solution is a compromise between the visual predation hypothesis and the angiosperm-primate coevolution hypothesis. It is worth noting that other models of primate origins have been proposed, and these include the possibility that no single ecological scenario can account for the origin of primates.<\/p>\r\n\r\n<h2 class=\"import-Normal\">The Origins of Primates<\/h2>\r\n<h3 class=\"import-Normal\"><strong>Paleocene: Mammals in the Wake of Dinosaur Extinctions<\/strong><\/h3>\r\n<p class=\"import-Normal\">Placental mammals, including primates, originated in the Mesozoic Era (approximately 251 million to 65.5 million years ago), the Age of Dinosaurs. During this time, most placental mammals were small, probably nocturnal, and probably avoided predators via camouflage and slow, quiet movement. It has been suggested that the success and diversity of the dinosaurs constituted a kind of ecological barrier to Mesozoic mammals. The extinction of the dinosaurs (and many other organisms) at the end of the Cretaceous Period (approximately 145.5\u201365.5 million years ago) might have opened up these ecological niches, leading to the increased diversity and disparity in mammals of the Tertiary Period (approximately 65.5\u20132.5 million years ago).<\/p>\r\n<p class=\"import-Normal\">The Paleocene was the first epoch in the Age of Mammals. Soon after the Cretaceous-Tertiary (K-T) extinction event, new groups of placental mammals appear in the fossil record. Many of these groups achieved a broad range of sizes and lifestyles as well as a great number of species before declining sometime in the Eocene (or soon thereafter). These groups were ultimately replaced by the modern orders of placental mammals (Figure 8.3). It is unknown whether these replacements occurred gradually, for example by competitive exclusion, or rapidly, perhaps by sudden geographic dispersals with replacement. In some senses, the Paleocene might have been a time of recovery from the extinction event; it was cooler and more seasonal globally than the subsequent Eocene.<\/p>\r\n\r\n\r\n[caption id=\"\" align=\"aligncenter\" width=\"628\"]<img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image26.jpg\" alt=\"Person in front of a mural depicting forest animals.\" width=\"628\" height=\"511\" \/> Figure 8.3: A mural of Eocene flora and fauna in North America. Credit: <a class=\"rId19\" href=\"https:\/\/flickr.com\/photos\/126377022@N07\/18404106406\">Image from page 27 of \"Annual report for the year ended June 30 ...\" (1951)<\/a> by <a class=\"rId20\" href=\"https:\/\/flickr.com\/photos\/internetarchivebookimages\/\">Internet Archive Book Images<\/a> has been designated to the <a class=\"rId21\" href=\"https:\/\/creativecommons.org\/publicdomain\/zero\/1.0\/\">public domain (CC0)<\/a>. This photograph of the mural \"Fauna and flora of middle Eocene in the Wyoming area\" by Jay Matternes, was originally published by the <a class=\"rId22\" href=\"https:\/\/www.si.edu\/\">Smithsonian<\/a>, and can be viewed in context in the <a class=\"rId23\" href=\"https:\/\/archive.org\/details\/annualreportfory1961united\/page\/7\/mode\/1up?view=theater\">online version of this book<\/a>.[\/caption]\r\n<h3 class=\"import-Normal\"><strong>Plesiadapiforms, the Archaic Primates<\/strong><\/h3>\r\n<p class=\"import-Normal\">The Paleocene epoch saw the emergence of several families of mammals that have been implicated in the origin of primates. These are the plesiadapiforms, which are archaic primates, meaning they possessed some primate features and lacked others. The word <em>plesiadapiform <\/em>means \u201calmost adapiform,\u201d a reference to some similarities between some plesiadapiforms and some adapiforms (or adapoids; later-appearing true primates)\u2014mainly in the molar teeth. Because enamel fossilizes better than other parts of the body, the molar teeth are the parts most often found and first discovered for any new species. Thus, dental similarities were often the first to be noticed by early mammalian paleontologists, partly explaining why plesiadapiforms were thought to be primates. Major morphological differences between plesidapiforms and euprimates (true primates) were observed later when more parts of plesiadapiform skeletons were discovered. Many plesiadapiforms have unusual anterior teeth and most have digits possessing claws rather than nails. So far, no plesiadapiform ever discovered has a postorbital bar (seen in extant <strong>[pb_glossary id=\"1712\"]strepsirrhines[\/pb_glossary]<\/strong>) or septum (as seen in <strong>[pb_glossary id=\"1713\"]haplorhines[\/pb_glossary]<\/strong>), and whether or not the <strong>[pb_glossary id=\"1711\"]auditory bulla[\/pb_glossary]<\/strong> was formed by the [pb_glossary id=\"1714\"]<strong>petrosal bone<\/strong> [\/pb_glossary]remains unclear for many plesiadapiform specimens. Nevertheless, there are compelling reasons (partly from new skeletal material) for including plesiadapiforms within the Order Primates.<\/p>\r\n\r\n<h4 class=\"import-Normal\"><em>Geographic and Temporal Distribution<\/em><\/h4>\r\n<p class=\"import-Normal\"><em>Purgatorius<\/em> is generally considered to be the earliest primate. This Paleocene mammal is known from teeth that are very plesiomorphic for a primate. It has some characteristics that suggest it is a basal plesiadapiform, but there is very little to link it specifically with euprimates (see Clemens 2004). Its ankle bones suggest a high degree of mobility, signaling an arboreal lifestyle (Chester et al. 2015). <em>Purgatorius<\/em> is plesiomorphic enough to have given rise to all primates, including the plesiadapiforms. However, new finds suggest that this genus was more diverse and had more differing tooth morphologies than previously appreciated (Wilson Mantilla et al. 2021). Plesiadapiform families were numerous and diverse during parts of the Paleocene in western North America and western Europe, with some genera (e.g., <em>Plesiadapis<\/em>; see Figure 8.4) living on both continents (Figure 8.5). Thus, there were probably corridors for plesiadapiform dispersal between the two continents, and it stands to reason that these mammals were living all across North America, including in the eastern half of the continent and at high latitudes. A few plesiadapiforms have been described from Asia (e.g., <em>Carpocristes<\/em>), but the affinities of these remain uncertain.<\/p>\r\n\r\n<div style=\"text-align: left;\">\r\n<table class=\"aligncenter\" style=\"width: 473.25pt;\"><caption>Figure 8.4: Families of plesiadapiforms with example genera and traits: a table. Credit: Plesiadapiforms table original to Explorations: An Open Invitation to Biological Anthropology (2nd ed.) by Jonathan M. G. Perry and Stephanie L. Canington is under a <a class=\"rId24\" href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/\">CC BY-NC 4.0 License<\/a>. Content derived from Fleagle 2013.<\/caption>\r\n<thead>\r\n<tr style=\"height: 25pt;\">\r\n<td class=\"Table1-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\r\n<p class=\"import-Normal\" style=\"text-align: center;\"><strong>Family<\/strong><\/p>\r\n&nbsp;<\/td>\r\n<td class=\"Table1-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\r\n<p class=\"import-Normal\" style=\"text-align: center;\"><strong>Genera<\/strong><\/p>\r\n&nbsp;<\/td>\r\n<td class=\"Table1-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\r\n<p class=\"import-Normal\" style=\"text-align: center;\"><strong>Morphology<\/strong><\/p>\r\n&nbsp;<\/td>\r\n<td class=\"Table1-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\r\n<p class=\"import-Normal\" style=\"text-align: center;\"><strong>Location<\/strong><\/p>\r\n&nbsp;<\/td>\r\n<td class=\"Table1-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\r\n<p class=\"import-Normal\" style=\"text-align: center;\"><strong>Age<\/strong><sup><strong>1<\/strong><\/sup><\/p>\r\n&nbsp;<\/td>\r\n<\/tr>\r\n<\/thead>\r\n<tbody>\r\n<tr class=\"Table1-R\" style=\"height: 17pt;\">\r\n<td class=\"Table1-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\r\n<p class=\"import-Normal\">Paromomyidae<\/p>\r\n<\/td>\r\n<td class=\"Table1-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\r\n<p class=\"import-Normal\"><em>Ignacius<\/em><\/p>\r\n<\/td>\r\n<td class=\"Table1-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\r\n<p class=\"import-Normal\">Long, dagger-like, lower incisor.<\/p>\r\n<\/td>\r\n<td class=\"Table1-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\r\n<p class=\"import-Normal\">North America and Europe<\/p>\r\n<\/td>\r\n<td class=\"Table1-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\r\n<p class=\"import-Normal\">Early Paleocene to Late Eocene<\/p>\r\n<\/td>\r\n<\/tr>\r\n<tr class=\"Table1-R\" style=\"height: 18pt;\">\r\n<td class=\"Table1-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\r\n<p class=\"import-Normal\">Carpolestidae<\/p>\r\n<\/td>\r\n<td class=\"Table1-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\r\n<p class=\"import-Normal\"><em>Carpolestes<\/em><\/p>\r\n<\/td>\r\n<td class=\"Table1-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\r\n<p class=\"import-Normal\">Plagiaulacoid dentition. Limb adaptations to terminal branch feeding. Grasping big toe.<\/p>\r\n<\/td>\r\n<td class=\"Table1-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\r\n<p class=\"import-Normal\">North America, Europe, and Asia<\/p>\r\n<\/td>\r\n<td class=\"Table1-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\r\n<p class=\"import-Normal\">Middle Paleocene to Early Eocene<\/p>\r\n<\/td>\r\n<\/tr>\r\n<tr class=\"Table1-R\" style=\"height: 16pt;\">\r\n<td class=\"Table1-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\r\n<p class=\"import-Normal\">Plesiadapidae<\/p>\r\n<\/td>\r\n<td class=\"Table1-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\r\n<p class=\"import-Normal\"><em>Plesiadapis<\/em><\/p>\r\n<\/td>\r\n<td class=\"Table1-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\r\n<p class=\"import-Normal\">Mitten-like upper incisor. Diastema. Large body size for group.<\/p>\r\n<\/td>\r\n<td class=\"Table1-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\r\n<p class=\"import-Normal\">North America and Europe<\/p>\r\n<\/td>\r\n<td class=\"Table1-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\r\n<p class=\"import-Normal\">Middle Paleocene to Early Eocene<\/p>\r\n<\/td>\r\n<\/tr>\r\n<tr class=\"Table1-R\" style=\"height: 1pt;\">\r\n<td class=\"Table1-C\" style=\"border-top: solid #000000 0.5pt; border-right: none #000000 0pt; border-bottom: none #000000 0pt; border-left: none #000000 0pt; padding: 0pt 5.4pt 0pt 5.4pt;\" colspan=\"4\">\r\n<p class=\"import-Normal\"><sup>1<\/sup> Derived from Fleagle 2013.<\/p>\r\n<\/td>\r\n<td class=\"Table1-C\" style=\"border-top: solid #000000 0.5pt; border-right: none #000000 0pt; border-bottom: none #000000 0pt; border-left: none #000000 0pt; padding: 0pt 5.4pt 0pt 5.4pt;\">\r\n<p class=\"import-Normal\"><\/p>\r\n<\/td>\r\n<\/tr>\r\n<tr>\r\n<td><\/td>\r\n<td><\/td>\r\n<td><\/td>\r\n<td><\/td>\r\n<td><\/td>\r\n<\/tr>\r\n<\/tbody>\r\n<\/table>\r\n<\/div>\r\n\r\n[caption id=\"attachment_278\" align=\"aligncenter\" width=\"555\"]<img class=\"wp-image-259 \" src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image5-5-e1691791897574.png\" alt=\"Global map with not fully formed continents.\" width=\"555\" height=\"308\" \/> Figure 8.5: Map of the world in the Paleocene, highlighting plesiadapiform localities on lands that would become North America, southern Europe, and eastern Asia. Credit: <a class=\"rId26\" href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/chapter\/__unknown__-10\/\">Paleocene Map with Plesiadapiform Localities (Figure 8.4)<\/a> original to<a class=\"rId27\" href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/\"> Expl<\/a><a class=\"rId28\" href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/\">orations: An Open Invitation to Biological Anthropology<\/a> by Elyssa Ebding at <a class=\"rId29\" href=\"https:\/\/www.csuchico.edu\/geop\/geoplace\/index.shtml\">GeoPlace, California State University, Chico<\/a> is under a <a class=\"rId30\" href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/\">CC BY-NC 4.0 License<\/a>. Localities based on Fleagle 2013, 211.[\/caption]\r\n<h4 class=\"import-Normal\"><em>General Morphological Features<\/em><\/h4>\r\n<p class=\"import-Normal\">Although there is much morphological variation among the families of plesiadapiforms, some common features unite the group. Most plesiadapiforms were small, the largest being about three kilograms (approximately 7 lbs.; <em>Plesiadapis cookei<\/em>). They had small brains and fairly large snouts, with eyes that faced more laterally than in euprimates. Many species show reduction and\/or loss of the canine and anterior premolars, with the resulting formation of a rodent-like <strong>[pb_glossary id=\"1172\"]diastema[\/pb_glossary] <\/strong>(a pronounced gap between the premolars and the incisors, with loss of at least the canine); this probably implies a herbivorous diet. Some families appear to have had very specialized diets, as suggested by unusual tooth and jaw shapes.<\/p>\r\n<p class=\"import-Normal\">Arguably the most interesting and unusual family of plesiadapiforms is the Carpolestidae. They are almost exclusively from North America (with a couple of possible members from Asia), and mainly from the Middle and Late Paleocene. Their molars are not very remarkable, being quite similar to those of some other plesiadapiforms (e.g., Plesiadapidae). However, their lower posterior premolars (p4) are laterally compressed and blade-like with vertical serrations topped by tiny cuspules. This unusual dental morphology is termed [pb_glossary id=\"1693\"]<strong><em>plagiaulacoid<\/em><\/strong> [\/pb_glossary] (Simpson 1933). The upper premolar occlusal surfaces are broad and are covered with many small cuspules; the blade-like lower premolar might have cut across these cuspules, between them, or both.<\/p>\r\n\r\n\r\n[caption id=\"\" align=\"alignleft\" width=\"314\"]<img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image1-5.png\" alt=\"Small brown animal with long tail.\" width=\"314\" height=\"178\" \/> Figure 8.6: An artistic rendition of Carpolestes simpsoni moving along a small diameter support. Credit: <a class=\"rId32\" href=\"https:\/\/commons.wikimedia.org\/wiki\/File:CarpolestesCL.png\">CarpolestesCL<\/a> by <a class=\"rId33\" href=\"https:\/\/commons.wikimedia.org\/wiki\/User:Sisyphos23\">Sisyphos23<\/a> is under a <a class=\"rId34\" href=\"https:\/\/creativecommons.org\/licenses\/by-sa\/3.0\/legalcode\">CC BY-SA 3.0 License<\/a>.[\/caption]\r\n<p class=\"import-Normal\">Many plesiadapiforms have robust limb bones with hallmarks of arboreality. Instead of having nails, most taxa had sharp claws on most or all of the digits. The extremities show grasping abilities comparable to those of primates and some arboreal marsupials. Nearly complete skeletons have yielded a tremendous wealth of information on locomotor and foraging habits. Many plesiadapiforms appear to have been able to cling to vertical substrates (like a broad tree trunk) using their sharp claws, propelling themselves upward using powerful hindlimbs, bounding along horizontal supports, grasping smaller branches, and moving head-first down tree trunks. In carpolestids in particular, the skeleton appears to have been especially well adapted to moving slowly and carefully in small terminal branches (Figure 8.6).<\/p>\r\n\r\n<h4 class=\"import-Normal\"><em><span style=\"background-color: #ccffcc;\">Debate: Relationship of Plesiadapiforms to True Primates<\/span> <span style=\"text-decoration: underline;\">(Transform to dig deeper \/special topic)<\/span><\/em><\/h4>\r\n<p class=\"import-Normal\">In the middle of the twentieth century, treeshrews (Order Scandentia) were often considered part of the Order Primates, based on anatomical similarities between some treeshrews and primates. For many people, plesiadapiforms represented intermediates between primates and treeshrews, so plesiadapiforms were included in Primates as well.<\/p>\r\n<p class=\"import-Normal\">Studies of reproduction and brain anatomy in treeshrews and lemurs suggested that treeshrews are not primates (e.g., Martin 1968). This was soon followed by the suggestion to also expel plesiadapiforms (Martin 1972) from the Order Primates. Like treeshrews, plesiadapiforms lack a postorbital bar, nails, and details of the ear region that characterize true primates. Many paleoanthropologists were reluctant to accept this move to banish plesiadapiforms (e.g., F. S. Szalay, P. D. Gingerich).<\/p>\r\n<p class=\"import-Normal\">Later, K. Christopher Beard (1990) found that in some ways, the digits of paromomyid plesiadapiforms are actually more similar to those of dermopterans (Order Dermoptera), the closest living relatives of primates, than they are to those of primates themselves (but see Krause 1991). At the same time, Richard Kay and colleagues (1990) found that cranial circulation patterns and auditory bulla morphology in the paromomyid, <em>Ignacius <\/em>(see Figure 8.4), are more like those of dermopterans than of primates.<\/p>\r\n<p class=\"import-Normal\">For many anthropologists, this one-two punch effectively removed plesiadapiforms from the Order Primates. In the last two decades, the tide of opinion has turned again, with many researchers reinstating plesiadapiforms as members of the Order Primates. New and more complete specimens demonstrate that the postcranial skeletons of plesiadapiforms, including the hands and feet, were primate-like, not dermorpteran-like (Bloch and Boyer 2002, 2007). New fine-grained CT scans of relatively complete plesiadapiform skulls revealed that they share some key traits with primates to the exclusion of other placental mammals (Bloch and Silcox 2006). Most significant was the suggestion that <em>Carpolestes simpsoni <\/em>possessed an auditory bulla formed by the [pb_glossary id=\"1696\"]<strong>petrosal <\/strong><strong>bone<\/strong>[\/pb_glossary], like in all living primates.<\/p>\r\n<p class=\"import-Normal\">The debate about the status of plesiadapiforms continues, owing to a persistent lack of key bones in some species and owing to genuine complexity of the anatomical traits involved. Maybe plesiadapiforms were the ancestral stock from which all primates arose, with some plesiadapiforms (e.g., carpolestids) nearer to the primate <strong>[pb_glossary id=\"1723\"]stem[\/pb_glossary]<\/strong> than others.<\/p>\r\n\r\n<h3 class=\"import-Normal\"><strong>Adapoids and Omomyoids, the First True Primates<\/strong><\/h3>\r\n<h4 class=\"import-Normal\"><em>Geographic and Temporal Distribution<\/em><\/h4>\r\n<p class=\"import-Normal\">The first universally accepted fossil primates are the adapoids (Superfamily [pb_glossary id=\"1695\"]<strong>Adapoidea<\/strong>[\/pb_glossary]) and the omomyoids (Superfamily <strong>[pb_glossary id=\"1694\"]Omomyoidea[\/pb_glossary])<\/strong>. These groups become quite distinct over evolutionary time, filling mutually exclusive niches for the most part. However, the earliest adapoids are very similar to the earliest omomyoids.<\/p>\r\n<p class=\"import-Normal\">The adapoids were mainly diurnal and herbivorous, with some achieving larger sizes than any plesiadapiforms (10 kg; 22 lbs.). By contrast, the omomyoids were mainly nocturnal, insectivorous and frugivorous, and small.<\/p>\r\n<p class=\"import-Normal\">Both groups appear suddenly at the start of the Eocene, where they are present in western North America, western Europe, and India (Figure 8.7). This wide dispersal of early primates was probably due to the presence of rainforest corridors extending far into northern latitudes.<\/p>\r\n\r\n\r\n[caption id=\"attachment_278\" align=\"aligncenter\" width=\"539\"]<img class=\"wp-image-261\" src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image22-3-e1691792023503.png\" alt=\"Global map with not fully formed continents and omomyoid localities.\" width=\"539\" height=\"317\" \/> Figure 8.7: Map of the world in the Eocene, highlighting adapoid and omomyoid localities on lands that would become North America, southern Europe, Africa, and Asia. Credit: <a class=\"rId36\" href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/chapter\/__unknown__-10\/\">Eocene Map with Adapoid and Omomyoid Localities (Figure 8.6)<\/a> original to <a class=\"rId37\" href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/\">Explorations: An Open Invitation to Biological Anthropology<\/a> by Elyssa Ebding at <a class=\"rId38\" href=\"https:\/\/www.csuchico.edu\/geop\/geoplace\/index.shtml\">GeoPlace, California State University, Chico<\/a> is under a <a class=\"rId39\" href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/\">CC BY-NC 4.0 License<\/a>. Localities based on Fleagle 2013, 229.[\/caption]\r\n<p class=\"import-Normal\">In North America and Europe, both groups achieved considerable diversity in the Middle Eocene, then mostly died out at the end of that epoch (Figure 8.8). In some Eocene rock formations in the western United States, adapoids and omomyoids make up a major part of the mammalian fauna. The Eocene of India has yielded a modest diversity of euprimates, some of which are so plesiomorphic that it is difficult to know whether they are adapoids or omomyoids (or even early anthropoids).<\/p>\r\n\r\n<div style=\"text-align: left;\">\r\n<table class=\"aligncenter\" style=\"width: 473.25pt;\"><caption>Figure 8.8: Families of adapoids and omomyoids with example genera and traits: a table. Credit: Adapoids and omomyoids table original to Explorations: An Open Invitation to Biological Anthropology (2nd ed.) by Jonathan M. G. Perry and Stephanie L. Canington is under a <a class=\"rId40\" href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/\">CC BY-NC 4.0 License<\/a>. Content derived from Fleagle 2013.<\/caption>\r\n<thead>\r\n<tr style=\"height: 25pt;\">\r\n<td class=\"Table2-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\r\n<p class=\"import-Normal\" style=\"text-align: center;\"><strong>Family<\/strong><\/p>\r\n&nbsp;<\/td>\r\n<td class=\"Table2-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\r\n<p class=\"import-Normal\" style=\"text-align: center;\"><strong>Genera<\/strong><\/p>\r\n&nbsp;<\/td>\r\n<td class=\"Table2-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\r\n<p class=\"import-Normal\" style=\"text-align: center;\"><strong>Morphology<\/strong><\/p>\r\n&nbsp;<\/td>\r\n<td class=\"Table2-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\r\n<p class=\"import-Normal\" style=\"text-align: center;\"><strong>Location<\/strong><\/p>\r\n&nbsp;<\/td>\r\n<td class=\"Table2-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\r\n<p class=\"import-Normal\" style=\"text-align: center;\"><strong>Age<\/strong><sup><strong>1<\/strong><\/sup><\/p>\r\n&nbsp;<\/td>\r\n<\/tr>\r\n<\/thead>\r\n<tbody>\r\n<tr class=\"Table2-R\" style=\"height: 18pt;\">\r\n<td class=\"Table2-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\r\n<p class=\"import-Normal\">Cercamoniidae<\/p>\r\n<\/td>\r\n<td class=\"Table2-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\r\n<p class=\"import-Normal\"><em>Donrussellia<\/em><\/p>\r\n<\/td>\r\n<td class=\"Table2-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\r\n<p class=\"import-Normal\">Variable in tooth number and jaw shape.<\/p>\r\n<\/td>\r\n<td class=\"Table2-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\r\n<p class=\"import-Normal\">Europe and Asia<\/p>\r\n<\/td>\r\n<td class=\"Table2-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\r\n<p class=\"import-Normal\">Early to Late Eocene<\/p>\r\n<\/td>\r\n<\/tr>\r\n<tr class=\"Table2-R\" style=\"height: 16pt;\">\r\n<td class=\"Table2-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\r\n<p class=\"import-Normal\">Asiadapidae<sup>2<\/sup><\/p>\r\n<\/td>\r\n<td class=\"Table2-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\r\n<p class=\"import-Normal\"><em>Asiadapis<\/em><\/p>\r\n<\/td>\r\n<td class=\"Table2-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\r\n<p class=\"import-Normal\">Plesiomorphic teeth and jaw resemble early Omomyids.<\/p>\r\n<\/td>\r\n<td class=\"Table2-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\r\n<p class=\"import-Normal\">Asia<\/p>\r\n<\/td>\r\n<td class=\"Table2-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\r\n<p class=\"import-Normal\">Early Eocene<\/p>\r\n<\/td>\r\n<\/tr>\r\n<tr class=\"Table2-R\" style=\"height: 16pt;\">\r\n<td class=\"Table2-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\r\n<p class=\"import-Normal\">Caenopithecidae<sup>3<\/sup><\/p>\r\n<\/td>\r\n<td class=\"Table2-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\r\n<p class=\"import-Normal\"><em>Darwinius<\/em><\/p>\r\n<\/td>\r\n<td class=\"Table2-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\r\n<p class=\"import-Normal\">Robust jaws with crested molars. Fewer premolars.<\/p>\r\n<\/td>\r\n<td class=\"Table2-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\r\n<p class=\"import-Normal\">Europe, Africa, North America, and Asia<\/p>\r\n<\/td>\r\n<td class=\"Table2-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\r\n<p class=\"import-Normal\">Middle to Late Eocene<\/p>\r\n<\/td>\r\n<\/tr>\r\n<tr class=\"Table2-R\" style=\"height: 16pt;\">\r\n<td class=\"Table2-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\r\n<p class=\"import-Normal\">Adapidae<\/p>\r\n<\/td>\r\n<td class=\"Table2-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\r\n<p class=\"import-Normal\"><em>Adapis<\/em><\/p>\r\n<\/td>\r\n<td class=\"Table2-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\r\n<p class=\"import-Normal\">Fused mandible. Long molar crests. Large size and large chewing muscles.<\/p>\r\n<\/td>\r\n<td class=\"Table2-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\r\n<p class=\"import-Normal\">Europe<\/p>\r\n<\/td>\r\n<td class=\"Table2-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\r\n<p class=\"import-Normal\">Late Eocene to Early Oligocene<\/p>\r\n<\/td>\r\n<\/tr>\r\n<tr class=\"Table2-R\" style=\"height: 16pt;\">\r\n<td class=\"Table2-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\r\n<p class=\"import-Normal\">Sivaladapidae<\/p>\r\n<\/td>\r\n<td class=\"Table2-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\r\n<p class=\"import-Normal\"><em>Sivaladapis<\/em><\/p>\r\n<\/td>\r\n<td class=\"Table2-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\r\n<p class=\"import-Normal\">Some large with robust jaws.<\/p>\r\n<\/td>\r\n<td class=\"Table2-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\r\n<p class=\"import-Normal\">Asia<\/p>\r\n<\/td>\r\n<td class=\"Table2-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\r\n<p class=\"import-Normal\">Middle Eocene to Late Miocene<\/p>\r\n<\/td>\r\n<\/tr>\r\n<tr class=\"Table2-R\" style=\"height: 16pt;\">\r\n<td class=\"Table2-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\r\n<p class=\"import-Normal\">Notharctidae<sup>4<\/sup><\/p>\r\n<\/td>\r\n<td class=\"Table2-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\r\n<p class=\"import-Normal\"><em>Notharctus<\/em><\/p>\r\n<\/td>\r\n<td class=\"Table2-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\r\n<p class=\"import-Normal\">Canine sexual dimorphism. Lemur-like skull. Clinging and leaping adaptations.<\/p>\r\n<\/td>\r\n<td class=\"Table2-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\r\n<p class=\"import-Normal\">North America and Europe<\/p>\r\n<\/td>\r\n<td class=\"Table2-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\r\n<p class=\"import-Normal\">Early to Middle Eocene<\/p>\r\n<\/td>\r\n<\/tr>\r\n<tr class=\"Table2-R\" style=\"height: 16pt;\">\r\n<td class=\"Table2-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\r\n<p class=\"import-Normal\">Omomyidae<sup>5<\/sup><\/p>\r\n<\/td>\r\n<td class=\"Table2-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\r\n<p class=\"import-Normal\"><em>Teilhardina<\/em><\/p>\r\n<\/td>\r\n<td class=\"Table2-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\r\n<p class=\"import-Normal\">Small, nocturnal, frugivorous or insectivorous. Tarsier-like skull in some.<\/p>\r\n<\/td>\r\n<td class=\"Table2-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\r\n<p class=\"import-Normal\">North America, Europe, and Asia<\/p>\r\n<\/td>\r\n<td class=\"Table2-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\r\n<p class=\"import-Normal\">Early Eocene to Early Miocene<\/p>\r\n<\/td>\r\n<\/tr>\r\n<tr class=\"Table2-R\" style=\"height: 16pt;\">\r\n<td class=\"Table2-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\r\n<p class=\"import-Normal\">Microchoeridae<sup>6<\/sup><\/p>\r\n<\/td>\r\n<td class=\"Table2-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\r\n<p class=\"import-Normal\"><em>Necrolemur<\/em><\/p>\r\n<\/td>\r\n<td class=\"Table2-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\r\n<p class=\"import-Normal\">Long bony ear tubes. Tarsier-like lower limb adaptations for leaping.<\/p>\r\n<\/td>\r\n<td class=\"Table2-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\r\n<p class=\"import-Normal\">Europe and Asia<\/p>\r\n<\/td>\r\n<td class=\"Table2-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\r\n<p class=\"import-Normal\">Early Eocene to Early Oligocene<\/p>\r\n<\/td>\r\n<\/tr>\r\n<tr class=\"Table2-R\" style=\"height: 1pt;\">\r\n<td class=\"Table2-C\" style=\"border-top: solid #000000 0.5pt; border-right: none #000000 0pt; border-bottom: none #000000 0pt; border-left: none #000000 0pt; padding: 0pt 5.4pt 0pt 5.4pt;\" colspan=\"4\">\r\n<p class=\"import-Normal\"><sup>1<\/sup> Derived from Fleagle 2013.<\/p>\r\n<p class=\"import-Normal\"><sup>2<\/sup> See Dunn et al. 2016 and Rose et al. 2018.<\/p>\r\n<p class=\"import-Normal\"><sup>3<\/sup> See Kirk and Williams 2011 and Seiffert et al. 2009.<\/p>\r\n<p class=\"import-Normal\"><sup>4<\/sup> See Gregory 1920.<\/p>\r\n<p class=\"import-Normal\"><sup>5<\/sup> See Beard and MacPhee 1994 and Strait 2001.<\/p>\r\n<p class=\"import-Normal\"><sup>6<\/sup> See Schmid 1979.<\/p>\r\n<\/td>\r\n<td class=\"Table2-C\" style=\"border-top: solid #000000 0.5pt; border-right: none #000000 0pt; border-bottom: none #000000 0pt; border-left: none #000000 0pt; padding: 0pt 5.4pt 0pt 5.4pt;\">\r\n<p class=\"import-Normal\"><\/p>\r\n<\/td>\r\n<\/tr>\r\n<tr>\r\n<td><\/td>\r\n<td><\/td>\r\n<td><\/td>\r\n<td><\/td>\r\n<td><\/td>\r\n<\/tr>\r\n<\/tbody>\r\n<\/table>\r\n<\/div>\r\n<p class=\"import-Normal\">Adapoids and omomyoids barely survived the Eocene-Oligocene extinctions, when colder temperatures, increased seasonality, and the retreat of rainforests to lower latitudes led to changes in mammalian biogeography. In North America, one genus (originally considered an omomyoid but recently reclassified as Adapoidea) persisted until the Miocene: <em>Ekgmowechashala<\/em> (Rose and Rensberger 1983). This taxon has highly unusual teeth and might have been a late immigrant to North America from Asia. In Asia, one family of adapoids, the Sivaladapidae, retained considerable diversity as late as the Late Miocene.<\/p>\r\n\r\n<h4 class=\"import-Normal\"><em>Adapoid Diversity<\/em><\/h4>\r\n<p class=\"import-Normal\">Adapoids were very diverse, particularly in the Eocene of North America and Europe. They can be divided into six families, with a few species of uncertain familial relationship. As a group, adapoids have some features in common, although much of what they share is plesiomorphic. Important features include the hallmarks of euprimates: postorbital bar, flattened nails, grasping extremities, and a petrosal bulla (Figures 8.9 and 8.10). In addition, some adapoids retain the ancestral dental formula of 2.1.4.3; that is, in each quadrant of the mouth, there are two incisors, one canine, four premolars, and three molars. In general, the incisors are small compared to the molars, but the canines are relatively large, with sexual dimorphism in some species. Cutting crests on the molars are well developed in some species, and the two halves of the mandible were fused at the midline in some species. Some adapoids were quite small (<em>Anchomomys <\/em>at a little over 100 g), and some were quite large (<em>Magnadapis<\/em> at 10 kg; 22 lbs.). Furthermore, the spaces and attachment features for the chewing muscles were truly enormous in some species, suggesting that these muscles were very large and powerful. Taken together, this suggests an overall adaptive profile of diurnal herbivory. The canine sexual dimorphism in some species suggests a possible mating pattern of polygyny, as males in polygynous primate species often compete with each other for mates and have especially large canine teeth.<\/p>\r\n\r\n\r\n[caption id=\"\" align=\"aligncenter\" width=\"548\"]<img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image18-1.jpg\" alt=\"Three partial animal crania.\" width=\"548\" height=\"350\" \/> Figure 8.9: Representative crania of Adapidae from Museum d\u2019Histoire Naturelle Victor Brun, a natural history museum in Montauban, France. The white scale bar is 1 cm long. Credit: <a class=\"rId43\" href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/chapter\/__unknown__-10\/\">Representative crania of adapids (European adapoids, (Figure 8.7)<\/a> from the <a class=\"rId44\" href=\"https:\/\/www.museum.montauban.com\/\">Museum d\u2019Histoire Naturelle Victor Brun in Montauban, France<\/a> original to <a class=\"rId45\" href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/\">Explorations: An Open Invitation to Biological Anthropology <\/a>by Jonathan M. G. Perry is under a <a class=\"rId46\" href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/\">CC BY-NC 4.0 License<\/a>.[\/caption]\r\n\r\n[caption id=\"\" align=\"aligncenter\" width=\"547\"]<img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image19-2.jpg\" alt=\"Side views of small rodentlike skeleton with long tail.\" width=\"547\" height=\"525\" \/> Figure 8.10: Darwinius masillae, a member of the Caenopithecidae. The slab on the left is Plate A and the slab on the right is Plate B. The parts of the skeleton in B that are outside of the dashed lines were fabricated. Credit: <a class=\"rId48\" href=\"https:\/\/commons.wikimedia.org\/wiki\/File:Darwinius%20masillae%20holotype%20slabs.jpg\">Darwinius masillae holotype slabs<\/a> by Jens L. Franzen, Philip D. Gingerich, J\u00f6rg Habersetzer1, J\u00f8rn H. Hurum, Wighart von Koenigswald, B. Holly Smith is under a <a class=\"rId49\" href=\"https:\/\/creativecommons.org\/licenses\/by\/2.5\/legalcode\">CC BY 2.5 License<\/a>. Originally from Franzen et al. 2009.[\/caption]\r\n<h4 class=\"import-Normal\"><em>Omomyoid Diversity<\/em><\/h4>\r\n<p class=\"import-Normal\">Like adapoids, omomyoids appeared suddenly at the start of the Eocene and then became very diverse with most species dying out before the Oligocene. Omomyoids are known from thousands of jaws with teeth, relatively complete skulls for about a half-dozen species, and very little postcranial material. Omomyoids were relatively small primates, with the largest being less than three kilograms (approximately 7 lbs.; <em>Macrotarsius montanus<\/em>). All known crania possess a postorbital bar, which in some has been described as \u201cincipient closure.\u201d Some\u2014but not all\u2014known crania have an elongated bony ear tube extending lateral to the location of the eardrum, a feature seen in living tarsiers and <strong>[pb_glossary id=\"2568\"]catarrhines[\/pb_glossary]<\/strong>. The anterior teeth tend to be large, with canines that are usually not much larger than the incisors. Often it is difficult to distinguish closely related species using molar morphology, but the premolars tend to be distinct from one species to another. The postcranial skeleton of most omomyoids shows hallmarks of leaping behavior reminiscent of that of tarsiers. In North America, omomyoids became very diverse and abundant. In fact, omomyoids from Wyoming are sufficiently abundant and from such stratigraphically controlled conditions that they have served as strong evidence for the gradual evolution of anatomical traits over time (Rose and Bown 1984).<\/p>\r\n<p class=\"import-Normal\"><em>Teilhardina <\/em>(Figure 8.11; see Figure 8.2) is one of the earliest and arguably the most plesiomorphic of omomyoids. <em>Teilhardina<\/em> has several species, most of which are from North America, with one from Europe (<em>T. belgica<\/em>) and one from Asia (<em>T. asiatica<\/em>). The species of this genus are anatomically similar and the deposits from which they are derived are roughly contemporaneous. Thus, this small primate likely dispersed across the northern continents very rapidly (Smith et al. 2006).<\/p>\r\n\r\n\r\n[caption id=\"\" align=\"aligncenter\" width=\"545\"]<img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image3-1.jpg\" alt=\"World map with primates jumping across forested areas.\" width=\"545\" height=\"289\" \/> Figure 8.11: A map of the world during the early Eocene showing one hypothesis for the direction of dispersal of the omomyoid Teilhardina. The map depicts primates hopping from continent to continent (East to West) via the forest corridors at high latitudes. Credit: <a href=\"https:\/\/www.pnas.org\/content\/103\/30\/11223\">Paleogeographic map showing hypothetical migration routes of Teilhardina (Figure 1)<\/a> by Thierry Smith, Kenneth D. Rose, and Philip D. Gingerich. 2006. <a href=\"https:\/\/www.pnas.org\/about\/rights-permissions\">Proceedings of the National Academy of Sciences of the United States of America <\/a>103 (30): 11223\u201311227. Copyright (2006) National Academy of Sciences. Image <a href=\"https:\/\/www.pnas.org\/about\/rights-permissions\">is used for non-commercial and educational purposes as outlined by PNAS.<\/a>[\/caption]\r\n<h2 class=\"import-Normal\">The Emergence of Modern Primate Groups<\/h2>\r\n<h3 class=\"import-Normal\"><strong>Origins of Crown Strepsirrhines<\/strong><\/h3>\r\n<p class=\"import-Normal\">Until the turn of this century, very little was known about the origins of the <strong>[pb_glossary id=\"1698\"]crown[\/pb_glossary]<\/strong> (living) strepsirrhines. The Quaternary record of Madagascar contains many amazing forms of lemurs, including giant sloth-like lemurs, lemurs with perhaps monkey-like habits, lemurs with koala-like habits, and even a giant aye-aye (Godfrey and Jungers 2002). However, in Madagascar, early Tertiary continental sediments are lacking, and there is no record of lemur fossils before the Pleistocene.<\/p>\r\n<p class=\"import-Normal\">The fossil record of galagos is slightly more informative. Namely, there are Miocene African fossils that are very likely progenitors of lorisids (Simpson 1967). However, these are much like modern galagos and do not reveal anything about the relationship between crown strepsirrhines and Eocene fossil primates (but see below regarding <em>Propotto<\/em>). A similar situation exists for lorises in Asia: there are Miocene representatives, but these are substantially like modern lorises. The discovery of the first definite [pb_glossary id=\"1699\"]<strong>toothcomb<\/strong>[\/pb_glossary] canine (a hallmark of stresirrhines) in 2003 provided the \u201csmoking gun\u201d for the origin of crown strepsirrhines (Seiffert et al. 2003). Recently, several other African primates have been recognized as having strepsirrhine affinities (Marivaux et al. 2013; Seiffert 2012). The enigmatic Fayum primate <em>Plesiopithecus<\/em> is known from a skull that has been compared to aye-ayes and to lorises (Godinot 2006; Simons and Rasmussen 1994a).<\/p>\r\n<p class=\"import-Normal\">The now-recognized diversity of stem strepsirrhines from the Eocene and Oligocene of Afro-Arabia is strong evidence to suggest that strepsirrhines originated in that geographic area. This implies that lorises dispersed to Asia subsequent to an African origin. It is unknown what the first strepsirrhines in Madagascar were like. However, it seems likely that the lemuriform-lorisiform split occurred in continental Africa, followed by dispersal of lemuriform stock to Madagascar. Recent evidence suggests that <em>Propotto<\/em>, a Miocene primate from Kenya originally described as a potto antecedent, actually forms a clade with <em>Plesiopithecus <\/em>and the aye-aye; this might suggest that strepsirrhines dispersed to Madagascar from continental Africa more than once (Gunnell et al. 2018).<\/p>\r\n\r\n<h3 class=\"import-Normal\"><strong>The Fossil Record of Tarsiers<\/strong><\/h3>\r\n<p class=\"import-Normal\">Tarsiers are so unusual that they fuel major debates about primate taxonomy. Tarsiers today are moderately diverse but geographically limited and not very different in their ecological habits\u2014especially considering that the split between them and their nearest living relative probably occurred over 50 million years ago. If omomyoids are excluded, then the fossil record of tarsiers is very limited. Two fossil species from the Miocene of Thailand have been placed in the genus <em>Tarsius<\/em>, as has an Eocene fossil from China (Beard et al. 1994). These, and <em>Xanthorhysis<\/em> from the Eocene of China, are all very tarsier-like. In fact, it is striking that <em>Tarsius eocaenus<\/em> from China was already so tarsier-like as early as the Eocene. This suggests that tarsiers achieved their current morphology very early in their evolution and have remained more or less the same while other primates changed dramatically. Two additional genera, <em>Afrotarsius<\/em> from the Oligocene of Egypt and Libya and <em>Afrasia<\/em> from the Eocene of Myanmar, have also been implicated in tarsier origins, though the relationship between them and tarsiers is unclear (Chaimanee et al. 2012). More recently, a partial skeleton of a small Eocene primate from China, <em>Archicebus achilles<\/em> (dated to approximately 55.8 million to 54.8 million years ago), was described as the most basal tarsiiform (Ni et al. 2013). This primate is reconstructed as a diurnal insectivore and an arboreal quadruped that did some leaping\u2014but not to the specialized degree seen in living tarsiers. The anatomy of the eye in living tarsiers suggests that their lineage passed through a diurnal stage, so <em>Archicebus<\/em> (and diurnal omomyoids) might represent such a stage.<\/p>\r\n\r\n<h3 class=\"import-Normal\"><strong>Climate Change and the Paleogeography of Modern Primate Origins<\/strong><\/h3>\r\n<p class=\"import-Normal\">Changing global climate has had profound effects on primate dispersal patterns and ecological habits over evolutionary time. Primates today are strongly tied to patches of trees and particular plant parts such as fruits, seeds, and immature leaves. It is no surprise, then, that the distribution of primates mirrors the distribution of forests. Today, primates are most diverse in the tropics, especially in tropical rainforests. Global temperature trends across the Tertiary have affected primate ranges. Following the Cretaceous-Tertiary extinction event, cooler temperatures and greater seasonality characterized the Paleocene. In the Eocene, temperatures (and probably rainfall) increased globally and rainforests likely extended to very high latitudes. During this time, euprimates became diverse. With cooling and increased aridity at the end of the Eocene, many primate extinctions occurred in the northern continents and the surviving primates were confined to lower latitudes in South America, Afro-Arabia, Asia, and southern Europe. Among these survivors are the progenitors of the living groups of primates: lemurs and lorises, tarsiers, [pb_glossary id=\"1700\"]<strong>platyrrhines<\/strong>[\/pb_glossary] (monkeys of the Americas), and catarrhines (monkeys and apes of Africa and Asia) (Figure 8.12).<\/p>\r\n\r\n\r\n[caption id=\"attachment_278\" align=\"aligncenter\" width=\"539\"]<img class=\"wp-image-265\" src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image2-5-e1691791570984.png\" alt=\"Map of world with gray continents.\" width=\"539\" height=\"306\" \/> Figure 8.12: Map of key localities of early anthropoids on land that becomes Africa and southern Asia. Credit: <a class=\"rId56\" href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/chapter\/__unknown__-10\/\">Oligocene Map with Key Early Anthropoid Localities (Figure 8.10)<\/a> original to <a class=\"rId57\" href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/\">Explorations: An Open Invitation to Biological Anthropology<\/a> by Elyssa Ebding at <a class=\"rId58\" href=\"https:\/\/www.csuchico.edu\/geop\/geoplace\/index.shtml\">GeoPlace, California State University, Chico<\/a> is under a <a class=\"rId59\" href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/\">CC BY-NC 4.0 License<\/a>. Localities based on Fleagle 2013, 265.[\/caption]\r\n<h3 class=\"import-Normal\"><strong>Competing Hypotheses for the Origin of Anthropoids<\/strong><\/h3>\r\n<p class=\"import-Normal\">There is considerable debate among paleoanthropologists as to the geographic origins of anthropoids. In addition, there is debate regarding the source group for anthropoids. Three different hypotheses have been articulated in the literature. These are the adapoid origin hypothesis, the omomyoid origin hypothesis, and the tarsier origin hypothesis (Figure 8.13).<\/p>\r\n\r\n\r\n[caption id=\"\" align=\"aligncenter\" width=\"419\"]<img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image24-1-1.jpg\" alt=\"Diagrams show three relationships among primate groups.\" width=\"419\" height=\"742\" \/> Figure 8.13: Competing models of anthropoid origins. Branch lengths are not to scale. The omomyoid origin model and tarsier origin model do not make specific reference to the evolutionary position of strepsirrhines; however, they were included here for completeness. <a href=\"https:\/\/docs.google.com\/document\/d\/1VUDKMBJYS_jNONjLxT04jQN0_z9Ua50BRN6auGSHUuU\/edit\">A full text description of this image is available<\/a>. Credit: <a class=\"rId61\" href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/chapter\/__unknown__-10\/\">Competing Trees for Anthropoid Origins (Figure 8.11)<\/a> original to <a class=\"rId62\" href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/\">Explorations: An Open Invitation to Biological Anthropology<\/a> by Jonathan M. G. Perry is under a <a class=\"rId63\" href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/\">CC BY-NC 4.0 License<\/a>.[\/caption]\r\n<h4 class=\"import-Normal\"><em>Adapoid Origin Hypothesis<\/em><\/h4>\r\n<p class=\"import-Normal\">Resemblances between some adapoids and some extant anthropoids include fusion of the [pb_glossary id=\"1702\"]<strong>mandibular symphysis<\/strong>[\/pb_glossary], overall robusticity of the chewing system, overall large body size, features that signal a diurnal lifestyle (like relatively small eye sockets), and ankle bone morphology. Another feature in common is canine sexual dimorphism, which is present in some species of adapoids (probably) and in several species of anthropoids.<\/p>\r\n<p class=\"import-Normal\">These features led some paleoanthropologists in the last half of the 20th century to suggest that anthropoids came from adapoid stock (Gingerich 1980; Simons and Rasmussen 1994b). One of the earliest supporters of the link between adapoids and anthropoids was Hans Georg Stehlin, who described much of the best material of adapoids and compared these Eocene primates to South American monkeys (Stehlin 1912). In more recent times, the adapoid origin hypothesis was reinforced by resemblances between these European adapoids (especially <em>Adapis <\/em>and <em>Leptadapis<\/em>) and some early anthropoids from the Fayum Basin (e.g., <em>Aegyptopithecus<\/em>, see below; Figure 8.14).<\/p>\r\n\r\n<div style=\"text-align: left;\">\r\n<table class=\"aligncenter\" style=\"width: 473.25pt;\"><caption>Figure 8.14: Families of early anthropoids with example genera and traits: a table. Credit: Early anthropoids table original to Explorations: An Open Invitation to Biological Anthropology (2nd ed.) by Jonathan M. G. Perry and Stephanie L. Canington is under a <a class=\"rId64\" href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/\">CC BY-NC 4.0 License<\/a>. Content derived from Fleagle 2013.<\/caption>\r\n<thead>\r\n<tr style=\"height: 25pt;\">\r\n<td class=\"Table3-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\r\n<p class=\"import-Normal\" style=\"text-align: center;\"><strong>Family<\/strong><\/p>\r\n&nbsp;<\/td>\r\n<td class=\"Table3-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\r\n<p class=\"import-Normal\" style=\"text-align: center;\"><strong>Genera<\/strong><\/p>\r\n&nbsp;<\/td>\r\n<td class=\"Table3-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\r\n<p class=\"import-Normal\" style=\"text-align: center;\"><strong>Morphology<\/strong><\/p>\r\n&nbsp;<\/td>\r\n<td class=\"Table3-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\r\n<p class=\"import-Normal\" style=\"text-align: center;\"><strong>Location<\/strong><\/p>\r\n&nbsp;<\/td>\r\n<td class=\"Table3-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\r\n<p class=\"import-Normal\" style=\"text-align: center;\"><strong>Age<\/strong><sup><strong>1<\/strong><\/sup><\/p>\r\n&nbsp;<\/td>\r\n<\/tr>\r\n<\/thead>\r\n<tbody>\r\n<tr class=\"Table3-R\" style=\"height: 18pt;\">\r\n<td class=\"Table3-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\r\n<p class=\"import-Normal\">Propliopithecidae<sup>2<\/sup><\/p>\r\n<\/td>\r\n<td class=\"Table3-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\r\n<p class=\"import-Normal\"><em>Aegyptopithecus<\/em><\/p>\r\n<\/td>\r\n<td class=\"Table3-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\r\n<p class=\"import-Normal\">Large size. Cranial sexual dimorphism, large canines. Robust jaws and rounded molars. Partially ossified ear tube (in some). Robust skeleton; quadruped.<\/p>\r\n<\/td>\r\n<td class=\"Table3-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\r\n<p class=\"import-Normal\">Africa<\/p>\r\n<\/td>\r\n<td class=\"Table3-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\r\n<p class=\"import-Normal\">Late Eocene to Early Oligocene<\/p>\r\n<\/td>\r\n<\/tr>\r\n<tr class=\"Table3-R\" style=\"height: 16pt;\">\r\n<td class=\"Table3-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\r\n<p class=\"import-Normal\">Parapithecidae<sup>3<\/sup><\/p>\r\n<\/td>\r\n<td class=\"Table3-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\r\n<p class=\"import-Normal\"><em>Apidium<\/em><\/p>\r\n<\/td>\r\n<td class=\"Table3-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\r\n<p class=\"import-Normal\">Medium size. Retention of three premolars per quadrant. Rounded molars and premolars with large central cusps. Adaptations for leaping in the lower limb.<\/p>\r\n<\/td>\r\n<td class=\"Table3-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\r\n<p class=\"import-Normal\">Africa<\/p>\r\n<\/td>\r\n<td class=\"Table3-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\r\n<p class=\"import-Normal\">Late Eocene to Late Oligocene<\/p>\r\n<\/td>\r\n<\/tr>\r\n<tr class=\"Table3-R\" style=\"height: 16pt;\">\r\n<td class=\"Table3-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\r\n<p class=\"import-Normal\">Proteopithecidae<sup>4<\/sup><\/p>\r\n<\/td>\r\n<td class=\"Table3-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\r\n<p class=\"import-Normal\"><em>Proteopithecus<\/em><\/p>\r\n<\/td>\r\n<td class=\"Table3-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\r\n<p class=\"import-Normal\">Small size. Retention of three premolars per quadrant. Arboreal quadrupeds that ate fruit.<\/p>\r\n<\/td>\r\n<td class=\"Table3-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\r\n<p class=\"import-Normal\">Africa<\/p>\r\n<\/td>\r\n<td class=\"Table3-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\r\n<p class=\"import-Normal\">Late Eocene<\/p>\r\n<\/td>\r\n<\/tr>\r\n<tr class=\"Table3-R\" style=\"height: 16pt;\">\r\n<td class=\"Table3-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\r\n<p class=\"import-Normal\">Oligopithecidae<sup>5<\/sup><\/p>\r\n<\/td>\r\n<td class=\"Table3-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\r\n<p class=\"import-Normal\"><em>Catopithecus<\/em><\/p>\r\n<\/td>\r\n<td class=\"Table3-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\r\n<p class=\"import-Normal\">Small size. Skull has postorbital septum and unfused mandible. Deep jaws. Diet of fruits. Generalized quadruped.<\/p>\r\n<\/td>\r\n<td class=\"Table3-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\r\n<p class=\"import-Normal\">Africa<\/p>\r\n<\/td>\r\n<td class=\"Table3-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\r\n<p class=\"import-Normal\">Late Eocene<\/p>\r\n<\/td>\r\n<\/tr>\r\n<tr class=\"Table3-R\" style=\"height: 16pt;\">\r\n<td class=\"Table3-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\r\n<p class=\"import-Normal\">Eosimiidae<\/p>\r\n<\/td>\r\n<td class=\"Table3-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\r\n<p class=\"import-Normal\"><em>Eosimias<\/em><\/p>\r\n<\/td>\r\n<td class=\"Table3-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\r\n<p class=\"import-Normal\">Deep jaw with vertical unfused symphysis. Pointed incisors and canines. Crowded premolars.<\/p>\r\n<\/td>\r\n<td class=\"Table3-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\r\n<p class=\"import-Normal\">Asia<\/p>\r\n<\/td>\r\n<td class=\"Table3-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\r\n<p class=\"import-Normal\">Middle Eocene<\/p>\r\n<\/td>\r\n<\/tr>\r\n<tr class=\"Table3-R\" style=\"height: 16pt;\">\r\n<td class=\"Table3-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\r\n<p class=\"import-Normal\">Amphipithecidae<sup>6<\/sup><\/p>\r\n<\/td>\r\n<td class=\"Table3-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\r\n<p class=\"import-Normal\"><em>Pondaungia<\/em><\/p>\r\n<\/td>\r\n<td class=\"Table3-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\r\n<p class=\"import-Normal\">Deep jaws. Molars generally rounded with wide basins.<\/p>\r\n<\/td>\r\n<td class=\"Table3-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\r\n<p class=\"import-Normal\">Asia<\/p>\r\n<\/td>\r\n<td class=\"Table3-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\r\n<p class=\"import-Normal\">Middle Eocene to Early Oligocene<\/p>\r\n<\/td>\r\n<\/tr>\r\n<tr class=\"Table3-R\" style=\"height: 1pt;\">\r\n<td class=\"Table3-C\" style=\"border-top: solid #000000 0.5pt; border-right: none #000000 0pt; border-bottom: none #000000 0pt; border-left: none #000000 0pt; padding: 0pt 5.4pt 0pt 5.4pt;\" colspan=\"4\">\r\n<p class=\"import-Normal\"><sup>1<\/sup> Derived from Fleagle 2013.<\/p>\r\n<p class=\"import-Normal\"><sup>2<\/sup> See Gebo and Simons 1987 and Simons et al. 2007.<\/p>\r\n<p class=\"import-Normal\"><sup>3<\/sup> See Feagle and Simons 1995 and Simons 2001.<\/p>\r\n<p class=\"import-Normal\"><sup>4<\/sup> See Simons and Seiffert 1999.<\/p>\r\n<p class=\"import-Normal\"><sup>5<\/sup> See Simons and Rasmussen 1996.<\/p>\r\n<p class=\"import-Normal\"><sup>6<\/sup> See Kay et al. 2004.<\/p>\r\n<\/td>\r\n<td class=\"Table3-C\" style=\"border-top: solid #000000 0.5pt; border-right: none #000000 0pt; border-bottom: none #000000 0pt; border-left: none #000000 0pt; padding: 0pt 5.4pt 0pt 5.4pt;\">\r\n<p class=\"import-Normal\"><\/p>\r\n<\/td>\r\n<\/tr>\r\n<tr>\r\n<td><\/td>\r\n<td><\/td>\r\n<td><\/td>\r\n<td><\/td>\r\n<td><\/td>\r\n<\/tr>\r\n<\/tbody>\r\n<\/table>\r\n<\/div>\r\n<p class=\"import-Normal\">Unfortunately for the adapoid hypothesis, most of the shared features listed above probably emerged independently in the two groups as adaptations to a diet of hard and\/or tough foods. For example, fusion of the mandibular symphysis likely evolved as a means to strengthen the jaw against forces that would pull the two halves away from each other, in the context of active chewing muscles on both sides of the head generating great bite forces. This context would also favor the development of robust jaws, large chewing muscles, shorter faces, and some other features shared by some adapoids and some anthropoids.<\/p>\r\n<p class=\"import-Normal\">As older and more plesiomorphic anthropoids were found in the Fayum Basin, it became clear that the earliest anthropoids from Africa did not possess these features of jaw robusticity (Seiffert et al. 2009). Furthermore, many adapoids never evolved these features. Fusion of the mandibular symphysis in adapoids is actually quite different from that in anthropoids and probably occurred during juvenile development in the former (Beecher 1983; Ravosa 1996). Eventually, the adapoid origin hypothesis fell out of favor among most paleoanthropologists, although the description of <em>Darwinius<\/em> is a recent revival of that idea (Franzen et al. 2009; but see Seiffert et al. 2009, Williams et al. 2010b).<\/p>\r\n\r\n<h4 class=\"import-Normal\"><em>Omomyoid Origin Hypothesis<\/em><\/h4>\r\n<p class=\"import-Normal\">Similarities in cranial and hindlimb morphology between some omomyoids and extant tarsiers have led to the suggestion that tarsiers arose from some kind of omomyoid. In particular, <em>Necrolemur<\/em> has many features in common with tarsiers, as does the North American <em>Shoshonius<\/em>, which is known from a few beautifully preserved (although distorted) crania. Tarsiers and <em>Shoshonius <\/em>share exclusively some features of the base of the cranium; however, <em>Shoshonius<\/em> does not have any sign of postorbital closure, and it lacks the bony ear tube of tarsiers. Nevertheless, some of the resemblances between some omomyoids and tarsiers suggest that tarsiers might have originated from within the Omomyoidea (Beard 2002; Beard and MacPhee 1994). In this scenario, although living tarsiers and living anthropoids might be sister taxa, they might have evolved from different omomyoids, possibly separated from each other by more than 50 million years of evolution, or from anthropoids evolved from some non-omomyoid fossil group. The arguments against the omomyoid origin hypothesis are essentially the arguments <em>for<\/em> the tarsier origin hypothesis (see below). Namely, tarsiers and anthropoids share many features (especially of the soft tissues) that must have been retained for many millions of years or must have evolved convergently in the two groups. Furthermore, a key hard-tissue feature shared between the two extant groups, the postorbital septum, was not present in any omomyoid. Therefore, that feature must have arisen convergently in the two extant groups or must have been lost in omomyoids. Neither scenario is very appealing, although recent arguments for <strong>convergent evolution<\/strong> of the postorbital septum in tarsiers and anthropoids have arisen from embryology and histology of the structure (DeLeon et al. 2016).<\/p>\r\n\r\n<h4 class=\"import-Normal\"><em>Tarsier Origin Hypothesis<\/em><\/h4>\r\n<p class=\"import-Normal\">Several paleoanthropologists have suggested that there is a relationship between tarsiers and anthropoids to the exclusion of omomyoids and adapoids (e.g., Cartmill and Kay 1978; Ross 2000; Williams and Kay 1995). Tarsiers and anthropoids today share several traits, including many soft-tissue features related to the olfactory system (e.g., the loss of a hairless external nose and loss of the median cleft running from the nose to the mouth, as possessed by strepsirrhines), and aspects of the visual system (e.g., the loss of a reflective layer at the back of the eye, similarities in carotid circulation to the brain, and mode of placentation). Unfortunately, none of these can be assessed directly in fossils. Some bony similarities between tarsiers and anthropoids include an extra air-filled chamber below the middle ear cavity, reduced bones within the nasal cavity, and substantial postorbital closure; these can be assessed in fossils, but the distribution of these traits in omomyoids does not yield clear answers. Furthermore, several similarities between tarsiers and anthropoids are probably due to similarities in sensory systems, which might have evolved in parallel for ecological reasons. Although early attempts to resolve the crown primates with molecular data were sometimes equivocal or in disagreement with one another, more recent analyses (including those of short interspersed elements) suggest that tarsiers and anthropoids are sister groups to the exclusion of lemurs and lorises (Williams et al. 2010a). However, this does not address omomyoids, all of which are far too ancient for DNA extraction.<\/p>\r\n<p class=\"import-Normal\">The above three hypotheses are not the only possibilities for anthropoid origins. It may be that anthropoids are neither the closest sister group of tarsiers, nor evolved from adapoids or omomyoids. In recent years, two new groups of Eocene Asian primates have been implicated in the origin of anthropoids: the eosimiids and the amphipithecids. It is possible that one or the other of these two groups gave rise to anthropoids. Regardless of the true configuration of the tree for crown primates, the three major extant groups probably diverged from each other quite long ago (Seiffert et al. 2004).<\/p>\r\n\r\n<h3 class=\"import-Normal\"><strong>Early Anthropoid Fossils in Africa<\/strong><\/h3>\r\n[caption id=\"\" align=\"aligncenter\" width=\"526\"]<img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image7-2.jpg\" alt=\"People digging in a sandy desert.\" width=\"526\" height=\"352\" \/> Figure 8.15: Egyptian workers sweeping Quarry I in the Fayum Basin (2004). This technique, called wind harvesting, removes the desert crust and permits wind to blow out fine sediment and reveal fossils. Credit: <a class=\"rId66\" href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/chapter\/__unknown__-10\/\">Egyptian workers sweeping Quarry I in the Fayum Basin (2004, Figure 8.12)<\/a> by Jonathan M. G. Perry is under a <a class=\"rId67\" href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/\">CC BY-NC 4.0 License<\/a>.[\/caption]\r\n\r\n[caption id=\"\" align=\"alignleft\" width=\"280\"]<img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image14-2.jpg\" alt=\"A person using a tool to expose bone in sand.\" width=\"280\" height=\"423\" \/> Figure 8.16: Elwyn Laverne Simons excavating Aegyptopithecus in the Fayum Basin. Credit: <a class=\"rId69\" href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/chapter\/__unknown__-10\/\">Elwyn Laverne Simons in the Fayum Basin (Figure 8.13)<\/a> used by permission of the <a class=\"rId70\" href=\"https:\/\/lemur.duke.edu\/\">Duke Lemur Center,<\/a> Division of Fossil Primates, is under a <a class=\"rId71\" href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/\">CC BY-NC 4.0 License<\/a>.[\/caption]\r\n<p class=\"import-Normal\">The classic localities yielding the greatest wealth of early anthropoid fossils are those from the Fayum Basin in Egypt (Simons 2008; Figure 8.15). The Fayum is a veritable oasis of fossil primates in an otherwise spotty early Tertiary African record. Since the 1960s, teams led by E. L. Simons have discovered several new species of early anthropoids, some of which are known from many parts of the skeleton and several individuals (Figure 8.16).<\/p>\r\n<p class=\"import-Normal\">The Fayum Jebel Qatrani Formation and Birket Qarun Formation between them have yielded a remarkable array of terrestrial, arboreal, and aquatic mammals. These include ungulates, bats, sea cows, elephants, hyraces, rodents, whales, and primates. Also, many other vertebrates, like water birds, were present. The area at the time of deposition (Late Eocene through Early Oligocene) was probably very wet, with slow-moving rivers, standing water, swampy conditions, and lots of trees (see Bown and Kraus 1988). In short, it was an excellent place for primates.<\/p>\r\n\r\n<h4 class=\"import-Normal\"><em>General Morphology of Anthropoids<\/em><\/h4>\r\n<p class=\"import-Normal\">The anthropoids known from the Fayum (and their close relatives from elsewhere in East Africa and Afro-Arabia) bear many of the anatomical hallmarks of extant anthropoids; however, there are plesiomorphic forms in several families that lack one or more anthropoid traits. All Fayum anthropoids known from skulls possess postorbital closure, most had fused mandibular symphyses, and most had ring-like [pb_glossary id=\"1704\"]<strong>ectotympanic<\/strong> [\/pb_glossary] bones. Tooth formulae were generally either 2.1.3.3 or 2.1.2.3. Fayum anthropoids ranged in size from the very small <em>Qatrania<\/em> and <em>Biretia <\/em>(less than 500 g) to the much-larger <em>Aegyptopithecus<\/em> (approximately 7 kg; 15 lbs.). Fruit was probably the main component of the diet for most or all of the anthropoids, with some of them supplementing with leaves (Kay and Simons 1980; Kirk and Simons 2001; Teaford et al. 1996). Most Fayum anthropoids were probably diurnal above-branch quadrupeds. Some of them (e.g., <em>Apidium<\/em>; see Figure 8.14) were probably very good leapers (Gebo and Simons 1987), but none show specializations for gibbon-style suspensory locomotion. Some of the Fayum anthropoids are known from hundreds of individuals, permitting the assessment of individual variation, sexual dimorphism, and in some cases growth and development. The description that follows provides greater detail for the two best known Fayum anthropoid families, the Propliopithecidae and the Parapithecidae; the additional families are summarized briefly.<\/p>\r\n\r\n<h4 class=\"import-Normal\"><em>Fayum Anthropoid Families<\/em><\/h4>\r\n<p class=\"import-Normal\">The Propliopithecidae (see Figure 8.14) include the largest anthropoids from the fauna, and they are known from several crania and some postcranial elements. They have been suggested to be stem catarrhines, although perhaps near the split between catarrhines and platyrrhines. The best known propliopithecid is <em>Aegyptopithecus<\/em>, known from many teeth, crania, and postcranial elements (Figure 8.17) .<\/p>\r\n\r\n\r\n[caption id=\"\" align=\"alignright\" width=\"431\"]<img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image4-2-1.jpg\" alt=\"Two animal skull side views.\" width=\"431\" height=\"281\" \/> Figure 8.17: Female (left) and male (right) skull material for Aegyptopithecus zeuxis. The mandibles are not associated with the crania. Credit: <a href=\"https:\/\/www.pnas.org\/doi\/full\/10.1073\/pnas.0703129104#supplementary-materials\">Female and male cranium of A. zeuxi (03129Fig5, Supporting Information)<\/a> by Elwyn L. Simons, Erik R. Seiffert, Timothy M. Ryan, and Yousry Attia. 2007. <a href=\"https:\/\/www.pnas.org\/about\/rights-permissions\">Proceedings of the National Academy of Sciences of the United States of America<\/a> 104 (21): 8731\u20138736. Copyright (2007) National Academy of Sciences. Image <a href=\"https:\/\/www.pnas.org\/about\/rights-permissions\">is used for non-commercial and educational purposes as outlined by PNAS.<\/a>[\/caption]\r\n<p class=\"import-Normal\">Parapithecidae are an extremely abundant and unusual family of anthropoids from the Fayum. The parapithecid <em>Apidium<\/em> is known from many jaws with teeth, crushed and distorted crania, and several skeletal elements. <em>Parapithecus<\/em> is known from cranial material including a beautiful, undistorted cranium. This genus shows extreme reduction of the incisors, including complete absence of the lower incisors in <em>P. grangeri <\/em>(Simons 2001). This trait is unique among primates. Parapithecids were once thought to be the ancestral stock of platyrrhines; however, their platyrrhine-like features are probably ancestral retentions, so the most conservative approach is to consider them stem anthropoids.<\/p>\r\n<p class=\"import-Normal\">The Proteopithecidae were small frugivores that probably mainly walked along horizontal branches on all fours. TThey are considered stem anthropoids. The best known genus, <em>Proteopithecus<\/em>, is represented by dentitions, crania, and postcranial elements.<\/p>\r\n<p class=\"import-Normal\">The Oligopithecidae share a mixture of traits that makes them difficult to classify more specifically within anthropoids. The best known member, <em>Catopithecus<\/em>, is known from crania that demonstrate a postorbital septum and from mandibles that lack symphyseal fusion. They share the catarrhine tooth formula of 2.1.2.3 and have a canine honing complex that involves the anterior lower premolar. The postcranial elements known for the group suggest generalized arboreal quadrupedalism. The best known member, <em>Catopithecus<\/em>, is known from crania that demonstrate a postorbital septum and from mandibles that lack symphyseal fusion (Simons and Rasmussen 1996). The jaws are deep, with broad muscle attachment areas and crested teeth. <em>Catopithecus<\/em> was probably a little less than a kilogram in weight.<\/p>\r\n<p class=\"import-Normal\">Other genera of putative anthropoids from the Fayum include the very poorly known <em>Arsinoea<\/em>, the contentious <em>Afrotarsius<\/em>, and the enigmatic <em>Nosmips<\/em>. The last of these possesses traits of several major primate <strong>[pb_glossary id=\"1705\"]clades[\/pb_glossary]<\/strong> and defies classification (Seiffert et al. 2010).<\/p>\r\n\r\n<h3 class=\"import-Normal\"><strong>Early Anthropoid Fossils in Asia<br style=\"clear: both;\" \/><\/strong><\/h3>\r\n<p class=\"import-Normal\">For the last half of the 1900s, researchers believed that Africa was the unquestioned homeland of early anthropoids (see Fleagle and Kay 1994). However, two very different groups of primates from Asia soon began to change that. One was an entirely new discovery (Eosimiidae), and the other was a poorly known group discovered decades prior (Amphipithecidae). Soon, attention on anthropoid origins began to shift eastward (see Ross and Kay 2004; Simons 2004). If anthropoids arose in Asia instead of Africa, then this implies that the African early anthropoids either emigrated from Asia or evolved their anthropoid traits in parallel with living anthropoids.<\/p>\r\n\r\n<h4 class=\"import-Normal\"><em>Eosimiids<\/em><\/h4>\r\n<p class=\"import-Normal\">First described in the 1990s, the eosimiids are best represented by <em>Eosimias <\/em>(see Figure 8.14; Figure 8.18). This tiny \u201cdawn monkey\u201d is known from relatively complete jaws with teeth, a few small fragments of the face, and some postcranial elements (Beard et al. 1994; Beard et al. 1996; Gebo et al. 2000). <em>Eosimias<\/em> (along with the other less-well-known genera in its family) bears some resemblance to tarsiers as well as anthropoids. Unfortunately, no good crania are known for this family, and the anatomy of, for example, the posterior orbital margin could be very revealing as to higher-level relationships.<\/p>\r\n\r\n\r\n[caption id=\"\" align=\"aligncenter\" width=\"550\"]<img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image16-1-1.jpg\" alt=\"Red-colored lower jaw of an animal.\" width=\"550\" height=\"232\" \/> Figure 8.18: Cast of the right half of the mandible of Eosimias centennicus, type specimen. The white scale bar is 1 cm long. Credit: <a class=\"rId74\" href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/chapter\/__unknown__-10\/\">Cast of the right half of the mandible of <\/a><a class=\"rId75\" href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/chapter\/__unknown__-10\/\"><em>Eosimias centennicus <\/em><\/a><a class=\"rId76\" href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/chapter\/__unknown__-10\/\">(Figure 8.15),<\/a> type specimen, from K. D. Rose cast collection, photo by Jonathan M. G. Perry is under a <a class=\"rId77\" href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/\">CC BY-NC 4.0 License<\/a>.[\/caption]\r\n<h4 class=\"import-Normal\"><em>Amphipithecids<\/em><\/h4>\r\n<p class=\"import-Normal\">Amphipithecids are small- to medium-size primates (up to 10 kg; 22 lbs.). Most are from the Eocene Pondaung Formation in Myanmar (Early\u2013Middle Eocene), but one genus is known from Thailand. Some dental similarities with anthropoids were noted early on, such as deep jaws and wide basins that separate low molar cusps. The best known genera were <em>Pondaungia<\/em> and <em>Amphipithecus <\/em>(Ciochon and Gunnell 2002; see Figure 8.14). Another amphipithecid, <em>Siamopithecus<\/em> from Thailand, has very rounded molars and was probably a seed-eater (Figure 8.19). In addition to teeth and jaws, some cranial fragments, ankle material, and ends of postcranial bones have been found for <em>Pondaungia<\/em>. There are important resemblances between the postcranial bones of <em>Pondaungia<\/em> and those of adapoids, suggesting adapoid affinities for the amphipithecidae. This would imply that the resemblances with anthropoids in the teeth are convergent, based on similarities in diet (see Ciochon and Gunnell 2002). Unfortunately, the association between postcranial bones and teeth is not definite. With other primates in these faunas (including eosimiids), one cannot be certain that the postcranial bones belong with the teeth. Some researchers suggest that some bones belong to a sivaladapid (or asiadapid) and others to an early anthropoid (Beard et al. 2007; Marivaux et al. 2003). Additional well-associated material of amphipithecids would help to clear up this uncertainty.<\/p>\r\n\r\n\r\n[caption id=\"\" align=\"aligncenter\" width=\"505\"]<img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image15-2.jpg\" alt=\"Four casts of jawbone fragments with teeth.\" width=\"505\" height=\"368\" \/> Figure 8.19: Casts of representative amphipithecid material. A. Pondaungia cotteri right lower jaw fragment with m2 and m3. B. Siamopithecus eocaenus right upper jaw fragment with p4-m3. C. S. eocaenus right lower jaw fragment with partial m1, m2, and m3 in lateral view. D. Same as in C but occlusal view. White scale bars are 1 cm long. Credit: <a class=\"rId79\" href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/chapter\/__unknown__-10\/\">Casts of representative amphipithecid material (Figure 8.16)l<\/a> from K. D. Rose cast collection, photo by Jonathan M. G. Perry is under a <a class=\"rId80\" href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/\">CC BY-NC 4.0 License<\/a>.[\/caption]\r\n<h3 class=\"import-Normal\"><strong>Platyrrhine Dispersal to South America<\/strong><\/h3>\r\n<p class=\"import-Normal\">Today there is an impressive diversity of primates in South and Central America. These are considered to be part of a single clade, the Platyrrhini. Primates colonized South America sometime in the Eocene from an African source. In the first half of the 20th century, the source of platyrrhines was a matter of major debate among paleontologists, with some favoring a North American origin (e.g., Simpson 1940).<\/p>\r\n<p class=\"import-Normal\">Part of the reason for this debate is that South America was an island in the Eocene. Primates needed to cross open ocean to get there from either North America or Africa, although the distance from the former was shorter. Morphology yields clues to platyrrhine origins. The first known primates in South America have more in common morphologically with African primates than with North American ones. At the time, anthropoids were popping up in North Africa, whereas the only euprimates in North America were adapoids and omomyoids. Despite lacking a bony ear tube, early platyrrhines shared a great deal with other anthropoids, including full postorbital closure and fusion of the mandibular symphysis.<\/p>\r\n<p class=\"import-Normal\">The means by which a population of small North African primates managed to disperse across the Atlantic and survive to colonize South America remains a mystery. The most plausible scenario is one of rafting. That is, primates must have been trapped on vegetation that was blown out to sea by a storm. The vegetation then became a sort of life raft, which eventually landed ashore, dumping its passengers in South America. Rodents probably arrived in South America in the same way (Antoine et al. 2012).<\/p>\r\n<p class=\"import-Normal\">Once ashore, platyrrhines must have crossed South America fairly rapidly because the earliest-known primates from that continent are from Peru (Bond et al. 2015). Soon after that, platyrrhines were in Bolivia, namely <em>Branisella<\/em>. By the Miocene, platyrrhines were living in extreme southern Argentina and were exploiting a variety of feeding niches. The Early Miocene platyrrhines were all somewhat plesiomorphic in their morphology, but some features that likely arose by ecological convergence suggest (to some) relationships with extant platyrrhine families. This has led to a lively debate about the pattern of primate evolution in South America (Kay 2015; Kay and Fleagle 2010; Rosenberger 2010). By the Middle Miocene, clear representatives of modern families were present in a diverse fauna from La Venta, Colombia (Wheeler 2010). The Plio-Pleistocene saw the emergence of giant platyrrhines as well as several taxa of platyrrhines living on Caribbean islands (Cooke et al. 2016).<\/p>\r\n<p class=\"import-Normal\">The story of platyrrhines seems to be one of amazing sweepstakes dispersal, followed by rapid diversification and widespread geographic colonization of much of South America. After that, dramatic extinctions resulted in the current, much-smaller geographic distribution of platyrrhines. These extinctions were probably caused by changing climates, leading to the contraction of forests. Platyrrhines dispersed to the Caribbean and to Central America, with subsequent extinctions in those regions that might have been related to interactions with humans. Unlike anthropoids of Africa and Asia, platyrrhines do not seem to have evolved any primarily terrestrial forms and so have always been highly dependent on forests.<\/p>\r\n\r\n<div class=\"textbox\">\r\n<h2 class=\"import-Normal\">Special Topic: Jonathan Perry and Primates of the Extreme South<\/h2>\r\n<p class=\"import-Normal\">Many primates are very vulnerable to ecological disturbance because they are heavily dependent on fruit to eat and trees to live in. This is one reason why so many primates are endangered today and why many of them went extinct due to climatic and vegetational changes in the past. I (Jonathan Perry) have conducted paleontological research focusing on primates that lived on the edge of their geographic distribution. This research has taken me to extreme environments in the Americas: southern Patagonia, the Canadian prairies, western Wyoming, and the badlands of eastern Oregon.<\/p>\r\n<p class=\"import-Normal\">Santa Cruz Province in Argentina is as far south as primates have ever lived. The Santa Cruz fauna of the Miocene has yielded a moderate diversity of platyrrhines, each with slightly different dietary adaptations. These include <em>Homunculus<\/em>, first described by Florentino Ameghino in 1891 (Figure 8.20). Recent fieldwork by my colleagues and I in Argentina has revealed several skulls of <em>Homunculus <\/em>as well as many parts of the skeleton (Kay et al. 2012). The emerging profile of this extinct primate is one of a dedicated arboreal quadruped that fed on fruits and leaves. Many of the foods eaten by <em>Homunculus<\/em> must have been very tough and were probably covered and impregnated with grit; we suspect this because the cheek teeth are very worn down, even in young individuals, and because the molar tooth roots were very large, presumably to resist strong bite forces (Perry et al. 2010, 2014).<\/p>\r\n\r\n\r\n[caption id=\"\" align=\"aligncenter\" width=\"497\"]<img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image9-2.jpg\" alt=\"An animal skull, a partial skull, and a fossil jaw with teeth.\" width=\"497\" height=\"634\" \/> Figure 8.20: Representative specimens of Homunculus patagonicus. A. Adult cranium in lateral view. B. Adult cranium surface reconstructed from microCT scans, with the teeth segmented out. C. Juvenile cranium. White scale bars are 1cm long. Credit: <a class=\"rId82\" href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/chapter\/__unknown__-10\/\">Representative specimens of <\/a><a class=\"rId83\" href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/chapter\/__unknown__-10\/\"><em>Homunculus patagonicus <\/em><\/a><a class=\"rId84\" href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/chapter\/__unknown__-10\/\">(Figure 8.17)<\/a> photo by Jonathan M. G. Perry is under a <a class=\"rId85\" href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/\">CC BY-NC 4.0 License<\/a>.[\/caption]\r\n<p class=\"import-Normal\">I began working in Argentina while a graduate student at Duke University. I participated as a field assistant in a team led by my Ph.D. advisor, Richard F. Kay, and Argentine colleagues Sergio F. Vizca\u00edno and M. Susana Bargo. Most of the localities examined belong to a suite of beach sites known since the 1800s and visited by many field parties from various museums in the early 1900s. Since 2003, our international team of paleontologists from the U.S. and Argentina has visited these localities every single year (Figure 8.21). Over time, new fossils and new students have led to new projects and new approaches, including the use of microcomputed tomography (microCT) to visualize and analyze internal structures of the skeleton.<\/p>\r\n\r\n\r\n[caption id=\"\" align=\"aligncenter\" width=\"491\"]<img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image23.jpg\" alt=\"Sandy rocky coastline. People digging on a grassy hillside.\" width=\"491\" height=\"561\" \/> Figure 8.21: Field localities in Argentina and Canada. A. Ca\u00f1adon Palos locality, coastal Santa Cruz Province, Argentina. B. Swift Current Creek locality, southwest Saskatchewan, Canada. Credits: A. <a class=\"rId87\" href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/chapter\/__unknown__-10\/\">Ca\u00f1adon Palos Field Locality in Argentina<\/a> by Jonathan M. G. Perry is under a <a class=\"rId88\" href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/\">CC BY-NC 4.0 License<\/a>. B. <a class=\"rId89\" href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/chapter\/__unknown__-10\/\">Swift Current Creek locality, Saskatchewan, Canada<\/a> by Jonathan M. G. Perry is under a <a class=\"rId90\" href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/\">CC BY-NC 4.0 License<\/a>.[\/caption]\r\n\r\n<\/div>\r\n<h2 class=\"import-Normal\">Planet of Apes<\/h2>\r\n<h3 class=\"import-Normal\"><strong>Geologic Activity and Climate Change in the Miocene<\/strong><\/h3>\r\n<p class=\"import-Normal\">The Miocene Epoch was a time of mammalian diversification and extinction, global climate change, and ecological turnover. In the Miocene, there was an initial warming trend across the globe with the expansion of subtropical forests, followed by widespread cooling and drying with the retreat of tropical forests and replacement with more open woodlands and eventually grasslands. It was also a time of major geologic activity. On one side of the globe, South America experienced the rise of the Andes Mountains. On the other side, the Indian subcontinent collided with mainland Asia, resulting in the rise of the Himalayan Mountains. In Africa, volcanic activity promoted the development of the East African Rift System. Critical to the story of ape evolution was the exposure of an intercontinental landbridge between East Africa and Eurasia, permitting a true planet of apes (Figure 8.22).<\/p>\r\n\r\n\r\n[caption id=\"attachment_278\" align=\"aligncenter\" width=\"580\"]<img class=\"wp-image-274\" src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image21-3-e1691792198797.png\" alt=\"Map of world with gray continents.\" width=\"580\" height=\"335\" \/> Figure 8.22: Map of the world in the Miocene, highlighting fossil ape localities across Africa, southern Europe, and southern Asia. Credit: <a class=\"rId92\" href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/chapter\/__unknown__-10\/\">Miocene Map with Fossil Ape Localities (Figure 8.19)<\/a> original to <a class=\"rId93\" href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/\">Explorations: An Open Invitation to Biological Anthropology<\/a> by Elyssa Ebding at <a class=\"rId94\" href=\"https:\/\/www.csuchico.edu\/geop\/geoplace\/index.shtml\">GeoPlace, California State University, Chico<\/a> is under a <a class=\"rId95\" href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/\">CC BY-NC 4.0 License<\/a>. Localities based on Fleagle 2013, 311.[\/caption]\r\n<h3 class=\"import-Normal\"><strong>Geographic Distribution: Africa, Asia, Europe<\/strong><\/h3>\r\n<p class=\"import-Normal\">The world of the Miocene had tremendous ape diversity compared to today. The earliest records of fossil apes are from Early Miocene deposits in Africa. However, something dramatic happened around 16 million years ago. With the closure of the ancient Tethys Sea, the subsequent exposure of the <em>Gomphotherium<\/em> Landbridge, and a period of global warming, the Middle\u2013Late Miocene saw waves of emigration of mammals (including primates) out of Africa and into Eurasia, with evidence of later African re-entry for some (Harrison 2010). Some of the mammals that dispersed from Africa to Eurasia and back were apes. Though most of these early apes left no modern descendants, some of them gave rise to the ancestors of modern apes\u2014including <strong>[pb_glossary id=\"800\"]hominins[\/pb_glossary]<\/strong> (Figure 8.23).<\/p>\r\n\r\n\r\n[caption id=\"\" align=\"aligncenter\" width=\"560\"]<img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image20-1.jpg\" alt=\"Miocene apes set against a geologic time scale.\" width=\"560\" height=\"796\" \/> Figure 8.23: Representative Miocene apes set against a geologic time scale. Credit: <a href=\"https:\/\/www.pnas.org\/content\/108\/14\/5554\">Range chart for Miocene hominoids of Western Eurasia (Figure 3)<\/a> by Isaac Casanovas-Vilar, David M. Alba, Miguel Garc\u00e9s, Josep M. Robles, and Salvador Moy\u00e0-Sol\u00e0. 2011. <a href=\"https:\/\/www.pnas.org\/about\/rights-permissions\">Proceedings of the National Academy of Sciences of the United States of America<\/a> 108 (14): 5554-5559. Copyright (2011) National Academy of Sciences. Image <a href=\"https:\/\/www.pnas.org\/about\/rights-permissions\">is used for non-commercial and educational purposes as outlined by PNAS.<\/a>[\/caption]\r\n<h3 class=\"import-Normal\"><strong>Where Are the Monkeys? Diversity in the Miocene<\/strong><\/h3>\r\n<p class=\"import-Normal\">Whereas the Oligocene deposits in the Fayum of Egypt have yielded the earliest-known catarrhine fossils, the Miocene demonstrates some diversification of Cercopithecoidea. However, compared to the numerous and diverse Miocene apes (see below), monkeys of the Miocene are very rare and restricted to a single extinct family, the Victoriapithecidae (Figure 8.24). This family contains the earliest definite cercopithecoids. These monkeys are found from northern and eastern Africa between 20 million and 12.5 million years ago (Miller et al. 2009). The best known early African monkey is <em>Victoriapithecus <\/em>(Figure 8.25), a small-bodied (approximately 7 kg; 15 lbs.), small-brained monkey. <strong>[pb_glossary id=\"1708\"]Bilophodonty[\/pb_glossary]<\/strong>, known to be a hallmark of molar teeth of modern cercopithecoid, was present to some extent in Victoriapithecids. <em>Victoriapithecus<\/em> has been reconstructed as being more frugivorous and perhaps spent more time on the ground (terrestrial locomotion) than in the trees (arboreal locomotion; Blue et al. 2006). The two major groups of cercopithecoids today are cercopithecines and colobines. The earliest records demonstrating clear members of each of these two groups are at the end of the Miocene. Examples include the early colobine <em>Microcolobus<\/em> from Kenya and the early cercopithecine <em>Pliopapio<\/em> from Ethiopia.<\/p>\r\n\r\n<div style=\"text-align: left;\">\r\n<table class=\"aligncenter\" style=\"width: 473.25pt; height: 349px;\"><caption>Figure 8.24: Some families of later anthropoids with example genera and traits: a table. Credit: Late anthropoids table original to Explorations: An Open Invitation to Biological Anthropology (2nd ed.) by Jonathan M. G. Perry and Stephanie L. Canington is under a <a class=\"rId100\" href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/\">CC BY-NC 4.0 License<\/a>. Content derived from Fleagle 2013.<\/caption>\r\n<thead>\r\n<tr style=\"height: 25pt;\">\r\n<td class=\"Table4-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt; border: 0.5pt solid #000000; height: 60px; width: 119.35px;\">\r\n<p class=\"import-Normal\" style=\"text-align: center;\"><strong>Family<\/strong><\/p>\r\n&nbsp;<\/td>\r\n<td class=\"Table4-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt; border: 0.5pt solid #000000; height: 60px; width: 103.417px;\">\r\n<p class=\"import-Normal\" style=\"text-align: center;\"><strong>Genera<\/strong><\/p>\r\n&nbsp;<\/td>\r\n<td class=\"Table4-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt; border: 0.5pt solid #000000; height: 60px; width: 191.65px;\">\r\n<p class=\"import-Normal\" style=\"text-align: center;\"><strong>Morphology<\/strong><\/p>\r\n&nbsp;<\/td>\r\n<td class=\"Table4-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt; border: 0.5pt solid #000000; height: 60px; width: 67.3667px;\">\r\n<p class=\"import-Normal\" style=\"text-align: center;\"><strong>Location<\/strong><\/p>\r\n&nbsp;<\/td>\r\n<td class=\"Table4-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt; border: 0.5pt solid #000000; height: 60px; width: 73.2167px;\">\r\n<p class=\"import-Normal\" style=\"text-align: center;\"><strong>Age<\/strong><sup><strong>1<\/strong><\/sup><\/p>\r\n&nbsp;<\/td>\r\n<\/tr>\r\n<\/thead>\r\n<tbody>\r\n<tr class=\"Table4-R\" style=\"height: 18pt;\">\r\n<td class=\"Table4-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt; border: 0.5pt solid #000000; height: 77px; width: 119.35px;\">\r\n<p class=\"import-Normal\">Victoriapithecidae<sup>2<\/sup><\/p>\r\n<\/td>\r\n<td class=\"Table4-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt; border: 0.5pt solid #000000; height: 77px; width: 103.417px;\">\r\n<p class=\"import-Normal\"><em>Victoriapithecus<\/em><\/p>\r\n<\/td>\r\n<td class=\"Table4-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt; border: 0.5pt solid #000000; height: 77px; width: 191.65px;\">\r\n<p class=\"import-Normal\">Long, sloping face. Round, narrowly spaced orbits. Deep cheek bones. Well-developed sagittal crest.<\/p>\r\n<\/td>\r\n<td class=\"Table4-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt; border: 0.5pt solid #000000; height: 77px; width: 67.3667px;\">\r\n<p class=\"import-Normal\">Africa<\/p>\r\n<\/td>\r\n<td class=\"Table4-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt; border: 0.5pt solid #000000; height: 77px; width: 73.2167px;\">\r\n<p class=\"import-Normal\">Early to Middle Miocene<\/p>\r\n<\/td>\r\n<\/tr>\r\n<tr class=\"Table4-R\" style=\"height: 16pt;\">\r\n<td class=\"Table4-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt; border: 0.5pt solid #000000; height: 61px; width: 119.35px;\">\r\n<p class=\"import-Normal\">Proconsulidae<sup>3<\/sup><\/p>\r\n<\/td>\r\n<td class=\"Table4-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt; border: 0.5pt solid #000000; height: 61px; width: 103.417px;\">\r\n<p class=\"import-Normal\"><em>Proconsul<\/em><\/p>\r\n<\/td>\r\n<td class=\"Table4-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt; border: 0.5pt solid #000000; height: 61px; width: 191.65px;\">\r\n<p class=\"import-Normal\">Short face. Generalized dentition. Arboreal quadruped. Probably tailless.<\/p>\r\n<\/td>\r\n<td class=\"Table4-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt; border: 0.5pt solid #000000; height: 61px; width: 67.3667px;\">\r\n<p class=\"import-Normal\">Africa and Arabia<\/p>\r\n<\/td>\r\n<td class=\"Table4-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt; border: 0.5pt solid #000000; height: 61px; width: 73.2167px;\">\r\n<p class=\"import-Normal\">Early to Middle Miocene<\/p>\r\n<\/td>\r\n<\/tr>\r\n<tr class=\"Table4-R\" style=\"height: 16pt;\">\r\n<td class=\"Table4-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt; border: 0.5pt solid #000000; height: 46px; width: 119.35px;\">\r\n<p class=\"import-Normal\">Pongidae<\/p>\r\n<\/td>\r\n<td class=\"Table4-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt; border: 0.5pt solid #000000; height: 46px; width: 103.417px;\">\r\n<p class=\"import-Normal\"><em>Gigantopithecus<\/em><\/p>\r\n<\/td>\r\n<td class=\"Table4-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt; border: 0.5pt solid #000000; height: 46px; width: 191.65px;\">\r\n<p class=\"import-Normal\">Largest primate ever. Deep jaws and low rounded molars.<\/p>\r\n<\/td>\r\n<td class=\"Table4-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt; border: 0.5pt solid #000000; height: 46px; width: 67.3667px;\">\r\n<p class=\"import-Normal\">Asia<\/p>\r\n<\/td>\r\n<td class=\"Table4-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt; border: 0.5pt solid #000000; height: 46px; width: 73.2167px;\">\r\n<p class=\"import-Normal\">Miocene to Present<\/p>\r\n<\/td>\r\n<\/tr>\r\n<tr class=\"Table4-R\" style=\"height: 1pt;\">\r\n<td class=\"Table4-C\" style=\"border-color: #000000; border-style: solid none none; border-width: 0.5pt 0pt 0pt; padding: 0pt 5.4pt; height: 90px; width: 526.983px;\" colspan=\"4\">\r\n<p class=\"import-Normal\"><sup>1<\/sup> Derived from Fleagle 2013.<\/p>\r\n<p class=\"import-Normal\"><sup>2<\/sup> See Benefit and McCrossin 1997 and Fleagle 2013.<\/p>\r\n<p class=\"import-Normal\"><sup>3<\/sup> See Begun 2007.<\/p>\r\n<\/td>\r\n<td class=\"Table4-C\" style=\"border-color: #000000; border-style: solid none none; border-width: 0.5pt 0pt 0pt; padding: 0pt 5.4pt; height: 90px; width: 73.2167px;\">\r\n<p class=\"import-Normal\"><\/p>\r\n<\/td>\r\n<\/tr>\r\n<tr style=\"height: 15px;\">\r\n<td style=\"height: 15px; width: 121.283px;\"><\/td>\r\n<td style=\"height: 15px; width: 105.35px;\"><\/td>\r\n<td style=\"height: 15px; width: 193.583px;\"><\/td>\r\n<td style=\"height: 15px; width: 69.3px;\"><\/td>\r\n<td style=\"height: 15px; width: 74.65px;\"><\/td>\r\n<\/tr>\r\n<\/tbody>\r\n<\/table>\r\n<\/div>\r\n\r\n[caption id=\"\" align=\"aligncenter\" width=\"447\"]<img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image13-5.png\" alt=\"Front view of skull with pointed teeth.\" width=\"447\" height=\"403\" \/> Figure 8.25: Skull of Victoriapithecus macinnesi. Credit: <a class=\"rId102\" href=\"https:\/\/commons.wikimedia.org\/wiki\/File:Victoriapithecus_macinnesi_skull.JPG\">Victoriapithecus macinnesi skull<\/a> photo taken at the <a class=\"rId103\" href=\"https:\/\/www.mnhn.fr\/en\">Musee d'Histoire Naturelle, Paris<\/a> by <a class=\"rId104\" href=\"https:\/\/commons.wikimedia.org\/wiki\/User:Ghedoghedo\">Ghedoghedo<\/a> is under a <a class=\"rId105\" href=\"https:\/\/creativecommons.org\/licenses\/by-sa\/3.0\/legalcode\">CC BY-SA 3.0 License<\/a>.[\/caption]\r\n<h3 class=\"import-Normal\"><strong>The Story of Us, the Apes<\/strong><\/h3>\r\n<h4 class=\"import-Normal\"><em>African Ape Diversity<\/em><\/h4>\r\n<p class=\"import-Normal\">The Early Miocene of Africa has yielded around 14 genera of early apes (Begun 2003). Many of these taxa have been reconstructed as frugivorous arboreal quadrupeds (Kay 1977). One of the best studied of these genera is the East African <em>Proconsul<\/em> (Family Proconsulidae; see Figure 8.24). Several species have been described, with body mass reconstructions ranging from 17 to 50 kg (approximately 37\u2013110 lbs.). A paleoenvironmental study reconstructed the habitat of <em>Proconsul <\/em>to be a dense, closed-canopy tropical forest (Michel et al. 2014). No caudal vertebrae (tail bones) have been found in direct association with <em>Proconsul <\/em>postcrania, and the morphology of the sacrum is consistent with <em>Proconsul<\/em> lacking a tail (Russo 2016; Ward et al. 1991).<\/p>\r\n<p class=\"import-Normal\">Overall, the African ape fossil record in the Late Miocene is sparse, with seven fossil localities dating between eleven and five million years ago (Pickford et al. 2009). Nevertheless, most species of great apes live in Africa today. Where did the progenitors of modern African apes arise? Did they evolve in Africa or somewhere else? The paucity of apes in the Late Miocene of Africa stands in contrast to the situation in Eurasia. There, ape diversity was high. Furthermore, several Eurasian ape fossils show morphological affinities with modern hominoids (apes). Because of this, some paleoanthropologists suggest that the ancestors of modern African great apes recolonized Africa from Eurasia toward the end of the Miocene (Begun 2002). However, discoveries of Late Miocene hominoids like the Kenyan <em>Nakalipithecus<\/em> (9.9 million to 9.8 million years ago), the Ethiopian <em>Chororapithecus<\/em> (10.7 million to 10.1 million years ago), and the late-Middle Miocene Namibian <em>Otavipithecus<\/em> (13 million to 12 million years ago) fuel an alternative hypothesis\u2014namely that African hominoid diversity was maintained throughout the Miocene and that one of these taxa might, in fact, be the last common ancestor of extant African apes (Kunimatsu et al. 2007; Mocke et al. 2002). The previously underappreciated diversity of Late Miocene apes in Africa might be due to poor sampling of the fossil record in Africa.<\/p>\r\n\r\n<h4 class=\"import-Normal\"><em>Eurasian Ape Diversity<\/em><\/h4>\r\n<p class=\"import-Normal\">With the establishment of the <em>Gomphotherium<\/em> Landbridge (a result of the closure of the Eastern Mediterranean seaway; R\u00f6gl 1999), the Middle Miocene was an exciting time for hominoid radiations outside of Africa (see Figure 8.23). Eurasian hominoid species exploited their environments in many different ways in the Miocene. Food exploitation ranged from soft-fruit feeding in some taxa to hard-object feeding in others, in part owing to seasonal fluctuations and the necessary adoptions of fallback foods (DeMiguel et al. 2014). For example, the molars of <em>Oreopithecus bambolii<\/em> (Family Hominidae) have relatively long lower-molar shearing crests, suggesting that this hominoid was very folivorous (Ungar and Kay 1995). Associated with variation in diet, there is great variation in the degree to which cranial features (e.g., zygomatic bone or supraorbital tori) are developed across the many taxa (Cameron 1997); however, Middle Miocene fossils tend to exhibit relatively thick molar enamel and relatively robust jaws (Andrews and Martin 1991).<\/p>\r\n<p class=\"import-Normal\">In Spain, the cranium with upper dentition, part of a mandible, and partial skeleton of <em>Pliobates <\/em>(Family Pliobatidae), a small-bodied ape (4\u20135 kg; 9\u201311 lbs.), was discovered in deposits dating to 11.6 million years ago (Alba et al. 2015). It is believed to be a frugivore with a relative brain size that overlaps with modern cercopithecoids. The fossilized postcrania of <em>Pliobates<\/em> suggest that this ape might have had a unique style of locomotion, including the tendency to walk across the branches of trees with its palms facing downward and flexible wrists that permitted rotation of the forearm during climbing. However, the anatomy of the distal humerus differs from those of living apes in ways that suggest that <em>Pliobates<\/em> was less efficient at stabilizing its elbow while suspended (Benefit and McCrossin 2015). Two other recently described apes from Spain, <em>Pierolapithecus <\/em>and <em>Anoiapithecus<\/em>, are known from relatively complete skeletons. <em>Pierolapithecus<\/em> had a very projecting face and thick molar enamel as well as some skeletal features that suggest (albeit controversially) a less suspensory locomotor style than in extant apes (Moy\u00e0-Sol\u00e0 et al. 2004). In contrast to <em>Pierolapithecus<\/em>, the slightly younger <em>Anoiapithecus<\/em> has a very flat face (Moy\u00e0-Sol\u00e0 et al. 2009).<\/p>\r\n<p class=\"import-Normal\">Postcranial evidence for suspensory or well-developed orthograde behaviors in apes does not appear until the Late Miocene of Europe. Primary evidence supporting these specialized locomotor modes includes the relatively short lumbar vertebrae of <em>Oreopithecus <\/em>(Figure 8.26) and <em>Dryopithecus<\/em> (Maclatchy 2004). Further, fossil material of the lower torso of <em>O. bambolii <\/em>(which dates to the <em>Pan<\/em>-hominin divergence) conveys a higher degree of flexion-extension abilities in the lumbar region (lower back) than what is possible in extant apes. Additionally, the hindlimb of <em>O. bambolii <\/em>is suggested to have supported powerful hip adduction during climbing (Hammond et al. 2020). The Late Miocene saw the extinction of most of the Eurasian hominoids in an event referred to as the Vallesian Crisis (Agust\u00ed et al. 2003). Among the latest surviving hominoid taxa in Eurasia were <em>Oreopithecus<\/em> and <em>Gigantopithecus<\/em>, the latter of which held out until the Pleistocene in Asia and was probably even sympatric with <em>Homo erectus<\/em> (Cachel 2015).<\/p>\r\n\r\n\r\n[caption id=\"\" align=\"aligncenter\" width=\"436\"]<img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image8-2-1.jpg\" alt=\"Posterior view of ancient ape skeleton.\" width=\"436\" height=\"775\" \/> Figure 8.26: Skeleton of Oreopithecus bambolii. Credit: <a class=\"rId107\" href=\"https:\/\/commons.wikimedia.org\/wiki\/File:Oreopithecus_bambolii_1.JPG\">Oreopithecus bambolii 1<\/a> by <a class=\"rId108\" href=\"https:\/\/commons.wikimedia.org\/wiki\/User:Ghedoghedo\">Ghedoghedo<\/a> is under a <a class=\"rId109\" href=\"https:\/\/creativecommons.org\/licenses\/by-sa\/3.0\/legalcode\">CC BY-SA 3.0 License<\/a>.[\/caption]\r\n<h3 class=\"import-Normal\"><strong>The Origins of Extant Apes<\/strong><\/h3>\r\n<p class=\"import-Normal\">The fossil record of the extant apes is somewhat underwhelming: it ranges from being practically nonexistent for some taxa (e.g., chimpanzees) to being a little better for others (e.g., humans). There are many possible reasons for these differences in fossil abundance, and many are associated with the environmental conditions necessary for the fossilization of bones. One way to understand the evolution of extant apes that is not so dependent on the fossil record is via molecular evolutionary analyses. This can include counting up the differences in the genetic sequence between two closely related species to estimate the amount of time since these species shared a common ancestor. This is called a molecular clock, and it is often calibrated using fossils of known absolute age that stand in for the last common ancestor of a particular clade. Molecular clock estimates have placed the Hylobatidae and Hominidae split between 19.7 million and 24.1 million years ago, the African ape and Asian ape split between 15.7 million and 19.3 million years ago, and the split of Hylobatidae into its current genera between 6.4 million and 8 million years ago (Israfil et al. 2011).<\/p>\r\n\r\n<h4 class=\"import-Normal\"><em>Small Ape Origins and Fossils<\/em><\/h4>\r\n<p class=\"import-Normal\">Unfortunately, the fossil record for the small (formerly \u201clesser\u201d) apes is meager, particularly in Miocene deposits. One possible early hylobatid is <em>Laccopithecus robustus<\/em>, a Late Miocene catarrhine from China (Harrison 2016). Although it does share some characteristics with modern gibbons and siamangs (including an overall small body size and a short face), <em>Laccopithecus<\/em> most likely represents a plesiomorphic stem catarrhine and is therefore distantly related to extant apes (Jablonski and Chaplin 2009). A more likely candidate for the hylobatid stem is another Late Miocene taxon from China, <em>Yuanmoupithecus xiaoyuan<\/em>. Interpretation of its phylogenetic standing, however, is complicated by contradicting dental features\u2014some of them quite plesiomorphic\u2014which some believe best place <em>Yuanmoupithecus<\/em> as a stem hylobatid (Harrison 2016). Recently, a Middle Miocene Indian fossil ape, <em>Kapi ramnagarensis<\/em>, has extended the fossil record of small apes by approximately five million years. Its teeth are suggestive of a shift to a more frugivorous diet and it is likely a stem hylobatid (Gilbert et al. 2020). The history of Hylobatidae becomes clearer in the Pleistocene, with fossils representing extant genera.<\/p>\r\n\r\n<h4 class=\"import-Normal\"><em>Great Ape Origins and Fossils<\/em><\/h4>\r\n<p class=\"import-Normal\">The most extensive fossil record of a modern great ape is that of our own genus, <em>Homo<\/em>. The evolution of our own species will be covered in Chapter 9. The evolutionary history of the Asian great ape, the orangutan (<em>Pongo<\/em>), is becoming clearer. Today, orangutans are found only on the islands of Borneo and Sumatra. However, Pleistocene-aged teeth, attributed to <em>Pongo<\/em>, have been found in Cambodia, China, Laos, Peninsular Malaysia, and Vietnam\u2014demonstrating the vastness of the orangutan\u2019s previous range (Ibrahim et al. 2013; Wang et al. 2014). <em>Sivapithecus <\/em>from the Miocene of India and Pakistan is represented by many specimens, including parts of the face. <em>Sivapithecus<\/em> is very similar to <em>Pongo<\/em>, especially in the face, and it probably is closely related to ancestral orangutans (Pilbeam 1982). Originally, jaws and teeth belonging to the former genus <em>Ramapithecus<\/em> were thought to be important in the origin of humans (Simons 1961), but now these are recognized as specimens of <em>Sivapithecus<\/em> (Kelley 2002). Postcranial bones of <em>Sivapithecus<\/em>, however, suggest a more generalized locomotor mode\u2014including terrestrial locomotion\u2014than seen in <em>Pongo <\/em>(Pilbeam et al. 1990). Stable carbon and oxygen isotope data from dental enamel have reconstructed the paleoecological space of <em>Sivapithecus <\/em>(as well as the contemporaneous Late Miocene pongine <em>Khoratpithecus<\/em>) within the canopies of forested habitats (Habinger et al. 2022).<\/p>\r\n<p class=\"import-Normal\">A probable close relative of <em>Sivapithecus <\/em>is the amazing <em>Gigantopithecus<\/em> (see Figure 8.24). Known only from teeth and jaws from China and India (e.g., Figure 8.27), this ape probably weighed as much as 270 kg (595 lbs.) and was likely the largest primate ever (Bocherens et al. 2017). Because of unique features of its teeth (including molarized premolars and patterns of wear) and its massive size, it has been reconstructed as a bamboo specialist, somewhat like the modern panda. Small silica particles (phytoliths) from grasses have been found stuck to the molars of <em>Gigantopithecus<\/em> (Ciochon et al. 1990). Recent studies evaluating the carbon isotope composition of the enamel sampled from <em>Gigantopithecus<\/em> teeth suggest that this ape exploited a wide range of vegetation, including fruits, leaves, roots, and bamboo (Bocherens et al. 2017). Its face is reminiscent of that of modern orangutans and it might belong in the same family, Pongidae (Kelley 2002).<\/p>\r\n\r\n\r\n[caption id=\"\" align=\"aligncenter\" width=\"488\"]<img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image12.jpg\" alt=\"Superior view of mandible and teeth.\" width=\"488\" height=\"533\" \/> Figure 8.27: Cast of the mandible of Gigantopithecus blacki. Credit: <a class=\"rId111\" href=\"https:\/\/commons.wikimedia.org\/wiki\/File:Gigantopithecus%20blacki%20mandible%20010112.jpg\">Gigantopithecus blacki mandible 010112<\/a> by <a class=\"rId112\" href=\"https:\/\/commons.wikimedia.org\/wiki\/User:Wilson44691\">Wilson44691<\/a> is under a <a class=\"rId113\" href=\"https:\/\/creativecommons.org\/licenses\/by-sa\/3.0\/legalcode\">CC BY-SA 3.0 License<\/a>.[\/caption]\r\n<p class=\"import-Normal\">In Africa, the first fossil to be confidently attributed to <em>Pan<\/em>, and known to be the earliest evidence of a chimpanzee, was described based on teeth found in Middle Pleistocene deposits in the Eastern Rift Valley of Kenya (McBrearty and Jablonski 2005). Paleoenvironmental reconstructions of this locality suggest that this early chimpanzee was living in close proximity to early <em>Homo<\/em> in a closed-canopy wooded habitat. Similarly, fossil teeth and mandibular remains attributed to two species of Middle-Late Miocene apes\u2014<em>Chororapithecus abyssinicus<\/em> (from Ethiopia; Suwa et al. 2007) and <em>Nakalipithecus nakayamai<\/em> (from Kenya; Kunimatsu et al. 2007)\u2014have been suggested as basal members of the gorilla clade.<\/p>\r\n<p class=\"import-Normal\">While the deposits of Eastern Africa have yielded a profound record of our fossil hominin ancestors, the continent\u2019s rainforests remain a \u201cpalaeontological desert\u201d (Rosas et al. 2022). Clearly, more work is needed to fill in the large gaps in the fossil record of the nonhuman great apes. The twentieth century witnessed the discovery of many hominin fossils in East Africa, which have been critical for improving our understanding of human evolution. While twenty-first-century conservationists fight to prevent the extinction of the living great apes, perhaps efforts by twenty-first-century paleoanthropologists will yield the evolutionary story of these, our closest relatives.<\/p>\r\n\r\n<div class=\"textbox shaded\">\r\n<h2 class=\"import-Normal\">Review Questions<strong>\r\n<\/strong><\/h2>\r\n<ul>\r\n \t<li>Compare three major hypotheses about primate origins, making reference to each one\u2019s key ecological reason for primate uniqueness.<\/li>\r\n \t<li>Explain how changes in temperature, rainfall, and vegetation led to major changes in primate biogeography over the Early Tertiary.<\/li>\r\n \t<li>List some euprimate features that plesiadapiforms have and some that they lack.<\/li>\r\n \t<li>Contrast adapoids and omomyoids in terms of life habits.<\/li>\r\n \t<li>Describe one piece of evidence for each of the adapoid, omomyoid, and tarsier origin hypotheses for anthropoids.<\/li>\r\n \t<li>Discuss the biogeography of the origins of African great apes and orangutans using examples from the Miocene ape fossil record.<\/li>\r\n<\/ul>\r\n<\/div>\r\n<h2 class=\"import-Normal\">Key Terms<strong>\r\n<\/strong><\/h2>\r\n<p class=\"import-Normal\"><strong>Adapoidea<\/strong>: Order: Primates. One of the earliest groups of euprimates (true primates; earliest records from the early Eocene).<\/p>\r\n<p class=\"import-Normal\"><strong>A<\/strong><strong>daptive radiations<\/strong>: Rapid diversifications of single lineages into many species which may present unique morphological features in response to different ecological settings.<\/p>\r\n<p class=\"import-Normal\"><strong>Ancestral traits<\/strong>: Features that were inherited from a common ancestor and which remain (largely) unchanged.<\/p>\r\n<p class=\"import-Normal\"><strong>Anthropoids<\/strong>:Group containing monkeys and apes, including humans.<\/p>\r\n<p class=\"import-Normal\"><strong>Auditory bulla<\/strong>: The rounded bony floor of the middle ear cavity.<\/p>\r\n<p class=\"import-Normal\"><strong>Bilophodonty<\/strong>: Dental condition in which the cusps of molar teeth form ridges (or lophs) separated from each other by valleys (seen, e.g., in modern catarrhine monkeys).<\/p>\r\n<p class=\"import-Normal\"><strong>Catarrhines<\/strong>: Order: Primates; Suborder: Anthropoidea; Infraorder: Catarrhini. Group, with origins in Africa and Asia, that contains monkeys and apes, including humans.<\/p>\r\n<p class=\"import-Normal\"><strong>Clade<\/strong>:Group containing all of the descendants of a single ancestor. A portion of a phylogenetic tree represented as a bifurcation (node) in a lineage and all of the branches leading forward in time from that bifurcation.<\/p>\r\n<p class=\"import-Normal\"><strong>Convergent evolution<\/strong>: The independent evolution of a morphological feature in animals not closely related (e.g., wings in birds and bats).<\/p>\r\n<p class=\"import-Normal\"><strong>Crown<\/strong>: Smallest monophyletic group (clade) containing a specified set of extant taxa and all descendants of their last common ancestor.<\/p>\r\n<p class=\"import-Normal\"><strong>Diastema<\/strong>: Space between adjacent teeth.<\/p>\r\n<p class=\"import-Normal\"><strong>Diffuse coevolution<\/strong>: The ecological interaction between whole groups of species (e.g., primates) with whole groups of other species (e.g., fruiting trees).<\/p>\r\n<p class=\"import-Normal\"><strong>Ectotympanic<\/strong>: Bony ring or tube that holds the tympanic membrane (eardrum).<\/p>\r\n<p class=\"import-Normal\"><strong>Euprimates<\/strong>: Order: Primates. True primates or primates of modern aspect.<\/p>\r\n<p class=\"import-Normal\"><strong>Haplorhines<\/strong>: Group containing catarrhines, platyrrhines, and tarsiers.<\/p>\r\n<p class=\"import-Normal\"><strong>Hominins<\/strong>: Modern humans and any extinct relatives more closely related to us than to chimpanzees.<\/p>\r\n<p class=\"import-Normal\"><strong>Mandibular symphysis<\/strong>: Fibrocartilaginous joint between the left and right mandibular segments, located in the midline of the body.<\/p>\r\n<p class=\"import-Normal\"><strong>Omomyoidea<\/strong>: Order: Primates; Superfamily: Omomyoidea. One of the earliest groups of euprimates (true primates; earliest record in the early Eocene).<\/p>\r\n<p class=\"import-Normal\"><strong>Petrosal bone<\/strong>: The portion of the temporal bone that houses the inner ear apparatus.<\/p>\r\n<p class=\"import-Normal\"><strong>Plagiaulacoid<\/strong>: Dental condition where at least one of the lower cheek-teeth (molars or premolars) is a laterally compressed blade.<\/p>\r\n<p class=\"import-Normal\"><strong>Platyrrhines<\/strong>: Order: Primates; Suborder: Anthropoidea; Infraorder: Platyrrhini. Group containing monkeys found in the Americas.<\/p>\r\n<p class=\"import-Normal\"><strong>Plesiadapiforms<\/strong>: Order: Plesiadapiformes. Archaic primates or primate-like placental mammals (Early Paleocene\u2013Late Eocene).<\/p>\r\n<p class=\"import-Normal\"><strong>P<\/strong><strong>lesiomorphic<\/strong>: Having features that are shared by different groups which arose from a common ancestor.<\/p>\r\n<p class=\"import-Normal\"><strong>Stem<\/strong>: Taxa that are basal to a given crown group but are more closely related to the crown group than to the closest living sister taxon of the crown group.<\/p>\r\n<p class=\"import-Normal\"><strong>Strepsirrhines<\/strong>: Order: Primates; Suborder: Stresirrhini. Group containing lemurs, lorises, and galagos (does not include tarsiers).<\/p>\r\n<p class=\"import-Normal\"><strong>Toothcomb<\/strong>: Dental condition found in modern strepsirrhines in which the lower incisors and canines are laterally compressed and protrude forward at a nearly horizontal inclination. This structure is used in grooming.<\/p>\r\n\r\n<h2 class=\"import-Normal\">About the Authors<strong>\r\n<\/strong><\/h2>\r\n<p class=\"import-Normal\"><strong data-wp-editing=\"1\"><img class=\"alignleft\" src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image17-1-1.jpg\" alt=\"A man with sunglasses, a full beard, and a bandana stands in a field. \" width=\"243\" height=\"309\" \/><\/strong><\/p>\r\n\r\n<h3 class=\"import-Normal\"><strong>Jonathan M. G. Perry, Ph.D.<\/strong><\/h3>\r\n<p class=\"import-Normal\">Western University of Health Sciences, Oregon, jperry@westernu.edu<\/p>\r\n<p class=\"import-Normal\">Jonathan Perry was trained as a paleontologist and primatologist at the University of Alberta, Duke University, and Stony Brook University. His research focuses on the relationship between food, feeding, and craniodental anatomy in primates both living and extinct. This work includes primate feeding behavior, comparative anatomy, biomechanics, and field paleontology. He has taught courses on primate evolution at the undergraduate and graduate level.<\/p>\r\n\r\n<\/div>\r\n&nbsp;\r\n\r\n&nbsp;\r\n<div class=\"__UNKNOWN__\">\r\n<p class=\"import-Normal\"><strong><img class=\"alignleft\" src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image10-5.png\" alt=\"A woman with long light brown hair stands in front of screen with scientific data and imagery. \" width=\"232\" height=\"211\" \/><\/strong><\/p>\r\n\r\n<h3 class=\"import-Normal\"><strong>Stephanie L. Canington, B.A., Ph.D.<\/strong><\/h3>\r\n<p class=\"import-Normal\">University of Pennsylvania, scaning@upenn.edu<\/p>\r\n<p class=\"import-Normal\">Stephanie Canington is a postdoctoral researcher at the University of Pennsylvania. Her current research is on the links between food properties, feeding behavior, and jaw morphology in lemurs that live in varying forms of captivity.<\/p>\r\n&nbsp;\r\n<h2 class=\"import-Normal\">For Further Exploration<strong>\r\n<\/strong><\/h2>\r\n<p class=\"import-Normal\">Beard, Chris. 2004. <em>The Hunt for the Dawn Monkey: Unearthing the Origins of Monkeys, Apes, and Humans<\/em>. Berkeley: University of California Press.<\/p>\r\n<p class=\"import-Normal\">Begun, David R. 2010. \u201cMiocene Hominids and the Origins of the African Apes and Humans.\u201d <em>Annual Review of Anthropology<\/em> 39: 67\u201384.<\/p>\r\n<p class=\"import-Normal\">Fleagle, John G. 2013. <em>Primate Adaptation and Evolution.<\/em> Third edition. San Diego, CA: Academic Press.<\/p>\r\n<p class=\"import-Normal\">Gebo, Daniel L., ed. 1993. <em>Postcranial Adaptations in Nonhuman Primates<\/em>. Dekalb: Northern Illinois University Press.<\/p>\r\n<p class=\"import-Normal\">Godfrey, Laurie R., and William L. Jungers. 2002. \u201cQuaternary Fossil Lemurs.\u201d In <em>The Primate Fossil Record, <\/em>edited by Walter C. Hartwig, 97\u2013121. Cambridge: Cambridge University Press.<\/p>\r\n<p class=\"import-Normal\">Godinot, Marc. 2006. \u201cLemuriform Origins as Viewed from the Fossil Record.\u201d <em>Folia Primatologica<\/em> 77 (6): 446\u2013464.<\/p>\r\n<p class=\"import-Normal\">Kay, Richard F. 2018. \u201c100 Years of Primate Paleontology.\u201d <em>American Journal of Physical Anthropology<\/em> 165 (4): 652\u2013676.<\/p>\r\n<p class=\"import-Normal\">Marivaux, Laurent. 2006. \u201cThe Eosimiid and Amphipithecid Primates (Anthropoidea) from the Oligocene of the Bugti Hills (Balochistan, Pakistan): New Insight into Early Higher Primate Evolution in South Asia.\u201d <em>Palaeovertebrata, Montpellier <\/em>34 (1\u20132): 29\u2013109.<\/p>\r\n<p class=\"import-Normal\">Martin, R. D. 1990. <em>Primate Origins and Evolution<\/em><em>: A <\/em><em>Phylogenetic Reconstruction<\/em>. Princeton: Princeton University Press.<\/p>\r\n<p class=\"import-Normal\">Rose, Kenneth D., Marc Godinot, and Thomas M. Bown. 1994. \u201cThe Early Radiation of Euprimates and the Initial Diversification of Omomyidae.\u201d In <em>Anthropoid Origins: The Fossil Evidence, <\/em>edited by John G. Fleagle and Richard F. Kay, 1\u201328. New York: Plenum Press.<\/p>\r\n<p class=\"import-Normal\">Ross, Callum F. 1999. \u201cHow to Carry Out Functional Morphology.\u201d <em>Evolutionary Anthropology<\/em> 7 (6): 217\u2013222.<\/p>\r\n<p class=\"import-Normal\">Seiffert, Erik R. 2012. \u201cEarly Primate Evolution in Afro-Arabia.\u201d Evolutionary Anthropology: Issues, News, and Reviews 21(6): 239\u2013253.<\/p>\r\n<p class=\"import-Normal\">Szalay, Frederic S., and Eric Delson. 1979. Evolutionary History of the Primates. New York: Academic Press.<\/p>\r\n<p class=\"import-Normal\">Ungar, Peter S. 2002. \u201cReconstructing the Diets of Fossil Primates.\u201d In <em>Reconstructing Behavior in the Primate Fossil Record<\/em>, edited by Joseph Plavcan, Richard F. Kay, William Jungers, and Carel P. van Schaik, 261\u2013296. New York: Kluwer Academic\/Plenum Publishers.<\/p>\r\n\r\n<h2 class=\"import-Normal\">References<\/h2>\r\n<p class=\"import-Normal\">Agust\u00ed, J., A. Sanz de Siria, and M. Garc\u00e9s M. 2003. \u201cExplaining the End of the Hominoid Experiment in Europe.\u201d <em>Journal of Human Evolution<\/em> 45 (2): 145\u2013153.<\/p>\r\n<p class=\"import-Normal\">Alba, David M., Sergio Alm\u00e9cija, Daniel DeMiguel, Josep Fortuny, Miriam P\u00e9rez de los R\u00edos, Marta Pina, Josep M. Robles, and Salvador Moy\u00e0-Sol\u00e0. 2015. \u201cMiocene Small-Bodied Ape from Eurasia Sheds Light on Hominoid Evolution.\u201d <em>Science<\/em> 350 (6260): aab2625.<\/p>\r\n<p class=\"import-Normal\">Andrews, Peter, and Lawrence Martin. 1991. \u201cHominoid Dietary Evolution.\u201d <em>Philosophical Transactions of the Royal Society of London B: Biological Sciences<\/em> 334 (1270): 199\u2013209.<\/p>\r\n<p class=\"import-Normal\">Antoine, Pierre-Oliver, Laurent Marivaux, Darren A. Croft, Guillaume Billet, Morgan Ganer\u00f8d, Carlos Jaramillo, Thomas Martin, et al. 2012. \u201cMiddle Eocene Rodents from Peruvian Amazonia Reveal the Pattern and Timing of Caviomorph Origins and Biogeography.\u201d <em>Proceedings of the Royal Society B: Biological Sciences<\/em> 279 (1732): 1319\u20131326.<\/p>\r\n<p class=\"import-Normal\">Beard, K. Christopher. 1990. \u201cGliding Behaviour and Palaeoecology of the Alleged Primate Family Paromomyidae (Mammalia, Dermoptera).\u201d <em>Nature<\/em> 345 (6273): 340\u2013341.<\/p>\r\n<p class=\"import-Normal\">Beard, K. Christopher. 2002. \u201cBasal Anthropoids.\u201d In <em>The Primate Fossil Record, <\/em>edited by William C. Hartwig, 133\u2013150. Cambridge: Cambridge University Press.<\/p>\r\n<p class=\"import-Normal\">Beard, K. Christopher, and R. D. E. MacPhee. 1994. \u201cCranial Anatomy of <em>Shoshonius<\/em> and the Antiquity of Anthropoidea.\u201d In <em>Anthropoid Origins: The Fossil Evidence<\/em>, edited by John G. Fleagle and Richard F. Kay, 55\u201398. New York: Plenum Press.<\/p>\r\n<p class=\"import-Normal\">Beard, K. Christopher, Laurent Marivaux, Soe Thura Tun, Aung Naing Soe, Yaowalak Chaimanee, Wanna Htoon, Bernard Marandat, Htun Htun Aung, and Jean-Jacques Jaeger. 2007. \u201cNew Sivaladapid Primates from the Eocene Pondaung Formation of Myanmar and the Anthropoid Status of Amphipithecidae.\u201d <em>Bulletin of Carnegie Museum of Natural History<\/em> 39: 67\u201376.<\/p>\r\n<p class=\"import-Normal\">Beard, K. Christopher, Tao Qi, Mary R. Dawson, Banyue Wang, and Chuankuei Li. 1994. \u201cA Diverse New Primate Fauna from Middle Eocene Fissure-Fillings in Southeastern China.\u201d <em>Nature<\/em> 368 (6472): 604\u2013609.<\/p>\r\n<p class=\"import-Normal\">Beard, K. Christopher, Yongsheng Tong, Mary R. Dawson, Jingwen Wang, and Xueshi Huang. 1996. \u201cEarliest Complete Dentition of an Anthropoid Primate from the Late Middle Eocene of Shanxi Province, China.\u201d <em>Science<\/em> 272 (5258): 82\u201385.<\/p>\r\n<p class=\"import-Normal\">Beecher, Robert M. 1983. \u201cEvolution of the Mandibular Symphysis in Notharctinae (Adapidae, Primates).\u201d <em>International Journal of Primatology<\/em> 4 (1): 99\u2013112.<\/p>\r\n<p class=\"import-Normal\">Begun, David R. 2002. \u201cEuropean Hominoids.\u201d In <em>The Primate Fossil Record<\/em>, edited by William C. Hartwig, 339\u2013368. Cambridge: Cambridge University Press.<\/p>\r\n<p class=\"import-Normal\">Begun, David R. 2003. \u201cPlanet of the Apes.\u201d <em>Scientific American<\/em> 289 (2): 74\u201383.<\/p>\r\n<p class=\"import-Normal\">Begun, David R. 2007. \u201cFossil Record of Miocene Hominoids.\u201d In <em>Handbook of Paleoanthropology<\/em>, edited by Winfried Henke and Ian Tattersall, 921\u2013977. New York: Springer.<\/p>\r\n<p class=\"import-Normal\">Benefit, Brenda R., and Monte L. McCrossin. 1997. \u201cEarliest Known Old World Monkey Skull.\u201d <em>Nature<\/em> 388 (6640): 368\u2013371.<\/p>\r\n<p class=\"import-Normal\">Benefit, Brenda R., and Monte L. McCrossin. 2015. \u201cA Window into Ape Evolution.\u201d <em>Science<\/em> 350 (6260): 515\u2013516.<\/p>\r\n<p class=\"import-Normal\">Bloch, Jonathan I., and David M. Boyer. 2002. \u201cGrasping Primate Origins.\u201d <em>Science<\/em> 298 (5598): 1606\u20131610.<\/p>\r\n<p class=\"import-Normal\">Bloch, Jonathan I., and David M. Boyer. 2007. \u201cNew Skeletons of Paleocene-Eocene Plesiadapiformes: A Diversity of Arboreal Positional Behaviors in Early Primates.\u201d In <em>Primate Origins: Adaptations and Evolution<\/em>, edited by Matthew J. Ravosa and Marian Dagosto, 535\u2013581. New York: Springer.<\/p>\r\n<p class=\"import-Normal\">Bloch, Jonathan I., and Mary T. Silcox. 2006. \u201cCranial Anatomy of the Paleocene Plesiadapiform <em>Carpolestes simpsoni<\/em> (Mammalia, Primates) Using Ultra High-Resolution X-ray Computed Tomography, and the Relationships of Plesiadapiforms to Euprimates.\u201d <em>Journal of Human Evolution<\/em>: 50 (1): 1\u201335.<\/p>\r\n<p class=\"import-Normal\">Blue, Kathleen T., Monte L. McCrossin, and Brenda R. Benefit. 2006. \u201cTerrestriality in a Middle Miocene Context: <em>Victoriapithecus<\/em> from Maboko, Kenya.\u201d In <em>Human Origins and Environmental Backgrounds<\/em>, edited by Hidemi Ishida, Russell Tuttle, Martin Pickford, Naomichi Ogihara, and Masato Nakatsukasa, 45\u201358. New York: Springer.<\/p>\r\n<p class=\"import-Normal\">Bocherens, Herv\u00e9, Friedemann Schrenk, Yaowalak Chaimanee, Ottmar Kullmer, Doris M\u00f6rike, Diana Pushkina, and Jean-Jacques Jaeger. 2017. \u201cFlexibility of Diet and Habitat in Pleistocene South Asian Mammals: Implications for the Fate of the Giant Fossil Ape <em>Gigantopithecus<\/em>.\u201d <em>Quaternary International<\/em> 434 (A): 148\u2013155.<\/p>\r\n<p class=\"import-Normal\">Bond, Mariano, Marcelo F. Tejedor, Kenneth E. Campbell Jr., Laura Chornogubsky, Nelson Novo, and Francisco Goin. 2015. \u201cEocene Primates of South America and the African Origins of New World Monkeys.\u201d <em>Nature<\/em> 520 (7548): 539\u2013541.<\/p>\r\n<p class=\"import-Normal\">Bown, T. M., and M. J. Kraus. 1988. \u201cGeology and Paleoenvironment of the Oligocene Jebel Qatrani Formation and Adjacent Rocks, Fayum Depression, Egypt.\u201d Professional Paper, 1452. Washington, DC: U.S. Geological Survey Professional Papers.<\/p>\r\n<p class=\"import-Normal\">Cachel, Susan. 2015.<em> Fossil Primates.<\/em> Vol. 69. Cambridge: Cambridge University Press.<\/p>\r\n<p class=\"import-Normal\">Cameron, David W. 1997. \u201cA Revised Systematic Scheme for the Eurasian Miocene Fossil Hominidae.\u201d <em>Journal of Human Evolution<\/em> 33 (4): 449\u2013477.<\/p>\r\n<p class=\"import-Normal\">Cartmill, Matt. 1972. \u201cArboreal Adaptations and the Origin of the Order Primates.\u201d In <em>The Functional and Evolutionary Biology of Primates<\/em>, edited by Russell Tuttle, 97\u2013122. Chicago: Aldine-Atherton.<\/p>\r\n<p class=\"import-Normal\">Cartmill, Matt. 1974. \u201cRethinking Primate Origins.\u201d <em>Science<\/em> 184 (4135): 436\u2013443.<\/p>\r\n<p class=\"import-Normal\">Cartmill, Matt, and Richard F. Kay. 1978. \u201cCraniodental Morphology, Tarsier Affinities, and Primate Suborders.\u201d In <em>Recent Advances in Primatology: Evolution,<\/em> edited by D. J. Chivers and K. A. Joysey, 205\u2013214. London: Academic Press.<\/p>\r\n<p class=\"import-Normal\">Casanovas-Vilar, Isaac, David M. Alba, Miguel Garc\u00e9s, Josep M. Robles, and Salvador Moy\u00e0-Sol\u00e0. 2011. \u201cUpdated Chronology for the Miocene Hominoid Radiation in Western Eurasia.\u201d <em>Proceedings of the National Academy of Sciences <\/em>108 (14): 5554-5559. https:\/\/doi:10.1073\/pnas.1018562108.<\/p>\r\n<p class=\"import-Normal\">Chaimanee, Yaowalak, Olivier Chavasseau, K. Christopher Beard, Aung Aung Kyaw, Aung Naing Soe, Chit Sein, Vincent Lazzari, et al. 2012. \u201cLate Middle Eocene Primate from Myanmar and the Initial Anthropoid Colonization of Africa.\u201d <em>Proceedings of the National Academy of Sciences<\/em> <em>of the United States of America <\/em>109 (26): 10293\u201310297.<\/p>\r\n<p class=\"import-Normal\">Chester, Stephen G. B., Jonathan I. Bloch, Doug M. Boyer, and William A. Clemens. 2015. \u201cOldest Known Euarchontan Tarsals and Affinities of Paleocene <em>Purgatorius<\/em> to Primates.\u201d <em>Proceedings of the National Academy of Sciences of the United States of America<\/em> 112 (5): 1487\u20131492.<\/p>\r\n<p class=\"import-Normal\">Ciochon, Russell L., and Gregg F. Gunnell. 2002. \u201cChronology of Primate Discoveries in Myanmar: Influences on the Anthropoid Origins Debate.\u201d <em>Yearbook of Physical Anthropology<\/em> 45(S35): 2\u201335.<\/p>\r\n<p class=\"import-Normal\">Ciochon, R. L., D. R. Piperno, and R. G. Thompson. 1990. \u201cOpal Phytoliths Found on the Teeth of the Extinct Ape <em>Gigantopithecus blacki<\/em>: Implications for Paleodietary Studies.\u201d <em>Proceedings of the National Academy of Sciences of the United States of America<\/em> 87 (20): 8120\u20138124.<\/p>\r\n<p class=\"import-Normal\">Clemens, William A. 2004. \u201c<em>Purgatorius<\/em> (Plesiadapiformes, Primates?, Mammalia), a Paleocene Immigrant into Northeastern Montana: Stratigraphic Occurrences and Incisor Proportions.\u201d <em>Bulletin of Carnegie Museum of Natural History<\/em> 36: 3\u201313.<\/p>\r\n<p class=\"import-Normal\">Cooke, Siobh\u00e1n B., Justin T. Gladman, Lauren B. Halenar, Zachary S. Klukkert, and Alfred L. Rosenberber. 2016. \u201cThe Paleobiology of the Recently Extinct Platyrrhines of Brazil and the Caribbean.\u201d In <em>Molecular Population Genetics, Evolutionary Biology and Biological Conservation of Neotropical Primates<\/em>, edited by Manuel Ruiz-Garcia and Joseph Mark Shostell, 41\u201389. New York: Nova Publishers.<\/p>\r\n<p class=\"import-Normal\">DeLeon, Valerie B., Timothy D. Smith, and Alfred L. Rosenberger. 2016. \u201cOntogeny of the Postorbital Region in Tarsiers and Other Primates.\u201d <em>Anatomical Record: Advances in Integrative Anatomy and Evolutionary Biology<\/em> 299 (12): 1631\u20131645.<\/p>\r\n<p class=\"import-Normal\">DeMiguel, Daniel, David M. Alba, and Salvador Moy\u00e0-Sol\u00e0. 2014. \u201cDietary Specialization during the Evolution of Western Eurasian Hominoids and the Extinction of European Great Apes.\u201d <em>PLoS ONE<\/em> 9 (5): e97442. https:\/\/doi.org\/10.1371\/journal.pone.0097442.<\/p>\r\n<p class=\"import-Normal\">Dunn, Rachel H., Kenneth D. Rose, Rajendra Rana, Kishore Kumar, Ashok Sahni, and Thierry Smith. 2016. \u201cNew Euprimate Postcrania from the Early Eocene of Gujarat, India, and the Strepsirrhine\u2013Haplorhine Divergence.\u201d <em>Journal of Human Evolution<\/em> 99: 25\u201351.<\/p>\r\n<p class=\"import-Normal\">Fleagle, John G. 2013. <em>Primate Adaptation and Evolution<\/em>, Third Edition. San Diego, CA: Academic Press.<\/p>\r\n<p class=\"import-Normal\">Fleagle, John G., and Richard F. Kay. 1994. <em>Anthropoid Origins<\/em>. New York: Plenum Press.<\/p>\r\n<p class=\"import-Normal\">Franzen, Jens Lorenz, Phillip D. Gingerich, J\u00f6rg Habersetzer, J\u00f8rn Hurum, von Wighart Koenigswald, and B. Holly Smith. 2009. \u201cComplete Primate Skeleton from the Middle Eocene of Messel in Germany: Morphology and Paleobiology.\u201d <em>PLoS ONE<\/em> 4 (5): e5723. doi:10.1371\/journal.pone.0005723.<\/p>\r\n<p class=\"import-Normal\">Gebo, Daniel L., Marian Dagosto, K. Christopher Beard, Tao Qi, and Jingwen Wang. 2000. \u201cThe Oldest Known Anthropoid Postcranial Fossils and the Early Evolution of Higher Primates.\u201d <em>Nature<\/em> 404 (6775): 276\u2013278.<\/p>\r\n<p class=\"import-Normal\">Gebo, Daniel L., and Elwyn L. Simons. 1987. \u201cMorphology and Locomotor Adaptations of the Foot in Early Oligocene Anthropoids.\u201d <em>American Journal of Physical Anthropology<\/em> 74 (1): 83\u2013101.<\/p>\r\n<p class=\"import-Normal\">Gilbert, Christopher C., Alejandra Ortiz, Kelsey D. Pugh, Christopher J. Campisano, Biren A. Patel, Ningthoujam Premjit Singh, John G. Fleagle, and Rajeev Patnaik. 2020. \u201cNew Middle Miocene Ape (Primates: Hylobatidae) from Ramnagar, India, Fills Major Gaps in the Hominoid Fossil Record.\u201d <em>Proceedings of the Royal Society B<\/em> 287(1934): 20201655.<\/p>\r\n<p class=\"import-Normal\">Gingerich, P. D. 1980. \u201cEocene Adapidae, Paleobiogeography, and the Origin of South American Platyrrhini.\u201d <em>In Evolutionary Biology of the New World Monkeys and Continental Drift, <\/em>edited by Russell L. Ciochon and A. Brunetto Chiarelli, 123\u2013138. New York: Plenum Press.<\/p>\r\n<p class=\"import-Normal\">Godfrey, Laurie R., and William L. Jungers. 2002. \u201cQuaternary Fossil Lemurs.\u201d In <em>The Primate Fossil Record<\/em>, edited by Walter C. Hartwig, 97\u2013121. Cambridge: Cambridge University Press.<\/p>\r\n<p class=\"import-Normal\">Godinot, Marc. 2006. \u201cLemuriform Origins as Viewed from the Fossil Record.\u201d <em>Folia Primatologica<\/em> 77 (6): 446\u2013464.<\/p>\r\n<p class=\"import-Normal\">Gregory, William K. 1920. \u201cOn the Structure and Relations of <em>Notharctus<\/em>, an American Eocene Primate.\u201d <em>Memoirs of the American Museum of Natural History<\/em> (N.S.) 3 (2).<\/p>\r\n<p class=\"import-Normal\">Gunnell, Gregg F., Doug M. Boyer, Anthony R. Friscia, Steven Heritage, Frederik Kyalo Manthi, Ellen R. Miller, Hesham M. Sallam, Nancy B. Simmons, Nancy J. Stevens, and Erik R. Seiffert. 2018. \u201cFossil Lemurs from Egypt and Kenya Suggest an African Origin for Madagascar\u2019s Aye-aye.\u201d <em>Nature Communications<\/em> 9 (3193): 1\u201312.<\/p>\r\n<p class=\"import-Normal\">Habinger, S. G., O. Chavasseau, J. J. Jaeger, Y. Chaimanee, A. N. Soe, C. Sein, and H. Bocherens. 2022. \u201cEvolutionary Ecology of Miocene Hominoid Primates in Southeast Asia.\u201d <em>Scientific Reports<\/em> 12 (1): 1\u201312.<\/p>\r\n<p class=\"import-Normal\">Hammond, Ashley, Lorenzo Rook, Alisha D.Anaya, Elisabetta Cioppi, Lo\u00efc Costeur, Salvadore Moy\u00e0-Sol\u00e0, and Sergio Alm\u00e9cija. 2020. \u201cInsights into the Lower Torso in Late Miocene Hominoid Oreopithecus bambolii.\u201d <em>Proceedings of the National Academy of Sciences<\/em> 117 (1): 278\u2013284.<\/p>\r\n<p class=\"import-Normal\">Harrison, Terry. 2010. \u201cApes among the Tangled Branches of Human Origins.\u201d <em>Science<\/em> 327 (5965): 532\u2013534.<\/p>\r\n<p class=\"import-Normal\">Harrison, Terry. 2016. \u201cThe Fossil Record and Evolutionary History of Hylobatids.\u201d In <em>Evolution of Gibbons and Siamang<\/em>, edited by Ullrich H. Reichard, Hirohisa Hirai, and Claudia Barelli, 91\u2013110. New York: Springer.<\/p>\r\n<p class=\"import-Normal\">Ibrahim, Yasamin Kh., Lim Tze Tshen, Kira E. Westaway, Earl of Cranbrook, Louise Humphrey, Ross Fatihah Muhammad, Jian-xin Zhao, and Lee Chai Peng. 2013. \u201cFirst Discovery of Pleistocene Orangutan (<em>Pongo<\/em> sp.) Fossils in Peninsular Malaysia: Biogeographic and Paleoenvironmental Implications.\u201d <em>Journal of Human Evolution<\/em> 65 (6): 770\u2013797.<\/p>\r\n<p class=\"import-Normal\">Israfil, Hulya, Sarah M. Zehr, Alan R. Mootnick, Maryellen Ruvolo, and Michael E. Steiper. 2011. \u201cUnresolved Molecular Phylogenies of Gibbons and Siamangs (Family: Hylobatidae) Based on Mitochondrial, Y-linked, and X-linked Loci Indicate a Rapid Miocene Radiation or Sudden Vicariance Event.\u201d <em>Molecular Phylogenetics and Evolution<\/em> 58 (3): 447\u2013455.<\/p>\r\n<p class=\"import-Normal\">Jablonski, Nina G., and George Chaplin. 2009. \u201cThe Fossil Record of Gibbons.\u201d In <em>The Gibbons<\/em>, edited by Danielle Whittaker and Susan Lappan, 111\u2013130. New York: Springer.<\/p>\r\n<p class=\"import-Normal\">Jones, F. Wood. 1916. <em>Arboreal Man<\/em>. London: Edward Arnold.<\/p>\r\n<p class=\"import-Normal\">Kay, Richard F. 1977. \u201cDiets of Early Miocene African Hominoids.\u201d <em>Nature<\/em> 268 (5621): 628\u2013630.<\/p>\r\n<p class=\"import-Normal\">Kay, Richard F. 2015. \u201cBiogeography in Deep Time: What Do Phylogenetics, Geology, and Paleoclimate Tell Us about Early Platyrrhine Evolution?\u201d <em>Molecular Phylogenetics and Evolution<\/em> 82 (B): 358\u2013374.<\/p>\r\n<p class=\"import-Normal\">Kay, Richard F., and John G. Fleagle. 2010. \u201cStem Taxa, Homoplasy, Long Lineages, and the Phylogenetic Position of <em>Dolichocebus<\/em>.\u201d <em>Journal of Human Evolution<\/em> 59 (2): 218\u2013222.<\/p>\r\n<p class=\"import-Normal\">Kay, Richard F., Jonathan M. G. Perry, Michael Malinzak, Kari L. Allen, E. Christopher Kirk, J. Michael Plavcan, and John G. Fleagle. 2012. \u201cPaleobiology of Santacrucian Primates.\u201d In <em>Early Miocene Paleobiology in Patagonia: High-Latitude Paleocommunities of the Santa Cruz Formation<\/em>, edited by Sergio F. Vizca\u00edno, Richard F. Kay, and M. Susana Bargo, 306\u2013330. Cambridge: Cambridge University Press.<\/p>\r\n<p class=\"import-Normal\">Kay, Richard F., Daniel O Schmitt, Christopher J. Vinyard, Jonathan M. G. Perry, Nobuo Shigehara, Masanaru Takai, and Naoko Egi. 2004. \u201cThe Paleobiology of Amphipithecidae, South Asian Late Eocene Primates.\u201d <em>Journal of Human Evolution<\/em> 46 (1): 3\u201325.<\/p>\r\n<p class=\"import-Normal\">Kay, Richard F., and Elwyn L. Simons. 1980. \u201cThe Ecology of Oligocene African Anthropoidea.\u201d <em>International Journal of Primatology<\/em> 1 (1): 21\u201337.<\/p>\r\n<p class=\"import-Normal\">Kay, Richard F., Richard W. Thorington, and Peter Houde. 1990. \u201cEocene Plesiadapiform Shows Affinities with Flying Lemurs Not Primates.\u201d <em>Nature<\/em> 345 (6273): 342\u2013344.<\/p>\r\n<p class=\"import-Normal\">Kelley, Jay. 2002. \u201cThe Hominoid Radiation in Asia.\u201d In <em>The Primate Fossil Record<\/em>, edited by Walter C. Hartwig, 369\u2013384. Cambridge: Cambridge University Press.<\/p>\r\n<p class=\"import-Normal\">Kirk, E. Christopher, and Elwyn L. Simons. 2001. \u201cDiets of Fossil Primates from the Fayum Depression of Egypt: A Quantitative Analysis of Molar Shearing.\u201d <em>Journal of Human Evolution<\/em> 40 (3): 203\u2013229.<\/p>\r\n<p class=\"import-Normal\">Kirk, E. Christopher, and Blythe A. Williams. 2011. \u201cNew Adapiform Primate of Old World Affinities from the Devil\u2019s Graveyard Formation of Texas.\u201d <em>Journal of Human Evolution<\/em> 61 (2): 156\u2013168.<\/p>\r\n<p class=\"import-Normal\">Krause, David W. 1991. \u201cWere Paromomyids Gliders? Maybe, Maybe Not.\u201d <em>Journal of Human Evolution<\/em> 21 (3): 177\u2013188.<\/p>\r\n<p class=\"import-Normal\">Kunimatsu, Yutaka, Masato Nakatsukasa, Yoshihiro Sawada, Tetsuya Sakai, Masayuki Hyodo, Hironobu Hyodo, Tetsumaru Itaya, et al. 2007. \u201cA New Late Miocene Great Ape from Kenya and Its Implications for the Origins of African Great Apes and Humans.\u201d <em>Proceedings of the National Academy of Sciences of the United States of America<\/em> 104 (49): 19220\u201319225.<\/p>\r\n<p class=\"import-Normal\">Maclatchy, Laura. 2004. \u201cThe Oldest Ape.\u201d <em>Evolutionary Anthropology: Issues, News, and Reviews<\/em> 13 (3): 90\u2013103.<\/p>\r\n<p class=\"import-Normal\">Marivaux, Laurent, Yaowalak Chaimanee, St\u00e9phane Ducrocq, Bernard Marandat, Jean Sudre, Aung Naing Soe, Soe Thura Tun, Wanna Htoon, and Jean-Jacques Jaeger. 2003. \u201cThe Anthropoid Status of a Primate from the Late Middle Eocene Pondaung Formation (Central Myanmar): Tarsal Evidence.\u201d <em>Proceedings of the National Academy of Sciences of the United States of America<\/em> 100 (23): 13173\u201313178.<\/p>\r\n<p class=\"import-Normal\">Marivaux, Laurent, Anusha Ramdarshan, El Mabrouk Essid, Wissem Marzougui, Hayet Khayati Ammar, Renaud Lebrun, Bernard Marandat, Gilles Merzeraud, Rodolphe Tabuce, and Monique Vianey-Liaud. 2013. \u201c<em>Djebelemur<\/em>, a Tiny Pre-ToothCombed Primate from the Eocene of Tunisia: A Glimpse into the Origin of Crown Strepsirrhines.\u201d <em>PLoS ONE<\/em> 8 (12): e80778. <a class=\"rId116\" href=\"https:\/\/doi.org\/10.1371\/journal.pone.0080778\">doi.org\/10.1371\/journal.pone.0080778<\/a>.<\/p>\r\n<p class=\"import-Normal\">Martin, R. D. 1968. \u201cTowards a New Definition of Primates.\u201d <em>Man<\/em> (N.S.) 3 (3): 377\u2013401.<\/p>\r\n<p class=\"import-Normal\">Martin, R. D. 1972. \u201cAdaptive Radiation and Behaviour of the Malagasy Primates.\u201d <em>Philosophical Transactions of the Royal Society B: Biological Sciences<\/em> 264 (862): 295\u2013352.<\/p>\r\n<p class=\"import-Normal\">Martin, R. D. 1990. <em>Primate Origins and Evolution, a Phylogenetic Reconstruction<\/em>. Princeton: Princeton University Press.<\/p>\r\n<p class=\"import-Normal\">McBrearty, Sally, and Nina G. Jablonski. 2005. \u201cFirst Fossil Chimpanzee.\u201d <em>Nature<\/em> 437 (7055): 105\u2013108.<\/p>\r\n<p class=\"import-Normal\">Michel, Lauren A., Daniel J. Peppe, James A. Lutz, Stephen G. Driese, Holly M. Dunsworth, William E. H. Harcourt-Smith, William H. Horner, Thomas Lehmann, Sheila Nightingale, and Kieran P. McNulty. 2014. \u201cRemnants of an Ancient Forest Provide Ecological Context for Early Miocene Fossil Apes.\u201d <em>Nature Communications<\/em> 5: 1-9.<\/p>\r\n<p class=\"import-Normal\">Miller, E. R., B. R. Benefit, M. L. McCrossin, J. M. Plavcan, M. G. Leakey, A. N. El-Barkooky, M. A. Hamdan, M. K. A. Gawad, S. M. Hassan, and E. L. Simons. 2009. \u201cSystematics of Early and Middle Miocene Old World Monkeys.\u201d <em>Journal of Human Evolution<\/em> 57 (3): 195\u2013211.<\/p>\r\n<p class=\"import-Normal\">Mocke, H., M. Pickford, B. Senut, and D. Gommery. 2022. \u201cNew Information about African Late Middle Miocene to Latest Miocene (13\u20135.5 Ma) Hominoidea. <em>Communications of the Geological Survey of Namibia<\/em> 24: 33\u201366.<\/p>\r\n<p class=\"import-Normal\">Moy\u00e0-Sol\u00e0, Salvadore, David M. Alba, Sergio Alm\u00e9cija, Isaac Casanovas-Vilar, Meike K\u00f6hler, Soledad De Esteban-Trivigno, Josep M. Robles, Jordi Galindo, and Josep Fortuny. 2009. \u201cA Unique Middle Miocene European Hominoid and the Origins of the Great Ape and Human Clade.\u201d <em>Proceedings of the National Academy of Sciences of the United States of America<\/em> 106 (24): 9601\u20139606.<\/p>\r\n<p class=\"import-Normal\">Moy\u00e0-Sol\u00e0, Salvador, Meike K\u00f6hler, David M. Alba, Isaac Casanovas-Vilar, and Jordi Galindo. 2004. \u201c<em>Pierolapithecus catalaunicus<\/em>, a New Middle Miocene Great Ape from Spain.\u201d <em>Science<\/em> 306 (5700): 1339\u20131344.<\/p>\r\n<p class=\"import-Normal\">Ni, Xijun, Daniel L. Gebo, Marian Dagosto, Jin Meng, Paul Tafforeau, John J. Flynn, and K. Christopher Beard. 2013. \u201cThe Oldest Known Primate Skeleton and Early Haplorhine Evolution.\u201d <em>Nature<\/em> 498 (7452): 60\u201364.<\/p>\r\n<p class=\"import-Normal\">Perry, Jonathan M. G., Richard F. Kay, Sergio F. Vizca\u00edno, and M. Susana Bargo. 2010. \u201cTooth Root Size, Chewing Muscle Leverage, and the Biology of <em>Homunculus patagonicus<\/em> (Primates) from the Late Early Miocene of Patagonia.\u201d <em>Ameghiniana<\/em> 47 (3): 355\u2013371.<\/p>\r\n<p class=\"import-Normal\">Perry, Jonathan M. G., Richard F. Kay, Sergio F. Vizca\u00edno, and M. Susana Bargo. 2014. \u201cOldest Known Cranium of a Juvenile New World Monkey (Early Miocene, Patagonia, Argentina): Implications for the Taxonomy and the Molar Eruption Pattern of Early Platyrrhines.\u201d <em>Journal of Human Evolution<\/em> 74: 67\u201381.<\/p>\r\n<p class=\"import-Normal\">Pickford, Martin, Yves Coppens, Brigitte Senut, Jorge Morales, and Jos\u00e9 Braga. 2009. \u201cLate Miocene Hominoid from Niger.\u201d <em>Comptes Rendus Palevol<\/em> 8 (4): 413\u2013425.<\/p>\r\n<p class=\"import-Normal\">Pilbeam, David. 1982. \u201cNew Hominoid Skull Material from the Miocene of Pakistan.\u201d <em>Nature<\/em> 295 (5846): 232\u2013234.<\/p>\r\n<p class=\"import-Normal\">Pilbeam, David, Michael D. Rose, John C. Barry, and S. M. Ibrahim Shah. 1990. \u201cNew <em>Sivapithecus<\/em> Humeri from Pakistan and the Relationship of <em>Sivapithecus<\/em> and <em>Pongo<\/em>.\u201d <em>Nature<\/em> 348 (6298): 237\u2013239.<\/p>\r\n<p class=\"import-Normal\">Rasmussen, D. Tab. 1990. \u201cPrimate Origins: Lessons from a Neotropical Marsupial.\u201d <em>American Journal of Primatology<\/em> 22 (4): 263\u2013277.<\/p>\r\n<p class=\"import-Normal\">Ravosa, Matthew J. 1996. \u201cMandibular Form and Function in North American and European Adapidae and Omomyidae.\u201d <em>Journal of Morphology<\/em> 229 (2): 171\u2013190.<\/p>\r\n<p class=\"import-Normal\">R\u00f6gl, Fred. 1999. \u201cMediterranean and Paratethys Palaeogeography during the Oligocene and Miocene.\u201d In <em>Hominoid Evolution and Climatic Change in Europe<\/em>, edited by Jorge Agust\u00ed, Lorenzo Rook, and Peter Andrews, 8\u201322. Cambridge: Cambridge University Press.<\/p>\r\n<p class=\"import-Normal\">Rosas, A., A. Garc\u00eda-Tabernero, D. Fidalgo, M. Fero Me\u00f1e, C. Ebana Ebana, F. Esono Mba, and P. Saladie. 2022. \u201cThe Scarcity of Fossils in the African Rainforest: Archaeo-Paleontological Surveys and Actualistic Taphonomy in Equatorial Guinea.\u201d <em>Historical Biology<\/em> 34 (8): 1\u20139.<\/p>\r\n<p class=\"import-Normal\">Rose, Kenneth D., and Thomas M. Bown. 1984. \u201cGradual Phyletic Evolution at the Generic Level in Early Eocene Omomyoid Primates.\u201d <em>Nature<\/em> 309 (5965): 250\u2013252.<\/p>\r\n<p class=\"import-Normal\">Rose, Kenneth D., Rachel H. Dunn, Kishor Kumar, Jonathan M. G. Perry, Kristen A. Prufrock, Rajendra S. Rana, and Thierry Smith. 2018. \u201cNew Fossils from Tadkeshwar Mine (Gujarat, India) Increase Primate Diversity from the Early Eocene Cambay Shale.\u201d <em>Journal of Human Evolution<\/em> 122: 93\u2013107.<\/p>\r\n<p class=\"import-Normal\">Rose, Kenneth D., and John M. Rensberger. 1983. \u201cUpper Dentition of <em>Ekgmowechashala<\/em> (Omomyoid Primate) from the John Day Formation, Oligo-Miocene of Oregon.\u201d <em>Folia Primatologica<\/em> 41(1-2): 102\u2013111.<\/p>\r\n<p class=\"import-Normal\">Rosenberger, Alfred L. 2010. \u201cPlatyrrhines, PAUP, Parallelism, and the Long Lineage Hypothesis: A Reply to Kay <em>et al. <\/em>(2008).\u201d <em>Journal of Human Evolution<\/em> 59 (2): 214\u2013217.<\/p>\r\n<p class=\"import-Normal\">Ross, Callum F. 2000. \u201cInto the Light: The Origins of Anthropoidea.\u201d <em>Annual Review of Anthropology<\/em> 29: 147\u2013194.<\/p>\r\n<p class=\"import-Normal\">Ross, Callum F., and Richard F. Kay, eds. 2004. <em>Anthropoid Origins: New Visions<\/em>. New York: Kluwer Academic\/Plenum Publishers.<\/p>\r\n<p class=\"import-Normal\">Russo, Gabrielle A. 2016. \u201cComparative Sacral Morphology and the Reconstructed Tail Lengths of Five Extinct Primates: <em>Proconsul heseloni<\/em>, <em>Epipliopithecus vindobonensis<\/em>, <em>Archaeolemur edwardsi<\/em>, <em>Megaladapis grandidieri<\/em>, and <em>Palaeopropithecus kelyus<\/em>.\u201d <em>Journal of Human Evolution<\/em> 90: 135\u2013162.<\/p>\r\n<p class=\"import-Normal\">Schmid, Peter. 1979. \u201cEvidence of Microchoerine Evolution from Dielsdorf (Z\u00fcrich Region, Switzerland): A Preliminary Report.\u201d <em>Folia Primatologica<\/em> 31 (4): 301\u2013311.<\/p>\r\n<p class=\"import-Normal\">Seiffert, Erik R. 2012. \u201cEarly Primate Evolution in Afro-Arabia.\u201d <em>Evolutionary Anthropology: Issues, News, and Reviews<\/em> 21 (6): 239\u2013253.<\/p>\r\n<p class=\"import-Normal\">Seiffert, Erik R., Jonathan M. G. Perry, Elwyn L. Simons, and Doug M. Boyer. 2009. \u201cConvergent Evolution of Anthropoid-like Adaptations in Eocene Adapiform Primates.\u201d <em>Nature<\/em> 461 (7267): 1118\u20131121.<\/p>\r\n<p class=\"import-Normal\">Seiffert, Erik R., Elwyn L. Simons, and Yousry Attia. 2003. \u201cFossil Evidence for an Ancient Divergence of Lorises and Galagos.\u201d <em>Nature<\/em> 422 (6930): 421\u2013424.<\/p>\r\n<p class=\"import-Normal\">Seiffert, Erik R., Elwyn L. Simons, Doug M. Boyer, Jonathan M. G. Perry, Timothy M. Ryan, and Hesham M. Sallam. 2010. \u201cA Fossil Primate of Uncertain Affinities from the Earliest Late Eocene of Egypt.\u201d <em>Proceedings of the National Academy of Sciences of the United States of America<\/em> 107 (21): 9712\u20139717.<\/p>\r\n<p class=\"import-Normal\">Seiffert, Erik R., Elwyn L. Simons, and Cornelia V. M. Simons. 2004. \u201cPhylogenetic, Biogeographic, and Adaptive Implications of New Fossil Evidence Bearing on Crown Anthropoid Origins and Early Stem Catarrhine Evolution.\u201d In <em>Anthropoid Origins: New Visions<\/em>, edited by Callum F. Ross and Richard F. Kay, 157\u2013182. New York: Kluwer\/Plenum Publishing.<\/p>\r\n<p class=\"import-Normal\">Simons, Elwyn L. 1961. \u201cThe Phyletic Position of <em>Ramapithecus<\/em>.\u201d <em>Postilla<\/em> 57: 1\u20139.<\/p>\r\n<p class=\"import-Normal\">Simons, Elwyn L. 2001. \u201cThe Cranium of <em>Parapithecus grangeri<\/em>, an Egyptian Oligocene Anthropoidean Primate.\u201d <em>Proceedings of the National Academy of Sciences of the United States of America<\/em> 98 (4): 7892\u20137897.<\/p>\r\n<p class=\"import-Normal\">Simons, Elwyn L. 2004. \u201cThe Cranium and Adaptations of <em>Parapithecus grangeri<\/em>, a Stem Anthropoid From the Fayum Oligocene of Egypt.\u201d In <em>Anthropoid Origins: New Visions<\/em>, edited by Callum F. Ross and Richard F. Kay, 183\u2013204. New York: Kluwer\/Plenum Publishing.<\/p>\r\n<p class=\"import-Normal\">Simons, Elwyn L. 2008. \u201cEocene and Oligocene Mammals of the Fayum, Egypt.\u201d In <em>Elwyn Simons: A Search for Origins<\/em>, edited by John G. Fleagle and Christopher C. Gilbert, 87\u2013105. New York: Springer.<\/p>\r\n<p class=\"import-Normal\">Simons, Elwyn L., and D. Tab Rasmussen. 1994a. \u201cA Remarkable Cranium of <em>Plesiopithecus teras<\/em> (Primates, Prosimii) from the Eocene of Egypt.\u201d <em>Proceedings of the National Academy of Sciences<\/em> <em>of the United States of America<\/em> 91(21): 9946\u20139950.<\/p>\r\n<p class=\"import-Normal\">Simons, Elwyn L., and D. Tab Rasmussen. 1994b. \u201cA Whole New World of Ancestors: Eocene Anthropoideans from Africa.\u201d <em>Evolutionary Anthropology<\/em> 3 (4): 128\u2013139.<\/p>\r\n<p class=\"import-Normal\">Simons, Elwyn L., and D. Tab Rasmussen. 1996. \u201cSkull of <em>Catopithecus browni<\/em>, an Early Tertiary Catarrhine.\u201d <em>American Journal of Physical Anthropology<\/em> 100 (2): 261\u2013292.<\/p>\r\n<p class=\"import-Normal\">Simons, Elwyn L., and Erik R. Seiffert. 1999. \u201cA Partial Skeleton of <em>Proteopithecus<\/em> <em>sylviae<\/em> (Primates Anthropoidea): First Associated Dental and Postcranial Remains of an Eocene Anthropoidean.\u201d <em>Comptes Rendus de l'Acad\u00e9mie des Sciences, Paris<\/em> 329 (12): 921\u2013927.<\/p>\r\n<p class=\"import-Normal\">Simons, Elwyn L., Erik R. Seiffert, Timothy M. Ryan, and Yousry Attia. 2007. \u201cA Remarkable Female Cranium of the Early Oligocene Anthropoid <em>Aegyptopithecus zeuxis<\/em> (Catarrhini, Propliopithecidae).\u201d <em>Proceedings of the National Academy of Sciences of the United States of America<\/em> 104 (21): 8731\u20138736.<\/p>\r\n<p class=\"import-Normal\">Simpson, George Gaylord. 1933. \u201cThe \u2018Plagiaulacoid\u2019 Type of Mammalian Dentition: A Study of Convergence.\u201d <em>Journal of Mammalogy<\/em> 14 (2): 97\u2013107.<\/p>\r\n<p class=\"import-Normal\">Simpson, George Gaylord. 1940. \u201cReview of the Mammal-Bearing Tertiary of South America.\u201d <em>Proceedings of the American Philosophical Society<\/em> 83 (5): 649\u2013709.<\/p>\r\n<p class=\"import-Normal\">Simpson, George Gaylord. 1967. \u201cThe Tertiary Lorisiform Primates of Africa.\u201d <em>Bulletin of the Museum of Comparative Zoology at Harvard University<\/em> 136: 39\u201362.<\/p>\r\n<p class=\"import-Normal\">Smith, G. Elliot. 1912. \u201cThe Evolution of Man.\u201d <em>Smithsonian Institute Annual Report <\/em>2012: 553\u2013572.<\/p>\r\n<p class=\"import-Normal\">Smith, Thierry, Kenneth D. Rose, and Philip D. Gingerich. 2006. \u201cRapid Asia\u2013Europe\u2013North America Geographic Dispersal of Earliest Eocene Primate <em>Teilhardina<\/em> during the Paleocene\u2013Eocene Thermal Maximum.\u201d <em>Proceedings of the National Academy of Sciences of the United States of America<\/em> 103 (30): 11223\u201311227.<\/p>\r\n<p class=\"import-Normal\">Stehlin, Hans G. 1912. \u201cDie s\u00e4ugetiere des schweizerischen Eocaens. Siebenter teil, erst h\u00e4lfte: <em>Adapis<\/em>\u201d [\u201cThe Mammals of the Swiss Eocene. Part Seven, First Half: Adapis\u201d]. <em>Abhandlungen der Schweizerischen Pal\u00e4ontologischen Gesellschaft<\/em> 38: 1165\u20131298.<\/p>\r\n<p class=\"import-Normal\">Strait, Suzanne G. 2001. \u201cDietary Reconstruction of Small-Bodied Omomyoid Primates.\u201d <em>Journal of Vertebrate Paleontology<\/em> 21 (2): 322\u2013334.<\/p>\r\n<p class=\"import-Normal\">Sussman, Robert W. 1991. \u201cPrimate Origins and the Evolution of Angiosperms.\u201d <em>American Journal of Primatology<\/em> 23 (4): 209\u2013223.<\/p>\r\n<p class=\"import-Normal\">Suwa, Gen, Reiko T. Kono, Shigehiro Katoh, Berhane Asfaw, and Yonas Beyene. 2007. \u201cA New Species of Great Ape from the Late Miocene Epoch in Ethiopia.\u201d <em>Nature<\/em> 448 (7156): 921\u2013924.<\/p>\r\n<p class=\"import-Normal\">Teaford, Mark F., Mary C. Maas, and Elwyn L. Simons. 1996. \u201cDental Microwear and Microstructure in Early Oligocene Primates from the Fayum, Egypt: Implications for Diet.\u201d <em>American Journal of Physical Anthropology<\/em> 101 (4): 527\u2013543.<\/p>\r\n<p class=\"import-Normal\">Ungar, Peter S., and Richard F. Kay. 1995. \u201cThe Dietary Adaptations of European Miocene Catarrhines.\u201d <em>Proceedings of the National Academy of Sciences of the United States of America<\/em> 92 (12): 5479\u20135481.<\/p>\r\n<p class=\"import-Normal\">Wang, Cui-Bin, Ling-Xia Zhao, Chang-Zhu Jin, Yuan Wang, Da-Gong Qin, and Wen-Shi Pan. 2014. \u201cNew Discovery of Early Pleistocene Orangutan Fossils from Sanhe Cave in Chongzuo, Guangxi, Southern China.\u201d <em>Quaternary International<\/em> 354: 68\u201374.<\/p>\r\n<p class=\"import-Normal\">Ward, C. V., A. Walker, and M. F. Teaford. 1991. \u201c<em>Proconsul<\/em> Did Not Have a Tail.\u201d <em>Journal of Human Evolution<\/em> 21 (3): 215\u2013220.<\/p>\r\n<p class=\"import-Normal\">Wheeler, Brandon C. 2010. \u201cCommunity Ecology of the Middle Miocene Primates of La Venta, Colombia: The Relationship between Ecological Diversity, Divergence Time, and Phylogenetic Richness.\u201d <em>Primates<\/em> 51 (2): 131\u2013138.<\/p>\r\n<p class=\"import-Normal\">Williams, Blythe A., and Richard F. Kay. 1995. \u201cThe Taxon Anthropoidea and the Crown Clade Concept.\u201d <em>Evolutionary Anthropology<\/em> 3 (6): 188\u2013190.<\/p>\r\n<p class=\"import-Normal\">Williams, Blythe A., Richard F. Kay, and E. Christopher Kirk. 2010a. \u201cNew Perspectives on Anthropoid Origins.\u201d <em>Proceedings of the National Academy<\/em> <em>of the United States of America<\/em> 107 (11): 4797\u20134804.<\/p>\r\n<p class=\"import-Normal\">Williams, Blythe A., Richard F. Kay, E. Christopher Kirk, and Callum F. Ross. 2010b. \u201c<em>Darwinius masillae<\/em> Is a European Middle Eocene Stem Strepsirrhine\u2014A Reply to Franzen et al.\u201d <em>Journal of Human Evolution<\/em> 59(5): 567\u2013573.<\/p>\r\n<p class=\"import-Normal\">Wilson Mantilla, G. P., S. G. B. Chester, W. A. Clemens, J. R. Moore, C. J. Sprain, B. T. Hovatter, W. S. Mitchell, W. W. Mans, R. Mundil, and P. R. Renne. 2021. \u201cEarliest Palaeocene Purgatoriids and the Initial Radiation of Stem Primates.\u201d <em>Royal Society Open Science<\/em> 8(2):210050. doi:10.1098\/rsos.210050.<\/p>\r\n\r\n<h2 class=\"import-Normal\">Acknowledgments<\/h2>\r\n<p class=\"import-Normal\">We are immensely grateful to the editors of this book, Drs. Beth Shook, Lara Braff, Katie Nelson, and Kelsie Aguilera, for their time and commitment to making this knowledge freely accessible to all, and for giving us the opportunity to participate in this important project.<\/p>\r\n\r\n<\/div>","rendered":"<div class=\"__UNKNOWN__\">\n<p class=\"import-Normal\">Jonathan M. G. Perry, Ph.D., Western University of Health Sciences<\/p>\n<p class=\"import-Normal\">Stephanie L. Canington, Ph.D., University of Pennsylvania<\/p>\n<p class=\"import-Normal\"><em>This chapter is a revision from &#8220;<\/em><a class=\"rId7\" href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/chapter\/__unknown__-10\/\"><em>Chapter 8: Primate Evolution<\/em><\/a><em>\u201d by Jonathan M. G. Perry and Stephanie L. Canington. In <\/em><a class=\"rId8\" href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/\"><em>Explorations: An Open Invitation to Biological Anthropology, first edition<\/em><\/a><em>, edited by Beth Shook, Katie Nelson, Kelsie Aguilera, and Lara Braff, which is licensed under <\/em><a class=\"rId9\" href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\"><em>CC BY-NC 4.0<\/em><\/a><em>. <\/em><\/p>\n<div class=\"textbox textbox--learning-objectives\">\n<header class=\"textbox__header\">\n<h2 class=\"textbox__title\"><span style=\"color: #ffffff;\">Learning Objectives<\/span><\/h2>\n<\/header>\n<div class=\"textbox__content\">\n<ul>\n<li>Understand the major trends in primate evolution from the origin of primates to the origin of our own species.<\/li>\n<li>Learn about primate adaptations and how they characterize major primate groups.<\/li>\n<li>Discuss the kinds of evidence that anthropologists use to find out how extinct primates are related to each other and to living primates.<\/li>\n<li>Recognize how the changing geography and climate of Earth have influenced where and when primates have thrived or gone extinct.<\/li>\n<\/ul>\n<\/div>\n<\/div>\n<p class=\"import-Normal\">The first fifty million years of primate evolution was a series of <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_1683\">adaptive radiations<\/a><\/strong> leading to the diversification of the earliest lemurs, monkeys, and apes. The primate story begins in the canopy and understory of conifer-dominated forests, with our small, furtive ancestors subsisting at night, beneath the notice of day-active dinosaurs.<\/p>\n<p class=\"import-Normal\">From the ancient <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_1684\"><strong>plesiadapiforms<\/strong><\/a> (archaic primates) to the earliest groups of true primates (<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_1686\"><strong>euprimates<\/strong><\/a>) (Bloch and Boyer 2002), the origin of our own order is characterized by the struggle for new food sources and microhabitats in the arboreal setting. Climate change forced major extinctions as the northern continents became increasingly dry, cold, and seasonal and as tropical rainforests gave way to deciduous forests, woodlands, and eventually grasslands. Lemurs, lorises, and tarsiers\u2014once diverse groups containing many species\u2014became rare, except for lemurs in Madagascar, where there were no anthropoid competitors and perhaps few predators. Meanwhile, <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_1685\">anthropoids<\/a><\/strong> (monkeys and apes) likely emerged in Asia and then dispersed across parts of the northern hemisphere, Africa, and ultimately South America. The movement of continents, shifting sea levels, and changing patterns of rainfall and vegetation contributed to the developing landscape of primate biogeography, morphology, and behavior. Today\u2019s primates provide modest reminders of the past diversity and remarkable adaptations of their extinct relatives. This chapter explores the major trends in primate evolution from the origin of the Order Primates to the beginnings of our own lineage, providing a window into these stories from our ancient past.<\/p>\n<h2 class=\"import-Normal\">Major Hypotheses About Primate Origins<\/h2>\n<p class=\"import-Normal\">For many groups of mammals, there is a key feature that led to their success. A good example is powered flight in bats. Primates lack a feature like this (see Chapter 5). Instead, if there is something unique about primates, it is probably a group of features rather than one single thing. Because of this, anthropologists and paleontologists struggle to describe an ecological scenario that could explain the rise and success of our own order. Three major hypotheses have been advanced to consider the origin of primates and to explain what makes our order distinct among mammals (Figure 8.1); these are described below.<\/p>\n<figure id=\"attachment_278\" aria-describedby=\"caption-attachment-278\" style=\"width: 634px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-256\" src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/03\/8.1.jpg\" alt=\"Primates swinging in tree, eating an insect, and eating fruit.\" width=\"634\" height=\"221\" srcset=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/03\/8.1.jpg 1150w, https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/03\/8.1-300x104.jpg 300w, https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/03\/8.1-1024x356.jpg 1024w, https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/03\/8.1-768x267.jpg 768w, https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/03\/8.1-65x23.jpg 65w, https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/03\/8.1-225x78.jpg 225w, https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/03\/8.1-350x122.jpg 350w\" sizes=\"auto, (max-width: 634px) 100vw, 634px\" \/><figcaption id=\"caption-attachment-278\" class=\"wp-caption-text\">Figure 8.1: The three major hypotheses are (a) the arboreal hypothesis, (b) the visual predation hypothesis, and (c) the angiosperm-primate coevolution hypothesis. Credit: Primate origin hypotheses original to Explorations: An Open Invitation to Biological Anthropology (2nd ed.) by <a class=\"rId13\" href=\"https:\/\/marynelsonstudio.com\">Mary Nelson<\/a> is under a <a class=\"rId14\" href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/\">CC BY-NC 4.0 License<\/a>.<\/figcaption><\/figure>\n<h3 class=\"import-Normal\"><strong>Arboreal Hypothesis<\/strong><\/h3>\n<p class=\"import-Normal\">In the 1800s, many anthropologists viewed all animals in relation to humans. That is, animals that were more like humans were considered to be more \u201cadvanced\u201d and those lacking humanlike features were considered more \u201cprimitive.\u201d This way of thinking was particularly obvious in studies of primates. A more modern way of referring to members of a group that lack certain evolutionary innovations seen in other members is to call them <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_1688\"><strong>plesiomorphic<\/strong><\/a> (literally \u201canciently shaped\u201d). The state of their morphological features is sometimes referred to as <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_1689\"><strong>ancestral<\/strong><strong> traits<\/strong><\/a>.<\/p>\n<p class=\"import-Normal\">Thus, when anthropologists sought features that separate primates from other mammals, they focused on features that were least developed in lemurs and lorises, more developed in monkeys, and most developed in apes (Figure 8.2). Frederic Wood Jones, one of the leading anatomist-anthropologists of the early 1900s, is usually credited with the Arboreal Hypothesis of primate origins (Jones 1916). This hypothesis holds that many of the features of primates evolved to improve locomotion in the trees; this way of getting around is referred to as arboreal. For example, the grasping hands and feet of primates are well suited to gripping tree branches of various sizes and our flexible joints are good for reorienting the extremities in many different ways. A mentor of Jones, Grafton Elliot Smith, had suggested that the reduced olfactory system, acute vision, and forward-facing eyes of primates are adaptations for making accurate leaps and bounds through a complex, three-dimensional canopy (Smith 1912). The forward orientation of the eyes in primates causes the visual fields to overlap, enhancing depth perception, especially at close range. Evidence to support this hypothesis includes the facts that many extant primates are arboreal, and the plesiomorphic members of most primate groups are dedicated arborealists. The Arboreal Hypothesis was well accepted by most anthropologists at the time and for decades afterward.<\/p>\n<figure style=\"width: 663px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image27-2.png\" alt=\"Diagram shows primates descended from Plesiadapiforms.\" width=\"663\" height=\"543\" \/><figcaption class=\"wp-caption-text\">Figure 8.2: Primate family tree showing major groups. Disconnected lines show uncertainty about relationships. Two lines lead to tarsiers from different possible groups of origin. <a href=\"https:\/\/docs.google.com\/document\/d\/1VUDKMBJYS_jNONjLxT04jQN0_z9Ua50BRN6auGSHUuU\/edit\" target=\"_blank\" rel=\"noopener\">A full text description of this image is available<\/a>. Credit: <a class=\"rId16\" href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/chapter\/__unknown__-10\/\">Primate family tree (Figure 8.2)<\/a> by Jonathan M. G. Perry is under a <a class=\"rId17\" href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/\">CC BY-NC 4.0 License<\/a>.<\/figcaption><\/figure>\n<h3 class=\"import-Normal\"><strong>Visual Predation Hypothesis<\/strong><\/h3>\n<p class=\"import-Normal\">In the late 1960s and early 1970s, Matt Cartmill studied and tested the idea that the characteristic features of primates evolved in the context of arboreal locomotion. Cartmill noted that squirrels climb trees (and even vertical walls) very effectively, even though they lack some of the key adaptations of primates. As members of the Order Rodentia, squirrels also lack the hand and foot anatomy of primates. They have claws instead of flattened nails and their eyes face more laterally than those of primates. Cartmill reasoned that there must be some other explanation for the unique traits of primates. He noted that some nonarboreal animals share at least some of these traits with primates; for example, cats and predatory birds have forward-facing eyes that enable visual field overlap. Cartmill suggested that the unique suite of features in primates is an adaptation to detecting insect prey and guiding the hands (or feet) to catch insects (Cartmill 1972). His hypothesis emphasizes the primary role of vision in prey detection and capture; it is explicitly comparative, relying on form-function relationships in other mammals and nonmammalian vertebrates. According to Cartmill, many of the key features of primates evolved for preying on insects in this special manner (Cartmill 1974).<\/p>\n<h3 class=\"import-Normal\"><strong>Angiosperm-Primate Coevolution Hypothesis<\/strong><\/h3>\n<p class=\"import-Normal\">The visual predation hypothesis was unpopular with some anthropologists. One reason for this is that many primates today are not especially predatory. Another is that, whereas primates do seem well adapted to moving around in the smallest, terminal branches of trees, insects are not necessarily easier to find there. A counterargument to the visual predation hypothesis is the angiosperm-primate coevolution hypothesis. Primate ecologist Robert Sussman (Sussman 1991) argued that the few primates that eat mostly insects often catch their prey on the ground rather than in tree branches. Furthermore, predatory primates often use their ears more than their eyes to detect prey. Finally, most early primate fossils show signs of having been omnivorous rather than insectivorous. Instead, he argued, the earliest primates were probably seeking fruit. Fruit (and flowers) of angiosperms (flowering plants) often develop in the terminal branches. Therefore, any mammal trying to access those fruits must possess anatomical traits that allow them to maintain their hold on thin branches and avoid falling while reaching for the fruits. Primates likely evolved their distinctive visual traits and extremities in the Paleocene (approximately 65 million to 54 million years ago) and Eocene (approximately 54 million to 34 million years ago) epochs, just when angiosperms were going through a revolution of their own\u2014the evolution of large, fleshy fruit that would have been attractive to a small arboreal mammal. Sussman argued that, just as primates were evolving anatomical traits that made them more efficient fruit foragers, angiosperms were also evolving fruit that would be more attractive to primates to promote better seed dispersal. This mutually beneficial relationship between the angiosperms and the primates was termed coevolution or more specifically <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_1691\"><strong>diffuse coevolution<\/strong>.<\/a><\/p>\n<p class=\"import-Normal\">At about the same time, D. Tab Rasmussen noted several parallel traits in primates and the South American woolly opossum, <em>Caluromys<\/em>. He argued that early primates were probably foraging on both fruits and insects (Rasmussen 1990). As is true of <em>Caluromys<\/em> today, early primates probably foraged for fruits in the terminal branches of angiosperms, and they probably used their visual sense to aid in catching insects. Insects are also attracted to fruit (and flowers), so these insects represent a convenient opportunity for a primarily fruit-eating primate to gather protein. This solution is a compromise between the visual predation hypothesis and the angiosperm-primate coevolution hypothesis. It is worth noting that other models of primate origins have been proposed, and these include the possibility that no single ecological scenario can account for the origin of primates.<\/p>\n<h2 class=\"import-Normal\">The Origins of Primates<\/h2>\n<h3 class=\"import-Normal\"><strong>Paleocene: Mammals in the Wake of Dinosaur Extinctions<\/strong><\/h3>\n<p class=\"import-Normal\">Placental mammals, including primates, originated in the Mesozoic Era (approximately 251 million to 65.5 million years ago), the Age of Dinosaurs. During this time, most placental mammals were small, probably nocturnal, and probably avoided predators via camouflage and slow, quiet movement. It has been suggested that the success and diversity of the dinosaurs constituted a kind of ecological barrier to Mesozoic mammals. The extinction of the dinosaurs (and many other organisms) at the end of the Cretaceous Period (approximately 145.5\u201365.5 million years ago) might have opened up these ecological niches, leading to the increased diversity and disparity in mammals of the Tertiary Period (approximately 65.5\u20132.5 million years ago).<\/p>\n<p class=\"import-Normal\">The Paleocene was the first epoch in the Age of Mammals. Soon after the Cretaceous-Tertiary (K-T) extinction event, new groups of placental mammals appear in the fossil record. Many of these groups achieved a broad range of sizes and lifestyles as well as a great number of species before declining sometime in the Eocene (or soon thereafter). These groups were ultimately replaced by the modern orders of placental mammals (Figure 8.3). It is unknown whether these replacements occurred gradually, for example by competitive exclusion, or rapidly, perhaps by sudden geographic dispersals with replacement. In some senses, the Paleocene might have been a time of recovery from the extinction event; it was cooler and more seasonal globally than the subsequent Eocene.<\/p>\n<figure style=\"width: 628px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image26.jpg\" alt=\"Person in front of a mural depicting forest animals.\" width=\"628\" height=\"511\" \/><figcaption class=\"wp-caption-text\">Figure 8.3: A mural of Eocene flora and fauna in North America. Credit: <a class=\"rId19\" href=\"https:\/\/flickr.com\/photos\/126377022@N07\/18404106406\">Image from page 27 of &#8220;Annual report for the year ended June 30 &#8230;&#8221; (1951)<\/a> by <a class=\"rId20\" href=\"https:\/\/flickr.com\/photos\/internetarchivebookimages\/\">Internet Archive Book Images<\/a> has been designated to the <a class=\"rId21\" href=\"https:\/\/creativecommons.org\/publicdomain\/zero\/1.0\/\">public domain (CC0)<\/a>. This photograph of the mural &#8220;Fauna and flora of middle Eocene in the Wyoming area&#8221; by Jay Matternes, was originally published by the <a class=\"rId22\" href=\"https:\/\/www.si.edu\/\">Smithsonian<\/a>, and can be viewed in context in the <a class=\"rId23\" href=\"https:\/\/archive.org\/details\/annualreportfory1961united\/page\/7\/mode\/1up?view=theater\">online version of this book<\/a>.<\/figcaption><\/figure>\n<h3 class=\"import-Normal\"><strong>Plesiadapiforms, the Archaic Primates<\/strong><\/h3>\n<p class=\"import-Normal\">The Paleocene epoch saw the emergence of several families of mammals that have been implicated in the origin of primates. These are the plesiadapiforms, which are archaic primates, meaning they possessed some primate features and lacked others. The word <em>plesiadapiform <\/em>means \u201calmost adapiform,\u201d a reference to some similarities between some plesiadapiforms and some adapiforms (or adapoids; later-appearing true primates)\u2014mainly in the molar teeth. Because enamel fossilizes better than other parts of the body, the molar teeth are the parts most often found and first discovered for any new species. Thus, dental similarities were often the first to be noticed by early mammalian paleontologists, partly explaining why plesiadapiforms were thought to be primates. Major morphological differences between plesidapiforms and euprimates (true primates) were observed later when more parts of plesiadapiform skeletons were discovered. Many plesiadapiforms have unusual anterior teeth and most have digits possessing claws rather than nails. So far, no plesiadapiform ever discovered has a postorbital bar (seen in extant <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_1712\">strepsirrhines<\/a><\/strong>) or septum (as seen in <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_1713\">haplorhines<\/a><\/strong>), and whether or not the <strong>auditory bulla<\/strong> was formed by the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_1714\"><strong>petrosal bone<\/strong> <\/a>remains unclear for many plesiadapiform specimens. Nevertheless, there are compelling reasons (partly from new skeletal material) for including plesiadapiforms within the Order Primates.<\/p>\n<h4 class=\"import-Normal\"><em>Geographic and Temporal Distribution<\/em><\/h4>\n<p class=\"import-Normal\"><em>Purgatorius<\/em> is generally considered to be the earliest primate. This Paleocene mammal is known from teeth that are very plesiomorphic for a primate. It has some characteristics that suggest it is a basal plesiadapiform, but there is very little to link it specifically with euprimates (see Clemens 2004). Its ankle bones suggest a high degree of mobility, signaling an arboreal lifestyle (Chester et al. 2015). <em>Purgatorius<\/em> is plesiomorphic enough to have given rise to all primates, including the plesiadapiforms. However, new finds suggest that this genus was more diverse and had more differing tooth morphologies than previously appreciated (Wilson Mantilla et al. 2021). Plesiadapiform families were numerous and diverse during parts of the Paleocene in western North America and western Europe, with some genera (e.g., <em>Plesiadapis<\/em>; see Figure 8.4) living on both continents (Figure 8.5). Thus, there were probably corridors for plesiadapiform dispersal between the two continents, and it stands to reason that these mammals were living all across North America, including in the eastern half of the continent and at high latitudes. A few plesiadapiforms have been described from Asia (e.g., <em>Carpocristes<\/em>), but the affinities of these remain uncertain.<\/p>\n<div style=\"text-align: left;\">\n<table class=\"aligncenter\" style=\"width: 473.25pt;\">\n<caption>Figure 8.4: Families of plesiadapiforms with example genera and traits: a table. Credit: Plesiadapiforms table original to Explorations: An Open Invitation to Biological Anthropology (2nd ed.) by Jonathan M. G. Perry and Stephanie L. Canington is under a <a class=\"rId24\" href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/\">CC BY-NC 4.0 License<\/a>. Content derived from Fleagle 2013.<\/caption>\n<thead>\n<tr style=\"height: 25pt;\">\n<td class=\"Table1-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\n<p class=\"import-Normal\" style=\"text-align: center;\"><strong>Family<\/strong><\/p>\n<p>&nbsp;<\/td>\n<td class=\"Table1-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\n<p class=\"import-Normal\" style=\"text-align: center;\"><strong>Genera<\/strong><\/p>\n<p>&nbsp;<\/td>\n<td class=\"Table1-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\n<p class=\"import-Normal\" style=\"text-align: center;\"><strong>Morphology<\/strong><\/p>\n<p>&nbsp;<\/td>\n<td class=\"Table1-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\n<p class=\"import-Normal\" style=\"text-align: center;\"><strong>Location<\/strong><\/p>\n<p>&nbsp;<\/td>\n<td class=\"Table1-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\n<p class=\"import-Normal\" style=\"text-align: center;\"><strong>Age<\/strong><sup><strong>1<\/strong><\/sup><\/p>\n<p>&nbsp;<\/td>\n<\/tr>\n<\/thead>\n<tbody>\n<tr class=\"Table1-R\" style=\"height: 17pt;\">\n<td class=\"Table1-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\n<p class=\"import-Normal\">Paromomyidae<\/p>\n<\/td>\n<td class=\"Table1-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\n<p class=\"import-Normal\"><em>Ignacius<\/em><\/p>\n<\/td>\n<td class=\"Table1-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\n<p class=\"import-Normal\">Long, dagger-like, lower incisor.<\/p>\n<\/td>\n<td class=\"Table1-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\n<p class=\"import-Normal\">North America and Europe<\/p>\n<\/td>\n<td class=\"Table1-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\n<p class=\"import-Normal\">Early Paleocene to Late Eocene<\/p>\n<\/td>\n<\/tr>\n<tr class=\"Table1-R\" style=\"height: 18pt;\">\n<td class=\"Table1-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\n<p class=\"import-Normal\">Carpolestidae<\/p>\n<\/td>\n<td class=\"Table1-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\n<p class=\"import-Normal\"><em>Carpolestes<\/em><\/p>\n<\/td>\n<td class=\"Table1-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\n<p class=\"import-Normal\">Plagiaulacoid dentition. Limb adaptations to terminal branch feeding. Grasping big toe.<\/p>\n<\/td>\n<td class=\"Table1-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\n<p class=\"import-Normal\">North America, Europe, and Asia<\/p>\n<\/td>\n<td class=\"Table1-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\n<p class=\"import-Normal\">Middle Paleocene to Early Eocene<\/p>\n<\/td>\n<\/tr>\n<tr class=\"Table1-R\" style=\"height: 16pt;\">\n<td class=\"Table1-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\n<p class=\"import-Normal\">Plesiadapidae<\/p>\n<\/td>\n<td class=\"Table1-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\n<p class=\"import-Normal\"><em>Plesiadapis<\/em><\/p>\n<\/td>\n<td class=\"Table1-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\n<p class=\"import-Normal\">Mitten-like upper incisor. Diastema. Large body size for group.<\/p>\n<\/td>\n<td class=\"Table1-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\n<p class=\"import-Normal\">North America and Europe<\/p>\n<\/td>\n<td class=\"Table1-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\n<p class=\"import-Normal\">Middle Paleocene to Early Eocene<\/p>\n<\/td>\n<\/tr>\n<tr class=\"Table1-R\" style=\"height: 1pt;\">\n<td class=\"Table1-C\" style=\"border-top: solid #000000 0.5pt; border-right: none #000000 0pt; border-bottom: none #000000 0pt; border-left: none #000000 0pt; padding: 0pt 5.4pt 0pt 5.4pt;\" colspan=\"4\">\n<p class=\"import-Normal\"><sup>1<\/sup> Derived from Fleagle 2013.<\/p>\n<\/td>\n<td class=\"Table1-C\" style=\"border-top: solid #000000 0.5pt; border-right: none #000000 0pt; border-bottom: none #000000 0pt; border-left: none #000000 0pt; padding: 0pt 5.4pt 0pt 5.4pt;\">\n<p class=\"import-Normal\">\n<\/td>\n<\/tr>\n<tr>\n<td><\/td>\n<td><\/td>\n<td><\/td>\n<td><\/td>\n<td><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<figure id=\"attachment_278\" aria-describedby=\"caption-attachment-278\" style=\"width: 555px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-259\" src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image5-5-e1691791897574.png\" alt=\"Global map with not fully formed continents.\" width=\"555\" height=\"308\" srcset=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image5-5-e1691791897574.png 1531w, https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image5-5-e1691791897574-300x167.png 300w, https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image5-5-e1691791897574-1024x569.png 1024w, https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image5-5-e1691791897574-768x426.png 768w, https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image5-5-e1691791897574-65x36.png 65w, https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image5-5-e1691791897574-225x125.png 225w, https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image5-5-e1691791897574-350x194.png 350w\" sizes=\"auto, (max-width: 555px) 100vw, 555px\" \/><figcaption id=\"caption-attachment-278\" class=\"wp-caption-text\">Figure 8.5: Map of the world in the Paleocene, highlighting plesiadapiform localities on lands that would become North America, southern Europe, and eastern Asia. Credit: <a class=\"rId26\" href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/chapter\/__unknown__-10\/\">Paleocene Map with Plesiadapiform Localities (Figure 8.4)<\/a> original to<a class=\"rId27\" href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/\"> Expl<\/a><a class=\"rId28\" href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/\">orations: An Open Invitation to Biological Anthropology<\/a> by Elyssa Ebding at <a class=\"rId29\" href=\"https:\/\/www.csuchico.edu\/geop\/geoplace\/index.shtml\">GeoPlace, California State University, Chico<\/a> is under a <a class=\"rId30\" href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/\">CC BY-NC 4.0 License<\/a>. Localities based on Fleagle 2013, 211.<\/figcaption><\/figure>\n<h4 class=\"import-Normal\"><em>General Morphological Features<\/em><\/h4>\n<p class=\"import-Normal\">Although there is much morphological variation among the families of plesiadapiforms, some common features unite the group. Most plesiadapiforms were small, the largest being about three kilograms (approximately 7 lbs.; <em>Plesiadapis cookei<\/em>). They had small brains and fairly large snouts, with eyes that faced more laterally than in euprimates. Many species show reduction and\/or loss of the canine and anterior premolars, with the resulting formation of a rodent-like <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_1172\">diastema<\/a> <\/strong>(a pronounced gap between the premolars and the incisors, with loss of at least the canine); this probably implies a herbivorous diet. Some families appear to have had very specialized diets, as suggested by unusual tooth and jaw shapes.<\/p>\n<p class=\"import-Normal\">Arguably the most interesting and unusual family of plesiadapiforms is the Carpolestidae. They are almost exclusively from North America (with a couple of possible members from Asia), and mainly from the Middle and Late Paleocene. Their molars are not very remarkable, being quite similar to those of some other plesiadapiforms (e.g., Plesiadapidae). However, their lower posterior premolars (p4) are laterally compressed and blade-like with vertical serrations topped by tiny cuspules. This unusual dental morphology is termed <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_1693\"><strong><em>plagiaulacoid<\/em><\/strong> <\/a> (Simpson 1933). The upper premolar occlusal surfaces are broad and are covered with many small cuspules; the blade-like lower premolar might have cut across these cuspules, between them, or both.<\/p>\n<figure style=\"width: 314px\" class=\"wp-caption alignleft\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image1-5.png\" alt=\"Small brown animal with long tail.\" width=\"314\" height=\"178\" \/><figcaption class=\"wp-caption-text\">Figure 8.6: An artistic rendition of Carpolestes simpsoni moving along a small diameter support. Credit: <a class=\"rId32\" href=\"https:\/\/commons.wikimedia.org\/wiki\/File:CarpolestesCL.png\">CarpolestesCL<\/a> by <a class=\"rId33\" href=\"https:\/\/commons.wikimedia.org\/wiki\/User:Sisyphos23\">Sisyphos23<\/a> is under a <a class=\"rId34\" href=\"https:\/\/creativecommons.org\/licenses\/by-sa\/3.0\/legalcode\">CC BY-SA 3.0 License<\/a>.<\/figcaption><\/figure>\n<p class=\"import-Normal\">Many plesiadapiforms have robust limb bones with hallmarks of arboreality. Instead of having nails, most taxa had sharp claws on most or all of the digits. The extremities show grasping abilities comparable to those of primates and some arboreal marsupials. Nearly complete skeletons have yielded a tremendous wealth of information on locomotor and foraging habits. Many plesiadapiforms appear to have been able to cling to vertical substrates (like a broad tree trunk) using their sharp claws, propelling themselves upward using powerful hindlimbs, bounding along horizontal supports, grasping smaller branches, and moving head-first down tree trunks. In carpolestids in particular, the skeleton appears to have been especially well adapted to moving slowly and carefully in small terminal branches (Figure 8.6).<\/p>\n<h4 class=\"import-Normal\"><em><span style=\"background-color: #ccffcc;\">Debate: Relationship of Plesiadapiforms to True Primates<\/span> <span style=\"text-decoration: underline;\">(Transform to dig deeper \/special topic)<\/span><\/em><\/h4>\n<p class=\"import-Normal\">In the middle of the twentieth century, treeshrews (Order Scandentia) were often considered part of the Order Primates, based on anatomical similarities between some treeshrews and primates. For many people, plesiadapiforms represented intermediates between primates and treeshrews, so plesiadapiforms were included in Primates as well.<\/p>\n<p class=\"import-Normal\">Studies of reproduction and brain anatomy in treeshrews and lemurs suggested that treeshrews are not primates (e.g., Martin 1968). This was soon followed by the suggestion to also expel plesiadapiforms (Martin 1972) from the Order Primates. Like treeshrews, plesiadapiforms lack a postorbital bar, nails, and details of the ear region that characterize true primates. Many paleoanthropologists were reluctant to accept this move to banish plesiadapiforms (e.g., F. S. Szalay, P. D. Gingerich).<\/p>\n<p class=\"import-Normal\">Later, K. Christopher Beard (1990) found that in some ways, the digits of paromomyid plesiadapiforms are actually more similar to those of dermopterans (Order Dermoptera), the closest living relatives of primates, than they are to those of primates themselves (but see Krause 1991). At the same time, Richard Kay and colleagues (1990) found that cranial circulation patterns and auditory bulla morphology in the paromomyid, <em>Ignacius <\/em>(see Figure 8.4), are more like those of dermopterans than of primates.<\/p>\n<p class=\"import-Normal\">For many anthropologists, this one-two punch effectively removed plesiadapiforms from the Order Primates. In the last two decades, the tide of opinion has turned again, with many researchers reinstating plesiadapiforms as members of the Order Primates. New and more complete specimens demonstrate that the postcranial skeletons of plesiadapiforms, including the hands and feet, were primate-like, not dermorpteran-like (Bloch and Boyer 2002, 2007). New fine-grained CT scans of relatively complete plesiadapiform skulls revealed that they share some key traits with primates to the exclusion of other placental mammals (Bloch and Silcox 2006). Most significant was the suggestion that <em>Carpolestes simpsoni <\/em>possessed an auditory bulla formed by the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_1696\"><strong>petrosal <\/strong><strong>bone<\/strong><\/a>, like in all living primates.<\/p>\n<p class=\"import-Normal\">The debate about the status of plesiadapiforms continues, owing to a persistent lack of key bones in some species and owing to genuine complexity of the anatomical traits involved. Maybe plesiadapiforms were the ancestral stock from which all primates arose, with some plesiadapiforms (e.g., carpolestids) nearer to the primate <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_1723\">stem<\/a><\/strong> than others.<\/p>\n<h3 class=\"import-Normal\"><strong>Adapoids and Omomyoids, the First True Primates<\/strong><\/h3>\n<h4 class=\"import-Normal\"><em>Geographic and Temporal Distribution<\/em><\/h4>\n<p class=\"import-Normal\">The first universally accepted fossil primates are the adapoids (Superfamily <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_1695\"><strong>Adapoidea<\/strong><\/a>) and the omomyoids (Superfamily <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_1694\">Omomyoidea<\/a>)<\/strong>. These groups become quite distinct over evolutionary time, filling mutually exclusive niches for the most part. However, the earliest adapoids are very similar to the earliest omomyoids.<\/p>\n<p class=\"import-Normal\">The adapoids were mainly diurnal and herbivorous, with some achieving larger sizes than any plesiadapiforms (10 kg; 22 lbs.). By contrast, the omomyoids were mainly nocturnal, insectivorous and frugivorous, and small.<\/p>\n<p class=\"import-Normal\">Both groups appear suddenly at the start of the Eocene, where they are present in western North America, western Europe, and India (Figure 8.7). This wide dispersal of early primates was probably due to the presence of rainforest corridors extending far into northern latitudes.<\/p>\n<figure id=\"attachment_278\" aria-describedby=\"caption-attachment-278\" style=\"width: 539px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-261\" src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image22-3-e1691792023503.png\" alt=\"Global map with not fully formed continents and omomyoid localities.\" width=\"539\" height=\"317\" srcset=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image22-3-e1691792023503.png 1476w, https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image22-3-e1691792023503-300x176.png 300w, https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image22-3-e1691792023503-1024x601.png 1024w, https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image22-3-e1691792023503-768x451.png 768w, https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image22-3-e1691792023503-65x38.png 65w, https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image22-3-e1691792023503-225x132.png 225w, https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image22-3-e1691792023503-350x206.png 350w\" sizes=\"auto, (max-width: 539px) 100vw, 539px\" \/><figcaption id=\"caption-attachment-278\" class=\"wp-caption-text\">Figure 8.7: Map of the world in the Eocene, highlighting adapoid and omomyoid localities on lands that would become North America, southern Europe, Africa, and Asia. Credit: <a class=\"rId36\" href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/chapter\/__unknown__-10\/\">Eocene Map with Adapoid and Omomyoid Localities (Figure 8.6)<\/a> original to <a class=\"rId37\" href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/\">Explorations: An Open Invitation to Biological Anthropology<\/a> by Elyssa Ebding at <a class=\"rId38\" href=\"https:\/\/www.csuchico.edu\/geop\/geoplace\/index.shtml\">GeoPlace, California State University, Chico<\/a> is under a <a class=\"rId39\" href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/\">CC BY-NC 4.0 License<\/a>. Localities based on Fleagle 2013, 229.<\/figcaption><\/figure>\n<p class=\"import-Normal\">In North America and Europe, both groups achieved considerable diversity in the Middle Eocene, then mostly died out at the end of that epoch (Figure 8.8). In some Eocene rock formations in the western United States, adapoids and omomyoids make up a major part of the mammalian fauna. The Eocene of India has yielded a modest diversity of euprimates, some of which are so plesiomorphic that it is difficult to know whether they are adapoids or omomyoids (or even early anthropoids).<\/p>\n<div style=\"text-align: left;\">\n<table class=\"aligncenter\" style=\"width: 473.25pt;\">\n<caption>Figure 8.8: Families of adapoids and omomyoids with example genera and traits: a table. Credit: Adapoids and omomyoids table original to Explorations: An Open Invitation to Biological Anthropology (2nd ed.) by Jonathan M. G. Perry and Stephanie L. Canington is under a <a class=\"rId40\" href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/\">CC BY-NC 4.0 License<\/a>. Content derived from Fleagle 2013.<\/caption>\n<thead>\n<tr style=\"height: 25pt;\">\n<td class=\"Table2-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\n<p class=\"import-Normal\" style=\"text-align: center;\"><strong>Family<\/strong><\/p>\n<p>&nbsp;<\/td>\n<td class=\"Table2-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\n<p class=\"import-Normal\" style=\"text-align: center;\"><strong>Genera<\/strong><\/p>\n<p>&nbsp;<\/td>\n<td class=\"Table2-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\n<p class=\"import-Normal\" style=\"text-align: center;\"><strong>Morphology<\/strong><\/p>\n<p>&nbsp;<\/td>\n<td class=\"Table2-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\n<p class=\"import-Normal\" style=\"text-align: center;\"><strong>Location<\/strong><\/p>\n<p>&nbsp;<\/td>\n<td class=\"Table2-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\n<p class=\"import-Normal\" style=\"text-align: center;\"><strong>Age<\/strong><sup><strong>1<\/strong><\/sup><\/p>\n<p>&nbsp;<\/td>\n<\/tr>\n<\/thead>\n<tbody>\n<tr class=\"Table2-R\" style=\"height: 18pt;\">\n<td class=\"Table2-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\n<p class=\"import-Normal\">Cercamoniidae<\/p>\n<\/td>\n<td class=\"Table2-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\n<p class=\"import-Normal\"><em>Donrussellia<\/em><\/p>\n<\/td>\n<td class=\"Table2-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\n<p class=\"import-Normal\">Variable in tooth number and jaw shape.<\/p>\n<\/td>\n<td class=\"Table2-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\n<p class=\"import-Normal\">Europe and Asia<\/p>\n<\/td>\n<td class=\"Table2-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\n<p class=\"import-Normal\">Early to Late Eocene<\/p>\n<\/td>\n<\/tr>\n<tr class=\"Table2-R\" style=\"height: 16pt;\">\n<td class=\"Table2-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\n<p class=\"import-Normal\">Asiadapidae<sup>2<\/sup><\/p>\n<\/td>\n<td class=\"Table2-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\n<p class=\"import-Normal\"><em>Asiadapis<\/em><\/p>\n<\/td>\n<td class=\"Table2-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\n<p class=\"import-Normal\">Plesiomorphic teeth and jaw resemble early Omomyids.<\/p>\n<\/td>\n<td class=\"Table2-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\n<p class=\"import-Normal\">Asia<\/p>\n<\/td>\n<td class=\"Table2-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\n<p class=\"import-Normal\">Early Eocene<\/p>\n<\/td>\n<\/tr>\n<tr class=\"Table2-R\" style=\"height: 16pt;\">\n<td class=\"Table2-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\n<p class=\"import-Normal\">Caenopithecidae<sup>3<\/sup><\/p>\n<\/td>\n<td class=\"Table2-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\n<p class=\"import-Normal\"><em>Darwinius<\/em><\/p>\n<\/td>\n<td class=\"Table2-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\n<p class=\"import-Normal\">Robust jaws with crested molars. Fewer premolars.<\/p>\n<\/td>\n<td class=\"Table2-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\n<p class=\"import-Normal\">Europe, Africa, North America, and Asia<\/p>\n<\/td>\n<td class=\"Table2-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\n<p class=\"import-Normal\">Middle to Late Eocene<\/p>\n<\/td>\n<\/tr>\n<tr class=\"Table2-R\" style=\"height: 16pt;\">\n<td class=\"Table2-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\n<p class=\"import-Normal\">Adapidae<\/p>\n<\/td>\n<td class=\"Table2-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\n<p class=\"import-Normal\"><em>Adapis<\/em><\/p>\n<\/td>\n<td class=\"Table2-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\n<p class=\"import-Normal\">Fused mandible. Long molar crests. Large size and large chewing muscles.<\/p>\n<\/td>\n<td class=\"Table2-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\n<p class=\"import-Normal\">Europe<\/p>\n<\/td>\n<td class=\"Table2-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\n<p class=\"import-Normal\">Late Eocene to Early Oligocene<\/p>\n<\/td>\n<\/tr>\n<tr class=\"Table2-R\" style=\"height: 16pt;\">\n<td class=\"Table2-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\n<p class=\"import-Normal\">Sivaladapidae<\/p>\n<\/td>\n<td class=\"Table2-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\n<p class=\"import-Normal\"><em>Sivaladapis<\/em><\/p>\n<\/td>\n<td class=\"Table2-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\n<p class=\"import-Normal\">Some large with robust jaws.<\/p>\n<\/td>\n<td class=\"Table2-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\n<p class=\"import-Normal\">Asia<\/p>\n<\/td>\n<td class=\"Table2-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\n<p class=\"import-Normal\">Middle Eocene to Late Miocene<\/p>\n<\/td>\n<\/tr>\n<tr class=\"Table2-R\" style=\"height: 16pt;\">\n<td class=\"Table2-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\n<p class=\"import-Normal\">Notharctidae<sup>4<\/sup><\/p>\n<\/td>\n<td class=\"Table2-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\n<p class=\"import-Normal\"><em>Notharctus<\/em><\/p>\n<\/td>\n<td class=\"Table2-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\n<p class=\"import-Normal\">Canine sexual dimorphism. Lemur-like skull. Clinging and leaping adaptations.<\/p>\n<\/td>\n<td class=\"Table2-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\n<p class=\"import-Normal\">North America and Europe<\/p>\n<\/td>\n<td class=\"Table2-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\n<p class=\"import-Normal\">Early to Middle Eocene<\/p>\n<\/td>\n<\/tr>\n<tr class=\"Table2-R\" style=\"height: 16pt;\">\n<td class=\"Table2-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\n<p class=\"import-Normal\">Omomyidae<sup>5<\/sup><\/p>\n<\/td>\n<td class=\"Table2-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\n<p class=\"import-Normal\"><em>Teilhardina<\/em><\/p>\n<\/td>\n<td class=\"Table2-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\n<p class=\"import-Normal\">Small, nocturnal, frugivorous or insectivorous. Tarsier-like skull in some.<\/p>\n<\/td>\n<td class=\"Table2-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\n<p class=\"import-Normal\">North America, Europe, and Asia<\/p>\n<\/td>\n<td class=\"Table2-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\n<p class=\"import-Normal\">Early Eocene to Early Miocene<\/p>\n<\/td>\n<\/tr>\n<tr class=\"Table2-R\" style=\"height: 16pt;\">\n<td class=\"Table2-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\n<p class=\"import-Normal\">Microchoeridae<sup>6<\/sup><\/p>\n<\/td>\n<td class=\"Table2-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\n<p class=\"import-Normal\"><em>Necrolemur<\/em><\/p>\n<\/td>\n<td class=\"Table2-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\n<p class=\"import-Normal\">Long bony ear tubes. Tarsier-like lower limb adaptations for leaping.<\/p>\n<\/td>\n<td class=\"Table2-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\n<p class=\"import-Normal\">Europe and Asia<\/p>\n<\/td>\n<td class=\"Table2-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\n<p class=\"import-Normal\">Early Eocene to Early Oligocene<\/p>\n<\/td>\n<\/tr>\n<tr class=\"Table2-R\" style=\"height: 1pt;\">\n<td class=\"Table2-C\" style=\"border-top: solid #000000 0.5pt; border-right: none #000000 0pt; border-bottom: none #000000 0pt; border-left: none #000000 0pt; padding: 0pt 5.4pt 0pt 5.4pt;\" colspan=\"4\">\n<p class=\"import-Normal\"><sup>1<\/sup> Derived from Fleagle 2013.<\/p>\n<p class=\"import-Normal\"><sup>2<\/sup> See Dunn et al. 2016 and Rose et al. 2018.<\/p>\n<p class=\"import-Normal\"><sup>3<\/sup> See Kirk and Williams 2011 and Seiffert et al. 2009.<\/p>\n<p class=\"import-Normal\"><sup>4<\/sup> See Gregory 1920.<\/p>\n<p class=\"import-Normal\"><sup>5<\/sup> See Beard and MacPhee 1994 and Strait 2001.<\/p>\n<p class=\"import-Normal\"><sup>6<\/sup> See Schmid 1979.<\/p>\n<\/td>\n<td class=\"Table2-C\" style=\"border-top: solid #000000 0.5pt; border-right: none #000000 0pt; border-bottom: none #000000 0pt; border-left: none #000000 0pt; padding: 0pt 5.4pt 0pt 5.4pt;\">\n<p class=\"import-Normal\">\n<\/td>\n<\/tr>\n<tr>\n<td><\/td>\n<td><\/td>\n<td><\/td>\n<td><\/td>\n<td><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<p class=\"import-Normal\">Adapoids and omomyoids barely survived the Eocene-Oligocene extinctions, when colder temperatures, increased seasonality, and the retreat of rainforests to lower latitudes led to changes in mammalian biogeography. In North America, one genus (originally considered an omomyoid but recently reclassified as Adapoidea) persisted until the Miocene: <em>Ekgmowechashala<\/em> (Rose and Rensberger 1983). This taxon has highly unusual teeth and might have been a late immigrant to North America from Asia. In Asia, one family of adapoids, the Sivaladapidae, retained considerable diversity as late as the Late Miocene.<\/p>\n<h4 class=\"import-Normal\"><em>Adapoid Diversity<\/em><\/h4>\n<p class=\"import-Normal\">Adapoids were very diverse, particularly in the Eocene of North America and Europe. They can be divided into six families, with a few species of uncertain familial relationship. As a group, adapoids have some features in common, although much of what they share is plesiomorphic. Important features include the hallmarks of euprimates: postorbital bar, flattened nails, grasping extremities, and a petrosal bulla (Figures 8.9 and 8.10). In addition, some adapoids retain the ancestral dental formula of 2.1.4.3; that is, in each quadrant of the mouth, there are two incisors, one canine, four premolars, and three molars. In general, the incisors are small compared to the molars, but the canines are relatively large, with sexual dimorphism in some species. Cutting crests on the molars are well developed in some species, and the two halves of the mandible were fused at the midline in some species. Some adapoids were quite small (<em>Anchomomys <\/em>at a little over 100 g), and some were quite large (<em>Magnadapis<\/em> at 10 kg; 22 lbs.). Furthermore, the spaces and attachment features for the chewing muscles were truly enormous in some species, suggesting that these muscles were very large and powerful. Taken together, this suggests an overall adaptive profile of diurnal herbivory. The canine sexual dimorphism in some species suggests a possible mating pattern of polygyny, as males in polygynous primate species often compete with each other for mates and have especially large canine teeth.<\/p>\n<figure style=\"width: 548px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image18-1.jpg\" alt=\"Three partial animal crania.\" width=\"548\" height=\"350\" \/><figcaption class=\"wp-caption-text\">Figure 8.9: Representative crania of Adapidae from Museum d\u2019Histoire Naturelle Victor Brun, a natural history museum in Montauban, France. The white scale bar is 1 cm long. Credit: <a class=\"rId43\" href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/chapter\/__unknown__-10\/\">Representative crania of adapids (European adapoids, (Figure 8.7)<\/a> from the <a class=\"rId44\" href=\"https:\/\/www.museum.montauban.com\/\">Museum d\u2019Histoire Naturelle Victor Brun in Montauban, France<\/a> original to <a class=\"rId45\" href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/\">Explorations: An Open Invitation to Biological Anthropology <\/a>by Jonathan M. G. Perry is under a <a class=\"rId46\" href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/\">CC BY-NC 4.0 License<\/a>.<\/figcaption><\/figure>\n<figure style=\"width: 547px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image19-2.jpg\" alt=\"Side views of small rodentlike skeleton with long tail.\" width=\"547\" height=\"525\" \/><figcaption class=\"wp-caption-text\">Figure 8.10: Darwinius masillae, a member of the Caenopithecidae. The slab on the left is Plate A and the slab on the right is Plate B. The parts of the skeleton in B that are outside of the dashed lines were fabricated. Credit: <a class=\"rId48\" href=\"https:\/\/commons.wikimedia.org\/wiki\/File:Darwinius%20masillae%20holotype%20slabs.jpg\">Darwinius masillae holotype slabs<\/a> by Jens L. Franzen, Philip D. Gingerich, J\u00f6rg Habersetzer1, J\u00f8rn H. Hurum, Wighart von Koenigswald, B. Holly Smith is under a <a class=\"rId49\" href=\"https:\/\/creativecommons.org\/licenses\/by\/2.5\/legalcode\">CC BY 2.5 License<\/a>. Originally from Franzen et al. 2009.<\/figcaption><\/figure>\n<h4 class=\"import-Normal\"><em>Omomyoid Diversity<\/em><\/h4>\n<p class=\"import-Normal\">Like adapoids, omomyoids appeared suddenly at the start of the Eocene and then became very diverse with most species dying out before the Oligocene. Omomyoids are known from thousands of jaws with teeth, relatively complete skulls for about a half-dozen species, and very little postcranial material. Omomyoids were relatively small primates, with the largest being less than three kilograms (approximately 7 lbs.; <em>Macrotarsius montanus<\/em>). All known crania possess a postorbital bar, which in some has been described as \u201cincipient closure.\u201d Some\u2014but not all\u2014known crania have an elongated bony ear tube extending lateral to the location of the eardrum, a feature seen in living tarsiers and <strong>catarrhines<\/strong>. The anterior teeth tend to be large, with canines that are usually not much larger than the incisors. Often it is difficult to distinguish closely related species using molar morphology, but the premolars tend to be distinct from one species to another. The postcranial skeleton of most omomyoids shows hallmarks of leaping behavior reminiscent of that of tarsiers. In North America, omomyoids became very diverse and abundant. In fact, omomyoids from Wyoming are sufficiently abundant and from such stratigraphically controlled conditions that they have served as strong evidence for the gradual evolution of anatomical traits over time (Rose and Bown 1984).<\/p>\n<p class=\"import-Normal\"><em>Teilhardina <\/em>(Figure 8.11; see Figure 8.2) is one of the earliest and arguably the most plesiomorphic of omomyoids. <em>Teilhardina<\/em> has several species, most of which are from North America, with one from Europe (<em>T. belgica<\/em>) and one from Asia (<em>T. asiatica<\/em>). The species of this genus are anatomically similar and the deposits from which they are derived are roughly contemporaneous. Thus, this small primate likely dispersed across the northern continents very rapidly (Smith et al. 2006).<\/p>\n<figure style=\"width: 545px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image3-1.jpg\" alt=\"World map with primates jumping across forested areas.\" width=\"545\" height=\"289\" \/><figcaption class=\"wp-caption-text\">Figure 8.11: A map of the world during the early Eocene showing one hypothesis for the direction of dispersal of the omomyoid Teilhardina. The map depicts primates hopping from continent to continent (East to West) via the forest corridors at high latitudes. Credit: <a href=\"https:\/\/www.pnas.org\/content\/103\/30\/11223\">Paleogeographic map showing hypothetical migration routes of Teilhardina (Figure 1)<\/a> by Thierry Smith, Kenneth D. Rose, and Philip D. Gingerich. 2006. <a href=\"https:\/\/www.pnas.org\/about\/rights-permissions\">Proceedings of the National Academy of Sciences of the United States of America <\/a>103 (30): 11223\u201311227. Copyright (2006) National Academy of Sciences. Image <a href=\"https:\/\/www.pnas.org\/about\/rights-permissions\">is used for non-commercial and educational purposes as outlined by PNAS.<\/a><\/figcaption><\/figure>\n<h2 class=\"import-Normal\">The Emergence of Modern Primate Groups<\/h2>\n<h3 class=\"import-Normal\"><strong>Origins of Crown Strepsirrhines<\/strong><\/h3>\n<p class=\"import-Normal\">Until the turn of this century, very little was known about the origins of the <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_1698\">crown<\/a><\/strong> (living) strepsirrhines. The Quaternary record of Madagascar contains many amazing forms of lemurs, including giant sloth-like lemurs, lemurs with perhaps monkey-like habits, lemurs with koala-like habits, and even a giant aye-aye (Godfrey and Jungers 2002). However, in Madagascar, early Tertiary continental sediments are lacking, and there is no record of lemur fossils before the Pleistocene.<\/p>\n<p class=\"import-Normal\">The fossil record of galagos is slightly more informative. Namely, there are Miocene African fossils that are very likely progenitors of lorisids (Simpson 1967). However, these are much like modern galagos and do not reveal anything about the relationship between crown strepsirrhines and Eocene fossil primates (but see below regarding <em>Propotto<\/em>). A similar situation exists for lorises in Asia: there are Miocene representatives, but these are substantially like modern lorises. The discovery of the first definite <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_1699\"><strong>toothcomb<\/strong><\/a> canine (a hallmark of stresirrhines) in 2003 provided the \u201csmoking gun\u201d for the origin of crown strepsirrhines (Seiffert et al. 2003). Recently, several other African primates have been recognized as having strepsirrhine affinities (Marivaux et al. 2013; Seiffert 2012). The enigmatic Fayum primate <em>Plesiopithecus<\/em> is known from a skull that has been compared to aye-ayes and to lorises (Godinot 2006; Simons and Rasmussen 1994a).<\/p>\n<p class=\"import-Normal\">The now-recognized diversity of stem strepsirrhines from the Eocene and Oligocene of Afro-Arabia is strong evidence to suggest that strepsirrhines originated in that geographic area. This implies that lorises dispersed to Asia subsequent to an African origin. It is unknown what the first strepsirrhines in Madagascar were like. However, it seems likely that the lemuriform-lorisiform split occurred in continental Africa, followed by dispersal of lemuriform stock to Madagascar. Recent evidence suggests that <em>Propotto<\/em>, a Miocene primate from Kenya originally described as a potto antecedent, actually forms a clade with <em>Plesiopithecus <\/em>and the aye-aye; this might suggest that strepsirrhines dispersed to Madagascar from continental Africa more than once (Gunnell et al. 2018).<\/p>\n<h3 class=\"import-Normal\"><strong>The Fossil Record of Tarsiers<\/strong><\/h3>\n<p class=\"import-Normal\">Tarsiers are so unusual that they fuel major debates about primate taxonomy. Tarsiers today are moderately diverse but geographically limited and not very different in their ecological habits\u2014especially considering that the split between them and their nearest living relative probably occurred over 50 million years ago. If omomyoids are excluded, then the fossil record of tarsiers is very limited. Two fossil species from the Miocene of Thailand have been placed in the genus <em>Tarsius<\/em>, as has an Eocene fossil from China (Beard et al. 1994). These, and <em>Xanthorhysis<\/em> from the Eocene of China, are all very tarsier-like. In fact, it is striking that <em>Tarsius eocaenus<\/em> from China was already so tarsier-like as early as the Eocene. This suggests that tarsiers achieved their current morphology very early in their evolution and have remained more or less the same while other primates changed dramatically. Two additional genera, <em>Afrotarsius<\/em> from the Oligocene of Egypt and Libya and <em>Afrasia<\/em> from the Eocene of Myanmar, have also been implicated in tarsier origins, though the relationship between them and tarsiers is unclear (Chaimanee et al. 2012). More recently, a partial skeleton of a small Eocene primate from China, <em>Archicebus achilles<\/em> (dated to approximately 55.8 million to 54.8 million years ago), was described as the most basal tarsiiform (Ni et al. 2013). This primate is reconstructed as a diurnal insectivore and an arboreal quadruped that did some leaping\u2014but not to the specialized degree seen in living tarsiers. The anatomy of the eye in living tarsiers suggests that their lineage passed through a diurnal stage, so <em>Archicebus<\/em> (and diurnal omomyoids) might represent such a stage.<\/p>\n<h3 class=\"import-Normal\"><strong>Climate Change and the Paleogeography of Modern Primate Origins<\/strong><\/h3>\n<p class=\"import-Normal\">Changing global climate has had profound effects on primate dispersal patterns and ecological habits over evolutionary time. Primates today are strongly tied to patches of trees and particular plant parts such as fruits, seeds, and immature leaves. It is no surprise, then, that the distribution of primates mirrors the distribution of forests. Today, primates are most diverse in the tropics, especially in tropical rainforests. Global temperature trends across the Tertiary have affected primate ranges. Following the Cretaceous-Tertiary extinction event, cooler temperatures and greater seasonality characterized the Paleocene. In the Eocene, temperatures (and probably rainfall) increased globally and rainforests likely extended to very high latitudes. During this time, euprimates became diverse. With cooling and increased aridity at the end of the Eocene, many primate extinctions occurred in the northern continents and the surviving primates were confined to lower latitudes in South America, Afro-Arabia, Asia, and southern Europe. Among these survivors are the progenitors of the living groups of primates: lemurs and lorises, tarsiers, <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_1700\"><strong>platyrrhines<\/strong><\/a> (monkeys of the Americas), and catarrhines (monkeys and apes of Africa and Asia) (Figure 8.12).<\/p>\n<figure id=\"attachment_278\" aria-describedby=\"caption-attachment-278\" style=\"width: 539px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-265\" src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image2-5-e1691791570984.png\" alt=\"Map of world with gray continents.\" width=\"539\" height=\"306\" srcset=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image2-5-e1691791570984.png 1492w, https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image2-5-e1691791570984-300x170.png 300w, https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image2-5-e1691791570984-1024x581.png 1024w, https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image2-5-e1691791570984-768x435.png 768w, https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image2-5-e1691791570984-65x37.png 65w, https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image2-5-e1691791570984-225x128.png 225w, https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image2-5-e1691791570984-350x198.png 350w\" sizes=\"auto, (max-width: 539px) 100vw, 539px\" \/><figcaption id=\"caption-attachment-278\" class=\"wp-caption-text\">Figure 8.12: Map of key localities of early anthropoids on land that becomes Africa and southern Asia. Credit: <a class=\"rId56\" href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/chapter\/__unknown__-10\/\">Oligocene Map with Key Early Anthropoid Localities (Figure 8.10)<\/a> original to <a class=\"rId57\" href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/\">Explorations: An Open Invitation to Biological Anthropology<\/a> by Elyssa Ebding at <a class=\"rId58\" href=\"https:\/\/www.csuchico.edu\/geop\/geoplace\/index.shtml\">GeoPlace, California State University, Chico<\/a> is under a <a class=\"rId59\" href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/\">CC BY-NC 4.0 License<\/a>. Localities based on Fleagle 2013, 265.<\/figcaption><\/figure>\n<h3 class=\"import-Normal\"><strong>Competing Hypotheses for the Origin of Anthropoids<\/strong><\/h3>\n<p class=\"import-Normal\">There is considerable debate among paleoanthropologists as to the geographic origins of anthropoids. In addition, there is debate regarding the source group for anthropoids. Three different hypotheses have been articulated in the literature. These are the adapoid origin hypothesis, the omomyoid origin hypothesis, and the tarsier origin hypothesis (Figure 8.13).<\/p>\n<figure style=\"width: 419px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image24-1-1.jpg\" alt=\"Diagrams show three relationships among primate groups.\" width=\"419\" height=\"742\" \/><figcaption class=\"wp-caption-text\">Figure 8.13: Competing models of anthropoid origins. Branch lengths are not to scale. The omomyoid origin model and tarsier origin model do not make specific reference to the evolutionary position of strepsirrhines; however, they were included here for completeness. <a href=\"https:\/\/docs.google.com\/document\/d\/1VUDKMBJYS_jNONjLxT04jQN0_z9Ua50BRN6auGSHUuU\/edit\">A full text description of this image is available<\/a>. Credit: <a class=\"rId61\" href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/chapter\/__unknown__-10\/\">Competing Trees for Anthropoid Origins (Figure 8.11)<\/a> original to <a class=\"rId62\" href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/\">Explorations: An Open Invitation to Biological Anthropology<\/a> by Jonathan M. G. Perry is under a <a class=\"rId63\" href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/\">CC BY-NC 4.0 License<\/a>.<\/figcaption><\/figure>\n<h4 class=\"import-Normal\"><em>Adapoid Origin Hypothesis<\/em><\/h4>\n<p class=\"import-Normal\">Resemblances between some adapoids and some extant anthropoids include fusion of the <strong>mandibular symphysis<\/strong>, overall robusticity of the chewing system, overall large body size, features that signal a diurnal lifestyle (like relatively small eye sockets), and ankle bone morphology. Another feature in common is canine sexual dimorphism, which is present in some species of adapoids (probably) and in several species of anthropoids.<\/p>\n<p class=\"import-Normal\">These features led some paleoanthropologists in the last half of the 20th century to suggest that anthropoids came from adapoid stock (Gingerich 1980; Simons and Rasmussen 1994b). One of the earliest supporters of the link between adapoids and anthropoids was Hans Georg Stehlin, who described much of the best material of adapoids and compared these Eocene primates to South American monkeys (Stehlin 1912). In more recent times, the adapoid origin hypothesis was reinforced by resemblances between these European adapoids (especially <em>Adapis <\/em>and <em>Leptadapis<\/em>) and some early anthropoids from the Fayum Basin (e.g., <em>Aegyptopithecus<\/em>, see below; Figure 8.14).<\/p>\n<div style=\"text-align: left;\">\n<table class=\"aligncenter\" style=\"width: 473.25pt;\">\n<caption>Figure 8.14: Families of early anthropoids with example genera and traits: a table. Credit: Early anthropoids table original to Explorations: An Open Invitation to Biological Anthropology (2nd ed.) by Jonathan M. G. Perry and Stephanie L. Canington is under a <a class=\"rId64\" href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/\">CC BY-NC 4.0 License<\/a>. Content derived from Fleagle 2013.<\/caption>\n<thead>\n<tr style=\"height: 25pt;\">\n<td class=\"Table3-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\n<p class=\"import-Normal\" style=\"text-align: center;\"><strong>Family<\/strong><\/p>\n<p>&nbsp;<\/td>\n<td class=\"Table3-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\n<p class=\"import-Normal\" style=\"text-align: center;\"><strong>Genera<\/strong><\/p>\n<p>&nbsp;<\/td>\n<td class=\"Table3-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\n<p class=\"import-Normal\" style=\"text-align: center;\"><strong>Morphology<\/strong><\/p>\n<p>&nbsp;<\/td>\n<td class=\"Table3-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\n<p class=\"import-Normal\" style=\"text-align: center;\"><strong>Location<\/strong><\/p>\n<p>&nbsp;<\/td>\n<td class=\"Table3-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\n<p class=\"import-Normal\" style=\"text-align: center;\"><strong>Age<\/strong><sup><strong>1<\/strong><\/sup><\/p>\n<p>&nbsp;<\/td>\n<\/tr>\n<\/thead>\n<tbody>\n<tr class=\"Table3-R\" style=\"height: 18pt;\">\n<td class=\"Table3-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\n<p class=\"import-Normal\">Propliopithecidae<sup>2<\/sup><\/p>\n<\/td>\n<td class=\"Table3-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\n<p class=\"import-Normal\"><em>Aegyptopithecus<\/em><\/p>\n<\/td>\n<td class=\"Table3-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\n<p class=\"import-Normal\">Large size. Cranial sexual dimorphism, large canines. Robust jaws and rounded molars. Partially ossified ear tube (in some). Robust skeleton; quadruped.<\/p>\n<\/td>\n<td class=\"Table3-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\n<p class=\"import-Normal\">Africa<\/p>\n<\/td>\n<td class=\"Table3-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\n<p class=\"import-Normal\">Late Eocene to Early Oligocene<\/p>\n<\/td>\n<\/tr>\n<tr class=\"Table3-R\" style=\"height: 16pt;\">\n<td class=\"Table3-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\n<p class=\"import-Normal\">Parapithecidae<sup>3<\/sup><\/p>\n<\/td>\n<td class=\"Table3-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\n<p class=\"import-Normal\"><em>Apidium<\/em><\/p>\n<\/td>\n<td class=\"Table3-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\n<p class=\"import-Normal\">Medium size. Retention of three premolars per quadrant. Rounded molars and premolars with large central cusps. Adaptations for leaping in the lower limb.<\/p>\n<\/td>\n<td class=\"Table3-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\n<p class=\"import-Normal\">Africa<\/p>\n<\/td>\n<td class=\"Table3-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\n<p class=\"import-Normal\">Late Eocene to Late Oligocene<\/p>\n<\/td>\n<\/tr>\n<tr class=\"Table3-R\" style=\"height: 16pt;\">\n<td class=\"Table3-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\n<p class=\"import-Normal\">Proteopithecidae<sup>4<\/sup><\/p>\n<\/td>\n<td class=\"Table3-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\n<p class=\"import-Normal\"><em>Proteopithecus<\/em><\/p>\n<\/td>\n<td class=\"Table3-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\n<p class=\"import-Normal\">Small size. Retention of three premolars per quadrant. Arboreal quadrupeds that ate fruit.<\/p>\n<\/td>\n<td class=\"Table3-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\n<p class=\"import-Normal\">Africa<\/p>\n<\/td>\n<td class=\"Table3-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\n<p class=\"import-Normal\">Late Eocene<\/p>\n<\/td>\n<\/tr>\n<tr class=\"Table3-R\" style=\"height: 16pt;\">\n<td class=\"Table3-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\n<p class=\"import-Normal\">Oligopithecidae<sup>5<\/sup><\/p>\n<\/td>\n<td class=\"Table3-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\n<p class=\"import-Normal\"><em>Catopithecus<\/em><\/p>\n<\/td>\n<td class=\"Table3-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\n<p class=\"import-Normal\">Small size. Skull has postorbital septum and unfused mandible. Deep jaws. Diet of fruits. Generalized quadruped.<\/p>\n<\/td>\n<td class=\"Table3-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\n<p class=\"import-Normal\">Africa<\/p>\n<\/td>\n<td class=\"Table3-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\n<p class=\"import-Normal\">Late Eocene<\/p>\n<\/td>\n<\/tr>\n<tr class=\"Table3-R\" style=\"height: 16pt;\">\n<td class=\"Table3-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\n<p class=\"import-Normal\">Eosimiidae<\/p>\n<\/td>\n<td class=\"Table3-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\n<p class=\"import-Normal\"><em>Eosimias<\/em><\/p>\n<\/td>\n<td class=\"Table3-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\n<p class=\"import-Normal\">Deep jaw with vertical unfused symphysis. Pointed incisors and canines. Crowded premolars.<\/p>\n<\/td>\n<td class=\"Table3-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\n<p class=\"import-Normal\">Asia<\/p>\n<\/td>\n<td class=\"Table3-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\n<p class=\"import-Normal\">Middle Eocene<\/p>\n<\/td>\n<\/tr>\n<tr class=\"Table3-R\" style=\"height: 16pt;\">\n<td class=\"Table3-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\n<p class=\"import-Normal\">Amphipithecidae<sup>6<\/sup><\/p>\n<\/td>\n<td class=\"Table3-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\n<p class=\"import-Normal\"><em>Pondaungia<\/em><\/p>\n<\/td>\n<td class=\"Table3-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\n<p class=\"import-Normal\">Deep jaws. Molars generally rounded with wide basins.<\/p>\n<\/td>\n<td class=\"Table3-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\n<p class=\"import-Normal\">Asia<\/p>\n<\/td>\n<td class=\"Table3-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\n<p class=\"import-Normal\">Middle Eocene to Early Oligocene<\/p>\n<\/td>\n<\/tr>\n<tr class=\"Table3-R\" style=\"height: 1pt;\">\n<td class=\"Table3-C\" style=\"border-top: solid #000000 0.5pt; border-right: none #000000 0pt; border-bottom: none #000000 0pt; border-left: none #000000 0pt; padding: 0pt 5.4pt 0pt 5.4pt;\" colspan=\"4\">\n<p class=\"import-Normal\"><sup>1<\/sup> Derived from Fleagle 2013.<\/p>\n<p class=\"import-Normal\"><sup>2<\/sup> See Gebo and Simons 1987 and Simons et al. 2007.<\/p>\n<p class=\"import-Normal\"><sup>3<\/sup> See Feagle and Simons 1995 and Simons 2001.<\/p>\n<p class=\"import-Normal\"><sup>4<\/sup> See Simons and Seiffert 1999.<\/p>\n<p class=\"import-Normal\"><sup>5<\/sup> See Simons and Rasmussen 1996.<\/p>\n<p class=\"import-Normal\"><sup>6<\/sup> See Kay et al. 2004.<\/p>\n<\/td>\n<td class=\"Table3-C\" style=\"border-top: solid #000000 0.5pt; border-right: none #000000 0pt; border-bottom: none #000000 0pt; border-left: none #000000 0pt; padding: 0pt 5.4pt 0pt 5.4pt;\">\n<p class=\"import-Normal\">\n<\/td>\n<\/tr>\n<tr>\n<td><\/td>\n<td><\/td>\n<td><\/td>\n<td><\/td>\n<td><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<p class=\"import-Normal\">Unfortunately for the adapoid hypothesis, most of the shared features listed above probably emerged independently in the two groups as adaptations to a diet of hard and\/or tough foods. For example, fusion of the mandibular symphysis likely evolved as a means to strengthen the jaw against forces that would pull the two halves away from each other, in the context of active chewing muscles on both sides of the head generating great bite forces. This context would also favor the development of robust jaws, large chewing muscles, shorter faces, and some other features shared by some adapoids and some anthropoids.<\/p>\n<p class=\"import-Normal\">As older and more plesiomorphic anthropoids were found in the Fayum Basin, it became clear that the earliest anthropoids from Africa did not possess these features of jaw robusticity (Seiffert et al. 2009). Furthermore, many adapoids never evolved these features. Fusion of the mandibular symphysis in adapoids is actually quite different from that in anthropoids and probably occurred during juvenile development in the former (Beecher 1983; Ravosa 1996). Eventually, the adapoid origin hypothesis fell out of favor among most paleoanthropologists, although the description of <em>Darwinius<\/em> is a recent revival of that idea (Franzen et al. 2009; but see Seiffert et al. 2009, Williams et al. 2010b).<\/p>\n<h4 class=\"import-Normal\"><em>Omomyoid Origin Hypothesis<\/em><\/h4>\n<p class=\"import-Normal\">Similarities in cranial and hindlimb morphology between some omomyoids and extant tarsiers have led to the suggestion that tarsiers arose from some kind of omomyoid. In particular, <em>Necrolemur<\/em> has many features in common with tarsiers, as does the North American <em>Shoshonius<\/em>, which is known from a few beautifully preserved (although distorted) crania. Tarsiers and <em>Shoshonius <\/em>share exclusively some features of the base of the cranium; however, <em>Shoshonius<\/em> does not have any sign of postorbital closure, and it lacks the bony ear tube of tarsiers. Nevertheless, some of the resemblances between some omomyoids and tarsiers suggest that tarsiers might have originated from within the Omomyoidea (Beard 2002; Beard and MacPhee 1994). In this scenario, although living tarsiers and living anthropoids might be sister taxa, they might have evolved from different omomyoids, possibly separated from each other by more than 50 million years of evolution, or from anthropoids evolved from some non-omomyoid fossil group. The arguments against the omomyoid origin hypothesis are essentially the arguments <em>for<\/em> the tarsier origin hypothesis (see below). Namely, tarsiers and anthropoids share many features (especially of the soft tissues) that must have been retained for many millions of years or must have evolved convergently in the two groups. Furthermore, a key hard-tissue feature shared between the two extant groups, the postorbital septum, was not present in any omomyoid. Therefore, that feature must have arisen convergently in the two extant groups or must have been lost in omomyoids. Neither scenario is very appealing, although recent arguments for <strong>convergent evolution<\/strong> of the postorbital septum in tarsiers and anthropoids have arisen from embryology and histology of the structure (DeLeon et al. 2016).<\/p>\n<h4 class=\"import-Normal\"><em>Tarsier Origin Hypothesis<\/em><\/h4>\n<p class=\"import-Normal\">Several paleoanthropologists have suggested that there is a relationship between tarsiers and anthropoids to the exclusion of omomyoids and adapoids (e.g., Cartmill and Kay 1978; Ross 2000; Williams and Kay 1995). Tarsiers and anthropoids today share several traits, including many soft-tissue features related to the olfactory system (e.g., the loss of a hairless external nose and loss of the median cleft running from the nose to the mouth, as possessed by strepsirrhines), and aspects of the visual system (e.g., the loss of a reflective layer at the back of the eye, similarities in carotid circulation to the brain, and mode of placentation). Unfortunately, none of these can be assessed directly in fossils. Some bony similarities between tarsiers and anthropoids include an extra air-filled chamber below the middle ear cavity, reduced bones within the nasal cavity, and substantial postorbital closure; these can be assessed in fossils, but the distribution of these traits in omomyoids does not yield clear answers. Furthermore, several similarities between tarsiers and anthropoids are probably due to similarities in sensory systems, which might have evolved in parallel for ecological reasons. Although early attempts to resolve the crown primates with molecular data were sometimes equivocal or in disagreement with one another, more recent analyses (including those of short interspersed elements) suggest that tarsiers and anthropoids are sister groups to the exclusion of lemurs and lorises (Williams et al. 2010a). However, this does not address omomyoids, all of which are far too ancient for DNA extraction.<\/p>\n<p class=\"import-Normal\">The above three hypotheses are not the only possibilities for anthropoid origins. It may be that anthropoids are neither the closest sister group of tarsiers, nor evolved from adapoids or omomyoids. In recent years, two new groups of Eocene Asian primates have been implicated in the origin of anthropoids: the eosimiids and the amphipithecids. It is possible that one or the other of these two groups gave rise to anthropoids. Regardless of the true configuration of the tree for crown primates, the three major extant groups probably diverged from each other quite long ago (Seiffert et al. 2004).<\/p>\n<h3 class=\"import-Normal\"><strong>Early Anthropoid Fossils in Africa<\/strong><\/h3>\n<figure style=\"width: 526px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image7-2.jpg\" alt=\"People digging in a sandy desert.\" width=\"526\" height=\"352\" \/><figcaption class=\"wp-caption-text\">Figure 8.15: Egyptian workers sweeping Quarry I in the Fayum Basin (2004). This technique, called wind harvesting, removes the desert crust and permits wind to blow out fine sediment and reveal fossils. Credit: <a class=\"rId66\" href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/chapter\/__unknown__-10\/\">Egyptian workers sweeping Quarry I in the Fayum Basin (2004, Figure 8.12)<\/a> by Jonathan M. G. Perry is under a <a class=\"rId67\" href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/\">CC BY-NC 4.0 License<\/a>.<\/figcaption><\/figure>\n<figure style=\"width: 280px\" class=\"wp-caption alignleft\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image14-2.jpg\" alt=\"A person using a tool to expose bone in sand.\" width=\"280\" height=\"423\" \/><figcaption class=\"wp-caption-text\">Figure 8.16: Elwyn Laverne Simons excavating Aegyptopithecus in the Fayum Basin. Credit: <a class=\"rId69\" href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/chapter\/__unknown__-10\/\">Elwyn Laverne Simons in the Fayum Basin (Figure 8.13)<\/a> used by permission of the <a class=\"rId70\" href=\"https:\/\/lemur.duke.edu\/\">Duke Lemur Center,<\/a> Division of Fossil Primates, is under a <a class=\"rId71\" href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/\">CC BY-NC 4.0 License<\/a>.<\/figcaption><\/figure>\n<p class=\"import-Normal\">The classic localities yielding the greatest wealth of early anthropoid fossils are those from the Fayum Basin in Egypt (Simons 2008; Figure 8.15). The Fayum is a veritable oasis of fossil primates in an otherwise spotty early Tertiary African record. Since the 1960s, teams led by E. L. Simons have discovered several new species of early anthropoids, some of which are known from many parts of the skeleton and several individuals (Figure 8.16).<\/p>\n<p class=\"import-Normal\">The Fayum Jebel Qatrani Formation and Birket Qarun Formation between them have yielded a remarkable array of terrestrial, arboreal, and aquatic mammals. These include ungulates, bats, sea cows, elephants, hyraces, rodents, whales, and primates. Also, many other vertebrates, like water birds, were present. The area at the time of deposition (Late Eocene through Early Oligocene) was probably very wet, with slow-moving rivers, standing water, swampy conditions, and lots of trees (see Bown and Kraus 1988). In short, it was an excellent place for primates.<\/p>\n<h4 class=\"import-Normal\"><em>General Morphology of Anthropoids<\/em><\/h4>\n<p class=\"import-Normal\">The anthropoids known from the Fayum (and their close relatives from elsewhere in East Africa and Afro-Arabia) bear many of the anatomical hallmarks of extant anthropoids; however, there are plesiomorphic forms in several families that lack one or more anthropoid traits. All Fayum anthropoids known from skulls possess postorbital closure, most had fused mandibular symphyses, and most had ring-like <strong>ectotympanic<\/strong>  bones. Tooth formulae were generally either 2.1.3.3 or 2.1.2.3. Fayum anthropoids ranged in size from the very small <em>Qatrania<\/em> and <em>Biretia <\/em>(less than 500 g) to the much-larger <em>Aegyptopithecus<\/em> (approximately 7 kg; 15 lbs.). Fruit was probably the main component of the diet for most or all of the anthropoids, with some of them supplementing with leaves (Kay and Simons 1980; Kirk and Simons 2001; Teaford et al. 1996). Most Fayum anthropoids were probably diurnal above-branch quadrupeds. Some of them (e.g., <em>Apidium<\/em>; see Figure 8.14) were probably very good leapers (Gebo and Simons 1987), but none show specializations for gibbon-style suspensory locomotion. Some of the Fayum anthropoids are known from hundreds of individuals, permitting the assessment of individual variation, sexual dimorphism, and in some cases growth and development. The description that follows provides greater detail for the two best known Fayum anthropoid families, the Propliopithecidae and the Parapithecidae; the additional families are summarized briefly.<\/p>\n<h4 class=\"import-Normal\"><em>Fayum Anthropoid Families<\/em><\/h4>\n<p class=\"import-Normal\">The Propliopithecidae (see Figure 8.14) include the largest anthropoids from the fauna, and they are known from several crania and some postcranial elements. They have been suggested to be stem catarrhines, although perhaps near the split between catarrhines and platyrrhines. The best known propliopithecid is <em>Aegyptopithecus<\/em>, known from many teeth, crania, and postcranial elements (Figure 8.17) .<\/p>\n<figure style=\"width: 431px\" class=\"wp-caption alignright\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image4-2-1.jpg\" alt=\"Two animal skull side views.\" width=\"431\" height=\"281\" \/><figcaption class=\"wp-caption-text\">Figure 8.17: Female (left) and male (right) skull material for Aegyptopithecus zeuxis. The mandibles are not associated with the crania. Credit: <a href=\"https:\/\/www.pnas.org\/doi\/full\/10.1073\/pnas.0703129104#supplementary-materials\">Female and male cranium of A. zeuxi (03129Fig5, Supporting Information)<\/a> by Elwyn L. Simons, Erik R. Seiffert, Timothy M. Ryan, and Yousry Attia. 2007. <a href=\"https:\/\/www.pnas.org\/about\/rights-permissions\">Proceedings of the National Academy of Sciences of the United States of America<\/a> 104 (21): 8731\u20138736. Copyright (2007) National Academy of Sciences. Image <a href=\"https:\/\/www.pnas.org\/about\/rights-permissions\">is used for non-commercial and educational purposes as outlined by PNAS.<\/a><\/figcaption><\/figure>\n<p class=\"import-Normal\">Parapithecidae are an extremely abundant and unusual family of anthropoids from the Fayum. The parapithecid <em>Apidium<\/em> is known from many jaws with teeth, crushed and distorted crania, and several skeletal elements. <em>Parapithecus<\/em> is known from cranial material including a beautiful, undistorted cranium. This genus shows extreme reduction of the incisors, including complete absence of the lower incisors in <em>P. grangeri <\/em>(Simons 2001). This trait is unique among primates. Parapithecids were once thought to be the ancestral stock of platyrrhines; however, their platyrrhine-like features are probably ancestral retentions, so the most conservative approach is to consider them stem anthropoids.<\/p>\n<p class=\"import-Normal\">The Proteopithecidae were small frugivores that probably mainly walked along horizontal branches on all fours. TThey are considered stem anthropoids. The best known genus, <em>Proteopithecus<\/em>, is represented by dentitions, crania, and postcranial elements.<\/p>\n<p class=\"import-Normal\">The Oligopithecidae share a mixture of traits that makes them difficult to classify more specifically within anthropoids. The best known member, <em>Catopithecus<\/em>, is known from crania that demonstrate a postorbital septum and from mandibles that lack symphyseal fusion. They share the catarrhine tooth formula of 2.1.2.3 and have a canine honing complex that involves the anterior lower premolar. The postcranial elements known for the group suggest generalized arboreal quadrupedalism. The best known member, <em>Catopithecus<\/em>, is known from crania that demonstrate a postorbital septum and from mandibles that lack symphyseal fusion (Simons and Rasmussen 1996). The jaws are deep, with broad muscle attachment areas and crested teeth. <em>Catopithecus<\/em> was probably a little less than a kilogram in weight.<\/p>\n<p class=\"import-Normal\">Other genera of putative anthropoids from the Fayum include the very poorly known <em>Arsinoea<\/em>, the contentious <em>Afrotarsius<\/em>, and the enigmatic <em>Nosmips<\/em>. The last of these possesses traits of several major primate <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_1705\">clades<\/a><\/strong> and defies classification (Seiffert et al. 2010).<\/p>\n<h3 class=\"import-Normal\"><strong>Early Anthropoid Fossils in Asia<br style=\"clear: both;\" \/><\/strong><\/h3>\n<p class=\"import-Normal\">For the last half of the 1900s, researchers believed that Africa was the unquestioned homeland of early anthropoids (see Fleagle and Kay 1994). However, two very different groups of primates from Asia soon began to change that. One was an entirely new discovery (Eosimiidae), and the other was a poorly known group discovered decades prior (Amphipithecidae). Soon, attention on anthropoid origins began to shift eastward (see Ross and Kay 2004; Simons 2004). If anthropoids arose in Asia instead of Africa, then this implies that the African early anthropoids either emigrated from Asia or evolved their anthropoid traits in parallel with living anthropoids.<\/p>\n<h4 class=\"import-Normal\"><em>Eosimiids<\/em><\/h4>\n<p class=\"import-Normal\">First described in the 1990s, the eosimiids are best represented by <em>Eosimias <\/em>(see Figure 8.14; Figure 8.18). This tiny \u201cdawn monkey\u201d is known from relatively complete jaws with teeth, a few small fragments of the face, and some postcranial elements (Beard et al. 1994; Beard et al. 1996; Gebo et al. 2000). <em>Eosimias<\/em> (along with the other less-well-known genera in its family) bears some resemblance to tarsiers as well as anthropoids. Unfortunately, no good crania are known for this family, and the anatomy of, for example, the posterior orbital margin could be very revealing as to higher-level relationships.<\/p>\n<figure style=\"width: 550px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image16-1-1.jpg\" alt=\"Red-colored lower jaw of an animal.\" width=\"550\" height=\"232\" \/><figcaption class=\"wp-caption-text\">Figure 8.18: Cast of the right half of the mandible of Eosimias centennicus, type specimen. The white scale bar is 1 cm long. Credit: <a class=\"rId74\" href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/chapter\/__unknown__-10\/\">Cast of the right half of the mandible of <\/a><a class=\"rId75\" href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/chapter\/__unknown__-10\/\"><em>Eosimias centennicus <\/em><\/a><a class=\"rId76\" href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/chapter\/__unknown__-10\/\">(Figure 8.15),<\/a> type specimen, from K. D. Rose cast collection, photo by Jonathan M. G. Perry is under a <a class=\"rId77\" href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/\">CC BY-NC 4.0 License<\/a>.<\/figcaption><\/figure>\n<h4 class=\"import-Normal\"><em>Amphipithecids<\/em><\/h4>\n<p class=\"import-Normal\">Amphipithecids are small- to medium-size primates (up to 10 kg; 22 lbs.). Most are from the Eocene Pondaung Formation in Myanmar (Early\u2013Middle Eocene), but one genus is known from Thailand. Some dental similarities with anthropoids were noted early on, such as deep jaws and wide basins that separate low molar cusps. The best known genera were <em>Pondaungia<\/em> and <em>Amphipithecus <\/em>(Ciochon and Gunnell 2002; see Figure 8.14). Another amphipithecid, <em>Siamopithecus<\/em> from Thailand, has very rounded molars and was probably a seed-eater (Figure 8.19). In addition to teeth and jaws, some cranial fragments, ankle material, and ends of postcranial bones have been found for <em>Pondaungia<\/em>. There are important resemblances between the postcranial bones of <em>Pondaungia<\/em> and those of adapoids, suggesting adapoid affinities for the amphipithecidae. This would imply that the resemblances with anthropoids in the teeth are convergent, based on similarities in diet (see Ciochon and Gunnell 2002). Unfortunately, the association between postcranial bones and teeth is not definite. With other primates in these faunas (including eosimiids), one cannot be certain that the postcranial bones belong with the teeth. Some researchers suggest that some bones belong to a sivaladapid (or asiadapid) and others to an early anthropoid (Beard et al. 2007; Marivaux et al. 2003). Additional well-associated material of amphipithecids would help to clear up this uncertainty.<\/p>\n<figure style=\"width: 505px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image15-2.jpg\" alt=\"Four casts of jawbone fragments with teeth.\" width=\"505\" height=\"368\" \/><figcaption class=\"wp-caption-text\">Figure 8.19: Casts of representative amphipithecid material. A. Pondaungia cotteri right lower jaw fragment with m2 and m3. B. Siamopithecus eocaenus right upper jaw fragment with p4-m3. C. S. eocaenus right lower jaw fragment with partial m1, m2, and m3 in lateral view. D. Same as in C but occlusal view. White scale bars are 1 cm long. Credit: <a class=\"rId79\" href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/chapter\/__unknown__-10\/\">Casts of representative amphipithecid material (Figure 8.16)l<\/a> from K. D. Rose cast collection, photo by Jonathan M. G. Perry is under a <a class=\"rId80\" href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/\">CC BY-NC 4.0 License<\/a>.<\/figcaption><\/figure>\n<h3 class=\"import-Normal\"><strong>Platyrrhine Dispersal to South America<\/strong><\/h3>\n<p class=\"import-Normal\">Today there is an impressive diversity of primates in South and Central America. These are considered to be part of a single clade, the Platyrrhini. Primates colonized South America sometime in the Eocene from an African source. In the first half of the 20th century, the source of platyrrhines was a matter of major debate among paleontologists, with some favoring a North American origin (e.g., Simpson 1940).<\/p>\n<p class=\"import-Normal\">Part of the reason for this debate is that South America was an island in the Eocene. Primates needed to cross open ocean to get there from either North America or Africa, although the distance from the former was shorter. Morphology yields clues to platyrrhine origins. The first known primates in South America have more in common morphologically with African primates than with North American ones. At the time, anthropoids were popping up in North Africa, whereas the only euprimates in North America were adapoids and omomyoids. Despite lacking a bony ear tube, early platyrrhines shared a great deal with other anthropoids, including full postorbital closure and fusion of the mandibular symphysis.<\/p>\n<p class=\"import-Normal\">The means by which a population of small North African primates managed to disperse across the Atlantic and survive to colonize South America remains a mystery. The most plausible scenario is one of rafting. That is, primates must have been trapped on vegetation that was blown out to sea by a storm. The vegetation then became a sort of life raft, which eventually landed ashore, dumping its passengers in South America. Rodents probably arrived in South America in the same way (Antoine et al. 2012).<\/p>\n<p class=\"import-Normal\">Once ashore, platyrrhines must have crossed South America fairly rapidly because the earliest-known primates from that continent are from Peru (Bond et al. 2015). Soon after that, platyrrhines were in Bolivia, namely <em>Branisella<\/em>. By the Miocene, platyrrhines were living in extreme southern Argentina and were exploiting a variety of feeding niches. The Early Miocene platyrrhines were all somewhat plesiomorphic in their morphology, but some features that likely arose by ecological convergence suggest (to some) relationships with extant platyrrhine families. This has led to a lively debate about the pattern of primate evolution in South America (Kay 2015; Kay and Fleagle 2010; Rosenberger 2010). By the Middle Miocene, clear representatives of modern families were present in a diverse fauna from La Venta, Colombia (Wheeler 2010). The Plio-Pleistocene saw the emergence of giant platyrrhines as well as several taxa of platyrrhines living on Caribbean islands (Cooke et al. 2016).<\/p>\n<p class=\"import-Normal\">The story of platyrrhines seems to be one of amazing sweepstakes dispersal, followed by rapid diversification and widespread geographic colonization of much of South America. After that, dramatic extinctions resulted in the current, much-smaller geographic distribution of platyrrhines. These extinctions were probably caused by changing climates, leading to the contraction of forests. Platyrrhines dispersed to the Caribbean and to Central America, with subsequent extinctions in those regions that might have been related to interactions with humans. Unlike anthropoids of Africa and Asia, platyrrhines do not seem to have evolved any primarily terrestrial forms and so have always been highly dependent on forests.<\/p>\n<div class=\"textbox\">\n<h2 class=\"import-Normal\">Special Topic: Jonathan Perry and Primates of the Extreme South<\/h2>\n<p class=\"import-Normal\">Many primates are very vulnerable to ecological disturbance because they are heavily dependent on fruit to eat and trees to live in. This is one reason why so many primates are endangered today and why many of them went extinct due to climatic and vegetational changes in the past. I (Jonathan Perry) have conducted paleontological research focusing on primates that lived on the edge of their geographic distribution. This research has taken me to extreme environments in the Americas: southern Patagonia, the Canadian prairies, western Wyoming, and the badlands of eastern Oregon.<\/p>\n<p class=\"import-Normal\">Santa Cruz Province in Argentina is as far south as primates have ever lived. The Santa Cruz fauna of the Miocene has yielded a moderate diversity of platyrrhines, each with slightly different dietary adaptations. These include <em>Homunculus<\/em>, first described by Florentino Ameghino in 1891 (Figure 8.20). Recent fieldwork by my colleagues and I in Argentina has revealed several skulls of <em>Homunculus <\/em>as well as many parts of the skeleton (Kay et al. 2012). The emerging profile of this extinct primate is one of a dedicated arboreal quadruped that fed on fruits and leaves. Many of the foods eaten by <em>Homunculus<\/em> must have been very tough and were probably covered and impregnated with grit; we suspect this because the cheek teeth are very worn down, even in young individuals, and because the molar tooth roots were very large, presumably to resist strong bite forces (Perry et al. 2010, 2014).<\/p>\n<figure style=\"width: 497px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image9-2.jpg\" alt=\"An animal skull, a partial skull, and a fossil jaw with teeth.\" width=\"497\" height=\"634\" \/><figcaption class=\"wp-caption-text\">Figure 8.20: Representative specimens of Homunculus patagonicus. A. Adult cranium in lateral view. B. Adult cranium surface reconstructed from microCT scans, with the teeth segmented out. C. Juvenile cranium. White scale bars are 1cm long. Credit: <a class=\"rId82\" href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/chapter\/__unknown__-10\/\">Representative specimens of <\/a><a class=\"rId83\" href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/chapter\/__unknown__-10\/\"><em>Homunculus patagonicus <\/em><\/a><a class=\"rId84\" href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/chapter\/__unknown__-10\/\">(Figure 8.17)<\/a> photo by Jonathan M. G. Perry is under a <a class=\"rId85\" href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/\">CC BY-NC 4.0 License<\/a>.<\/figcaption><\/figure>\n<p class=\"import-Normal\">I began working in Argentina while a graduate student at Duke University. I participated as a field assistant in a team led by my Ph.D. advisor, Richard F. Kay, and Argentine colleagues Sergio F. Vizca\u00edno and M. Susana Bargo. Most of the localities examined belong to a suite of beach sites known since the 1800s and visited by many field parties from various museums in the early 1900s. Since 2003, our international team of paleontologists from the U.S. and Argentina has visited these localities every single year (Figure 8.21). Over time, new fossils and new students have led to new projects and new approaches, including the use of microcomputed tomography (microCT) to visualize and analyze internal structures of the skeleton.<\/p>\n<figure style=\"width: 491px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image23.jpg\" alt=\"Sandy rocky coastline. People digging on a grassy hillside.\" width=\"491\" height=\"561\" \/><figcaption class=\"wp-caption-text\">Figure 8.21: Field localities in Argentina and Canada. A. Ca\u00f1adon Palos locality, coastal Santa Cruz Province, Argentina. B. Swift Current Creek locality, southwest Saskatchewan, Canada. Credits: A. <a class=\"rId87\" href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/chapter\/__unknown__-10\/\">Ca\u00f1adon Palos Field Locality in Argentina<\/a> by Jonathan M. G. Perry is under a <a class=\"rId88\" href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/\">CC BY-NC 4.0 License<\/a>. B. <a class=\"rId89\" href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/chapter\/__unknown__-10\/\">Swift Current Creek locality, Saskatchewan, Canada<\/a> by Jonathan M. G. Perry is under a <a class=\"rId90\" href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/\">CC BY-NC 4.0 License<\/a>.<\/figcaption><\/figure>\n<\/div>\n<h2 class=\"import-Normal\">Planet of Apes<\/h2>\n<h3 class=\"import-Normal\"><strong>Geologic Activity and Climate Change in the Miocene<\/strong><\/h3>\n<p class=\"import-Normal\">The Miocene Epoch was a time of mammalian diversification and extinction, global climate change, and ecological turnover. In the Miocene, there was an initial warming trend across the globe with the expansion of subtropical forests, followed by widespread cooling and drying with the retreat of tropical forests and replacement with more open woodlands and eventually grasslands. It was also a time of major geologic activity. On one side of the globe, South America experienced the rise of the Andes Mountains. On the other side, the Indian subcontinent collided with mainland Asia, resulting in the rise of the Himalayan Mountains. In Africa, volcanic activity promoted the development of the East African Rift System. Critical to the story of ape evolution was the exposure of an intercontinental landbridge between East Africa and Eurasia, permitting a true planet of apes (Figure 8.22).<\/p>\n<figure id=\"attachment_278\" aria-describedby=\"caption-attachment-278\" style=\"width: 580px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-274\" src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image21-3-e1691792198797.png\" alt=\"Map of world with gray continents.\" width=\"580\" height=\"335\" srcset=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image21-3-e1691792198797.png 1507w, https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image21-3-e1691792198797-300x173.png 300w, https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image21-3-e1691792198797-1024x591.png 1024w, https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image21-3-e1691792198797-768x443.png 768w, https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image21-3-e1691792198797-65x38.png 65w, https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image21-3-e1691792198797-225x130.png 225w, https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image21-3-e1691792198797-350x202.png 350w\" sizes=\"auto, (max-width: 580px) 100vw, 580px\" \/><figcaption id=\"caption-attachment-278\" class=\"wp-caption-text\">Figure 8.22: Map of the world in the Miocene, highlighting fossil ape localities across Africa, southern Europe, and southern Asia. Credit: <a class=\"rId92\" href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/chapter\/__unknown__-10\/\">Miocene Map with Fossil Ape Localities (Figure 8.19)<\/a> original to <a class=\"rId93\" href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/\">Explorations: An Open Invitation to Biological Anthropology<\/a> by Elyssa Ebding at <a class=\"rId94\" href=\"https:\/\/www.csuchico.edu\/geop\/geoplace\/index.shtml\">GeoPlace, California State University, Chico<\/a> is under a <a class=\"rId95\" href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/\">CC BY-NC 4.0 License<\/a>. Localities based on Fleagle 2013, 311.<\/figcaption><\/figure>\n<h3 class=\"import-Normal\"><strong>Geographic Distribution: Africa, Asia, Europe<\/strong><\/h3>\n<p class=\"import-Normal\">The world of the Miocene had tremendous ape diversity compared to today. The earliest records of fossil apes are from Early Miocene deposits in Africa. However, something dramatic happened around 16 million years ago. With the closure of the ancient Tethys Sea, the subsequent exposure of the <em>Gomphotherium<\/em> Landbridge, and a period of global warming, the Middle\u2013Late Miocene saw waves of emigration of mammals (including primates) out of Africa and into Eurasia, with evidence of later African re-entry for some (Harrison 2010). Some of the mammals that dispersed from Africa to Eurasia and back were apes. Though most of these early apes left no modern descendants, some of them gave rise to the ancestors of modern apes\u2014including <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_800\">hominins<\/a><\/strong> (Figure 8.23).<\/p>\n<figure style=\"width: 560px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image20-1.jpg\" alt=\"Miocene apes set against a geologic time scale.\" width=\"560\" height=\"796\" \/><figcaption class=\"wp-caption-text\">Figure 8.23: Representative Miocene apes set against a geologic time scale. Credit: <a href=\"https:\/\/www.pnas.org\/content\/108\/14\/5554\">Range chart for Miocene hominoids of Western Eurasia (Figure 3)<\/a> by Isaac Casanovas-Vilar, David M. Alba, Miguel Garc\u00e9s, Josep M. Robles, and Salvador Moy\u00e0-Sol\u00e0. 2011. <a href=\"https:\/\/www.pnas.org\/about\/rights-permissions\">Proceedings of the National Academy of Sciences of the United States of America<\/a> 108 (14): 5554-5559. Copyright (2011) National Academy of Sciences. Image <a href=\"https:\/\/www.pnas.org\/about\/rights-permissions\">is used for non-commercial and educational purposes as outlined by PNAS.<\/a><\/figcaption><\/figure>\n<h3 class=\"import-Normal\"><strong>Where Are the Monkeys? Diversity in the Miocene<\/strong><\/h3>\n<p class=\"import-Normal\">Whereas the Oligocene deposits in the Fayum of Egypt have yielded the earliest-known catarrhine fossils, the Miocene demonstrates some diversification of Cercopithecoidea. However, compared to the numerous and diverse Miocene apes (see below), monkeys of the Miocene are very rare and restricted to a single extinct family, the Victoriapithecidae (Figure 8.24). This family contains the earliest definite cercopithecoids. These monkeys are found from northern and eastern Africa between 20 million and 12.5 million years ago (Miller et al. 2009). The best known early African monkey is <em>Victoriapithecus <\/em>(Figure 8.25), a small-bodied (approximately 7 kg; 15 lbs.), small-brained monkey. <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_1708\">Bilophodonty<\/a><\/strong>, known to be a hallmark of molar teeth of modern cercopithecoid, was present to some extent in Victoriapithecids. <em>Victoriapithecus<\/em> has been reconstructed as being more frugivorous and perhaps spent more time on the ground (terrestrial locomotion) than in the trees (arboreal locomotion; Blue et al. 2006). The two major groups of cercopithecoids today are cercopithecines and colobines. The earliest records demonstrating clear members of each of these two groups are at the end of the Miocene. Examples include the early colobine <em>Microcolobus<\/em> from Kenya and the early cercopithecine <em>Pliopapio<\/em> from Ethiopia.<\/p>\n<div style=\"text-align: left;\">\n<table class=\"aligncenter\" style=\"width: 473.25pt; height: 349px;\">\n<caption>Figure 8.24: Some families of later anthropoids with example genera and traits: a table. Credit: Late anthropoids table original to Explorations: An Open Invitation to Biological Anthropology (2nd ed.) by Jonathan M. G. Perry and Stephanie L. Canington is under a <a class=\"rId100\" href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/\">CC BY-NC 4.0 License<\/a>. Content derived from Fleagle 2013.<\/caption>\n<thead>\n<tr style=\"height: 25pt;\">\n<td class=\"Table4-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt; border: 0.5pt solid #000000; height: 60px; width: 119.35px;\">\n<p class=\"import-Normal\" style=\"text-align: center;\"><strong>Family<\/strong><\/p>\n<p>&nbsp;<\/td>\n<td class=\"Table4-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt; border: 0.5pt solid #000000; height: 60px; width: 103.417px;\">\n<p class=\"import-Normal\" style=\"text-align: center;\"><strong>Genera<\/strong><\/p>\n<p>&nbsp;<\/td>\n<td class=\"Table4-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt; border: 0.5pt solid #000000; height: 60px; width: 191.65px;\">\n<p class=\"import-Normal\" style=\"text-align: center;\"><strong>Morphology<\/strong><\/p>\n<p>&nbsp;<\/td>\n<td class=\"Table4-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt; border: 0.5pt solid #000000; height: 60px; width: 67.3667px;\">\n<p class=\"import-Normal\" style=\"text-align: center;\"><strong>Location<\/strong><\/p>\n<p>&nbsp;<\/td>\n<td class=\"Table4-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt; border: 0.5pt solid #000000; height: 60px; width: 73.2167px;\">\n<p class=\"import-Normal\" style=\"text-align: center;\"><strong>Age<\/strong><sup><strong>1<\/strong><\/sup><\/p>\n<p>&nbsp;<\/td>\n<\/tr>\n<\/thead>\n<tbody>\n<tr class=\"Table4-R\" style=\"height: 18pt;\">\n<td class=\"Table4-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt; border: 0.5pt solid #000000; height: 77px; width: 119.35px;\">\n<p class=\"import-Normal\">Victoriapithecidae<sup>2<\/sup><\/p>\n<\/td>\n<td class=\"Table4-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt; border: 0.5pt solid #000000; height: 77px; width: 103.417px;\">\n<p class=\"import-Normal\"><em>Victoriapithecus<\/em><\/p>\n<\/td>\n<td class=\"Table4-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt; border: 0.5pt solid #000000; height: 77px; width: 191.65px;\">\n<p class=\"import-Normal\">Long, sloping face. Round, narrowly spaced orbits. Deep cheek bones. Well-developed sagittal crest.<\/p>\n<\/td>\n<td class=\"Table4-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt; border: 0.5pt solid #000000; height: 77px; width: 67.3667px;\">\n<p class=\"import-Normal\">Africa<\/p>\n<\/td>\n<td class=\"Table4-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt; border: 0.5pt solid #000000; height: 77px; width: 73.2167px;\">\n<p class=\"import-Normal\">Early to Middle Miocene<\/p>\n<\/td>\n<\/tr>\n<tr class=\"Table4-R\" style=\"height: 16pt;\">\n<td class=\"Table4-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt; border: 0.5pt solid #000000; height: 61px; width: 119.35px;\">\n<p class=\"import-Normal\">Proconsulidae<sup>3<\/sup><\/p>\n<\/td>\n<td class=\"Table4-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt; border: 0.5pt solid #000000; height: 61px; width: 103.417px;\">\n<p class=\"import-Normal\"><em>Proconsul<\/em><\/p>\n<\/td>\n<td class=\"Table4-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt; border: 0.5pt solid #000000; height: 61px; width: 191.65px;\">\n<p class=\"import-Normal\">Short face. Generalized dentition. Arboreal quadruped. Probably tailless.<\/p>\n<\/td>\n<td class=\"Table4-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt; border: 0.5pt solid #000000; height: 61px; width: 67.3667px;\">\n<p class=\"import-Normal\">Africa and Arabia<\/p>\n<\/td>\n<td class=\"Table4-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt; border: 0.5pt solid #000000; height: 61px; width: 73.2167px;\">\n<p class=\"import-Normal\">Early to Middle Miocene<\/p>\n<\/td>\n<\/tr>\n<tr class=\"Table4-R\" style=\"height: 16pt;\">\n<td class=\"Table4-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt; border: 0.5pt solid #000000; height: 46px; width: 119.35px;\">\n<p class=\"import-Normal\">Pongidae<\/p>\n<\/td>\n<td class=\"Table4-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt; border: 0.5pt solid #000000; height: 46px; width: 103.417px;\">\n<p class=\"import-Normal\"><em>Gigantopithecus<\/em><\/p>\n<\/td>\n<td class=\"Table4-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt; border: 0.5pt solid #000000; height: 46px; width: 191.65px;\">\n<p class=\"import-Normal\">Largest primate ever. Deep jaws and low rounded molars.<\/p>\n<\/td>\n<td class=\"Table4-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt; border: 0.5pt solid #000000; height: 46px; width: 67.3667px;\">\n<p class=\"import-Normal\">Asia<\/p>\n<\/td>\n<td class=\"Table4-C\" style=\"vertical-align: middle; padding: 0pt 5.4pt; border: 0.5pt solid #000000; height: 46px; width: 73.2167px;\">\n<p class=\"import-Normal\">Miocene to Present<\/p>\n<\/td>\n<\/tr>\n<tr class=\"Table4-R\" style=\"height: 1pt;\">\n<td class=\"Table4-C\" style=\"border-color: #000000; border-style: solid none none; border-width: 0.5pt 0pt 0pt; padding: 0pt 5.4pt; height: 90px; width: 526.983px;\" colspan=\"4\">\n<p class=\"import-Normal\"><sup>1<\/sup> Derived from Fleagle 2013.<\/p>\n<p class=\"import-Normal\"><sup>2<\/sup> See Benefit and McCrossin 1997 and Fleagle 2013.<\/p>\n<p class=\"import-Normal\"><sup>3<\/sup> See Begun 2007.<\/p>\n<\/td>\n<td class=\"Table4-C\" style=\"border-color: #000000; border-style: solid none none; border-width: 0.5pt 0pt 0pt; padding: 0pt 5.4pt; height: 90px; width: 73.2167px;\">\n<p class=\"import-Normal\">\n<\/td>\n<\/tr>\n<tr style=\"height: 15px;\">\n<td style=\"height: 15px; width: 121.283px;\"><\/td>\n<td style=\"height: 15px; width: 105.35px;\"><\/td>\n<td style=\"height: 15px; width: 193.583px;\"><\/td>\n<td style=\"height: 15px; width: 69.3px;\"><\/td>\n<td style=\"height: 15px; width: 74.65px;\"><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<figure style=\"width: 447px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image13-5.png\" alt=\"Front view of skull with pointed teeth.\" width=\"447\" height=\"403\" \/><figcaption class=\"wp-caption-text\">Figure 8.25: Skull of Victoriapithecus macinnesi. Credit: <a class=\"rId102\" href=\"https:\/\/commons.wikimedia.org\/wiki\/File:Victoriapithecus_macinnesi_skull.JPG\">Victoriapithecus macinnesi skull<\/a> photo taken at the <a class=\"rId103\" href=\"https:\/\/www.mnhn.fr\/en\">Musee d&#8217;Histoire Naturelle, Paris<\/a> by <a class=\"rId104\" href=\"https:\/\/commons.wikimedia.org\/wiki\/User:Ghedoghedo\">Ghedoghedo<\/a> is under a <a class=\"rId105\" href=\"https:\/\/creativecommons.org\/licenses\/by-sa\/3.0\/legalcode\">CC BY-SA 3.0 License<\/a>.<\/figcaption><\/figure>\n<h3 class=\"import-Normal\"><strong>The Story of Us, the Apes<\/strong><\/h3>\n<h4 class=\"import-Normal\"><em>African Ape Diversity<\/em><\/h4>\n<p class=\"import-Normal\">The Early Miocene of Africa has yielded around 14 genera of early apes (Begun 2003). Many of these taxa have been reconstructed as frugivorous arboreal quadrupeds (Kay 1977). One of the best studied of these genera is the East African <em>Proconsul<\/em> (Family Proconsulidae; see Figure 8.24). Several species have been described, with body mass reconstructions ranging from 17 to 50 kg (approximately 37\u2013110 lbs.). A paleoenvironmental study reconstructed the habitat of <em>Proconsul <\/em>to be a dense, closed-canopy tropical forest (Michel et al. 2014). No caudal vertebrae (tail bones) have been found in direct association with <em>Proconsul <\/em>postcrania, and the morphology of the sacrum is consistent with <em>Proconsul<\/em> lacking a tail (Russo 2016; Ward et al. 1991).<\/p>\n<p class=\"import-Normal\">Overall, the African ape fossil record in the Late Miocene is sparse, with seven fossil localities dating between eleven and five million years ago (Pickford et al. 2009). Nevertheless, most species of great apes live in Africa today. Where did the progenitors of modern African apes arise? Did they evolve in Africa or somewhere else? The paucity of apes in the Late Miocene of Africa stands in contrast to the situation in Eurasia. There, ape diversity was high. Furthermore, several Eurasian ape fossils show morphological affinities with modern hominoids (apes). Because of this, some paleoanthropologists suggest that the ancestors of modern African great apes recolonized Africa from Eurasia toward the end of the Miocene (Begun 2002). However, discoveries of Late Miocene hominoids like the Kenyan <em>Nakalipithecus<\/em> (9.9 million to 9.8 million years ago), the Ethiopian <em>Chororapithecus<\/em> (10.7 million to 10.1 million years ago), and the late-Middle Miocene Namibian <em>Otavipithecus<\/em> (13 million to 12 million years ago) fuel an alternative hypothesis\u2014namely that African hominoid diversity was maintained throughout the Miocene and that one of these taxa might, in fact, be the last common ancestor of extant African apes (Kunimatsu et al. 2007; Mocke et al. 2002). The previously underappreciated diversity of Late Miocene apes in Africa might be due to poor sampling of the fossil record in Africa.<\/p>\n<h4 class=\"import-Normal\"><em>Eurasian Ape Diversity<\/em><\/h4>\n<p class=\"import-Normal\">With the establishment of the <em>Gomphotherium<\/em> Landbridge (a result of the closure of the Eastern Mediterranean seaway; R\u00f6gl 1999), the Middle Miocene was an exciting time for hominoid radiations outside of Africa (see Figure 8.23). Eurasian hominoid species exploited their environments in many different ways in the Miocene. Food exploitation ranged from soft-fruit feeding in some taxa to hard-object feeding in others, in part owing to seasonal fluctuations and the necessary adoptions of fallback foods (DeMiguel et al. 2014). For example, the molars of <em>Oreopithecus bambolii<\/em> (Family Hominidae) have relatively long lower-molar shearing crests, suggesting that this hominoid was very folivorous (Ungar and Kay 1995). Associated with variation in diet, there is great variation in the degree to which cranial features (e.g., zygomatic bone or supraorbital tori) are developed across the many taxa (Cameron 1997); however, Middle Miocene fossils tend to exhibit relatively thick molar enamel and relatively robust jaws (Andrews and Martin 1991).<\/p>\n<p class=\"import-Normal\">In Spain, the cranium with upper dentition, part of a mandible, and partial skeleton of <em>Pliobates <\/em>(Family Pliobatidae), a small-bodied ape (4\u20135 kg; 9\u201311 lbs.), was discovered in deposits dating to 11.6 million years ago (Alba et al. 2015). It is believed to be a frugivore with a relative brain size that overlaps with modern cercopithecoids. The fossilized postcrania of <em>Pliobates<\/em> suggest that this ape might have had a unique style of locomotion, including the tendency to walk across the branches of trees with its palms facing downward and flexible wrists that permitted rotation of the forearm during climbing. However, the anatomy of the distal humerus differs from those of living apes in ways that suggest that <em>Pliobates<\/em> was less efficient at stabilizing its elbow while suspended (Benefit and McCrossin 2015). Two other recently described apes from Spain, <em>Pierolapithecus <\/em>and <em>Anoiapithecus<\/em>, are known from relatively complete skeletons. <em>Pierolapithecus<\/em> had a very projecting face and thick molar enamel as well as some skeletal features that suggest (albeit controversially) a less suspensory locomotor style than in extant apes (Moy\u00e0-Sol\u00e0 et al. 2004). In contrast to <em>Pierolapithecus<\/em>, the slightly younger <em>Anoiapithecus<\/em> has a very flat face (Moy\u00e0-Sol\u00e0 et al. 2009).<\/p>\n<p class=\"import-Normal\">Postcranial evidence for suspensory or well-developed orthograde behaviors in apes does not appear until the Late Miocene of Europe. Primary evidence supporting these specialized locomotor modes includes the relatively short lumbar vertebrae of <em>Oreopithecus <\/em>(Figure 8.26) and <em>Dryopithecus<\/em> (Maclatchy 2004). Further, fossil material of the lower torso of <em>O. bambolii <\/em>(which dates to the <em>Pan<\/em>-hominin divergence) conveys a higher degree of flexion-extension abilities in the lumbar region (lower back) than what is possible in extant apes. Additionally, the hindlimb of <em>O. bambolii <\/em>is suggested to have supported powerful hip adduction during climbing (Hammond et al. 2020). The Late Miocene saw the extinction of most of the Eurasian hominoids in an event referred to as the Vallesian Crisis (Agust\u00ed et al. 2003). Among the latest surviving hominoid taxa in Eurasia were <em>Oreopithecus<\/em> and <em>Gigantopithecus<\/em>, the latter of which held out until the Pleistocene in Asia and was probably even sympatric with <em>Homo erectus<\/em> (Cachel 2015).<\/p>\n<figure style=\"width: 436px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image8-2-1.jpg\" alt=\"Posterior view of ancient ape skeleton.\" width=\"436\" height=\"775\" \/><figcaption class=\"wp-caption-text\">Figure 8.26: Skeleton of Oreopithecus bambolii. Credit: <a class=\"rId107\" href=\"https:\/\/commons.wikimedia.org\/wiki\/File:Oreopithecus_bambolii_1.JPG\">Oreopithecus bambolii 1<\/a> by <a class=\"rId108\" href=\"https:\/\/commons.wikimedia.org\/wiki\/User:Ghedoghedo\">Ghedoghedo<\/a> is under a <a class=\"rId109\" href=\"https:\/\/creativecommons.org\/licenses\/by-sa\/3.0\/legalcode\">CC BY-SA 3.0 License<\/a>.<\/figcaption><\/figure>\n<h3 class=\"import-Normal\"><strong>The Origins of Extant Apes<\/strong><\/h3>\n<p class=\"import-Normal\">The fossil record of the extant apes is somewhat underwhelming: it ranges from being practically nonexistent for some taxa (e.g., chimpanzees) to being a little better for others (e.g., humans). There are many possible reasons for these differences in fossil abundance, and many are associated with the environmental conditions necessary for the fossilization of bones. One way to understand the evolution of extant apes that is not so dependent on the fossil record is via molecular evolutionary analyses. This can include counting up the differences in the genetic sequence between two closely related species to estimate the amount of time since these species shared a common ancestor. This is called a molecular clock, and it is often calibrated using fossils of known absolute age that stand in for the last common ancestor of a particular clade. Molecular clock estimates have placed the Hylobatidae and Hominidae split between 19.7 million and 24.1 million years ago, the African ape and Asian ape split between 15.7 million and 19.3 million years ago, and the split of Hylobatidae into its current genera between 6.4 million and 8 million years ago (Israfil et al. 2011).<\/p>\n<h4 class=\"import-Normal\"><em>Small Ape Origins and Fossils<\/em><\/h4>\n<p class=\"import-Normal\">Unfortunately, the fossil record for the small (formerly \u201clesser\u201d) apes is meager, particularly in Miocene deposits. One possible early hylobatid is <em>Laccopithecus robustus<\/em>, a Late Miocene catarrhine from China (Harrison 2016). Although it does share some characteristics with modern gibbons and siamangs (including an overall small body size and a short face), <em>Laccopithecus<\/em> most likely represents a plesiomorphic stem catarrhine and is therefore distantly related to extant apes (Jablonski and Chaplin 2009). A more likely candidate for the hylobatid stem is another Late Miocene taxon from China, <em>Yuanmoupithecus xiaoyuan<\/em>. Interpretation of its phylogenetic standing, however, is complicated by contradicting dental features\u2014some of them quite plesiomorphic\u2014which some believe best place <em>Yuanmoupithecus<\/em> as a stem hylobatid (Harrison 2016). Recently, a Middle Miocene Indian fossil ape, <em>Kapi ramnagarensis<\/em>, has extended the fossil record of small apes by approximately five million years. Its teeth are suggestive of a shift to a more frugivorous diet and it is likely a stem hylobatid (Gilbert et al. 2020). The history of Hylobatidae becomes clearer in the Pleistocene, with fossils representing extant genera.<\/p>\n<h4 class=\"import-Normal\"><em>Great Ape Origins and Fossils<\/em><\/h4>\n<p class=\"import-Normal\">The most extensive fossil record of a modern great ape is that of our own genus, <em>Homo<\/em>. The evolution of our own species will be covered in Chapter 9. The evolutionary history of the Asian great ape, the orangutan (<em>Pongo<\/em>), is becoming clearer. Today, orangutans are found only on the islands of Borneo and Sumatra. However, Pleistocene-aged teeth, attributed to <em>Pongo<\/em>, have been found in Cambodia, China, Laos, Peninsular Malaysia, and Vietnam\u2014demonstrating the vastness of the orangutan\u2019s previous range (Ibrahim et al. 2013; Wang et al. 2014). <em>Sivapithecus <\/em>from the Miocene of India and Pakistan is represented by many specimens, including parts of the face. <em>Sivapithecus<\/em> is very similar to <em>Pongo<\/em>, especially in the face, and it probably is closely related to ancestral orangutans (Pilbeam 1982). Originally, jaws and teeth belonging to the former genus <em>Ramapithecus<\/em> were thought to be important in the origin of humans (Simons 1961), but now these are recognized as specimens of <em>Sivapithecus<\/em> (Kelley 2002). Postcranial bones of <em>Sivapithecus<\/em>, however, suggest a more generalized locomotor mode\u2014including terrestrial locomotion\u2014than seen in <em>Pongo <\/em>(Pilbeam et al. 1990). Stable carbon and oxygen isotope data from dental enamel have reconstructed the paleoecological space of <em>Sivapithecus <\/em>(as well as the contemporaneous Late Miocene pongine <em>Khoratpithecus<\/em>) within the canopies of forested habitats (Habinger et al. 2022).<\/p>\n<p class=\"import-Normal\">A probable close relative of <em>Sivapithecus <\/em>is the amazing <em>Gigantopithecus<\/em> (see Figure 8.24). Known only from teeth and jaws from China and India (e.g., Figure 8.27), this ape probably weighed as much as 270 kg (595 lbs.) and was likely the largest primate ever (Bocherens et al. 2017). Because of unique features of its teeth (including molarized premolars and patterns of wear) and its massive size, it has been reconstructed as a bamboo specialist, somewhat like the modern panda. Small silica particles (phytoliths) from grasses have been found stuck to the molars of <em>Gigantopithecus<\/em> (Ciochon et al. 1990). Recent studies evaluating the carbon isotope composition of the enamel sampled from <em>Gigantopithecus<\/em> teeth suggest that this ape exploited a wide range of vegetation, including fruits, leaves, roots, and bamboo (Bocherens et al. 2017). Its face is reminiscent of that of modern orangutans and it might belong in the same family, Pongidae (Kelley 2002).<\/p>\n<figure style=\"width: 488px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image12.jpg\" alt=\"Superior view of mandible and teeth.\" width=\"488\" height=\"533\" \/><figcaption class=\"wp-caption-text\">Figure 8.27: Cast of the mandible of Gigantopithecus blacki. Credit: <a class=\"rId111\" href=\"https:\/\/commons.wikimedia.org\/wiki\/File:Gigantopithecus%20blacki%20mandible%20010112.jpg\">Gigantopithecus blacki mandible 010112<\/a> by <a class=\"rId112\" href=\"https:\/\/commons.wikimedia.org\/wiki\/User:Wilson44691\">Wilson44691<\/a> is under a <a class=\"rId113\" href=\"https:\/\/creativecommons.org\/licenses\/by-sa\/3.0\/legalcode\">CC BY-SA 3.0 License<\/a>.<\/figcaption><\/figure>\n<p class=\"import-Normal\">In Africa, the first fossil to be confidently attributed to <em>Pan<\/em>, and known to be the earliest evidence of a chimpanzee, was described based on teeth found in Middle Pleistocene deposits in the Eastern Rift Valley of Kenya (McBrearty and Jablonski 2005). Paleoenvironmental reconstructions of this locality suggest that this early chimpanzee was living in close proximity to early <em>Homo<\/em> in a closed-canopy wooded habitat. Similarly, fossil teeth and mandibular remains attributed to two species of Middle-Late Miocene apes\u2014<em>Chororapithecus abyssinicus<\/em> (from Ethiopia; Suwa et al. 2007) and <em>Nakalipithecus nakayamai<\/em> (from Kenya; Kunimatsu et al. 2007)\u2014have been suggested as basal members of the gorilla clade.<\/p>\n<p class=\"import-Normal\">While the deposits of Eastern Africa have yielded a profound record of our fossil hominin ancestors, the continent\u2019s rainforests remain a \u201cpalaeontological desert\u201d (Rosas et al. 2022). Clearly, more work is needed to fill in the large gaps in the fossil record of the nonhuman great apes. The twentieth century witnessed the discovery of many hominin fossils in East Africa, which have been critical for improving our understanding of human evolution. While twenty-first-century conservationists fight to prevent the extinction of the living great apes, perhaps efforts by twenty-first-century paleoanthropologists will yield the evolutionary story of these, our closest relatives.<\/p>\n<div class=\"textbox shaded\">\n<h2 class=\"import-Normal\">Review Questions<strong><br \/>\n<\/strong><\/h2>\n<ul>\n<li>Compare three major hypotheses about primate origins, making reference to each one\u2019s key ecological reason for primate uniqueness.<\/li>\n<li>Explain how changes in temperature, rainfall, and vegetation led to major changes in primate biogeography over the Early Tertiary.<\/li>\n<li>List some euprimate features that plesiadapiforms have and some that they lack.<\/li>\n<li>Contrast adapoids and omomyoids in terms of life habits.<\/li>\n<li>Describe one piece of evidence for each of the adapoid, omomyoid, and tarsier origin hypotheses for anthropoids.<\/li>\n<li>Discuss the biogeography of the origins of African great apes and orangutans using examples from the Miocene ape fossil record.<\/li>\n<\/ul>\n<\/div>\n<h2 class=\"import-Normal\">Key Terms<strong><br \/>\n<\/strong><\/h2>\n<p class=\"import-Normal\"><strong>Adapoidea<\/strong>: Order: Primates. One of the earliest groups of euprimates (true primates; earliest records from the early Eocene).<\/p>\n<p class=\"import-Normal\"><strong>A<\/strong><strong>daptive radiations<\/strong>: Rapid diversifications of single lineages into many species which may present unique morphological features in response to different ecological settings.<\/p>\n<p class=\"import-Normal\"><strong>Ancestral traits<\/strong>: Features that were inherited from a common ancestor and which remain (largely) unchanged.<\/p>\n<p class=\"import-Normal\"><strong>Anthropoids<\/strong>:Group containing monkeys and apes, including humans.<\/p>\n<p class=\"import-Normal\"><strong>Auditory bulla<\/strong>: The rounded bony floor of the middle ear cavity.<\/p>\n<p class=\"import-Normal\"><strong>Bilophodonty<\/strong>: Dental condition in which the cusps of molar teeth form ridges (or lophs) separated from each other by valleys (seen, e.g., in modern catarrhine monkeys).<\/p>\n<p class=\"import-Normal\"><strong>Catarrhines<\/strong>: Order: Primates; Suborder: Anthropoidea; Infraorder: Catarrhini. Group, with origins in Africa and Asia, that contains monkeys and apes, including humans.<\/p>\n<p class=\"import-Normal\"><strong>Clade<\/strong>:Group containing all of the descendants of a single ancestor. A portion of a phylogenetic tree represented as a bifurcation (node) in a lineage and all of the branches leading forward in time from that bifurcation.<\/p>\n<p class=\"import-Normal\"><strong>Convergent evolution<\/strong>: The independent evolution of a morphological feature in animals not closely related (e.g., wings in birds and bats).<\/p>\n<p class=\"import-Normal\"><strong>Crown<\/strong>: Smallest monophyletic group (clade) containing a specified set of extant taxa and all descendants of their last common ancestor.<\/p>\n<p class=\"import-Normal\"><strong>Diastema<\/strong>: Space between adjacent teeth.<\/p>\n<p class=\"import-Normal\"><strong>Diffuse coevolution<\/strong>: The ecological interaction between whole groups of species (e.g., primates) with whole groups of other species (e.g., fruiting trees).<\/p>\n<p class=\"import-Normal\"><strong>Ectotympanic<\/strong>: Bony ring or tube that holds the tympanic membrane (eardrum).<\/p>\n<p class=\"import-Normal\"><strong>Euprimates<\/strong>: Order: Primates. True primates or primates of modern aspect.<\/p>\n<p class=\"import-Normal\"><strong>Haplorhines<\/strong>: Group containing catarrhines, platyrrhines, and tarsiers.<\/p>\n<p class=\"import-Normal\"><strong>Hominins<\/strong>: Modern humans and any extinct relatives more closely related to us than to chimpanzees.<\/p>\n<p class=\"import-Normal\"><strong>Mandibular symphysis<\/strong>: Fibrocartilaginous joint between the left and right mandibular segments, located in the midline of the body.<\/p>\n<p class=\"import-Normal\"><strong>Omomyoidea<\/strong>: Order: Primates; Superfamily: Omomyoidea. One of the earliest groups of euprimates (true primates; earliest record in the early Eocene).<\/p>\n<p class=\"import-Normal\"><strong>Petrosal bone<\/strong>: The portion of the temporal bone that houses the inner ear apparatus.<\/p>\n<p class=\"import-Normal\"><strong>Plagiaulacoid<\/strong>: Dental condition where at least one of the lower cheek-teeth (molars or premolars) is a laterally compressed blade.<\/p>\n<p class=\"import-Normal\"><strong>Platyrrhines<\/strong>: Order: Primates; Suborder: Anthropoidea; Infraorder: Platyrrhini. Group containing monkeys found in the Americas.<\/p>\n<p class=\"import-Normal\"><strong>Plesiadapiforms<\/strong>: Order: Plesiadapiformes. Archaic primates or primate-like placental mammals (Early Paleocene\u2013Late Eocene).<\/p>\n<p class=\"import-Normal\"><strong>P<\/strong><strong>lesiomorphic<\/strong>: Having features that are shared by different groups which arose from a common ancestor.<\/p>\n<p class=\"import-Normal\"><strong>Stem<\/strong>: Taxa that are basal to a given crown group but are more closely related to the crown group than to the closest living sister taxon of the crown group.<\/p>\n<p class=\"import-Normal\"><strong>Strepsirrhines<\/strong>: Order: Primates; Suborder: Stresirrhini. Group containing lemurs, lorises, and galagos (does not include tarsiers).<\/p>\n<p class=\"import-Normal\"><strong>Toothcomb<\/strong>: Dental condition found in modern strepsirrhines in which the lower incisors and canines are laterally compressed and protrude forward at a nearly horizontal inclination. This structure is used in grooming.<\/p>\n<h2 class=\"import-Normal\">About the Authors<strong><br \/>\n<\/strong><\/h2>\n<p class=\"import-Normal\"><strong data-wp-editing=\"1\"><img loading=\"lazy\" decoding=\"async\" class=\"alignleft\" src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image17-1-1.jpg\" alt=\"A man with sunglasses, a full beard, and a bandana stands in a field.\" width=\"243\" height=\"309\" \/><\/strong><\/p>\n<h3 class=\"import-Normal\"><strong>Jonathan M. G. Perry, Ph.D.<\/strong><\/h3>\n<p class=\"import-Normal\">Western University of Health Sciences, Oregon, jperry@westernu.edu<\/p>\n<p class=\"import-Normal\">Jonathan Perry was trained as a paleontologist and primatologist at the University of Alberta, Duke University, and Stony Brook University. His research focuses on the relationship between food, feeding, and craniodental anatomy in primates both living and extinct. This work includes primate feeding behavior, comparative anatomy, biomechanics, and field paleontology. He has taught courses on primate evolution at the undergraduate and graduate level.<\/p>\n<\/div>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<div class=\"__UNKNOWN__\">\n<p class=\"import-Normal\"><strong><img loading=\"lazy\" decoding=\"async\" class=\"alignleft\" src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image10-5.png\" alt=\"A woman with long light brown hair stands in front of screen with scientific data and imagery.\" width=\"232\" height=\"211\" \/><\/strong><\/p>\n<h3 class=\"import-Normal\"><strong>Stephanie L. Canington, B.A., Ph.D.<\/strong><\/h3>\n<p class=\"import-Normal\">University of Pennsylvania, scaning@upenn.edu<\/p>\n<p class=\"import-Normal\">Stephanie Canington is a postdoctoral researcher at the University of Pennsylvania. Her current research is on the links between food properties, feeding behavior, and jaw morphology in lemurs that live in varying forms of captivity.<\/p>\n<p>&nbsp;<\/p>\n<h2 class=\"import-Normal\">For Further Exploration<strong><br \/>\n<\/strong><\/h2>\n<p class=\"import-Normal\">Beard, Chris. 2004. <em>The Hunt for the Dawn Monkey: Unearthing the Origins of Monkeys, Apes, and Humans<\/em>. Berkeley: University of California Press.<\/p>\n<p class=\"import-Normal\">Begun, David R. 2010. \u201cMiocene Hominids and the Origins of the African Apes and Humans.\u201d <em>Annual Review of Anthropology<\/em> 39: 67\u201384.<\/p>\n<p class=\"import-Normal\">Fleagle, John G. 2013. <em>Primate Adaptation and Evolution.<\/em> Third edition. San Diego, CA: Academic Press.<\/p>\n<p class=\"import-Normal\">Gebo, Daniel L., ed. 1993. <em>Postcranial Adaptations in Nonhuman Primates<\/em>. Dekalb: Northern Illinois University Press.<\/p>\n<p class=\"import-Normal\">Godfrey, Laurie R., and William L. Jungers. 2002. \u201cQuaternary Fossil Lemurs.\u201d In <em>The Primate Fossil Record, <\/em>edited by Walter C. Hartwig, 97\u2013121. Cambridge: Cambridge University Press.<\/p>\n<p class=\"import-Normal\">Godinot, Marc. 2006. \u201cLemuriform Origins as Viewed from the Fossil Record.\u201d <em>Folia Primatologica<\/em> 77 (6): 446\u2013464.<\/p>\n<p class=\"import-Normal\">Kay, Richard F. 2018. \u201c100 Years of Primate Paleontology.\u201d <em>American Journal of Physical Anthropology<\/em> 165 (4): 652\u2013676.<\/p>\n<p class=\"import-Normal\">Marivaux, Laurent. 2006. \u201cThe Eosimiid and Amphipithecid Primates (Anthropoidea) from the Oligocene of the Bugti Hills (Balochistan, Pakistan): New Insight into Early Higher Primate Evolution in South Asia.\u201d <em>Palaeovertebrata, Montpellier <\/em>34 (1\u20132): 29\u2013109.<\/p>\n<p class=\"import-Normal\">Martin, R. D. 1990. <em>Primate Origins and Evolution<\/em><em>: A <\/em><em>Phylogenetic Reconstruction<\/em>. Princeton: Princeton University Press.<\/p>\n<p class=\"import-Normal\">Rose, Kenneth D., Marc Godinot, and Thomas M. Bown. 1994. \u201cThe Early Radiation of Euprimates and the Initial Diversification of Omomyidae.\u201d In <em>Anthropoid Origins: The Fossil Evidence, <\/em>edited by John G. Fleagle and Richard F. Kay, 1\u201328. New York: Plenum Press.<\/p>\n<p class=\"import-Normal\">Ross, Callum F. 1999. \u201cHow to Carry Out Functional Morphology.\u201d <em>Evolutionary Anthropology<\/em> 7 (6): 217\u2013222.<\/p>\n<p class=\"import-Normal\">Seiffert, Erik R. 2012. \u201cEarly Primate Evolution in Afro-Arabia.\u201d Evolutionary Anthropology: Issues, News, and Reviews 21(6): 239\u2013253.<\/p>\n<p class=\"import-Normal\">Szalay, Frederic S., and Eric Delson. 1979. Evolutionary History of the Primates. New York: Academic Press.<\/p>\n<p class=\"import-Normal\">Ungar, Peter S. 2002. \u201cReconstructing the Diets of Fossil Primates.\u201d In <em>Reconstructing Behavior in the Primate Fossil Record<\/em>, edited by Joseph Plavcan, Richard F. Kay, William Jungers, and Carel P. van Schaik, 261\u2013296. New York: Kluwer Academic\/Plenum Publishers.<\/p>\n<h2 class=\"import-Normal\">References<\/h2>\n<p class=\"import-Normal\">Agust\u00ed, J., A. Sanz de Siria, and M. Garc\u00e9s M. 2003. \u201cExplaining the End of the Hominoid Experiment in Europe.\u201d <em>Journal of Human Evolution<\/em> 45 (2): 145\u2013153.<\/p>\n<p class=\"import-Normal\">Alba, David M., Sergio Alm\u00e9cija, Daniel DeMiguel, Josep Fortuny, Miriam P\u00e9rez de los R\u00edos, Marta Pina, Josep M. Robles, and Salvador Moy\u00e0-Sol\u00e0. 2015. \u201cMiocene Small-Bodied Ape from Eurasia Sheds Light on Hominoid Evolution.\u201d <em>Science<\/em> 350 (6260): aab2625.<\/p>\n<p class=\"import-Normal\">Andrews, Peter, and Lawrence Martin. 1991. \u201cHominoid Dietary Evolution.\u201d <em>Philosophical Transactions of the Royal Society of London B: Biological Sciences<\/em> 334 (1270): 199\u2013209.<\/p>\n<p class=\"import-Normal\">Antoine, Pierre-Oliver, Laurent Marivaux, Darren A. Croft, Guillaume Billet, Morgan Ganer\u00f8d, Carlos Jaramillo, Thomas Martin, et al. 2012. \u201cMiddle Eocene Rodents from Peruvian Amazonia Reveal the Pattern and Timing of Caviomorph Origins and Biogeography.\u201d <em>Proceedings of the Royal Society B: Biological Sciences<\/em> 279 (1732): 1319\u20131326.<\/p>\n<p class=\"import-Normal\">Beard, K. Christopher. 1990. \u201cGliding Behaviour and Palaeoecology of the Alleged Primate Family Paromomyidae (Mammalia, Dermoptera).\u201d <em>Nature<\/em> 345 (6273): 340\u2013341.<\/p>\n<p class=\"import-Normal\">Beard, K. Christopher. 2002. \u201cBasal Anthropoids.\u201d In <em>The Primate Fossil Record, <\/em>edited by William C. Hartwig, 133\u2013150. Cambridge: Cambridge University Press.<\/p>\n<p class=\"import-Normal\">Beard, K. Christopher, and R. D. E. MacPhee. 1994. \u201cCranial Anatomy of <em>Shoshonius<\/em> and the Antiquity of Anthropoidea.\u201d In <em>Anthropoid Origins: The Fossil Evidence<\/em>, edited by John G. Fleagle and Richard F. Kay, 55\u201398. New York: Plenum Press.<\/p>\n<p class=\"import-Normal\">Beard, K. Christopher, Laurent Marivaux, Soe Thura Tun, Aung Naing Soe, Yaowalak Chaimanee, Wanna Htoon, Bernard Marandat, Htun Htun Aung, and Jean-Jacques Jaeger. 2007. \u201cNew Sivaladapid Primates from the Eocene Pondaung Formation of Myanmar and the Anthropoid Status of Amphipithecidae.\u201d <em>Bulletin of Carnegie Museum of Natural History<\/em> 39: 67\u201376.<\/p>\n<p class=\"import-Normal\">Beard, K. Christopher, Tao Qi, Mary R. Dawson, Banyue Wang, and Chuankuei Li. 1994. \u201cA Diverse New Primate Fauna from Middle Eocene Fissure-Fillings in Southeastern China.\u201d <em>Nature<\/em> 368 (6472): 604\u2013609.<\/p>\n<p class=\"import-Normal\">Beard, K. Christopher, Yongsheng Tong, Mary R. Dawson, Jingwen Wang, and Xueshi Huang. 1996. \u201cEarliest Complete Dentition of an Anthropoid Primate from the Late Middle Eocene of Shanxi Province, China.\u201d <em>Science<\/em> 272 (5258): 82\u201385.<\/p>\n<p class=\"import-Normal\">Beecher, Robert M. 1983. \u201cEvolution of the Mandibular Symphysis in Notharctinae (Adapidae, Primates).\u201d <em>International Journal of Primatology<\/em> 4 (1): 99\u2013112.<\/p>\n<p class=\"import-Normal\">Begun, David R. 2002. \u201cEuropean Hominoids.\u201d In <em>The Primate Fossil Record<\/em>, edited by William C. Hartwig, 339\u2013368. Cambridge: Cambridge University Press.<\/p>\n<p class=\"import-Normal\">Begun, David R. 2003. \u201cPlanet of the Apes.\u201d <em>Scientific American<\/em> 289 (2): 74\u201383.<\/p>\n<p class=\"import-Normal\">Begun, David R. 2007. \u201cFossil Record of Miocene Hominoids.\u201d In <em>Handbook of Paleoanthropology<\/em>, edited by Winfried Henke and Ian Tattersall, 921\u2013977. New York: Springer.<\/p>\n<p class=\"import-Normal\">Benefit, Brenda R., and Monte L. McCrossin. 1997. \u201cEarliest Known Old World Monkey Skull.\u201d <em>Nature<\/em> 388 (6640): 368\u2013371.<\/p>\n<p class=\"import-Normal\">Benefit, Brenda R., and Monte L. McCrossin. 2015. \u201cA Window into Ape Evolution.\u201d <em>Science<\/em> 350 (6260): 515\u2013516.<\/p>\n<p class=\"import-Normal\">Bloch, Jonathan I., and David M. Boyer. 2002. \u201cGrasping Primate Origins.\u201d <em>Science<\/em> 298 (5598): 1606\u20131610.<\/p>\n<p class=\"import-Normal\">Bloch, Jonathan I., and David M. Boyer. 2007. \u201cNew Skeletons of Paleocene-Eocene Plesiadapiformes: A Diversity of Arboreal Positional Behaviors in Early Primates.\u201d In <em>Primate Origins: Adaptations and Evolution<\/em>, edited by Matthew J. Ravosa and Marian Dagosto, 535\u2013581. New York: Springer.<\/p>\n<p class=\"import-Normal\">Bloch, Jonathan I., and Mary T. Silcox. 2006. \u201cCranial Anatomy of the Paleocene Plesiadapiform <em>Carpolestes simpsoni<\/em> (Mammalia, Primates) Using Ultra High-Resolution X-ray Computed Tomography, and the Relationships of Plesiadapiforms to Euprimates.\u201d <em>Journal of Human Evolution<\/em>: 50 (1): 1\u201335.<\/p>\n<p class=\"import-Normal\">Blue, Kathleen T., Monte L. McCrossin, and Brenda R. Benefit. 2006. \u201cTerrestriality in a Middle Miocene Context: <em>Victoriapithecus<\/em> from Maboko, Kenya.\u201d In <em>Human Origins and Environmental Backgrounds<\/em>, edited by Hidemi Ishida, Russell Tuttle, Martin Pickford, Naomichi Ogihara, and Masato Nakatsukasa, 45\u201358. New York: Springer.<\/p>\n<p class=\"import-Normal\">Bocherens, Herv\u00e9, Friedemann Schrenk, Yaowalak Chaimanee, Ottmar Kullmer, Doris M\u00f6rike, Diana Pushkina, and Jean-Jacques Jaeger. 2017. \u201cFlexibility of Diet and Habitat in Pleistocene South Asian Mammals: Implications for the Fate of the Giant Fossil Ape <em>Gigantopithecus<\/em>.\u201d <em>Quaternary International<\/em> 434 (A): 148\u2013155.<\/p>\n<p class=\"import-Normal\">Bond, Mariano, Marcelo F. Tejedor, Kenneth E. Campbell Jr., Laura Chornogubsky, Nelson Novo, and Francisco Goin. 2015. \u201cEocene Primates of South America and the African Origins of New World Monkeys.\u201d <em>Nature<\/em> 520 (7548): 539\u2013541.<\/p>\n<p class=\"import-Normal\">Bown, T. M., and M. J. Kraus. 1988. \u201cGeology and Paleoenvironment of the Oligocene Jebel Qatrani Formation and Adjacent Rocks, Fayum Depression, Egypt.\u201d Professional Paper, 1452. Washington, DC: U.S. Geological Survey Professional Papers.<\/p>\n<p class=\"import-Normal\">Cachel, Susan. 2015.<em> Fossil Primates.<\/em> Vol. 69. Cambridge: Cambridge University Press.<\/p>\n<p class=\"import-Normal\">Cameron, David W. 1997. \u201cA Revised Systematic Scheme for the Eurasian Miocene Fossil Hominidae.\u201d <em>Journal of Human Evolution<\/em> 33 (4): 449\u2013477.<\/p>\n<p class=\"import-Normal\">Cartmill, Matt. 1972. \u201cArboreal Adaptations and the Origin of the Order Primates.\u201d In <em>The Functional and Evolutionary Biology of Primates<\/em>, edited by Russell Tuttle, 97\u2013122. Chicago: Aldine-Atherton.<\/p>\n<p class=\"import-Normal\">Cartmill, Matt. 1974. \u201cRethinking Primate Origins.\u201d <em>Science<\/em> 184 (4135): 436\u2013443.<\/p>\n<p class=\"import-Normal\">Cartmill, Matt, and Richard F. Kay. 1978. \u201cCraniodental Morphology, Tarsier Affinities, and Primate Suborders.\u201d In <em>Recent Advances in Primatology: Evolution,<\/em> edited by D. J. Chivers and K. A. Joysey, 205\u2013214. London: Academic Press.<\/p>\n<p class=\"import-Normal\">Casanovas-Vilar, Isaac, David M. Alba, Miguel Garc\u00e9s, Josep M. Robles, and Salvador Moy\u00e0-Sol\u00e0. 2011. \u201cUpdated Chronology for the Miocene Hominoid Radiation in Western Eurasia.\u201d <em>Proceedings of the National Academy of Sciences <\/em>108 (14): 5554-5559. https:\/\/doi:10.1073\/pnas.1018562108.<\/p>\n<p class=\"import-Normal\">Chaimanee, Yaowalak, Olivier Chavasseau, K. Christopher Beard, Aung Aung Kyaw, Aung Naing Soe, Chit Sein, Vincent Lazzari, et al. 2012. \u201cLate Middle Eocene Primate from Myanmar and the Initial Anthropoid Colonization of Africa.\u201d <em>Proceedings of the National Academy of Sciences<\/em> <em>of the United States of America <\/em>109 (26): 10293\u201310297.<\/p>\n<p class=\"import-Normal\">Chester, Stephen G. B., Jonathan I. Bloch, Doug M. Boyer, and William A. Clemens. 2015. \u201cOldest Known Euarchontan Tarsals and Affinities of Paleocene <em>Purgatorius<\/em> to Primates.\u201d <em>Proceedings of the National Academy of Sciences of the United States of America<\/em> 112 (5): 1487\u20131492.<\/p>\n<p class=\"import-Normal\">Ciochon, Russell L., and Gregg F. Gunnell. 2002. \u201cChronology of Primate Discoveries in Myanmar: Influences on the Anthropoid Origins Debate.\u201d <em>Yearbook of Physical Anthropology<\/em> 45(S35): 2\u201335.<\/p>\n<p class=\"import-Normal\">Ciochon, R. L., D. R. Piperno, and R. G. Thompson. 1990. \u201cOpal Phytoliths Found on the Teeth of the Extinct Ape <em>Gigantopithecus blacki<\/em>: Implications for Paleodietary Studies.\u201d <em>Proceedings of the National Academy of Sciences of the United States of America<\/em> 87 (20): 8120\u20138124.<\/p>\n<p class=\"import-Normal\">Clemens, William A. 2004. \u201c<em>Purgatorius<\/em> (Plesiadapiformes, Primates?, Mammalia), a Paleocene Immigrant into Northeastern Montana: Stratigraphic Occurrences and Incisor Proportions.\u201d <em>Bulletin of Carnegie Museum of Natural History<\/em> 36: 3\u201313.<\/p>\n<p class=\"import-Normal\">Cooke, Siobh\u00e1n B., Justin T. Gladman, Lauren B. Halenar, Zachary S. Klukkert, and Alfred L. Rosenberber. 2016. \u201cThe Paleobiology of the Recently Extinct Platyrrhines of Brazil and the Caribbean.\u201d In <em>Molecular Population Genetics, Evolutionary Biology and Biological Conservation of Neotropical Primates<\/em>, edited by Manuel Ruiz-Garcia and Joseph Mark Shostell, 41\u201389. New York: Nova Publishers.<\/p>\n<p class=\"import-Normal\">DeLeon, Valerie B., Timothy D. Smith, and Alfred L. Rosenberger. 2016. \u201cOntogeny of the Postorbital Region in Tarsiers and Other Primates.\u201d <em>Anatomical Record: Advances in Integrative Anatomy and Evolutionary Biology<\/em> 299 (12): 1631\u20131645.<\/p>\n<p class=\"import-Normal\">DeMiguel, Daniel, David M. Alba, and Salvador Moy\u00e0-Sol\u00e0. 2014. \u201cDietary Specialization during the Evolution of Western Eurasian Hominoids and the Extinction of European Great Apes.\u201d <em>PLoS ONE<\/em> 9 (5): e97442. https:\/\/doi.org\/10.1371\/journal.pone.0097442.<\/p>\n<p class=\"import-Normal\">Dunn, Rachel H., Kenneth D. Rose, Rajendra Rana, Kishore Kumar, Ashok Sahni, and Thierry Smith. 2016. \u201cNew Euprimate Postcrania from the Early Eocene of Gujarat, India, and the Strepsirrhine\u2013Haplorhine Divergence.\u201d <em>Journal of Human Evolution<\/em> 99: 25\u201351.<\/p>\n<p class=\"import-Normal\">Fleagle, John G. 2013. <em>Primate Adaptation and Evolution<\/em>, Third Edition. San Diego, CA: Academic Press.<\/p>\n<p class=\"import-Normal\">Fleagle, John G., and Richard F. Kay. 1994. <em>Anthropoid Origins<\/em>. New York: Plenum Press.<\/p>\n<p class=\"import-Normal\">Franzen, Jens Lorenz, Phillip D. Gingerich, J\u00f6rg Habersetzer, J\u00f8rn Hurum, von Wighart Koenigswald, and B. Holly Smith. 2009. \u201cComplete Primate Skeleton from the Middle Eocene of Messel in Germany: Morphology and Paleobiology.\u201d <em>PLoS ONE<\/em> 4 (5): e5723. doi:10.1371\/journal.pone.0005723.<\/p>\n<p class=\"import-Normal\">Gebo, Daniel L., Marian Dagosto, K. Christopher Beard, Tao Qi, and Jingwen Wang. 2000. \u201cThe Oldest Known Anthropoid Postcranial Fossils and the Early Evolution of Higher Primates.\u201d <em>Nature<\/em> 404 (6775): 276\u2013278.<\/p>\n<p class=\"import-Normal\">Gebo, Daniel L., and Elwyn L. Simons. 1987. \u201cMorphology and Locomotor Adaptations of the Foot in Early Oligocene Anthropoids.\u201d <em>American Journal of Physical Anthropology<\/em> 74 (1): 83\u2013101.<\/p>\n<p class=\"import-Normal\">Gilbert, Christopher C., Alejandra Ortiz, Kelsey D. Pugh, Christopher J. Campisano, Biren A. Patel, Ningthoujam Premjit Singh, John G. Fleagle, and Rajeev Patnaik. 2020. \u201cNew Middle Miocene Ape (Primates: Hylobatidae) from Ramnagar, India, Fills Major Gaps in the Hominoid Fossil Record.\u201d <em>Proceedings of the Royal Society B<\/em> 287(1934): 20201655.<\/p>\n<p class=\"import-Normal\">Gingerich, P. D. 1980. \u201cEocene Adapidae, Paleobiogeography, and the Origin of South American Platyrrhini.\u201d <em>In Evolutionary Biology of the New World Monkeys and Continental Drift, <\/em>edited by Russell L. Ciochon and A. Brunetto Chiarelli, 123\u2013138. New York: Plenum Press.<\/p>\n<p class=\"import-Normal\">Godfrey, Laurie R., and William L. Jungers. 2002. \u201cQuaternary Fossil Lemurs.\u201d In <em>The Primate Fossil Record<\/em>, edited by Walter C. Hartwig, 97\u2013121. Cambridge: Cambridge University Press.<\/p>\n<p class=\"import-Normal\">Godinot, Marc. 2006. \u201cLemuriform Origins as Viewed from the Fossil Record.\u201d <em>Folia Primatologica<\/em> 77 (6): 446\u2013464.<\/p>\n<p class=\"import-Normal\">Gregory, William K. 1920. \u201cOn the Structure and Relations of <em>Notharctus<\/em>, an American Eocene Primate.\u201d <em>Memoirs of the American Museum of Natural History<\/em> (N.S.) 3 (2).<\/p>\n<p class=\"import-Normal\">Gunnell, Gregg F., Doug M. Boyer, Anthony R. Friscia, Steven Heritage, Frederik Kyalo Manthi, Ellen R. Miller, Hesham M. Sallam, Nancy B. Simmons, Nancy J. Stevens, and Erik R. Seiffert. 2018. \u201cFossil Lemurs from Egypt and Kenya Suggest an African Origin for Madagascar\u2019s Aye-aye.\u201d <em>Nature Communications<\/em> 9 (3193): 1\u201312.<\/p>\n<p class=\"import-Normal\">Habinger, S. G., O. Chavasseau, J. J. Jaeger, Y. Chaimanee, A. N. Soe, C. Sein, and H. Bocherens. 2022. \u201cEvolutionary Ecology of Miocene Hominoid Primates in Southeast Asia.\u201d <em>Scientific Reports<\/em> 12 (1): 1\u201312.<\/p>\n<p class=\"import-Normal\">Hammond, Ashley, Lorenzo Rook, Alisha D.Anaya, Elisabetta Cioppi, Lo\u00efc Costeur, Salvadore Moy\u00e0-Sol\u00e0, and Sergio Alm\u00e9cija. 2020. \u201cInsights into the Lower Torso in Late Miocene Hominoid Oreopithecus bambolii.\u201d <em>Proceedings of the National Academy of Sciences<\/em> 117 (1): 278\u2013284.<\/p>\n<p class=\"import-Normal\">Harrison, Terry. 2010. \u201cApes among the Tangled Branches of Human Origins.\u201d <em>Science<\/em> 327 (5965): 532\u2013534.<\/p>\n<p class=\"import-Normal\">Harrison, Terry. 2016. \u201cThe Fossil Record and Evolutionary History of Hylobatids.\u201d In <em>Evolution of Gibbons and Siamang<\/em>, edited by Ullrich H. Reichard, Hirohisa Hirai, and Claudia Barelli, 91\u2013110. New York: Springer.<\/p>\n<p class=\"import-Normal\">Ibrahim, Yasamin Kh., Lim Tze Tshen, Kira E. Westaway, Earl of Cranbrook, Louise Humphrey, Ross Fatihah Muhammad, Jian-xin Zhao, and Lee Chai Peng. 2013. \u201cFirst Discovery of Pleistocene Orangutan (<em>Pongo<\/em> sp.) Fossils in Peninsular Malaysia: Biogeographic and Paleoenvironmental Implications.\u201d <em>Journal of Human Evolution<\/em> 65 (6): 770\u2013797.<\/p>\n<p class=\"import-Normal\">Israfil, Hulya, Sarah M. Zehr, Alan R. Mootnick, Maryellen Ruvolo, and Michael E. Steiper. 2011. \u201cUnresolved Molecular Phylogenies of Gibbons and Siamangs (Family: Hylobatidae) Based on Mitochondrial, Y-linked, and X-linked Loci Indicate a Rapid Miocene Radiation or Sudden Vicariance Event.\u201d <em>Molecular Phylogenetics and Evolution<\/em> 58 (3): 447\u2013455.<\/p>\n<p class=\"import-Normal\">Jablonski, Nina G., and George Chaplin. 2009. \u201cThe Fossil Record of Gibbons.\u201d In <em>The Gibbons<\/em>, edited by Danielle Whittaker and Susan Lappan, 111\u2013130. New York: Springer.<\/p>\n<p class=\"import-Normal\">Jones, F. Wood. 1916. <em>Arboreal Man<\/em>. London: Edward Arnold.<\/p>\n<p class=\"import-Normal\">Kay, Richard F. 1977. \u201cDiets of Early Miocene African Hominoids.\u201d <em>Nature<\/em> 268 (5621): 628\u2013630.<\/p>\n<p class=\"import-Normal\">Kay, Richard F. 2015. \u201cBiogeography in Deep Time: What Do Phylogenetics, Geology, and Paleoclimate Tell Us about Early Platyrrhine Evolution?\u201d <em>Molecular Phylogenetics and Evolution<\/em> 82 (B): 358\u2013374.<\/p>\n<p class=\"import-Normal\">Kay, Richard F., and John G. Fleagle. 2010. \u201cStem Taxa, Homoplasy, Long Lineages, and the Phylogenetic Position of <em>Dolichocebus<\/em>.\u201d <em>Journal of Human Evolution<\/em> 59 (2): 218\u2013222.<\/p>\n<p class=\"import-Normal\">Kay, Richard F., Jonathan M. G. Perry, Michael Malinzak, Kari L. Allen, E. Christopher Kirk, J. Michael Plavcan, and John G. Fleagle. 2012. \u201cPaleobiology of Santacrucian Primates.\u201d In <em>Early Miocene Paleobiology in Patagonia: High-Latitude Paleocommunities of the Santa Cruz Formation<\/em>, edited by Sergio F. Vizca\u00edno, Richard F. Kay, and M. Susana Bargo, 306\u2013330. Cambridge: Cambridge University Press.<\/p>\n<p class=\"import-Normal\">Kay, Richard F., Daniel O Schmitt, Christopher J. Vinyard, Jonathan M. G. Perry, Nobuo Shigehara, Masanaru Takai, and Naoko Egi. 2004. \u201cThe Paleobiology of Amphipithecidae, South Asian Late Eocene Primates.\u201d <em>Journal of Human Evolution<\/em> 46 (1): 3\u201325.<\/p>\n<p class=\"import-Normal\">Kay, Richard F., and Elwyn L. Simons. 1980. \u201cThe Ecology of Oligocene African Anthropoidea.\u201d <em>International Journal of Primatology<\/em> 1 (1): 21\u201337.<\/p>\n<p class=\"import-Normal\">Kay, Richard F., Richard W. Thorington, and Peter Houde. 1990. \u201cEocene Plesiadapiform Shows Affinities with Flying Lemurs Not Primates.\u201d <em>Nature<\/em> 345 (6273): 342\u2013344.<\/p>\n<p class=\"import-Normal\">Kelley, Jay. 2002. \u201cThe Hominoid Radiation in Asia.\u201d In <em>The Primate Fossil Record<\/em>, edited by Walter C. Hartwig, 369\u2013384. Cambridge: Cambridge University Press.<\/p>\n<p class=\"import-Normal\">Kirk, E. Christopher, and Elwyn L. Simons. 2001. \u201cDiets of Fossil Primates from the Fayum Depression of Egypt: A Quantitative Analysis of Molar Shearing.\u201d <em>Journal of Human Evolution<\/em> 40 (3): 203\u2013229.<\/p>\n<p class=\"import-Normal\">Kirk, E. Christopher, and Blythe A. Williams. 2011. \u201cNew Adapiform Primate of Old World Affinities from the Devil\u2019s Graveyard Formation of Texas.\u201d <em>Journal of Human Evolution<\/em> 61 (2): 156\u2013168.<\/p>\n<p class=\"import-Normal\">Krause, David W. 1991. \u201cWere Paromomyids Gliders? Maybe, Maybe Not.\u201d <em>Journal of Human Evolution<\/em> 21 (3): 177\u2013188.<\/p>\n<p class=\"import-Normal\">Kunimatsu, Yutaka, Masato Nakatsukasa, Yoshihiro Sawada, Tetsuya Sakai, Masayuki Hyodo, Hironobu Hyodo, Tetsumaru Itaya, et al. 2007. \u201cA New Late Miocene Great Ape from Kenya and Its Implications for the Origins of African Great Apes and Humans.\u201d <em>Proceedings of the National Academy of Sciences of the United States of America<\/em> 104 (49): 19220\u201319225.<\/p>\n<p class=\"import-Normal\">Maclatchy, Laura. 2004. \u201cThe Oldest Ape.\u201d <em>Evolutionary Anthropology: Issues, News, and Reviews<\/em> 13 (3): 90\u2013103.<\/p>\n<p class=\"import-Normal\">Marivaux, Laurent, Yaowalak Chaimanee, St\u00e9phane Ducrocq, Bernard Marandat, Jean Sudre, Aung Naing Soe, Soe Thura Tun, Wanna Htoon, and Jean-Jacques Jaeger. 2003. \u201cThe Anthropoid Status of a Primate from the Late Middle Eocene Pondaung Formation (Central Myanmar): Tarsal Evidence.\u201d <em>Proceedings of the National Academy of Sciences of the United States of America<\/em> 100 (23): 13173\u201313178.<\/p>\n<p class=\"import-Normal\">Marivaux, Laurent, Anusha Ramdarshan, El Mabrouk Essid, Wissem Marzougui, Hayet Khayati Ammar, Renaud Lebrun, Bernard Marandat, Gilles Merzeraud, Rodolphe Tabuce, and Monique Vianey-Liaud. 2013. \u201c<em>Djebelemur<\/em>, a Tiny Pre-ToothCombed Primate from the Eocene of Tunisia: A Glimpse into the Origin of Crown Strepsirrhines.\u201d <em>PLoS ONE<\/em> 8 (12): e80778. <a class=\"rId116\" href=\"https:\/\/doi.org\/10.1371\/journal.pone.0080778\">doi.org\/10.1371\/journal.pone.0080778<\/a>.<\/p>\n<p class=\"import-Normal\">Martin, R. D. 1968. \u201cTowards a New Definition of Primates.\u201d <em>Man<\/em> (N.S.) 3 (3): 377\u2013401.<\/p>\n<p class=\"import-Normal\">Martin, R. D. 1972. \u201cAdaptive Radiation and Behaviour of the Malagasy Primates.\u201d <em>Philosophical Transactions of the Royal Society B: Biological Sciences<\/em> 264 (862): 295\u2013352.<\/p>\n<p class=\"import-Normal\">Martin, R. D. 1990. <em>Primate Origins and Evolution, a Phylogenetic Reconstruction<\/em>. Princeton: Princeton University Press.<\/p>\n<p class=\"import-Normal\">McBrearty, Sally, and Nina G. Jablonski. 2005. \u201cFirst Fossil Chimpanzee.\u201d <em>Nature<\/em> 437 (7055): 105\u2013108.<\/p>\n<p class=\"import-Normal\">Michel, Lauren A., Daniel J. Peppe, James A. Lutz, Stephen G. Driese, Holly M. Dunsworth, William E. H. Harcourt-Smith, William H. Horner, Thomas Lehmann, Sheila Nightingale, and Kieran P. McNulty. 2014. \u201cRemnants of an Ancient Forest Provide Ecological Context for Early Miocene Fossil Apes.\u201d <em>Nature Communications<\/em> 5: 1-9.<\/p>\n<p class=\"import-Normal\">Miller, E. R., B. R. Benefit, M. L. McCrossin, J. M. Plavcan, M. G. Leakey, A. N. El-Barkooky, M. A. Hamdan, M. K. A. Gawad, S. M. Hassan, and E. L. Simons. 2009. \u201cSystematics of Early and Middle Miocene Old World Monkeys.\u201d <em>Journal of Human Evolution<\/em> 57 (3): 195\u2013211.<\/p>\n<p class=\"import-Normal\">Mocke, H., M. Pickford, B. Senut, and D. Gommery. 2022. \u201cNew Information about African Late Middle Miocene to Latest Miocene (13\u20135.5 Ma) Hominoidea. <em>Communications of the Geological Survey of Namibia<\/em> 24: 33\u201366.<\/p>\n<p class=\"import-Normal\">Moy\u00e0-Sol\u00e0, Salvadore, David M. Alba, Sergio Alm\u00e9cija, Isaac Casanovas-Vilar, Meike K\u00f6hler, Soledad De Esteban-Trivigno, Josep M. Robles, Jordi Galindo, and Josep Fortuny. 2009. \u201cA Unique Middle Miocene European Hominoid and the Origins of the Great Ape and Human Clade.\u201d <em>Proceedings of the National Academy of Sciences of the United States of America<\/em> 106 (24): 9601\u20139606.<\/p>\n<p class=\"import-Normal\">Moy\u00e0-Sol\u00e0, Salvador, Meike K\u00f6hler, David M. Alba, Isaac Casanovas-Vilar, and Jordi Galindo. 2004. \u201c<em>Pierolapithecus catalaunicus<\/em>, a New Middle Miocene Great Ape from Spain.\u201d <em>Science<\/em> 306 (5700): 1339\u20131344.<\/p>\n<p class=\"import-Normal\">Ni, Xijun, Daniel L. Gebo, Marian Dagosto, Jin Meng, Paul Tafforeau, John J. Flynn, and K. Christopher Beard. 2013. \u201cThe Oldest Known Primate Skeleton and Early Haplorhine Evolution.\u201d <em>Nature<\/em> 498 (7452): 60\u201364.<\/p>\n<p class=\"import-Normal\">Perry, Jonathan M. G., Richard F. Kay, Sergio F. Vizca\u00edno, and M. Susana Bargo. 2010. \u201cTooth Root Size, Chewing Muscle Leverage, and the Biology of <em>Homunculus patagonicus<\/em> (Primates) from the Late Early Miocene of Patagonia.\u201d <em>Ameghiniana<\/em> 47 (3): 355\u2013371.<\/p>\n<p class=\"import-Normal\">Perry, Jonathan M. G., Richard F. Kay, Sergio F. Vizca\u00edno, and M. Susana Bargo. 2014. \u201cOldest Known Cranium of a Juvenile New World Monkey (Early Miocene, Patagonia, Argentina): Implications for the Taxonomy and the Molar Eruption Pattern of Early Platyrrhines.\u201d <em>Journal of Human Evolution<\/em> 74: 67\u201381.<\/p>\n<p class=\"import-Normal\">Pickford, Martin, Yves Coppens, Brigitte Senut, Jorge Morales, and Jos\u00e9 Braga. 2009. \u201cLate Miocene Hominoid from Niger.\u201d <em>Comptes Rendus Palevol<\/em> 8 (4): 413\u2013425.<\/p>\n<p class=\"import-Normal\">Pilbeam, David. 1982. \u201cNew Hominoid Skull Material from the Miocene of Pakistan.\u201d <em>Nature<\/em> 295 (5846): 232\u2013234.<\/p>\n<p class=\"import-Normal\">Pilbeam, David, Michael D. Rose, John C. Barry, and S. M. Ibrahim Shah. 1990. \u201cNew <em>Sivapithecus<\/em> Humeri from Pakistan and the Relationship of <em>Sivapithecus<\/em> and <em>Pongo<\/em>.\u201d <em>Nature<\/em> 348 (6298): 237\u2013239.<\/p>\n<p class=\"import-Normal\">Rasmussen, D. Tab. 1990. \u201cPrimate Origins: Lessons from a Neotropical Marsupial.\u201d <em>American Journal of Primatology<\/em> 22 (4): 263\u2013277.<\/p>\n<p class=\"import-Normal\">Ravosa, Matthew J. 1996. \u201cMandibular Form and Function in North American and European Adapidae and Omomyidae.\u201d <em>Journal of Morphology<\/em> 229 (2): 171\u2013190.<\/p>\n<p class=\"import-Normal\">R\u00f6gl, Fred. 1999. \u201cMediterranean and Paratethys Palaeogeography during the Oligocene and Miocene.\u201d In <em>Hominoid Evolution and Climatic Change in Europe<\/em>, edited by Jorge Agust\u00ed, Lorenzo Rook, and Peter Andrews, 8\u201322. Cambridge: Cambridge University Press.<\/p>\n<p class=\"import-Normal\">Rosas, A., A. Garc\u00eda-Tabernero, D. Fidalgo, M. Fero Me\u00f1e, C. Ebana Ebana, F. Esono Mba, and P. Saladie. 2022. \u201cThe Scarcity of Fossils in the African Rainforest: Archaeo-Paleontological Surveys and Actualistic Taphonomy in Equatorial Guinea.\u201d <em>Historical Biology<\/em> 34 (8): 1\u20139.<\/p>\n<p class=\"import-Normal\">Rose, Kenneth D., and Thomas M. Bown. 1984. \u201cGradual Phyletic Evolution at the Generic Level in Early Eocene Omomyoid Primates.\u201d <em>Nature<\/em> 309 (5965): 250\u2013252.<\/p>\n<p class=\"import-Normal\">Rose, Kenneth D., Rachel H. Dunn, Kishor Kumar, Jonathan M. G. Perry, Kristen A. Prufrock, Rajendra S. Rana, and Thierry Smith. 2018. \u201cNew Fossils from Tadkeshwar Mine (Gujarat, India) Increase Primate Diversity from the Early Eocene Cambay Shale.\u201d <em>Journal of Human Evolution<\/em> 122: 93\u2013107.<\/p>\n<p class=\"import-Normal\">Rose, Kenneth D., and John M. Rensberger. 1983. \u201cUpper Dentition of <em>Ekgmowechashala<\/em> (Omomyoid Primate) from the John Day Formation, Oligo-Miocene of Oregon.\u201d <em>Folia Primatologica<\/em> 41(1-2): 102\u2013111.<\/p>\n<p class=\"import-Normal\">Rosenberger, Alfred L. 2010. \u201cPlatyrrhines, PAUP, Parallelism, and the Long Lineage Hypothesis: A Reply to Kay <em>et al. <\/em>(2008).\u201d <em>Journal of Human Evolution<\/em> 59 (2): 214\u2013217.<\/p>\n<p class=\"import-Normal\">Ross, Callum F. 2000. \u201cInto the Light: The Origins of Anthropoidea.\u201d <em>Annual Review of Anthropology<\/em> 29: 147\u2013194.<\/p>\n<p class=\"import-Normal\">Ross, Callum F., and Richard F. Kay, eds. 2004. <em>Anthropoid Origins: New Visions<\/em>. New York: Kluwer Academic\/Plenum Publishers.<\/p>\n<p class=\"import-Normal\">Russo, Gabrielle A. 2016. \u201cComparative Sacral Morphology and the Reconstructed Tail Lengths of Five Extinct Primates: <em>Proconsul heseloni<\/em>, <em>Epipliopithecus vindobonensis<\/em>, <em>Archaeolemur edwardsi<\/em>, <em>Megaladapis grandidieri<\/em>, and <em>Palaeopropithecus kelyus<\/em>.\u201d <em>Journal of Human Evolution<\/em> 90: 135\u2013162.<\/p>\n<p class=\"import-Normal\">Schmid, Peter. 1979. \u201cEvidence of Microchoerine Evolution from Dielsdorf (Z\u00fcrich Region, Switzerland): A Preliminary Report.\u201d <em>Folia Primatologica<\/em> 31 (4): 301\u2013311.<\/p>\n<p class=\"import-Normal\">Seiffert, Erik R. 2012. \u201cEarly Primate Evolution in Afro-Arabia.\u201d <em>Evolutionary Anthropology: Issues, News, and Reviews<\/em> 21 (6): 239\u2013253.<\/p>\n<p class=\"import-Normal\">Seiffert, Erik R., Jonathan M. G. Perry, Elwyn L. Simons, and Doug M. Boyer. 2009. \u201cConvergent Evolution of Anthropoid-like Adaptations in Eocene Adapiform Primates.\u201d <em>Nature<\/em> 461 (7267): 1118\u20131121.<\/p>\n<p class=\"import-Normal\">Seiffert, Erik R., Elwyn L. Simons, and Yousry Attia. 2003. \u201cFossil Evidence for an Ancient Divergence of Lorises and Galagos.\u201d <em>Nature<\/em> 422 (6930): 421\u2013424.<\/p>\n<p class=\"import-Normal\">Seiffert, Erik R., Elwyn L. Simons, Doug M. Boyer, Jonathan M. G. Perry, Timothy M. Ryan, and Hesham M. Sallam. 2010. \u201cA Fossil Primate of Uncertain Affinities from the Earliest Late Eocene of Egypt.\u201d <em>Proceedings of the National Academy of Sciences of the United States of America<\/em> 107 (21): 9712\u20139717.<\/p>\n<p class=\"import-Normal\">Seiffert, Erik R., Elwyn L. Simons, and Cornelia V. M. Simons. 2004. \u201cPhylogenetic, Biogeographic, and Adaptive Implications of New Fossil Evidence Bearing on Crown Anthropoid Origins and Early Stem Catarrhine Evolution.\u201d In <em>Anthropoid Origins: New Visions<\/em>, edited by Callum F. Ross and Richard F. Kay, 157\u2013182. New York: Kluwer\/Plenum Publishing.<\/p>\n<p class=\"import-Normal\">Simons, Elwyn L. 1961. \u201cThe Phyletic Position of <em>Ramapithecus<\/em>.\u201d <em>Postilla<\/em> 57: 1\u20139.<\/p>\n<p class=\"import-Normal\">Simons, Elwyn L. 2001. \u201cThe Cranium of <em>Parapithecus grangeri<\/em>, an Egyptian Oligocene Anthropoidean Primate.\u201d <em>Proceedings of the National Academy of Sciences of the United States of America<\/em> 98 (4): 7892\u20137897.<\/p>\n<p class=\"import-Normal\">Simons, Elwyn L. 2004. \u201cThe Cranium and Adaptations of <em>Parapithecus grangeri<\/em>, a Stem Anthropoid From the Fayum Oligocene of Egypt.\u201d In <em>Anthropoid Origins: New Visions<\/em>, edited by Callum F. Ross and Richard F. Kay, 183\u2013204. New York: Kluwer\/Plenum Publishing.<\/p>\n<p class=\"import-Normal\">Simons, Elwyn L. 2008. \u201cEocene and Oligocene Mammals of the Fayum, Egypt.\u201d In <em>Elwyn Simons: A Search for Origins<\/em>, edited by John G. Fleagle and Christopher C. Gilbert, 87\u2013105. New York: Springer.<\/p>\n<p class=\"import-Normal\">Simons, Elwyn L., and D. Tab Rasmussen. 1994a. \u201cA Remarkable Cranium of <em>Plesiopithecus teras<\/em> (Primates, Prosimii) from the Eocene of Egypt.\u201d <em>Proceedings of the National Academy of Sciences<\/em> <em>of the United States of America<\/em> 91(21): 9946\u20139950.<\/p>\n<p class=\"import-Normal\">Simons, Elwyn L., and D. Tab Rasmussen. 1994b. \u201cA Whole New World of Ancestors: Eocene Anthropoideans from Africa.\u201d <em>Evolutionary Anthropology<\/em> 3 (4): 128\u2013139.<\/p>\n<p class=\"import-Normal\">Simons, Elwyn L., and D. Tab Rasmussen. 1996. \u201cSkull of <em>Catopithecus browni<\/em>, an Early Tertiary Catarrhine.\u201d <em>American Journal of Physical Anthropology<\/em> 100 (2): 261\u2013292.<\/p>\n<p class=\"import-Normal\">Simons, Elwyn L., and Erik R. Seiffert. 1999. \u201cA Partial Skeleton of <em>Proteopithecus<\/em> <em>sylviae<\/em> (Primates Anthropoidea): First Associated Dental and Postcranial Remains of an Eocene Anthropoidean.\u201d <em>Comptes Rendus de l&#8217;Acad\u00e9mie des Sciences, Paris<\/em> 329 (12): 921\u2013927.<\/p>\n<p class=\"import-Normal\">Simons, Elwyn L., Erik R. Seiffert, Timothy M. Ryan, and Yousry Attia. 2007. \u201cA Remarkable Female Cranium of the Early Oligocene Anthropoid <em>Aegyptopithecus zeuxis<\/em> (Catarrhini, Propliopithecidae).\u201d <em>Proceedings of the National Academy of Sciences of the United States of America<\/em> 104 (21): 8731\u20138736.<\/p>\n<p class=\"import-Normal\">Simpson, George Gaylord. 1933. \u201cThe \u2018Plagiaulacoid\u2019 Type of Mammalian Dentition: A Study of Convergence.\u201d <em>Journal of Mammalogy<\/em> 14 (2): 97\u2013107.<\/p>\n<p class=\"import-Normal\">Simpson, George Gaylord. 1940. \u201cReview of the Mammal-Bearing Tertiary of South America.\u201d <em>Proceedings of the American Philosophical Society<\/em> 83 (5): 649\u2013709.<\/p>\n<p class=\"import-Normal\">Simpson, George Gaylord. 1967. \u201cThe Tertiary Lorisiform Primates of Africa.\u201d <em>Bulletin of the Museum of Comparative Zoology at Harvard University<\/em> 136: 39\u201362.<\/p>\n<p class=\"import-Normal\">Smith, G. Elliot. 1912. \u201cThe Evolution of Man.\u201d <em>Smithsonian Institute Annual Report <\/em>2012: 553\u2013572.<\/p>\n<p class=\"import-Normal\">Smith, Thierry, Kenneth D. Rose, and Philip D. Gingerich. 2006. \u201cRapid Asia\u2013Europe\u2013North America Geographic Dispersal of Earliest Eocene Primate <em>Teilhardina<\/em> during the Paleocene\u2013Eocene Thermal Maximum.\u201d <em>Proceedings of the National Academy of Sciences of the United States of America<\/em> 103 (30): 11223\u201311227.<\/p>\n<p class=\"import-Normal\">Stehlin, Hans G. 1912. \u201cDie s\u00e4ugetiere des schweizerischen Eocaens. Siebenter teil, erst h\u00e4lfte: <em>Adapis<\/em>\u201d [\u201cThe Mammals of the Swiss Eocene. Part Seven, First Half: Adapis\u201d]. <em>Abhandlungen der Schweizerischen Pal\u00e4ontologischen Gesellschaft<\/em> 38: 1165\u20131298.<\/p>\n<p class=\"import-Normal\">Strait, Suzanne G. 2001. \u201cDietary Reconstruction of Small-Bodied Omomyoid Primates.\u201d <em>Journal of Vertebrate Paleontology<\/em> 21 (2): 322\u2013334.<\/p>\n<p class=\"import-Normal\">Sussman, Robert W. 1991. \u201cPrimate Origins and the Evolution of Angiosperms.\u201d <em>American Journal of Primatology<\/em> 23 (4): 209\u2013223.<\/p>\n<p class=\"import-Normal\">Suwa, Gen, Reiko T. Kono, Shigehiro Katoh, Berhane Asfaw, and Yonas Beyene. 2007. \u201cA New Species of Great Ape from the Late Miocene Epoch in Ethiopia.\u201d <em>Nature<\/em> 448 (7156): 921\u2013924.<\/p>\n<p class=\"import-Normal\">Teaford, Mark F., Mary C. Maas, and Elwyn L. Simons. 1996. \u201cDental Microwear and Microstructure in Early Oligocene Primates from the Fayum, Egypt: Implications for Diet.\u201d <em>American Journal of Physical Anthropology<\/em> 101 (4): 527\u2013543.<\/p>\n<p class=\"import-Normal\">Ungar, Peter S., and Richard F. Kay. 1995. \u201cThe Dietary Adaptations of European Miocene Catarrhines.\u201d <em>Proceedings of the National Academy of Sciences of the United States of America<\/em> 92 (12): 5479\u20135481.<\/p>\n<p class=\"import-Normal\">Wang, Cui-Bin, Ling-Xia Zhao, Chang-Zhu Jin, Yuan Wang, Da-Gong Qin, and Wen-Shi Pan. 2014. \u201cNew Discovery of Early Pleistocene Orangutan Fossils from Sanhe Cave in Chongzuo, Guangxi, Southern China.\u201d <em>Quaternary International<\/em> 354: 68\u201374.<\/p>\n<p class=\"import-Normal\">Ward, C. V., A. Walker, and M. F. Teaford. 1991. \u201c<em>Proconsul<\/em> Did Not Have a Tail.\u201d <em>Journal of Human Evolution<\/em> 21 (3): 215\u2013220.<\/p>\n<p class=\"import-Normal\">Wheeler, Brandon C. 2010. \u201cCommunity Ecology of the Middle Miocene Primates of La Venta, Colombia: The Relationship between Ecological Diversity, Divergence Time, and Phylogenetic Richness.\u201d <em>Primates<\/em> 51 (2): 131\u2013138.<\/p>\n<p class=\"import-Normal\">Williams, Blythe A., and Richard F. Kay. 1995. \u201cThe Taxon Anthropoidea and the Crown Clade Concept.\u201d <em>Evolutionary Anthropology<\/em> 3 (6): 188\u2013190.<\/p>\n<p class=\"import-Normal\">Williams, Blythe A., Richard F. Kay, and E. Christopher Kirk. 2010a. \u201cNew Perspectives on Anthropoid Origins.\u201d <em>Proceedings of the National Academy<\/em> <em>of the United States of America<\/em> 107 (11): 4797\u20134804.<\/p>\n<p class=\"import-Normal\">Williams, Blythe A., Richard F. Kay, E. Christopher Kirk, and Callum F. Ross. 2010b. \u201c<em>Darwinius masillae<\/em> Is a European Middle Eocene Stem Strepsirrhine\u2014A Reply to Franzen et al.\u201d <em>Journal of Human Evolution<\/em> 59(5): 567\u2013573.<\/p>\n<p class=\"import-Normal\">Wilson Mantilla, G. P., S. G. B. Chester, W. A. Clemens, J. R. Moore, C. J. Sprain, B. T. Hovatter, W. S. Mitchell, W. W. Mans, R. Mundil, and P. R. Renne. 2021. \u201cEarliest Palaeocene Purgatoriids and the Initial Radiation of Stem Primates.\u201d <em>Royal Society Open Science<\/em> 8(2):210050. doi:10.1098\/rsos.210050.<\/p>\n<h2 class=\"import-Normal\">Acknowledgments<\/h2>\n<p class=\"import-Normal\">We are immensely grateful to the editors of this book, Drs. Beth Shook, Lara Braff, Katie Nelson, and Kelsie Aguilera, for their time and commitment to making this knowledge freely accessible to all, and for giving us the opportunity to participate in this important project.<\/p>\n<\/div>\n<div class=\"glossary\"><span class=\"screen-reader-text\" id=\"definition\">definition<\/span><template id=\"term_281_1683\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_281_1683\"><div tabindex=\"-1\"><div>\n<p>\u00a0As you may have noticed, the textbook for this course is an Open Educational Resource (OER). This means you have free and unrestricted access to all the material, with no need to purchase a costly textbook. As students in the <em>Culture and Biology<\/em> course, you will be assigned to critically analyze sections of the textbook. You will also be encouraged to bring your own research into the discussion, enriching the learning experience for yourself and others. Your active engagement with the textbook is not just for your benefit; it could lead to content that may be included in future editions of the textbook. This is a unique opportunity to collaborate with your peers and contribute to an academic project that will be more relevant to students in Quebec, Canada, and beyond.<\/p>\n<\/div>\n<p>As you read through each chapter, you'll notice highlighted sections. These highlights represent a colour-coded system of recommended edits from the previous semester. These edits are designed to improve the textbook's clarity, relevance, and educational value. Our focus was on five key factors:<\/p>\n<p><span style=\"background-color: #ccffcc\">Condense\/re-phrase<\/span> : Recommended by the professor, this factor addresses the issue of redundancy and overly lengthy text. We aimed to simplify the chapters by condensing and rephrasing content.<\/p>\n<p><span style=\"background-color: #ff99cc\">Eliminate<\/span> : Suggested to remove irrelevant or unnecessary information, this factor helps to focus the chapters on essential content.<\/p>\n<p><span style=\"background-color: #ff9900\">Refer to other chapters<\/span>: Due to frequent repetition across chapters, we decided that referring to other chapters that had already covered certain information would reduce length and redundancy.<\/p>\n<p><span style=\"background-color: #00ffff\">Replace with information from Canada\/Quebec<\/span>: One of the project's main objectives was to include content more relevant to students in Quebec and Canada. We identified sections where information could be replaced with content specific to these regions.<\/p>\n<p><span style=\"background-color: #ffff00\">Assumptions<\/span>: This factor was suggested to address the presentation of theories as established facts by the authors of the chapters. As students, it is crucial for us to understand that theories are a set of ideas used to explain facts, but they are not the sole explanations and should not be presented with absolute certainty. Presenting theories as facts can hinder our comprehensive understanding of the past, which requires considering multiple perspectives.<\/p>\n<p>These edits were made during the initial stages of the project, marking the first steps in what will become a series of outstanding contributions by students. The color-coding system you see is not a permanent structure; it serves as a draft to guide and inspire further enhancements and revisions. This is an evolving project, and your input is essential in shaping it into a resource that truly reflects the needs and perspectives of its readers. We strongly encourage you to engage deeply with the textbook, offering your valuable analysis and ideas. Your contributions have the potential to enrich the content, making it more relevant and impactful for current and future students.<\/p>\n<p>You may notice some sections where only the paragraph title is highlighted. This indicates that the following content would be highlighted in the same color, but we opted not to, in order to avoid overwhelming the textbook with too many colors.\u00a0You may also come across sentences that are both in parentheses and underlined (<span style=\"text-decoration: underline\">example<\/span>). These are personal suggestions open to interpretation. Like the color-coded edits, these sentences are not final; they are included to encourage further engagement with the textbook. We invite you to reflect on these suggestions and consider how they might be expanded, revised, or even reimagined.<\/p>\n<p>This textbook is a living document, continually shaped by those who engage with it. Your insights and analyses are crucial in making it more relevant and impactful.\u00a0By challenging assumptions and sharing your unique perspectives, you enhance not only your own learning but also the future of this textbook. 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tabindex=\"-1\"><div class=\"__UNKNOWN__\">\n<p class=\"import-Normal\"><span style=\"color: #000000;\">Bonnie Yoshida-Levine Ph.D., Grossmont College<\/span><\/p>\n<p class=\"import-Normal\"><span style=\"color: #000000;\"><em>This chapter is a revision from <\/em><em>\"<\/em><a class=\"rId7\" style=\"color: #000000;\" href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/chapter\/__unknown__-15\/\"><em>Chapter 10: Early Members of the Genus Homo<\/em><\/a><em>\" by Bonnie Yoshida-Levine. In <\/em><a class=\"rId8\" style=\"color: #000000;\" href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/\"><em>Explorations: An Open Invitation to Biological Anthropology, first edition<\/em><\/a><em>, edited by Beth Shook, Katie Nelson, Kelsie Aguilera, and Lara Braff, which is licensed under <\/em><a class=\"rId9\" style=\"color: #000000;\" href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\"><em>CC BY-NC 4.0<\/em><\/a><em>.<\/em><\/span><\/p>\n<div class=\"textbox textbox--learning-objectives\">\n<header class=\"textbox__header\">\n<h2 class=\"textbox__title\"><span style=\"color: #ffffff;\">Learning Objectives<\/span><\/h2>\n<\/header>\n<div class=\"textbox__content\">\n<ul>\n<li>Describe how early Pleistocene climate change influenced the evolution of the genus Homo.<\/li>\n<li>Identify the characteristics that define the genus Homo.<\/li>\n<li>Describe the skeletal anatomy of Homo habilis\u00a0and Homo erectus based on the fossil evidence.<\/li>\n<li>Assess opposing points of view about how early Homo should be classified.<\/li>\n<\/ul>\n<\/div>\n<\/div>\n<p><span style=\"color: #000000;\">The boy was no older than nine years when he perished by the swampy shores of the lake. After death, his slender, long-limbed body sank into the mud of the lake shallows. His bones fossilized and lay undisturbed for 1.5 million years. In the 1980s, fossil hunter Kamoya Kimeu, working on the western shore of Lake Turkana, Kenya, glimpsed a dark-colored piece of bone eroding in a hillside. This small skull fragment led to the discovery of what is arguably the world\u2019s most complete early hominin fossil\u2014a youth identified as a member of the species <em>Homo erectus<\/em>. Now known as Nariokotome Boy, after the nearby lake village, the skeleton has provided a wealth of information about the early evolution of our own genus, <em>Homo <\/em>(see Figure 10.1). Today, a stone monument with an inscription in three languages\u2014English, Swahili, and the local Turkana language\u2014marks the site of this momentous fossil discovery.<\/span><\/p>\n<p>&nbsp;<\/p>\n<p><img class=\"aligncenter\" src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/06\/image8-1.jpg\" alt=\"Front view of near-complete skeleton\" width=\"407\" height=\"407\" \/><\/p>\n<figure style=\"width: 405px\" class=\"wp-caption aligncenter\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image13-1.jpg\" alt=\"Reconstructed head and shoulders of a young Homo erectus.\" width=\"405\" height=\"308\" \/><figcaption class=\"wp-caption-text\">Figure 10.1a-b: a. Skeleton of a young male Homo erectus known as \u201cNariokotome Boy\u201d; b. an artist\u2019s depiction of how he may have looked during his life. This is the most complete hominin fossil from this time period ever found. Credit: a.<a href=\"https:\/\/humanorigins.si.edu\/evidence\/human-fossils\/fossils\/knm-wt-15000\"> KNM-WT 15000 Turkana Boy Skeleton<\/a> by<a href=\"https:\/\/www.si.edu\/\"> Smithsonian<\/a> [exhibit:<a href=\"https:\/\/humanorigins.si.edu\/research\"> Human Evolution<\/a> Evidence, Human Fossils, Fossils, KNM-WT 15000] is<a href=\"https:\/\/www.si.edu\/termsofuse\/\"> copyrighted and used for educational and non-commercial purposes as outlined by the Smithsonian<\/a>. b. <a href=\"https:\/\/commons.wikimedia.org\/wiki\/File:Homo-erectus_Turkana-Boy_%28Ausschnitt%29_Fundort_Nariokotome,_Kenia,_Rekonstruktion_im_Neanderthal_Museum.jpg\">Homo-erectus Turkana-Boy (Ausschnitt) Fundort Nariokotome, Kenia, Rekonstruktion im Neanderthal Museum<\/a> by Neanderthal Museum is under a <a href=\"https:\/\/creativecommons.org\/licenses\/by-sa\/4.0\/deed.en\">CC BY-SA 4.0 License<\/a>.<\/figcaption><\/figure>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\"><span style=\"color: #000000;\">Chapter 9 described our oldest human ancestors, primarily members of the genus <em>Australopithecus<\/em>, who lived between 2 million and 4 million years ago. This chapter introduces the earliest members of the genus <em>Homo<\/em>, focusing on <em>Homo habilis<\/em> and <em>Homo erectus<\/em>.<\/span><\/p>\n<h2 class=\"import-Normal\"><span style=\"color: #000000;\">Defining the Genus <em>Homo<\/em><\/span><\/h2>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\"><span style=\"color: #000000;\">Because Anthropology is fundamentally concerned with what makes us human, defining our own genus takes on special significance for anthropologists. Ever since scientists acknowledged the existence of extinct species of humans, they have debated which of them display sufficient \u201chumanness\u201d to merit classification in the genus <em>Homo<\/em>. When grouping species into a common genus, biologists consider criteria such as physical characteristics (morphology), evidence of recent common ancestry, and adaptive strategy (use of the environment). However, there is disagreement about which of those criteria should be prioritized, as well as how specific fossils should be interpreted in light of the criteria.<\/span><\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\"><span style=\"color: #000000;\">Nevertheless, there is general agreement that species classified as <em>Homo<\/em> should share characteristics that are broadly similar within our species. These include the following:<\/span><\/p>\n<ul>\n<li class=\"import-Normal\" style=\"background-color: transparent; text-align: left; text-indent: 18pt;\"><span style=\"color: #000000;\">a relatively large brain size, <del>indicating a high degree of intelligence;<\/del><\/span><\/li>\n<li class=\"import-Normal\" style=\"background-color: transparent; text-align: left; text-indent: 18pt;\"><span style=\"color: #000000;\">a smaller and flatter face<\/span><\/li>\n<li class=\"import-Normal\" style=\"background-color: transparent; text-align: left; text-indent: 18pt;\"><span style=\"color: #000000;\">smaller jaws and teeth<\/span><\/li>\n<li class=\"import-Normal\" style=\"background-color: transparent; text-align: left; text-indent: 18pt;\"><span style=\"color: #000000;\">increased reliance on culture, particularly the use of stone tools, to exploit a greater diversity of environments (adaptive zone).<\/span><\/li>\n<\/ul>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\"><span style=\"color: #000000;\">Some researchers would include larger overall body size and limb proportions (longer legs\/shorter arms) in this list. While these criteria seem relatively clear-cut, evaluating them in the fossil record has proved more difficult, particularly for the earliest members of the genus. There are several reasons for this. First, many fossil specimens dating to this time period are incomplete and poorly preserved. Second, early <em>Homo<\/em> fossils appear quite variable in brain size, facial features, and teeth and body size, and there is not yet consensus about how to best make sense of this diversity. Finally, there is growing evidence that the evolution of the genus <em>Homo<\/em> proceeded in a mosaic pattern: in other words, these characteristics did not appear all at once in a single species; rather, they were patchily distributed in different species from different regions and time periods. Consequently, different researchers have come up with conflicting classification schemes depending on which criteria they think are most important.<\/span><\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\"><span style=\"color: #000000; background-color: #ff99cc;\">In this chapter, we will take several pathways toward examining the origin and evolution of the genus <em>Homo<\/em>. First, we will explore the environmental conditions of the Pleistocene epoch in which the genus <em>Homo<\/em> evolved. Next we will examine the fossil evidence for the two principal species traditionally identified as early Homo: <em>Homo habilis<\/em> and <em>Homo erectus<\/em>. Then we will use data from fossils and archaeological sites to reconstruct the behavior of early members of <em>Homo<\/em>, including tool manufacture, subsistence practices, migratory patterns, and social structure. Finally, we will consider these together in an attempt to characterize the key adaptive strategies of early <em>Homo<\/em> and how they put our early ancestors on the trajectory that led to our own species, <em>Homo sapiens<\/em>.<\/span><\/p>\n<h2 class=\"import-Normal\"><span style=\"color: #000000;\">Climate Change and Human Evolution<\/span><\/h2>\n<p class=\"import-Normal\"><span style=\"color: #000000;\">A key goal in the study of human origins is to learn about the environmental pressures that may have shaped human evolution. As indicated in Chapter 7, scientists use a variety of techniques to reconstruct ancient environments. These include stable isotopes, core samples from oceans and lakes, windblown dust, analysis of geological formations and volcanoes, and fossils of ancient plant and animal communities. Such studies have provided valuable information about the environmental context of early <em>Homo<\/em>.<\/span><\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\"><span style=\"color: #000000;\">The early hominin species covered in Chapter 9, such as <em>Ardipithecus ramidus<\/em> and <em>Australopithecus afarensis<\/em>, evolved during the late <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_1404\">Pliocene<\/a><\/strong> epoch. The Pliocene (5.3 million to 2.6 million years ago) was marked by cooler and drier conditions, with ice caps forming permanently at the poles. Still, Earth\u2019s climate during the Pliocene was considerably warmer and wetter than at present.<\/span><\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\"><span style=\"color: #000000;\">The subsequent <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_1549\">Pleistocene<\/a> <\/strong>epoch (2.6 million years to 11,000 years ago) ushered in major environmental change. The Pleistocene is popularly referred to as the Ice Age. Since the term \u201cIce Age\u201d tends to conjure up images of glaciers and woolly mammoths, one would naturally assume that this was a period of uniformly cold climate around the globe. But this is not actually the case. Instead, climate became much more variable, cycling abruptly between warm\/wet (interglacial) and cold\/dry (glacial) cycles. These patterns were influenced by changes in Earth\u2019s elliptical orbit around the sun. As is shown in Figure 10.2, each cycle averaged about 41,000 years during the early Pleistocene; the cycles then lengthened to about 100,000 years starting around 1.25 million years ago. Since mountain ranges, wind patterns, ocean currents, and volcanic activity can all influence climate patterns, there were wide-ranging regional and local effects.<\/span><\/p>\n<figure style=\"width: 655px\" class=\"wp-caption aligncenter\"><img class=\"\" src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image7-3.png\" alt=\"Graph depicts five million years of climate change from sediment cores.\" width=\"655\" height=\"197\" \/><figcaption class=\"wp-caption-text\">Figure 10.2: Temperature estimates during the last five million years, extrapolated from deep-sea core data. Lower temperatures and increased temperature oscillations start at 2.6 million years ago. Glacial\/interglacial cycles during the early part of the epoch are shorter, each averaging about 41,000 years. Credit: <a href=\"https:\/\/commons.wikimedia.org\/wiki\/File:Five_Myr_Climate_Change.png\">Five Myr Climate Change<\/a> by<a href=\"https:\/\/commons.wikimedia.org\/wiki\/User:Dragons_flight\"> Dragons flight<\/a> (Robert A. Rohde), based on data from Lisiechi and Raymo (2005), is under a<a href=\"https:\/\/creativecommons.org\/licenses\/by-sa\/3.0\/legalcode\"> CC BY-SA 3.0 License.<\/a><\/figcaption><\/figure>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\"><span style=\"color: #000000;\">Data on ancient geography and climate help us understand how our ancestors moved and migrated to different parts of the world\u2014as well as the constraints under which they operated. When periods of global cooling dominated, sea levels were lower as more water was captured as glacial ice. This exposed continental margins and opened pathways between land masses. During glacial periods, the large Indonesian islands of Sumatra, Java, and Borneo were connected to the Southeast Asian mainland, while New Guinea was part of the southern landmass of greater Australia. There was a land bridge connection between Britain and continental Europe, and an icy, treeless plain known as Beringia connected Northern Asia and Alaska. At the same time, glaciation made some northern areas inaccessible to human habitation. For example, there is evidence that hominin species were in Britain 950,000 years ago, but it does not appear that Britain was continuously occupied during this period. <span style=\"text-decoration: underline;\">(It is speculated)<\/span> These early humans may have died out or been forced to abandon the region during glacial periods.<\/span><\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\"><span style=\"color: #000000;\">In Africa, paleoclimate research has determined that grasslands (shown in Figure 10.3) expanded and shrank multiple times during this period, even as they expanded over the long term (deMenocal 2014). From studies of fossils, paleontologists have been able to reconstruct Pleistocene animal communities and to consider how they were affected by the changing climate. Among the African animal populations, the number of grazing animal species such as antelope increased. Although the African and Eurasian continents are connected by land, the Sahara desert and the mountainous topography of North Africa serve as natural barriers to crossing. But the fossil record shows that at different times animal species have moved back and forth between Africa and Eurasia. During the early Pleistocene, there is evidence of African mammal species such as baboons, hippos, antelope, and African buffalo migrating out of Africa into Eurasia during periods of aridity (Belmaker 2010).<\/span><\/p>\n<p>&nbsp;<\/p>\n<figure style=\"width: 583px\" class=\"wp-caption aligncenter\"><img class=\"\" src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image3-2.jpg\" alt=\"Dry grassy field with a few trees and mountains in the far distance.\" width=\"583\" height=\"406\" \/><figcaption class=\"wp-caption-text\">Figure 10.3: A savanna grassland in East Africa. Habitats such as this were becoming increasingly common during the Pleistocene. Credit: <a href=\"https:\/\/www.flickr.com\/photos\/ilri\/5130992564\">Savanna grasslands of East Africa<\/a> by<a href=\"https:\/\/www.flickr.com\/photos\/ilri\/\"> International Livestock Research Institute (ILRI)\/Elsworth<\/a> is under a<a href=\"https:\/\/creativecommons.org\/licenses\/by-nc-sa\/2.0\/\"> CC BY-NC-SA 2.0 License<\/a>.<\/figcaption><\/figure>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\"><span style=\"color: #000000;\">This changing environment was <del>undoubtedly<\/del> challenging for our ancestors, but it offered new opportunities to make a living. <span style=\"background-color: #ffff00;\">One solution adopted by some hominins was to specialize in feeding on the new types of plants growing in this landscape. The robust australopithecines (described in Chapter 9) likely developed their large molar teeth with thick enamel in order to exploit this particular dietary niche.<\/span><\/span><\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\"><span style=\"color: #000000; background-color: #ffff00;\">Members of the genus <em>Homo <\/em>took a different route. Faced with the unstable African climate and shifting landscape, they evolved bigger brains that enabled them to rely on cultural solutions such as crafting stone tools that opened up new foraging opportunities. This strategy of behavioral flexibility served them well during this unpredictable time and led to new innovations such as increased meat-eating, cooperative hunting, and the exploitation of new environments outside Africa. <\/span><\/p>\n<h2 class=\"import-Normal\"><span style=\"color: #000000;\"><em>Homo habilis<\/em>: The Earliest Members of Our Genus<\/span><\/h2>\n<p class=\"import-Normal\"><span style=\"color: #000000;\"><em>Homo habilis<\/em> has traditionally been considered the earliest species placed in the genus <em>Homo<\/em>. However, as we will see, there is substantial disagreement among paleoanthropologists about the fossils classified as <em>Homo habilis<\/em>, including whether they come from a single species or multiple, or even whether they should be part of the genus <em>Homo <\/em>at all.<\/span><\/p>\n<p class=\"import-Normal\"><span style=\"color: #000000;\"><em>Homo habilis<\/em> has a somewhat larger brain size\u2014an average of 650 cubic centimeters (cc)\u2014compared to <em>Australopithecus<\/em> with less than 500 cc. Additionally, the skull is more rounded and the face less prognathic. However, the postcranial remains show a body size and proportions similar to <em>Australopithecus<\/em>.<\/span><\/p>\n<p class=\"import-Normal\"><span style=\"color: #000000;\">Known dates for fossils identified as <em>Homo habilis<\/em> range from about 2.5 million years ago to 1.7 million years ago. Recently, a partial lower jaw dated to 2.8 million years from the site of Ledi-Gararu in Ethiopia has been tentatively identified as belonging to the genus <em>Homo<\/em> (Villmoare et al. 2015). If this classification holds up, it would push the origins of our genus back even further.<\/span><\/p>\n<p>&nbsp;<\/p>\n<figure style=\"width: 554px\" class=\"wp-caption aligncenter\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image16.jpg\" alt=\"Africa map with South Africa, Tanzania, Kenya, and Ethiopia shaded.\" width=\"554\" height=\"717\" \/><figcaption class=\"wp-caption-text\">Figure 10.4: Map showing major sites where <em>Homo habilis<\/em> fossils have been found. Ledi-Geraru is located in Ethiopia, Koobi Fora and Lake Turkana Basin are located in Kenya, the Olduvai Gorge is located in Tanzania, and Tuang, Malapa, Rising Star and Sterkfontein are located in South Africa. Credit: <a href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/chapter\/__unknown__-15\/\">Homo habilis site map (Figure 10.4)<\/a> original to <a href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\">Explorations: An Open Invitation to Biological Anthropology<\/a> by Chelsea Barron at<a href=\"https:\/\/www.csuchico.edu\/geop\/geoplace\/index.shtml\"> GeoPlace, California State University, Chico<\/a> is under a<a href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/\"> CC BY-NC 4.0 License<\/a>.<\/figcaption><\/figure>\n<h3 class=\"import-Normal\"><span style=\"color: #000000;\"><strong><del>Discovery and Naming<\/del> <span style=\"text-decoration: underline;\">(just add paragraph not own section)<\/span><\/strong><\/span><\/h3>\n<p class=\"import-Normal\"><span style=\"color: #000000; background-color: #ccffcc;\">The first fossils to be named <em>Homo habilis<\/em> were discovered at the site of Olduvai Gorge in Tanzania, East Africa, by members of a team led by Louis and Mary Leakey (Figure 10.4). The Leakey family had been conducting fieldwork in the area since the 1930s and had discovered other hominin fossils at the site, such as the robust <em>Paranthropos boisei<\/em>. The key specimen, a juvenile individual, was actually found by their 20-year-old son Jonathan Leakey. Louis Leakey invited South African paleoanthropologist Philip Tobias and British anatomist John Napier to reconstruct and analyze the remains. The fossil of the juvenile shown in Figure 10.5 (now known as OH-7) consisted of a lower jaw, parts of the parietal bones of the skull, and some hand and finger bones. The fossil was dated by potassium-argon dating to about 1.75 million years. In 1964, the team published their findings in the scientific journal <em>Nature <\/em>(Leakey et al. 1964)<em>. <\/em>As described in the publication, the new fossils had smaller molar teeth that were less \u201cbulgy\u201d than australopithecine teeth. Although the primary specimen was not yet fully grown, an estimate of its anticipated adult brain size would make it somewhat larger-brained than australopithecines such as <em>Austalopithecus africanus<\/em>. The hand bones were capable of a precision grip like a human\u2019s hand. This increased the likelihood that stone tools found earlier at Olduvai Gorge were made by this group of hominins. Based on these findings, the authors inferred that it was a new species that should be classified in the genus <em>Homo<\/em>. They gave it the name <em>Homo habilis<\/em>, meaning \u201chandy\u201d or \u201cskilled.\u201d<\/span><\/p>\n<p>&nbsp;<\/p>\n<\/div>\n<figure id=\"attachment_317\" aria-describedby=\"caption-attachment-317\" style=\"width: 641px\" class=\"wp-caption aligncenter\"><img class=\"wp-image-317\" src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/10.5.jpg\" alt=\"Two lateral right views of skulls and a jaw with blackened teeth.\" width=\"641\" height=\"214\" \/><figcaption id=\"caption-attachment-317\" class=\"wp-caption-text\">Figure 10.5a-c: Homo habilis fossil specimens. From left to right they are: a. lateral right view of OH-24 (found at Olduvai Gorge), b. lateral right view of KNM-ER-1813 (from Koobi Fora, Kenya), and c. the jaw of OH-7, which was the type specimen found in 1960 at Olduvai Gorge, Tanzania. Credit: a. <a href=\"https:\/\/efossils.org\/page\/boneviewer\/Homo%20habilis\/OH%2024\">Homo habilis: OH 24 lateral right view<\/a> by \u00a9<a href=\"https:\/\/www.efossils.org\/\">eFossils<\/a> is under a <a href=\"https:\/\/creativecommons.org\/licenses\/by-nc-sa\/2.0\/\">CC BY-NC-SA 2.0 License<\/a> and is <a href=\"https:\/\/efossils.org\/page\/frequently-asked-questions\">used as outlined by eFossils<\/a>. b. <a href=\"https:\/\/www.efossils.org\/page\/boneviewer\/Homo%20habilis\/KNM-ER%201813\">Homo habilis: KNM-ER 1813 lateral right view<\/a> by \u00a9<a href=\"https:\/\/www.efossils.org\/\">eFossils<\/a> is under a <a href=\"https:\/\/creativecommons.org\/licenses\/by-nc-sa\/2.0\/\">CC BY-NC-SA 2.0 License<\/a> and is <a href=\"https:\/\/efossils.org\/page\/frequently-asked-questions\">used as outlined by eFossils<\/a>. c. <a href=\"https:\/\/boneclones.com\/product\/homo-habilis-oh-7-jaw-KO-196\">Homo habilis OH 7 Jaw<\/a> by<a href=\"https:\/\/boneclones.com\/\"> \u00a9BoneClones<\/a> is used by permission and available here under a<a href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/\"> CC BY-NC 4.0 License<\/a>.<\/figcaption><\/figure>\n<div class=\"__UNKNOWN__\">\n<h3 class=\"import-Normal\"><span style=\"color: #000000;\"><strong>Controversies over Classification of <\/strong><strong><em>Homo habilis<\/em><\/strong><em><br style=\"clear: both;\" \/><\/em><\/span><\/h3>\n<p class=\"import-Normal\"><span style=\"color: #000000;\">Since its initial discovery, many more Homo habilis were discovered in East and South African sites during the 1970s and 1980s (Figure 10.6). As more fossils joined the ranks of <em>Homo habilis<\/em>, several trends became apparent. First, the fossils were quite variable. While some resembled the fossil specimen first published by Leakey and colleagues, others had larger cranial capacity and tooth size. A well-preserved fossil skull from East Lake Turkana labeled KNM-ER-1470 displayed a larger cranial size along with a strikingly wide face. The diversity of the <em>Homo habilis<\/em> fossils prompted some scientists to question whether they displayed too much variation to all belong to the same species. They proposed splitting the fossils into at least two groups. The first group resembling the original small-brained specimen would retain the species name <em>Homo habilis<\/em>; the second group consisting of the larger-brained fossils such as KNM-ER-1470 would be assigned the new name of <em>Homo rudolfensis <\/em>(see Figure 10.7). Researchers who favored keeping all fossils in <em>Homo habilis<\/em> argued that sexual dimorphism, adaptation to local environments, or<strong> developmental plasticity<\/strong> could be the cause of the differences. For example, modern human body size and body proportions are influenced by variations in climates and nutritional circumstances.<\/span><\/p>\n<div style=\"text-align: left;\">\n<table class=\"aligncenter\" style=\"width: 467.5pt; height: 367px;\">\n<caption>Figure 10.6: Key Homo habilis fossil locations and the corresponding fossils and dates. Credit: <a href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/chapter\/__unknown__-15\/\">Homo habilis table (Figure 10.6)<\/a> original to <a href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/\">Explorations: An Open Invitation to Biological Anthropology<\/a> by Bonnie Yoshida-Levine is under a<a href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/\"> CC BY-NC 4.0 License<\/a>.<\/caption>\n<thead>\n<tr style=\"height: 0;\">\n<td class=\"Table1-C\" style=\"padding: 0pt 5.4pt; border: 0.5pt solid #000000; height: 60px; width: 130.2px;\">\n<p class=\"import-Normal\"><span style=\"color: #000000;\"><strong>Location of Fossils<\/strong><\/span><\/p>\n<\/td>\n<td class=\"Table1-C\" style=\"padding: 0pt 5.4pt; border: 0.5pt solid #000000; height: 60px; width: 52.7px;\">\n<p class=\"import-Normal\"><span style=\"color: #000000;\"><strong>Dates<\/strong><\/span><\/p>\n<\/td>\n<td class=\"Table1-C\" style=\"padding: 0pt 5.4pt; border: 0.5pt solid #000000; height: 60px; width: 320.9px;\">\n<p class=\"import-Normal\"><span style=\"color: #000000;\"><strong><br \/>\nDescription <\/strong><\/span><\/p>\n<p>&nbsp;<\/td>\n<\/tr>\n<\/thead>\n<tbody>\n<tr class=\"Table1-R\" style=\"height: 0;\">\n<td class=\"Table1-C\" style=\"padding: 0pt 5.4pt; border: 0.5pt solid #000000; height: 61px; width: 130.2px;\">\n<p class=\"import-Normal\"><span style=\"color: #000000;\">Ledi-Gararu, Ethiopia<\/span><\/p>\n<\/td>\n<td class=\"Table1-C\" style=\"padding: 0pt 5.4pt; border: 0.5pt solid #000000; height: 61px; width: 52.7px;\">\n<p class=\"import-Normal\"><span style=\"color: #000000;\">2.8 mya<\/span><\/p>\n<\/td>\n<td class=\"Table1-C\" style=\"padding: 0pt 5.4pt; border: 0.5pt solid #000000; height: 61px; width: 320.9px;\">\n<p class=\"import-Normal\"><span style=\"color: #000000;\">Partial lower jaw with evidence of both <em>Australopithecus<\/em> and <em>Homo<\/em> traits; tentatively considered oldest Early <em>Homo<\/em> fossil evidence.<\/span><\/p>\n<\/td>\n<\/tr>\n<tr class=\"Table1-R\" style=\"height: 0;\">\n<td class=\"Table1-C\" style=\"padding: 0pt 5.4pt; border: 0.5pt solid #000000; height: 77px; width: 130.2px;\">\n<p class=\"import-Normal\"><span style=\"color: #000000;\">Olduvai Gorge, Tanzania<\/span><\/p>\n<\/td>\n<td class=\"Table1-C\" style=\"padding: 0pt 5.4pt; border: 0.5pt solid #000000; height: 77px; width: 52.7px;\">\n<p class=\"import-Normal\"><span style=\"color: #000000;\">1.7 mya to 1.8 mya<\/span><\/p>\n<\/td>\n<td class=\"Table1-C\" style=\"padding: 0pt 5.4pt; border: 0.5pt solid #000000; height: 77px; width: 320.9px;\">\n<p class=\"import-Normal\"><span style=\"color: #000000;\">Several different specimens classified as Homo habilis, including the type specimen found by Leakey, a relatively complete foot, and a skull with a cranial capacity of about 600 cc.<\/span><\/p>\n<\/td>\n<\/tr>\n<tr class=\"Table1-R\" style=\"height: 0;\">\n<td class=\"Table1-C\" style=\"padding: 0pt 5.4pt; border: 0.5pt solid #000000; height: 93px; width: 130.2px;\">\n<p class=\"import-Normal\"><span style=\"color: #000000;\">Koobi Fora, Lake Turkana Basin, Kenya<\/span><\/p>\n<\/td>\n<td class=\"Table1-C\" style=\"padding: 0pt 5.4pt; border: 0.5pt solid #000000; height: 93px; width: 52.7px;\">\n<p class=\"import-Normal\"><span style=\"color: #000000;\">1.9 mya<\/span><\/p>\n<\/td>\n<td class=\"Table1-C\" style=\"padding: 0pt 5.4pt; border: 0.5pt solid #000000; height: 93px; width: 320.9px;\">\n<p class=\"import-Normal\"><span style=\"color: #000000;\">Several fossils from the Lake Turkana basin show considerable size differences, leading some anthropologists to classify the larger specimen (KNM-ER-1470) as a separate species,<em> Homo rudolfensis<\/em>.<\/span><\/p>\n<\/td>\n<\/tr>\n<tr class=\"Table1-R\" style=\"height: 0;\">\n<td class=\"Table1-C\" style=\"padding: 0pt 5.4pt; border: 0.5pt solid #000000; height: 61px; width: 130.2px;\">\n<p class=\"import-Normal\"><span style=\"color: #000000;\">Sterkfontein and other possible South African cave sites<\/span><\/p>\n<\/td>\n<td class=\"Table1-C\" style=\"padding: 0pt 5.4pt; border: 0.5pt solid #000000; height: 61px; width: 52.7px;\">\n<p class=\"import-Normal\"><span style=\"color: #000000;\">about 1.7 mya<\/span><\/p>\n<\/td>\n<td class=\"Table1-C\" style=\"padding: 0pt 5.4pt; border: 0.5pt solid #000000; height: 61px; width: 320.9px;\">\n<p class=\"import-Normal\"><span style=\"color: #000000;\">South African caves have yielded fragmentary remains identified as <em>Homo habilis<\/em>, but secure dates and specifics about the fossils are lacking.<\/span><\/p>\n<\/td>\n<\/tr>\n<tr style=\"height: 15px;\">\n<td style=\"height: 15px; width: 132.133px;\"><\/td>\n<td style=\"height: 15px; width: 54.6333px;\"><\/td>\n<td style=\"height: 15px; width: 322.333px;\"><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<figure style=\"width: 228px\" class=\"wp-caption alignleft\"><img class=\"\" src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image10-1.jpg\" alt=\"Front view of black and white skull, missing lower jawbone.\" width=\"228\" height=\"228\" \/><figcaption class=\"wp-caption-text\">Figure 10.7: Cast of the Homo habilis cranium KNM-ER-1470. This cranium has a wide, flat face, larger brain size, and larger teeth than other Homo habilis fossils, leading some scientists to give it a separate species name, Homo rudolfensis. Credit: <a href=\"https:\/\/boneclones.com\/product\/homo-rudolfensis-skull-knm-er-1470-BH-013\">Homo rudolfensis Cranium KNM-ER 1470<\/a> by<a href=\"https:\/\/boneclones.com\/\"> \u00a9BoneClones<\/a> is used by permission and available here under a<a href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/\"> CC BY-NC 4.0 License<\/a>.<\/figcaption><\/figure>\n<p class=\"import-Normal\"><span style=\"color: #000000;\">Given the incomplete and fragmentary fossil record from this time period, it is not surprising that classification has proved contentious. As a scholarly consensus has not yet emerged on the classification status of early <em>Homo<\/em>, this chapter makes use of the single (inclusive) <em>Homo habilis<\/em> species designation.<\/span><\/p>\n<p class=\"import-Normal\"><span style=\"color: #000000;\">There is also disagreement on whether <em>Homo habilis<\/em> legitimately belongs in the genus <em>Homo<\/em>. Most of the fossils first classified as <em>Homo habilis<\/em> were skulls and teeth. When arm, leg, and foot bones were later found, making it possible to estimate body size, the specimens turned out to be quite small in stature with long arms and short legs. Analysis of the relative strength of limb bones suggested that the species, though bipedal, was much more adapted to arboreal climbing than <em>Homo erectus<\/em> and <em>Homo sapiens <\/em>(Ruff 2009). This has prompted some scientists to assert that <em>Homo habilis<\/em> behaved more like an australopithecine\u2014with a shorter gait and the ability to move around in the trees (Wood and Collard 1999). They were also skeptical of the claim that the brain size of <em>Homo habilis<\/em> was much larger than that of <em>Australopithecus<\/em>. They have proposed reclassifying some or all of the <em>Homo habilis<\/em> fossils into the genus <em>Australopithecus<\/em>, or even placing them into a newly created genus (Wood 2014).<\/span><\/p>\n<p class=\"import-Normal\"><span style=\"color: #000000;\">Other scholars have interpreted the fossil evidence differently. A recent reanalysis of <em>Homo habilis\/rudolfensis<\/em> fossils concluded that they sort into the genus <em>Homo<\/em> rather than <em>Australopithecus <\/em>(see Hominin Species Summaries at chapter end). In particular, statistical analysis performed indicates that the <em>Homo habilis<\/em> fossils differ significantly in average cranial capacity from the australopithecines. They also note that some australopithecine species such as the recently discovered <em>Australopithecus sediba<\/em> have relatively long legs, so body size may not have been as significant as brain- and tooth-size differences (Anton et al. 2014).<\/span><\/p>\n<div class=\"textbox\">\n<h2 class=\"import-Normal\"><span style=\"color: #000000;\">Special Topic: Kamoya Kimeu<\/span><\/h2>\n<p class=\"import-Normal\"><span style=\"color: #000000;\">Kamoya Kimeu (1938\u20132022) is arguably the most prolific fossil hunter in the history of paleoanthropology (Figure 10.8). In addition to his many decades of work as a field excavator and project supervisor in East Africa, he also trained field workers and scholars and has served as curator for prehistoric sites for the National Museum of Kenya.<\/span><\/p>\n<figure style=\"width: 228px\" class=\"wp-caption alignleft\"><img class=\"\" src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image4-1.jpg\" alt=\"Man smiling at camera with lake and mountain in the background.\" width=\"228\" height=\"351\" \/><figcaption class=\"wp-caption-text\">Figure 10.8: Kamoya Kimeu (1938-2022). Credit: Photograph of Kamoya Kimeu by \u00a9Dr. Mark Teaford is used by permission.<\/figcaption><\/figure>\n<p><span style=\"color: #000000;\">Kamoya Kimeu was born in 1938 in rural southeastern Kenya. Despite a formal education that did not go past the sixth grade, he had an aptitude for languages and familiarity with the plants and animals in the East African bush that led him to a job in Tanzania as a field excavator for Louis and Mary Leakey in 1960. In the years that followed, Kimeu found dozens of major hominin fossils. These included a <em>Paranthropus boisei <\/em>mandible at Olduvai Gorge, <em>Homo habilis <\/em>specimen KNM-ER-1813 from the Turkana Basin (shown in Figure 10.5), and a key early modern<em> Homo sapiens<\/em> fossil from the Omo Valley, Ethiopia. Kimeu\u2019s most famous fossil discovery was the skeleton of a young <em>Homo erectus<\/em> by the Nariokotome river bed in 1984. This finding was highly significant because it was a nearly complete early hominin skeleton and provided insight into child development within this species. In recognition of his work, Kimeu was awarded the National Geographic Society La Gorce Medal by U.S. President Ronald Reagan in 1985.<\/span><\/p>\n<p class=\"import-Normal\"><span style=\"color: #000000;\">Traditionally, there has been a divide between African field workers and foreign research scientists, who would typically conduct seasonal field work in Africa, then travel back to their home institutions to publish their findings. Although Kimeu received widespread acclaim for the Nariokotome discovery, as well as a personal acknowledgement in the publication of the find in the journal <em>Nature<\/em>, he was not credited as an author. More recently, Kimeu\u2019s intellectual contributions to the field of paleoanthropology have been recognized. In 2021, he received an honorary doctorate degree from Case Western Reserve University in Ohio. Kimeu\u2019s most lasting legacy may be his mentorship of countless field workers and students. Today, there are a small but growing number of Black African paleoanthropologists taking on principal roles in the science of human origins.<\/span><\/p>\n<\/div>\n<h2 class=\"import-Normal\"><span style=\"color: #000000;\"><em>Homo habilis<\/em> Culture and Lifeways<br \/>\n<\/span><\/h2>\n<h3 class=\"import-Normal\"><span style=\"color: #000000;\"><strong>Early Stone Tools<\/strong><\/span><\/h3>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\"><span style=\"color: #000000;\"><span style=\"background-color: #ffff00;\">The larger brains and smaller teeth of early <em>Homo <\/em>are linked to a different adaptive strategy than that of earlier hominins: one dependent on modifying rocks to make stone tools and exploit new food sources.<\/span> As discussed in Chapter 9, the 3.3-million-year-old stone tools from the Lomekwi 3 site in Kenya were made by earlier hominin species than <em>Homo<\/em>. However, stone tools become more frequent at sites dating to about 2 million years ago, the time of <em>Homo habilis <\/em>(Roche et al. 2009). This suggests that these hominins were increasingly reliant on stone tools to make a living.<\/span><\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\"><span style=\"color: #000000;\">Stone tools are assigned a good deal of importance in the study of human origins. Examining the form of the tools, the raw materials selected, and how they were made and used can provide insight into the thought processes of early humans and how they modified their environment in order to survive. Paleoanthropologists have traditionally classified collections of stone tools into industries, based on their form and mode of manufacture. There is not an exact correspondence between a tool industry and a hominin species; however, some general associations can be made between tool industries and particular hominins, locations, and time periods.<\/span><\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\"><span style=\"color: #000000;\">The <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_1394\">Oldowan<\/a><\/strong> tool industry is named after the site of Olduvai Gorge in Tanzania where the tools were first discovered. The time period of the Oldowan is generally estimated to be 2.5 mya to 1.6 mya. The tools of this industry are described as \u201cflake and chopper\u201d tools\u2014the choppers consisting of stone cobbles with a few flakes struck off them (Figure 10.9). To a casual observer, these tools might not look much different from randomly broken rocks. However, they are harder to make than their crude appearance suggests. The rock selected as the core must be struck by the rock serving as a hammerstone at just the right angle so that one or more flat flakes are removed. This requires selecting rocks that will fracture predictably instead of chunking, as well as the ability to plan ahead and envision the steps needed to create the finished product. The process leaves both the core and the flakes with sharp cutting edges that can be used for a variety of purposes.<\/span><\/p>\n<figure style=\"width: 505px\" class=\"wp-caption aligncenter\"><img class=\"\" src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image11-1-1.png\" alt=\"Three stones with chunks missing from the tops and sides.\" width=\"505\" height=\"281\" \/><figcaption class=\"wp-caption-text\">Figure 10.9: Drawing of an Oldowan-style tool. This drawing shows a chopper; the flakes removed from the cores functioned as cutting tools. Credit: <a href=\"https:\/\/commons.wikimedia.org\/wiki\/File:Chopping_tool.gif\">Chopping tool<\/a> by Jos\u00e9-Manuel Benito \u00c1lvarez is under a <a href=\"https:\/\/creativecommons.org\/licenses\/by-sa\/2.5\/legalcode\">CC BY-SA 2.5 License<\/a>.<\/figcaption><\/figure>\n<h3 class=\"import-Normal\"><span style=\"color: #000000;\"><strong>Stone Tool Use and the Diet of Early <\/strong><strong><em>Homo<\/em><\/strong><\/span><\/h3>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\"><span style=\"color: #000000;\">What were the hominins doing with the tools? One key activity seems to have been butchering animals. Studies of animal bones at the site show cut marks on bones, and leg bones are often cracked open, suggesting that they were extracting the marrow from the bone cavities. It is interesting to consider whether the hominins hunted these animals or acquired them through other means. The butchered bones come from a variety of African mammals, ranging from small antelope to animals as big as wildebeest and elephants! It is difficult to envision slow, small-bodied <em>Homo habilis<\/em> with their Oldowan tools bringing down such large animals. One possibility is that the hominins were scavenging carcasses from lions and other large cats. Paleoanthropologist Robert Blumenschine has investigated this hypothesis by observing the behavior of present-day animal carnivores and scavengers on the African savanna. When lions abandon a kill after eating their fill, scavenging animals arrive almost immediately to pick apart the carcass. By the time slow-footed hominins arrived on the scene, the carcass would be mostly stripped of meat. However, if hominins could use stone tools to break into the leg bone cavities, they could get to the marrow, a fatty, calorie-dense source of protein (Blumenschine et al. 1987). Reconstructing activities that happened millions of years ago is obviously a difficult undertaking, and paleoanthropologists continue to debate whether scavenging or hunting was more commonly practiced during this time.<\/span><\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\"><span style=\"color: #000000;\">Regardless of how they were acquiring the meat, these activities suggest an important dietary shift from the way that the australopithecines were eating. The Oldowan toolmakers were exploiting a new ecological niche that provided them with more protein and calories. And it was not just limited to meat-eating\u2014stone tool use could have made available numerous other subsistence opportunities. A study of microscopic wear patterns on a sample of Oldowan tools indicates that they were used for processing plant materials such as wood, roots or tubers, and grass seeds and stems (Lemorini et al. 2014). In fact, it has been pointed out that the Oldowan toolmakers\u2019 cutting ability (whether for the purposes of consuming meat and plants or for making tools, shelters, or clothing) represents a new and unique innovation, never seen before in the natural world (Roche et al. 2009).<\/span><\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\"><span style=\"color: #000000; background-color: #ff99cc;\">Overall, increasing the use of stone tools allowed hominins to expand their ecological niche and exert more control over their environment. As we\u2019ll see shortly, this pattern continued and became more pronounced with <em>Homo erectus<\/em>.<\/span><\/p>\n<h2 class=\"import-Normal\"><span style=\"color: #000000;\"><em>Homo erectus<\/em>: Biological and Cultural Innovations<\/span><\/h2>\n<p class=\"import-Normal\"><span style=\"color: #000000;\">Two million years ago, a new hominin appeared on the scene. Known as <em>Homo erectus<\/em>, the prevailing scientific view was that this species was much more like us. These hominins were equipped with bigger brains and large bodies with limb proportions similar to our own. Perhaps most importantly, their way of life is now one that is recognizably human, with more advanced tools, hunting, use of fire, and colonizing new environments outside of Africa.<\/span><\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\"><span style=\"color: #000000;\">As will be apparent below, new data suggests that the story is not quite as simple. The fossil record for <em>Homo erectus<\/em> is much more abundant than that of <em>Homo habilis<\/em>, but it is also more complex and varied\u2014both with regard to the fossils as well as the geographic context in which they are found. <span style=\"background-color: #ff99cc;\">We will first summarize the anatomical characteristics that define <em>Homo erectus<\/em>, and then discuss the fossil evidence from Africa and the primary geographic regions outside Africa where the species has been located.<\/span><\/span><\/p>\n<h3 class=\"import-Normal\"><span style=\"color: #000000;\"><strong><em>Homo erectus<\/em><\/strong><strong> Anatomy<\/strong><\/span><\/h3>\n<figure style=\"width: 289px\" class=\"wp-caption alignright\"><img class=\"\" src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image6-2.png\" alt=\"Lateral view of skull with large brow ridges.\" width=\"289\" height=\"289\" \/><figcaption class=\"wp-caption-text\">Figure 10.10: Replica of Homo erectus from Java, Indonesia. This cranium (known as Sangiran 17) dates to approximately 1.3 million to 1 million years ago. Note the large brow ridges and the occipital torus that gives the back of the skull a squared-off appearance. Credit: <a href=\"https:\/\/www.efossils.org\/page\/boneviewer\/Homo%20erectus\/Sangiran%2017\">Homo erectus: Sangiran 17 lateral left view<\/a>\u00a0 by \u00a9<a href=\"https:\/\/www.efossils.org\/\">eFossils<\/a> is under a <a href=\"https:\/\/creativecommons.org\/licenses\/by-nc-sa\/2.0\/\">CC BY-NC-SA 2.0 License<\/a> and is <a href=\"https:\/\/efossils.org\/page\/frequently-asked-questions\">used as outlined by eFossils<\/a>.<\/figcaption><\/figure>\n<p class=\"import-Normal\"><span style=\"color: #000000;\">Compared to <em>Homo habilis<\/em>, <em>Homo erectus<\/em> showed increased brain size, smaller teeth, and a larger body. However, it also displayed key differences from later hominin species including our own. Although the head of <em>Homo erectus<\/em> was less ape-like in appearance than the australopithecines, it did not resemble modern humans (Figure 10.10). Compared to <em>Homo habilis<\/em>, <em>Homo erectus<\/em> had a larger brain size: an average of about 900 cc compared to 650 cc to 750 cc. Instead of a rounded shape like our skulls, the <em>erectus <\/em>skull was long and low like a football, with a receding forehead, and a horizontal ridge called an <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_1552\">occipital torus<\/a><\/strong> that gave the back of the skull a squared-off appearance. The cranial bones are thicker than those of modern humans, and some <em>Homo erectus<\/em> skulls have a slight thickening along the sagittal suture called a <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_1553\">sagittal keel<\/a><\/strong>. Large, shelf-like brow ridges hang over the eyes. The face shows less <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_1554\"> prognathism<\/a><\/strong>, and the back teeth are smaller than those of <em>Homo habilis. <\/em>Instead of a pointed chin, like ours, the mandible of <em>Homo erectus<\/em> recedes back.<\/span><\/p>\n<p class=\"import-Normal\"><span style=\"color: #000000;\">Apart from these features, there is significant variation among <em>Homo <\/em><em>erectus<\/em> fossils from different regions. Scientists have long noted differences between the fossils from Africa and those from Indonesia and China. For example, the Asian fossils tend to have a thicker skull and larger brow ridges than the African specimens, and the sagittal keel described above is more pronounced. <em>Homo erectus<\/em> fossils from the Republic of Georgia (described in the next section) also display distinctive characteristics. As with <em>Homo habilis<\/em>, this diversity has prompted a classification debate about whether or not <em>Homo erectus<\/em> should be split into multiple species. When African <em>Homo erectus<\/em> is characterized as a separate species, it is called <em>Homo ergaster<\/em>, while the Asian variant retains the <em>erectus <\/em>species name because it was discovered first. Here, the species name <em>Homo erectus<\/em> will be used for both variants.<\/span><\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\"><span style=\"color: #000000;\"><em>Homo erectus<\/em> was thought to have a body size and proportions more similar to modern humans. Unlike <em>Homo habilis<\/em> and the australopithecines, both of whom were small-statured with long arms and short legs, <em>Homo erectus<\/em> shows evidence of being fully committed to life on the ground. This meant long, powerfully muscled legs that enabled these hominins to cover more ground efficiently. Indeed, studies of the <em>Homo erectus<\/em> body form have linked several characteristics of the species to long-distance running in the more open savanna environment (Bramble and Lieberman 2004). Many experts think that hominins around this time had lost much of their body hair, were particularly efficient at sweating, and had darker-pigmented skin\u2014all traits that would support the active lifestyle of such a large-bodied hominin (see Special Topic box, \u201cHow We Became Sweaty, Hairless Primates\u201d).<\/span><\/p>\n<h2 class=\"import-Normal\"><span style=\"color: #000000;\">Special Topic: How We Became Hairless, Sweaty Primates <span style=\"text-decoration: underline;\">(include here)<\/span><\/span><\/h2>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\"><span style=\"color: #000000;\">Much of the information about the body form of <em>Homo erectus<\/em> comes from the Nariokotome fossil of the <em>Homo erectus<\/em> youth, described at the beginning of the chapter (see Figure 10.1). However, <em>Homo erectus<\/em> fossils are turning out to be more varied than previously thought. <em>Homo erectus <\/em>fossils from sites in Africa, as well as from Dmanisi, Georgia, show smaller body sizes than the Nariokotome boy. Even the Nariokotome skeleton itself has been reassessed: some now predict he would have been about 5 feet and 4 inches when fully grown rather than over 6 feet as initially hypothesized, although there is still disagreement about which measurement is more accurate. One explanation for the range of body sizes could be adaptation to a range of different local environments, just as humans today show reduced body size in poor nutritional environments (Anton and Snodgrass 2012).<\/span><\/p>\n<h3 class=\"import-Normal\"><span style=\"color: #000000;\"><strong><em>Homo erectus<\/em><\/strong><strong> in Africa <\/strong><\/span><\/h3>\n<p class=\"import-Normal\"><span style=\"color: #000000;\">Although the earliest discoveries of <em>Homo erectus<\/em> fossils were from Asia, the greatest quantity and best-preserved fossils of the species come from East African sites. The earliest fossils in Africa identified as <em>Homo erectus <\/em>come from the East African site of Koobi Fora, around Lake Turkana in Kenya, and are dated to about 1.8 million years ago. Other fossil remains have been found in East African sites in Kenya, Tanzania, and Ethiopia. Other notable African <em>Homo erectus<\/em> finds are a female pelvis from the site of Gona, Ethiopia (Simpson et al. 2008), and a cranium with massive brow ridges from Olduvai Gorge known as Olduvai 9, thought to be about 1.4 million years old.<\/span><\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\"><span style=\"color: #000000;\">Until recently, <em>Homo erectus<\/em>\u2019 presence in southern Africa has not been well documented. However, work at the Drimolen cave site in South Africa has yielded new fossils of <em>Paranthropus robustus<\/em>, and the cranium of a 2\u20133 year old child tentatively identified as <em>Homo erectus<\/em>, dated to about 2 million years (Herries et al. 2020). If substantiated, this would be the oldest discovery to date of <em>Homo erectus<\/em> anywhere.<\/span><\/p>\n<h3 class=\"import-Normal\"><span style=\"color: #000000;\"><strong>Regional Discoveries Outside Africa<\/strong><\/span><\/h3>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\"><span style=\"color: #000000;\">It is generally agreed that<em> Homo erectus<\/em> was the first hominin to migrate out of Africa and colonize Asia and later Europe (although recent discoveries in Asia may challenge this view). Key locations and discoveries of <em>Homo erectus<\/em> fossils, along with the fossils\u2019 estimated ages, are summarized in Figures 10.11 and 10.12.<\/span><\/p>\n<figure style=\"width: 594px\" class=\"wp-caption aligncenter\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image17-3.jpg\" alt=\"World map with England, Spain, Georgia, Kenya, China, and Java shaded.\" width=\"594\" height=\"459\" \/><figcaption class=\"wp-caption-text\">Figure 10.11:\u00a0 Map showing the locations of Homo erectus fossils around Africa and Eurasia. <a href=\"https:\/\/docs.google.com\/document\/d\/1VUDKMBJYS_jNONjLxT04jQN0_z9Ua50BRN6auGSHUuU\/edit\">A full text description of this image is available<\/a>. Credit: <a href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/chapter\/__unknown__-15\/\">Homo erectus site map<\/a> original to <a href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/\">Explorations: An Open Invitation to Biological Anthropology<\/a> by Chelsea Barron at<a href=\"https:\/\/www.csuchico.edu\/geop\/geoplace\/index.shtml\"> GeoPlace, California State University, Chico<\/a> is under a<a href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/\"> CC BY-NC 4.0 License<\/a>.<\/figcaption><\/figure>\n<div style=\"text-align: left;\">\n<table class=\"aligncenter\" style=\"width: 467.5pt;\">\n<caption>Figure 10.12: Regional comparisons of Homo erectus fossils. Credit: <a href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/chapter\/__unknown__-15\/\">Regional comparisons of Homo erectus fossils (Figure 10.12)<\/a> original to <a href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/\">Explorations: An Open Invitation to Biological Anthropology<\/a> is under a <a href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/\">CC BY-NC 4.0 License<\/a>.<\/caption>\n<thead>\n<tr style=\"height: 0;\">\n<td class=\"Table2-C\" style=\"padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\n<p class=\"import-Normal\"><span style=\"color: #000000;\"><strong>Region<\/strong><\/span><\/p>\n<p>&nbsp;<\/td>\n<td class=\"Table2-C\" style=\"padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\n<p class=\"import-Normal\"><span style=\"color: #000000;\"><strong>Sites<\/strong><\/span><\/p>\n<p>&nbsp;<\/td>\n<td class=\"Table2-C\" style=\"padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\n<p class=\"import-Normal\"><span style=\"color: #000000;\"><strong>Dates<\/strong><\/span><\/p>\n<p>&nbsp;<\/td>\n<td class=\"Table2-C\" style=\"padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\n<p class=\"import-Normal\"><span style=\"color: #000000;\"><strong>Significance of Fossils<\/strong><\/span><\/p>\n<p>&nbsp;<\/td>\n<\/tr>\n<\/thead>\n<tbody>\n<tr class=\"Table2-R\" style=\"height: 0;\">\n<td class=\"Table2-C\" style=\"padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\n<p class=\"import-Normal\"><span style=\"color: #000000;\">East Africa<\/span><\/p>\n<\/td>\n<td class=\"Table2-C\" style=\"padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\n<p class=\"import-Normal\"><span style=\"color: #000000;\">East and West Lake Turkana, Kenya; Olduvai Gorge, Tanzania<\/span><\/p>\n<\/td>\n<td class=\"Table2-C\" style=\"padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\n<p class=\"import-Normal\"><span style=\"color: #000000;\">1.8 to 1.4 mya<\/span><\/p>\n<\/td>\n<td class=\"Table2-C\" style=\"padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\n<p class=\"import-Normal\"><span style=\"color: #000000;\">Earliest evidence of <em>H. erectus<\/em>; significant variation in skull and facial features.<\/span><\/p>\n<\/td>\n<\/tr>\n<tr class=\"Table2-R\" style=\"height: 0;\">\n<td class=\"Table2-C\" style=\"padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\n<p class=\"import-Normal\"><span style=\"color: #000000;\">South Africa<\/span><\/p>\n<\/td>\n<td class=\"Table2-C\" style=\"padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\n<p class=\"import-Normal\"><span style=\"color: #000000;\">Drimolen Cave, South Africa<\/span><\/p>\n<\/td>\n<td class=\"Table2-C\" style=\"padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\n<p class=\"import-Normal\"><span style=\"color: #000000;\">2 mya<\/span><\/p>\n<\/td>\n<td class=\"Table2-C\" style=\"padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\n<p class=\"import-Normal\"><span style=\"color: #000000;\">Recent find of a 2\u20133 year old child would be oldest <em>H. erectus<\/em> anywhere to date.<\/span><\/p>\n<\/td>\n<\/tr>\n<tr class=\"Table2-R\" style=\"height: 0;\">\n<td class=\"Table2-C\" style=\"padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\n<p class=\"import-Normal\"><span style=\"color: #000000;\">Western<\/span><\/p>\n<p class=\"import-Normal\"><span style=\"color: #000000;\">Eurasia<\/span><\/p>\n<\/td>\n<td class=\"Table2-C\" style=\"padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\n<p class=\"import-Normal\"><span style=\"color: #000000;\">Dmanisi, Republic of Georgia<\/span><\/p>\n<\/td>\n<td class=\"Table2-C\" style=\"padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\n<p class=\"import-Normal\"><span style=\"color: #000000;\">1.75 mya<\/span><\/p>\n<\/td>\n<td class=\"Table2-C\" style=\"padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\n<p class=\"import-Normal\"><span style=\"color: #000000;\">Smaller brains and bodies than <em>H. erectus<\/em> from other regions.<\/span><\/p>\n<\/td>\n<\/tr>\n<tr class=\"Table2-R\" style=\"height: 0;\">\n<td class=\"Table2-C\" style=\"padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\n<p class=\"import-Normal\"><span style=\"color: #000000;\">Western Europe<\/span><\/p>\n<\/td>\n<td class=\"Table2-C\" style=\"padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\n<p class=\"import-Normal\"><span style=\"color: #000000;\">Atapuerca, Spain (Sima del Elefante and Gran Dolina caves)<\/span><\/p>\n<\/td>\n<td class=\"Table2-C\" style=\"padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\n<p class=\"import-Normal\"><span style=\"color: #000000;\">1.2 mya\u2013 400,000 ya<\/span><\/p>\n<\/td>\n<td class=\"Table2-C\" style=\"padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\n<p class=\"import-Normal\"><span style=\"color: #000000;\">Partial jaw from Atapuerca is oldest evidence of <em>H. erectus<\/em> in Western Europe.<\/span><\/p>\n<p class=\"import-Normal\"><span style=\"color: #000000;\">Fossils from Gran Dolina (dated to about 800,000 years) sometimes referred to as <em>H. antecessor.<\/em><\/span><\/p>\n<\/td>\n<\/tr>\n<tr class=\"Table2-R\" style=\"height: 0;\">\n<td class=\"Table2-C\" style=\"padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\n<p class=\"import-Normal\"><span style=\"color: #000000;\">Indonesia<\/span><\/p>\n<\/td>\n<td class=\"Table2-C\" style=\"padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\n<p class=\"import-Normal\"><span style=\"color: #000000;\">Ngandong, Java; Sangiran, Java<\/span><\/p>\n<\/td>\n<td class=\"Table2-C\" style=\"padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\n<p class=\"import-Normal\"><span style=\"color: #000000;\">1.6 mya<\/span><\/p>\n<\/td>\n<td class=\"Table2-C\" style=\"padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\n<p class=\"import-Normal\"><span style=\"color: #000000;\">Early dispersal of <em>H. erectus <\/em>to East Asia; Asian <em>H. erectus <\/em>features.<\/span><\/p>\n<\/td>\n<\/tr>\n<tr class=\"Table2-R\" style=\"height: 0;\">\n<td class=\"Table2-C\" style=\"padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\n<p class=\"import-Normal\"><span style=\"color: #000000;\">China<\/span><\/p>\n<\/td>\n<td class=\"Table2-C\" style=\"padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\n<p class=\"import-Normal\"><span style=\"color: #000000;\">Zhoukoudian, China;<\/span><\/p>\n<p class=\"import-Normal\"><span style=\"color: #000000;\">Loess Plateau (Lantian)<\/span><\/p>\n<\/td>\n<td class=\"Table2-C\" style=\"padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\n<p class=\"import-Normal\"><span style=\"color: #000000;\">780,000\u2013 400,000 ya;<\/span><\/p>\n<p class=\"import-Normal\"><span style=\"color: #000000;\">2.1 mya<\/span><\/p>\n<\/td>\n<td class=\"Table2-C\" style=\"padding: 0pt 5.4pt 0pt 5.4pt; border: solid #000000 0.5pt;\">\n<p class=\"import-Normal\"><span style=\"color: #000000;\">Large sample of <em>H. erectus<\/em> fossils and artifacts.<\/span><\/p>\n<p class=\"import-Normal\"><span style=\"color: #000000;\">Recent evidence of stone tools from Loess Plateau suggests great antiquity of <em>Homo<\/em> in East Asia.<\/span><\/p>\n<\/td>\n<\/tr>\n<tr>\n<td><\/td>\n<td><\/td>\n<td><\/td>\n<td><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<h4 class=\"import-Normal\"><span style=\"color: #000000;\"><em>Indonesia<\/em><\/span><\/h4>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\"><span style=\"color: #000000;\">The first discovery of<em> Homo erectus<\/em> was in the late 1800s in Java, Indonesia. A Dutch anatomist named Eugene Dubois searched for human fossils with the belief that since orangutans lived there, it might be a good place to look for remains of early humans. He discovered a portion of a skull, a femur, and other bone fragments on a riverbank. While the femur looked human, the top of the skull was smaller and thicker than that of a modern person. Dubois named the fossil <em>Pithecanthropus erectus<\/em> (\u201cupright ape-man\u201d), popularized in the media at the time as \u201cJava Man.\u201d After later discoveries of similar fossils in China and Africa, they were combined into a single species (retaining the <em>erectus<\/em> name) under the genus <em>Homo<\/em>.<\/span><\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\"><span style=\"color: #000000;\">Although <em>Homo erectus<\/em> has a long history in Indonesia, the region\u2019s geology has complicated the dating of fossils and sites. Fossils from the Sangiran Dome, Java, had previously been estimated to be as old as 1.8 million years, but scientists using new dating methods have arrived at a later date of about 1.3 mya (Matsu\u2019ura et al. 2020). On the recent end of the timeline, a cache of <em>H. erectus<\/em> fossils from the site of Ngandong in Java has yielded a surprisingly young date of 43,000 years, although a newer study with different dating methods concluded that they were between 117,000 to 108,000 years old (Rizal et al. 2020).<\/span><\/p>\n<h4 class=\"import-Normal\"><span style=\"color: #000000;\"><em>China<\/em><\/span><\/h4>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\"><span style=\"color: #000000;\">There is evidence of<em> Homo erectus <\/em>in China from several regions and time periods.<em> Homo erectus<\/em> fossils from northern China, collectively known as \u201cPeking Man,\u201d are some of the most famous human fossils in the world. Dated to about 400,000\u2013700,000 years ago, they were excavated from the site of Zhoukoudian, near the outskirts of Beijing. Hundreds of bones and teeth, including six nearly complete skulls, were excavated from a cave in the 1920s and 1930s. Much of the fossils\u2019 fame comes from the fact that they disappeared under mysterious circumstances. As Japan advanced into China during World War II, Chinese authorities, concerned for the security of the fossils, packed up the boxes and arranged for them to be transported to the United States. But in the chaos of the war, they vanished and were never heard about again. Fortunately, an anatomist named Frans Weidenreich had previously studied the bones and made casts and measurements of the skulls, so this valuable information was not lost. More recent excavations at Longgushan \u201cDragon Bone Cave\u201d at Zhoukoudian\u2014of tools, living sites, and food remains\u2014have revealed much about the lifestyle of <em>Homo erectus <\/em>during this time.<\/span><\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\"><span style=\"color: #000000;\">Despite this long history of research, China, compared to Africa, was perceived as somewhat peripheral to the study of hominin evolution. Although <em>Homo erectus<\/em> fossils have been found at several sites in China, with dates that make them comparable to those of Indonesian <em>Homo erectus<\/em>, none seemed to approximate the antiquity of African sites. The notable finds at sites like Nariokotome and Olorgesaille took center stage during the 1970s and 1980s, as scientists focused on elucidating the species\u2019 anatomy and adaptations in its African homeland. In contrast, fewer research projects were focused on East Asian sites (Dennell and Roebroeks 2005; Qiu 2016).<\/span><\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\"><span style=\"color: #000000;\">However, isolated claims of very ancient hominin occupation kept cropping up from different locations in Asia. While some were dismissed because of problems with dating methods or stratigraphic context, the 2018 publication of the discovery of 2.1-million-year-old stone tools from China caught everyone\u2019s attention. Based on paleomagnetic techniques that date the associated soils and windblown dust, these tools indicate that hominins in Asia predated those from the Georgian site of Dmanisi by at least 300,000 years (Zhu et al. 2018). In fact, the tools are older than any <em>Homo erectus<\/em> fossils anywhere. Since no fossils were found with the tools, it isn\u2019t known which species made them, but it opens up the intriguing possibility that hominins could have migrated out of Africa earlier than <em>Homo erectus<\/em>. These new discoveries are shaking up previously held views of the East Asian human fossil record.<\/span><\/p>\n<h4 class=\"import-Normal\"><span style=\"color: #000000;\"><em>Western Eurasia<\/em><\/span><\/h4>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\"><span style=\"color: #000000;\">An extraordinary collection of fossils from the site of Dmanisi in the Republic of Georgia has revealed the presence of <em>Homo erectus<\/em> in Western Eurasia between 1.75 million and 1.86 million years ago. Dmanisi is located in the Caucasus mountains in Georgia. When archaeologists began excavating a medieval settlement near the town in the 1980s and came across the bones of extinct animals, they shifted their focus from the historic to the prehistoric era, but they probably did not anticipate going back quite so far in time. The first hominin fossils were discovered in the early 1990s, and since that time, at least five relatively well-preserved crania have been excavated.<\/span><\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\"><span style=\"color: #000000;\">There are several surprising things about the Dmanisi fossils. Compared to African <em>Homo erectus,<\/em> they have smaller brains and bodies. However, despite the small brain size, they show clear signs of <em>Homo erectus<\/em> traits such as heavy brow ridges and reduced facial prognathism. Paleoanthropologists have pointed to some aspects of their anatomy (such as the shoulders) that appear rather primitive, although their body proportions seem fully committed to terrestrial bipedalism. One explanation for these differences could be that the Dmanisi hominins represent a very early form of <em>Homo erectus<\/em> that left Africa before increases in brain and body size evolved in the African population.<\/span><\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\"><span style=\"color: #000000;\">Second, although the fossils at this location are from the same geological context, they show a great deal of variation in brain size and in facial features. One skull (Skull 5) has a cranial capacity of only 550 cc, smaller than many <em>Homo habilis <\/em>fossils, along with larger teeth and a protruding face. Scientists disagree on what these differences mean. Some contend that the Dmanisi fossils cannot all belong to a single species because each one is so different. Others assert that the variability of the Dmanisi fossils proves that they, along with all early Homo fossils, including <em>H. habilis<\/em> and <em>H.<\/em><em>rudolfensis, <\/em>could <em>all <\/em>be grouped into <em>Homo erectus<\/em> (Lordkipanidze et al. 2013). Regardless of which point of view ends up dominating, the Dmanisi hominins are clearly central to the question of how to define the early members of the genus <em>Homo<\/em>.<\/span><\/p>\n<h4 class=\"import-Normal\"><span style=\"color: #000000;\"><em>Europe<\/em><\/span><\/h4>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\"><span style=\"color: #000000;\">Until recently, there was scant evidence of any <em>Homo erectus<\/em> presence in Europe, and it was assumed that hominins did not colonize Europe until much later than East Asia or Eurasia. One explanation for this was that the harsh climate of Western Europe served as a barrier to settlement. However, recent fossil finds from Spain suggest that <em>Homo erectus<\/em> could have made it into Europe over a million years ago. In 2008 a mandible from the Atapuerca region in Spain was discovered, dating to about 1.2 million years ago. A more extensive assemblage of fossils from the site of Gran Dolina in Atapuerca have been dated to about 800,000 years ago. In England in 2013 fossilized hominin footprints of adults and children dated to 950,000 years ago were found at the site of Happisburgh, Norfolk, which would make them the oldest human footprints found outside Africa (Ashton et al. 2014).<\/span><\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\"><span style=\"color: #000000;\">At this time, researchers aren\u2019t in agreement as to whether the first Europeans belonged to <em>Homo erectus<\/em> proper or to a later descendent species. Some scientists refer to the early fossils from Spain by the species name <em>Homo antecessor<\/em>.<\/span><\/p>\n<div class=\"textbox\">\n<h2 class=\"import-Normal\"><span style=\"color: #000000;\">Special Topic: How We Became Hairless, Sweaty Primates<\/span><\/h2>\n<p class=\"import-Normal\"><span style=\"color: #000000;\">As an anthropology instructor teaching human evolution, my students often ask me about human body hair: When did our ancestors lose it and why? It is assumed that our earliest ancestors were as hairy as modern-day apes. Yet, today, we lack thick hair on most parts of our bodies except in the armpits, pubic regions, and tops of our heads. Humans actually have about the same number of hair follicles per unit of skin as chimpanzees, but, the hairs on most of our body are so thin as to be practically invisible. When did we develop this peculiar pattern of hairlessness? Which selective pressures in our ancestral environment were responsible for this unusual characteristic?<\/span><\/p>\n<p class=\"import-Normal\"><span style=\"color: #000000;\">Many experts believe that the driving force behind our loss of body hair was the need to effectively cool ourselves. Along with the lack of hair, humans are also distinguished by being exceptionally sweaty: we sweat larger quantities and more efficiently than any other primate. Humans have a larger amount of eccrine sweat glands than other primates and these glands generate an enormous volume of watery sweat. Sweating produces liquid on the skin that cools the body off as it evaporates. It seems likely that hairlessness and sweating evolved together, as a recent DNA analysis has identified a shared genetic pathway between hair follicles and eccrine sweat gland production (Kamberov et al. 2015).<\/span><\/p>\n<p class=\"import-Normal\"><span style=\"color: #000000;\">Which particular environmental conditions led to such adaptations? In this chapter, we learned that the climate was a driving force behind many changes seen in the hominin lineage during the Pleistocene. At that time, the climate was increasingly arid and the forest canopy in parts of Africa was being replaced with a more open grassland environment, resulting in increased sun exposure for our ancestors. Compared to the earlier australopithecines, members of the genus <em>Homo<\/em> were also developing larger bodies and brains, starting to obtain meat by hunting or scavenging carcasses, and crafting sophisticated stone tools.<\/span><\/p>\n<p class=\"import-Normal\"><span style=\"color: #000000;\">According to Nina Jablonski, an expert on the evolution of human skin, the loss of body hair and increased sweating capacity are part of the package of traits characterizing the genus <em>Homo<\/em>. While larger brains and long-legged bodies made it possible for humans to cover long distances while foraging, this new body form had to cool itself effectively to handle a more active lifestyle. Preventing the brain from overheating was especially critical. The ability to keep cool may have also enabled hominins to forage during the hottest part of the day, giving them an advantage over savanna predators, like lions, that typically rest during this time (Jablonski 2010).<\/span><\/p>\n<p class=\"import-Normal\"><span style=\"color: #000000;\">When did these changes occur? Although hair and soft tissue do not typically fossilize, several indirect methods have been used to explore this question. One method tracks a human skin color gene. Since chimpanzees have light skin under their hair, it is probable that early hominins also had light skin color. Apes and other mammals with thick fur coats have protection against the sun\u2019s rays. As our ancestors lost their fur, it is likely that increased melanin pigmentation was selected for as a way to shield our ancestors from harmful ultraviolet radiation. A recent genetic analysis determined that one of the genes responsible for melanin production originated about 1.2 million years ago (Rogers et al 2004).<\/span><\/p>\n<p class=\"import-Normal\"><span style=\"color: #000000;\">Another line of evidence tracks the coevolution of a rather unpleasant human companion\u2014the louse. A genetic study identified human body louse as the youngest of the three varieties of lice that infest humans, splitting off as a distinct variety around 70,000 years ago (Kittler et al. 2003). Because human body lice can only spread through clothing, this may have been about the time when humans started to regularly wear clothing. However, the split between human head and pubic lice is estimated to have occurred much earlier, about three million years ago (Bower 2003; Reed et al. 2007). When humans lost much of their body hair, lice that used to roam freely around the body were now confined to two areas: the head and pubic region. As a result of this separation, the lice population split into two distinct groups.<\/span><\/p>\n<p class=\"import-Normal\"><span style=\"color: #000000;\">Other explanations have been suggested for the loss of human body hair. For example, being hairless makes it more difficult for skin parasites like lice, fleas, and ticks to live on us. Additionally, after bipedality evolved, hairless bodies would also make reproductive organs and female breasts more visible, suggesting that sexual selection may have played a role.<\/span><\/p>\n<\/div>\n<\/div>\n<h2 class=\"__UNKNOWN__\"><span style=\"color: #000000;\"><em>Homo erectus <\/em>Lifeways<br \/>\n<\/span><\/h2>\n<div class=\"__UNKNOWN__\">\n<p class=\"import-Normal\"><span style=\"color: #000000; background-color: #ff99cc;\">Now, our examination of <em>Homo erectus<\/em> will turn to its lifeways\u2014how the species utilized its environment in order to survive. This includes making inferences about diet, technology, life history, environments occupied, and perhaps even social organization. As will be apparent, <em>Homo erectus <\/em>shows significant cultural innovations in these areas, some that you will probably recognize as more \u201chuman-like\u201d than any of the hominins previously covered.<\/span><\/p>\n<h3 class=\"import-Normal\"><span style=\"color: #000000;\"><strong>Tool Technology: Acheulean Tool Industry<\/strong><\/span><\/h3>\n<figure style=\"width: 423px\" class=\"wp-caption alignleft\"><img class=\"\" src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image9-3.png\" alt=\"Front, back, side, and top views of oval-shaped stone core with chunks removed.\" width=\"423\" height=\"341\" \/><figcaption class=\"wp-caption-text\">Figure 10.13: Drawing of an Acheulean handaxe. This specimen is from Spain. When drawing a stone tool, artists typically show front and back faces, as well as top and side profiles. Credit: <a href=\"https:\/\/commons.wikimedia.org\/wiki\/File:Hand_axe_spanish.gif\">Hand axe spanish<\/a> by<a href=\"https:\/\/commons.wikimedia.org\/wiki\/User:Locutus_Borg\"> Jos\u00e9-Manuel Benito (user: Locutus Borg<\/a>) has been designated to the<a href=\"https:\/\/creativecommons.org\/share-your-work\/public-domain\/cc0\/\"> public domain (CC0)<\/a>.<\/figcaption><\/figure>\n<p>In early African sites associated with <em>Homo erectus<\/em>, stone tools such as flakes and choppers identified to the Oldowan Industry dominate. Starting at about 1.5 million years ago, some <em>Homo erectus<\/em> populations began making different forms of tools. These tools\u2014classified together as constituting the <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_1556\">Acheulean <\/a><\/strong> tool industry\u2014are more complex in form and more consistent in their manufacture. Unlike the Oldowan tools, which were cobbles modified by striking off a few flakes, Acheulean toolmakers carefully shaped both sides of the tool. This type of technique, known as bifacial flaking, requires more planning and skill on the part of the toolmaker; he or she would need to be aware of principles of symmetry when crafting the tool. One of the most common tool forms, the handaxe, is shown in Figure 10.13. As with the tool illustrated below, handaxes tend to be thicker at the base and then come to a rounded point at the tip. Besides handaxes, forms such as scrapers, cleavers, and flake tools are present at <em>Homo erectus<\/em> sites.<\/p>\n<p class=\"import-Normal\"><span style=\"color: #000000;\">One striking aspect of Acheulean tools is their uniformity. They are more standardized in form and mode of manufacture than the earlier Oldowan tools. For example, the aforementioned handaxes vary in size, but they are remarkably consistent in regard to their shape and proportions. They were also an incredibly stable tool form over time\u2014lasting well over a million years with little change.<\/span><\/p>\n<p class=\"import-Normal\"><span style=\"color: #000000;\">Curiously, the Acheulean tools so prominent at African sites are mostly absent in <em>Homo erectus<\/em> sites in East Asia. Instead, Oldowan-type choppers and scrapers are found at those sites. If this technology seemed to be so important to African <em>Homo erectus<\/em>, why didn\u2019t East Asian <em>Homo erectus<\/em> also use the tools? One reason could be environmental differences between the two regions. It has been suggested that <em>Asian Homo<\/em> <em>erectus<\/em> populations used perishable material such as bamboo to make tools. Another possibility is that <em>Homo erectus<\/em> (or even an earlier hominin) migrated to East Asia before the Acheulean technology developed in Africa. The recent discovery of the 2.1-million-year-old tools in China gives credence to this last explanation.<\/span><\/p>\n<p class=\"import-Normal\"><span style=\"color: #000000;\">What (if anything) do the Acheulean tools tell us about the mind of <em>Homo erectus<\/em>? Clearly, they took a fair amount of skill to manufacture. Apart from the actual shaping of the tool, other decisions made by toolmakers can reveal their use of foresight and planning. Did they just pick the most convenient rocks to make their tools, or did they search out a particular raw material that would be ideal for a particular tool? Analysis of Acheulean stone tools suggest that at some sites, the toolmakers selected their raw materials carefully\u2014traveling to particular rock outcrops to quarry stones and perhaps even removing large slabs of rock at the quarries to get at the most desirable material. Such complex activities would require advanced planning and communication with other individuals. However, other <em>Homo erectus<\/em> sites lack evidence of such selectivity; instead of traveling even a short distance for better raw material, the hominins tended to use what was available in their immediate area (Shipton et al. 2018).<\/span><\/p>\n<p class=\"import-Normal\"><span style=\"color: #000000;\">In contrast to <em>Homo erectus<\/em> tools, the tools of early modern <em>Homo sapiens<\/em> during the Upper Paleolithic display tremendous diversity across regions and time periods. Additionally, Upper Paleolithic tools and artifacts communicate information such as status and group membership. Such innovation and social signaling seem to have been absent in <em>Homo erectus<\/em>, suggesting that they had a different relationship with their tools than did <em>Homo sapiens<\/em> (Coolidge and Wynn 2017). Some scientists assert that these contrasts in tool form and manufacture may signify key cognitive differences between the species, such as the ability to use a complex language.<\/span><\/p>\n<h2 class=\"import-Normal\"><span style=\"color: #000000;\"><strong>Subsistence and Diet<\/strong><\/span><\/h2>\n<p class=\"import-Normal\"><span style=\"color: #000000;\">In reconstructing the diet of <em>Homo erectus<\/em>, researchers can draw from multiple lines of evidence. These include stone tools used by <em>Homo erectus<\/em>, animal bones and occasionally plant remains from <em>Homo erectus<\/em> sites, and the bones and teeth of the fossils themselves. These data sources suggest that compared to the australopithecines, <em>Homo erectus<\/em> consumed more animal protein. Coinciding with the appearance of <em>Homo erectus<\/em> fossils in Africa are archaeological sites with much more abundant stone tools and larger concentrations of butchered animal bones.<\/span><\/p>\n<figure style=\"width: 253px\" class=\"wp-caption alignright\"><img class=\"\" src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image5-2.png\" alt=\"Five men excavating and note-taking at an archaeological site.\" width=\"253\" height=\"380\" \/><figcaption class=\"wp-caption-text\">Figure 10.14: Excavations at the site of Olorgesailie, Kenya. Dated from between 1.2 million years ago and 490,000 years ago, Olorgesailie has some of the most abundant and well-preserved evidence of Homo erectus activity in the world. Fossils of large mammals, such as elephants, along with thousands of Acheulean tools, have been uncovered over the decades. Credit: <a href=\"https:\/\/humanorigins.si.edu\/research\/olorgesailie-kenya\">Elephant Butchery Site Olorgesailie, Kenya<\/a> by<a href=\"https:\/\/www.si.edu\/\"> Smithsonian<\/a> [exhibit:<a href=\"https:\/\/humanorigins.si.edu\/research\"> Human Evolution Research<\/a>,<a href=\"https:\/\/humanorigins.si.edu\/research\/east-african-research-projects\"> East African Research Projects<\/a>, Olorgesailie, Kenya] is<a href=\"https:\/\/www.si.edu\/termsofuse\/\"> copyrighted and used for educational and non-commercial purposes as outlined by the Smithsonian<\/a>.<\/figcaption><\/figure>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\"><span style=\"color: #000000;\">It makes sense that a larger body and brain would be correlated with a dietary shift to more calorically dense foods. This is because the brain is a very energetically greedy organ. Indeed, our own human brains require more than 20% of one\u2019s calorie total intake to maintain. When biologists consider the evolution of intelligence in any animal species, it is often framed as a cost\/benefit analysis: For large brains to evolve, there has to be a compelling benefit to having them and a way to generate enough energy to fuel them.<\/span><\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\"><span style=\"color: #000000;\">One solution that would allow for an increase in human brain size would be a corresponding reduction in the size of the digestive tract (gut). According to the \u201cexpensive tissue hypothesis,\u201d initially formulated by Leslie Aiello and Peter Wheeler (1995), a smaller gut would allow for a larger brain without the need for a corresponding increase in the organism\u2019s metabolic rate. More meat in the diet could also fuel the larger brain and body size seen in the genus <em>Homo<\/em>. Some researchers also believe that body fat percentages increased in hominins (particularly females) around this time, which would have allowed them to be better buffered against environmental disruption such as food shortages (Anton and Snodgrass 2012).<\/span><\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\"><span style=\"color: #000000;\">As indicated above, evidence from archaeology and the inferences about <em>Homo erectus<\/em> body size suggest increased meat eating. How much hunting did <em>Homo erectus<\/em> engage in compared to the earlier Oldowan toolmakers? Although experts continue to debate the relative importance of hunting versus scavenging, there seems to be stronger evidence of hunting for these hominins. For example, at sites such as Olorgesailie in Kenya (Figure 10.14), there are numerous associations of Acheulean tools with butchered remains of large animals.<\/span><\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\"><span style=\"color: #000000;\">However, <em>Homo erectus<\/em> certainly ate more than just meat. Studies of the tooth surfaces and microscopic wear patterns on hominin teeth indicate that these hominins ate a variety of foods, including some hard, brittle plant foods (Unger and Scott 2009). This would make sense, considering the environment was changing to be more dominated by grasslands in some areas. Roots, bulbs, and tubers (known as underground storage organs) of open savanna plants may have been a primary food source. Indeed, hunter-gatherer groups such as the Hadza of Tanzania rely heavily on such foods, especially during periods when game is scarce. In the unstable environment of the early Pleistocene, dietary versatility would be a definite advantage.<\/span><\/p>\n<h3 class=\"import-Normal\"><span style=\"color: #000000;\"><strong>Tool Use, Cooking, and Fire<\/strong><\/span><\/h3>\n<p class=\"import-Normal\"><span style=\"color: #000000;\">One key characteristic of the genus <em>Homo<\/em> is smaller teeth compared to <em>Australopithecus<\/em>. Why would teeth get smaller? In addition to new types of foods, changes in how food was prepared and consumed likely led to a decrease in tooth size. Think about how you would eat if you didn\u2019t have access to cutting tools. <span style=\"background-color: #ffff00;\">What you couldn\u2019t rip apart with your hands would have to be bitten off with your teeth\u2014actions that would require bigger, more powerful teeth and jaws. As stone tools became increasingly important, hominins began to cut up, tenderize, and process meat and plants, such that they did not have to use their teeth so vigorously.<\/span><\/span><\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\"><span style=\"color: #000000;\">Cooking food could also have contributed to the reduction in tooth and jaw size. In fact, anthropologist Richard Wrangham (2009) asserts that cooking played a crucial role in human evolution. Cooking provides a head start in the digestive process because of how heat begins to break down food before food even enters the body, and it can help the body extract more nutrients out of meat and plant foods such as starchy tubers.<\/span><\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\"><span style=\"color: #000000;\">Obviously cooking requires fire, and the earliest use of fire is a fascinating topic in the study of human evolution. Fire is not only produced by humans; it occurs naturally as a result of lightning strikes. Like other wild animals, early hominins must have been terrified of wildfires, but at some point in time they learned to control fire and put it to good use. Documenting the earliest evidence of fire has been a contentious issue in archaeology because of the difficulty in distinguishing between human-controlled fire and natural burning at hominin sites. Burned areas and ash deposits must have direct associations with human activity to make a case for deliberate fire use. Unfortunately, such evidence is rare at ancient hominin sites, which have been profoundly altered by humans, animals, and geological forces over millions of years. Recently, newer methods\u2014including microscopic analysis of burned rock and bone\u2014have revealed clear evidence of fire use at Koobi Fora, Kenya, dating to 1.5 million years ago (Hlubik et al. 2017).<\/span><\/p>\n<h3 class=\"import-Normal\"><span style=\"color: #000000;\"><strong>Migration out of Africa<\/strong><\/span><\/h3>\n<p class=\"import-Normal\"><span style=\"color: #000000;\"><em>Homo erectus<\/em> is generally thought to be the first hominin species to have left Africa. It is hypothesized that they settled in places in Eurasia, such as the Republic of Georgia, Indonesia, and northern China, where fossil evidence of <em>Homo erectus<\/em> exists. But why would this species have traveled such vast distances to these far-flung regions? To answer this question, we have to consider what we have learned about the biology, culture, and environmental circumstances of <em>Homo erectus. <\/em><span style=\"background-color: #ffff00;\">The larger brain and body size of <em>Homo erectus<\/em> were fueled by a diet consisting of more meat, and their longer, more powerful legs made it possible to walk and run longer distances to acquire food. Since they were eating higher on the food chain, it was necessary for them to extend their home range to find sufficient game. Cultural developments\u2014including better stone tools and new technology such as fire\u2014gave them greater flexibility in adapting to different environments.<\/span> Finally, the major Pleistocene climate shift discussed earlier in the chapter certainly played a role. Changes in air temperature, precipitation, access to water sources, and other habitat alteration had far-reaching effects on animal and plant communities; this included <em>Homo erectus<\/em>. If hominins were relying more on hunting, the migration patterns of their prey could have led them to traverse increasingly long distances.<\/span><\/p>\n<h3 class=\"import-Normal\"><span style=\"color: #000000;\"><strong>Life History<\/strong><\/span><\/h3>\n<p class=\"import-Normal\"><span style=\"color: #000000;\">The <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_1558\">life history <\/a><\/strong> of a species refers to its overall pattern of growth, development, and reproduction during its lifetime, with the assumption that these characteristics have been shaped by natural selection. The field of <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_1559\">human behavioral ecology<\/a><\/strong>, explored in more detail in Appendix C, examines the roots of human behavior and life history. Our species, <em>Homo sapiens<\/em>, is characterized by a unique life history pattern of slow development, an extended period of juvenile dependence, and a long lifespan. Whereas the offspring of great apes achieve self-sufficiency early, human children are dependent on their parents long after weaning. Additionally, human fathers and grandparents (particularly postmenopausal grandmothers) devote substantial time and energy to caring for their children.<\/span><\/p>\n<figure style=\"width: 310px\" class=\"wp-caption alignleft\"><img class=\"\" src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image15-3.png\" alt=\"One man is shooting a bow and arrow; another man is carrying a bow with a dog beside him.\" width=\"310\" height=\"465\" \/><figcaption class=\"wp-caption-text\">Figure 10.15: Hadza men practice bowing. Native to Tanzania, the Hadza have retained many traditional foraging practices. Although most do not subsist entirely upon wild foods today, their way of life may shed light on how humans lived for most of their evolutionary history. Credit: <a href=\"https:\/\/commons.wikimedia.org\/wiki\/File:Hadzabe1.jpg\">Hadzabe1<\/a> by<a href=\"https:\/\/commons.wikimedia.org\/wiki\/User:Idobi\"> Idobi<\/a> is under a<a href=\"https:\/\/creativecommons.org\/licenses\/by-sa\/3.0\/legalcode\"> CC BY-SA 3.0 License<\/a>.<\/figcaption><\/figure>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\"><span style=\"color: #000000;\">Human behavioral ecologists who study modern hunter-gatherer societies have observed that foraging is no easy business (Figure 10.15). Members of these groups engage in complex foraging techniques that take many years to master. An extended juvenile period gives children the time to acquire these skills. It also allows time for large human brains to grow and mature. On the back end, a longer developmental period results in skilled, successful adults, capable of living a long time (Hill and Kaplan 1999). Despite the time and energy demands, females could have offspring at more closely spaced intervals if they could depend on help from fathers and grandmothers (Hawkes et al. 1998).<\/span><\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\"><span style=\"color: #000000;\">What can the study of <em>Homo erectus<\/em> reveal about its life history pattern? Well-preserved fossils such as the Nariokotome boy can provide some insights. We know that apes such as chimpanzees reach maturity more quickly than humans, and there is some evidence that the australopithecines had a growth rate more akin to that of chimpanzees. Scientists have conducted extensive studies of the Nariokotome skeleton\u2019s bones and teeth to assess growth and development. On the one hand, examination of the long bone ends (epiphyses) of the skeleton suggested that he was an early adolescent with a relatively large body mass, though growth had not yet been completed. On the other hand, study of the dentition, including measurement of microscopic layers of tooth enamel called <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_1573\">perikymata<\/a><\/strong>, revealed a much younger age of 8 or 9. According to Christopher Dean and Holly Smith (2009), the best explanation for this discrepancy between the dental and skeletal age is that <em>Homo erectus<\/em> had its own distinct growth pattern\u2014reaching maturity more slowly than chimpanzees but faster than <em>Homo sapiens<\/em>. This suggests that the human life history pattern of slow maturation and lengthy dependency was a more recent development. More work remains on refining this pattern for early <em>Homo<\/em>, but it is an important topic that sheds light on how and when we developed our unique life history characteristics.<\/span><\/p>\n<h2 class=\"import-Normal\"><span style=\"color: #000000;\">The Big Picture of Early <em>Homo<\/em><\/span><\/h2>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\"><span style=\"color: #000000;\">We are discovering that the evolution of the genus <em>Homo<\/em> is more complex than what was previously thought. The earlier view of a simple progression from <em>Australopithecus<\/em> to <em>Homo habilis<\/em> to <em>Homo erectus<\/em> as clearly delineated stages in human evolution just doesn\u2019t hold up anymore.<\/span><\/p>\n<p class=\"import-Normal\"><span style=\"color: #000000;\">As is apparent from the information presented here, there is tremendous variability during this time. While fossils classified as <em>Homo habilis<\/em> show many of the characteristics of the genus <em>Homo<\/em>, such as brain expansion and smaller tooth size, the small body size and long arms are more akin to australopithecines. There is also tremendous variability within the fossils assigned to <em>Homo habilis<\/em>, so there is little consensus on whether it is one or multiple species of <em>Homo<\/em>, a member of the genus <em>Australopithecus<\/em>, or even a yet-to-be-defined new genus. Similarly, there are considerable differences in skull morphology and body size and form of <em>Homo erectus<\/em>, of which some specimens show more similarity to <em>Homo habilis<\/em> than previously thought.<\/span><\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\"><span style=\"color: #000000;\">What does this diversity mean for how we should view early <em>Homo<\/em>? First, there isn\u2019t an abrupt break between <em>Australopithecus<\/em> and <em>Homo habilis<\/em> or even between <em>Homo habilis<\/em> and <em>Homo erectus<\/em>. Characteristics we define as <em>Homo<\/em> don\u2019t appear as a unified package; they appear in the fossil record at different times. This is known as <strong>mosaic evolution<\/strong>. Indeed, fossil species such as <em>Australopithecus sediba<\/em>, as well as <em>Homo naledi<\/em> and <em>Homo floresiensis<\/em> (who will be introduced in Chapter 11), have displayed unexpected combinations of primitive and derived traits.<\/span><\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\"><span style=\"color: #000000;\">We can consider several explanations for the diversity we see within early <em>Homo<\/em> from about 2.5 million to 1.5 million years ago. One possibility is the existence of multiple contemporaneous species of early <em>Homo <\/em>during this period. In light of the pattern of environmental instability discussed earlier, it shouldn\u2019t be surprising to see fossils from different parts of Africa and Eurasia display tremendous variability. Multiple hominin forms could also evolve in the same region, as they diversified in order to occupy different ecological niches. However, even the presence of multiple species of hominin does not preclude their interacting and interbreeding with one another. As you\u2019ll see in Appendix D, sequencing of ancient hominin genomes has led to deeper understanding of genetic relationships between extinct species such as the Neanderthals and Denisovans.<\/span><\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\"><span style=\"color: #000000;\">Diversity of brain and body sizes could also reflect developmental plasticity\u2014short-term adaptations within a lifetime (Anton et al. 2014). These have the advantage of being more flexible than genetic natural selection, which could only occur over many generations. For example, among human populations today, different body sizes are thought to be adaptations to different climate or nutritional environments. Under Pleistocene conditions of intense variability, a more flexible strategy of adaptation would be valuable.<\/span><\/p>\n<p class=\"import-Normal\"><span style=\"color: #000000;\">New discoveries are also questioning old assumptions about the behavior of <em>Homo habilis<\/em> and <em>Homo erectus<\/em>. Just as the fossil evidence doesn\u2019t neatly separate <em>Australopithecus<\/em> and <em>Homo<\/em>, evidence of the lifeways of early <em>Homo <\/em>show similar diversity. For example, one of the traditional dividing lines between <em>Homo <\/em>and <em>Australopithecus<\/em> was thought to be stone tools: <em>Homo<\/em> made them; <em>Australopithecus <\/em>didn\u2019t. However, the recent discovery of stone tools from Kenya dating to 3.3 million years ago challenges this point of view. Similarly, the belief that <em>Homo erectus<\/em> was the first species to settle outside Africa may now come into question with the report of 2.1-million-year-old stone tools from China. If this find is supported by additional evidence, it may cause a reevaluation of <em>Homo erectus<\/em> being the first to leave Africa. Instead, there could have been multiple earlier migrations of hominins such as <em>Homo habilis<\/em> or even <em>Australopithecus <\/em>species.<\/span><\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\"><span style=\"color: #000000;\">These various lines of evidence about the genus <em>Homo <\/em>point out the need for a more nuanced view of this period of human evolution. Rather than obvious demarcations between species and their corresponding behavioral advancements, it now looks like many behaviors were shared among species. Earlier hominins that we previously didn\u2019t think had the capability could have been doing things like expanding out of Africa or using stone tools. Meanwhile, some other hominins that we had considered more advanced didn\u2019t actually have the full suite of \u201chuman\u201d characteristics previously expected.<\/span><\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\"><span style=\"color: #000000;\">From a student\u2019s perspective, all this complexity probably seems frustrating. It would be ideal if the human story were a straightforward, sequential narrative. Unfortunately, it seems that human evolution was not a nice, neat trajectory of increasingly humanlike traits and behaviors; rather, it is emblematic of the untidy but exciting nature of the study of human evolution.<\/span><\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\"><span style=\"color: #000000;\">Despite some haziness dominating the early <em>Homo<\/em> narrative, we can identify some overall trends for the million-year period associated with early <em>Homo. <\/em>These trends include brain expansion, a reduction in facial prognathism, smaller jaw and tooth size, larger body size, and evidence of full terrestrial bipedalism. These traits are associated with a key behavioral shift that emphasizes culture as a flexible strategy to adapt to unpredictable environmental circumstances. Included in this repertoire are the creation and use of stone tools to process meat obtained by scavenging and later hunting, a utilization of fire and cooking, and the roots of the human life history pattern of prolonged childhood, cooperation in child raising, and the practice of skilled foraging techniques. In fact, it\u2019s apparent that the cultural innovations are driving the biological changes, and vice versa, fueling a feedback loop that continues during the later stages of human evolution.<\/span><\/p>\n<h2 class=\"import-Normal\"><span style=\"color: #000000;\">Hominin Species Summaries<\/span><\/h2>\n<div style=\"text-align: left;\">\n<table class=\"aligncenter\" style=\"width: 344.15pt;\">\n<tbody>\n<tr class=\"Table3-R\" style=\"height: 23pt;\">\n<td class=\"Table3-C\" style=\"padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\"><span style=\"color: #000000;\"><strong>Hominin<\/strong><\/span><\/p>\n<\/td>\n<td class=\"Table3-C\" style=\"padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\"><span style=\"color: #000000;\"><em>Homo habilis <\/em><\/span><\/p>\n<\/td>\n<\/tr>\n<tr class=\"Table3-R\" style=\"height: 23pt;\">\n<td class=\"Table3-C\" style=\"padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\"><span style=\"color: #000000;\"><strong>Dates<\/strong><\/span><\/p>\n<\/td>\n<td class=\"Table3-C\" style=\"padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\"><span style=\"color: #000000;\">2.5 million years ago to 1.7 million years ago<\/span><\/p>\n<\/td>\n<\/tr>\n<tr class=\"Table3-R\" style=\"height: 23pt;\">\n<td class=\"Table3-C\" style=\"padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\"><span style=\"color: #000000;\"><strong>Region(s)<\/strong><\/span><\/p>\n<\/td>\n<td class=\"Table3-C\" style=\"padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\"><span style=\"color: #000000;\">East and South Africa<\/span><\/p>\n<\/td>\n<\/tr>\n<tr class=\"Table3-R\" style=\"height: 36pt;\">\n<td class=\"Table3-C\" style=\"padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\"><span style=\"color: #000000;\"><strong>Famous discoveries<\/strong><\/span><\/p>\n<\/td>\n<td class=\"Table3-C\" style=\"padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\"><span style=\"color: #000000;\">Olduvai Gorge, Tanzania; Koobi Fora, Kenya; Sterkfontein, South Africa<\/span><\/p>\n<\/td>\n<\/tr>\n<tr class=\"Table3-R\" style=\"height: 23pt;\">\n<td class=\"Table3-C\" style=\"padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\"><span style=\"color: #000000;\"><strong>Brain size<\/strong><\/span><\/p>\n<\/td>\n<td class=\"Table3-C\" style=\"padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\"><span style=\"color: #000000;\">650 cc average (range from 510 cc to 775 cc)<\/span><\/p>\n<\/td>\n<\/tr>\n<tr class=\"Table3-R\" style=\"height: 23pt;\">\n<td class=\"Table3-C\" style=\"padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\"><span style=\"color: #000000;\"><strong>Dentition<\/strong><\/span><\/p>\n<\/td>\n<td class=\"Table3-C\" style=\"padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\"><span style=\"color: #000000;\">Smaller teeth with thinner enamel compared to <em>Australopithecus<\/em>; parabolic dental arcade shape<\/span><\/p>\n<\/td>\n<\/tr>\n<tr class=\"Table3-R\" style=\"height: 36pt;\">\n<td class=\"Table3-C\" style=\"padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\"><span style=\"color: #000000;\"><strong>Cranial features<\/strong><\/span><\/p>\n<\/td>\n<td class=\"Table3-C\" style=\"padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\"><span style=\"color: #000000;\">Rounder cranium and less facial prognathism than <em>Australopithecus<\/em><\/span><\/p>\n<\/td>\n<\/tr>\n<tr class=\"Table3-R\" style=\"height: 36pt;\">\n<td class=\"Table3-C\" style=\"padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\"><span style=\"color: #000000;\"><strong>Postcranial features<\/strong><\/span><\/p>\n<\/td>\n<td class=\"Table3-C\" style=\"padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\"><span style=\"color: #000000;\">Small stature; similar body plan to <em>Australopithecus<\/em><\/span><\/p>\n<\/td>\n<\/tr>\n<tr class=\"Table3-R\" style=\"height: 23pt;\">\n<td class=\"Table3-C\" style=\"padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\"><span style=\"color: #000000;\"><strong>Culture<\/strong><\/span><\/p>\n<\/td>\n<td class=\"Table3-C\" style=\"padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\"><span style=\"color: #000000;\">Oldowan tools<\/span><\/p>\n<\/td>\n<\/tr>\n<tr class=\"Table3-R\" style=\"height: 23pt;\">\n<td class=\"Table3-C\" style=\"padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\"><span style=\"color: #000000;\"><strong>Other<\/strong><\/span><\/p>\n<\/td>\n<td class=\"Table3-C\" style=\"padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\"><span style=\"color: #000000;\">N\/A<\/span><\/p>\n<\/td>\n<\/tr>\n<tr>\n<td><\/td>\n<td><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<div style=\"text-align: left;\">\n<table class=\"aligncenter\" style=\"width: 344.15pt;\">\n<tbody>\n<tr class=\"Table4-R\" style=\"height: 23pt;\">\n<td class=\"Table4-C\" style=\"padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\"><span style=\"color: #000000;\"><strong>Hominin<\/strong><\/span><\/p>\n<\/td>\n<td class=\"Table4-C\" style=\"padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\"><span style=\"color: #000000;\"><em>Homo <\/em><em>erectus<\/em><\/span><\/p>\n<\/td>\n<\/tr>\n<tr class=\"Table4-R\" style=\"height: 23pt;\">\n<td class=\"Table4-C\" style=\"padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\"><span style=\"color: #000000;\"><strong>Dates<\/strong><\/span><\/p>\n<\/td>\n<td class=\"Table4-C\" style=\"padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\"><span style=\"color: #000000;\">1.8 million years ago to about 110,000 years ago<\/span><\/p>\n<\/td>\n<\/tr>\n<tr class=\"Table4-R\" style=\"height: 23pt;\">\n<td class=\"Table4-C\" style=\"padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\"><span style=\"color: #000000;\"><strong>Region(s)<\/strong><\/span><\/p>\n<\/td>\n<td class=\"Table4-C\" style=\"padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\"><span style=\"color: #000000;\">East and South Africa; West Eurasia; China and Southeast Asia<\/span><\/p>\n<\/td>\n<\/tr>\n<tr class=\"Table4-R\" style=\"height: 36pt;\">\n<td class=\"Table4-C\" style=\"padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\"><span style=\"color: #000000;\"><strong>Famous discoveries<\/strong><\/span><\/p>\n<\/td>\n<td class=\"Table4-C\" style=\"padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\"><span style=\"color: #000000;\">Lake Turkana, Olorgesailie, Kenya; Java, Indonesia; Zhoukoudian, China; Dmanisi, Republic of Georgia<\/span><\/p>\n<\/td>\n<\/tr>\n<tr class=\"Table4-R\" style=\"height: 23pt;\">\n<td class=\"Table4-C\" style=\"padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\"><span style=\"color: #000000;\"><strong>Brain size<\/strong><\/span><\/p>\n<\/td>\n<td class=\"Table4-C\" style=\"padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\"><span style=\"color: #000000;\">Average 900 cc; range between 650 cc and 1,100 cc<\/span><\/p>\n<\/td>\n<\/tr>\n<tr class=\"Table4-R\" style=\"height: 23pt;\">\n<td class=\"Table4-C\" style=\"padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\"><span style=\"color: #000000;\"><strong>Dentition<\/strong><\/span><\/p>\n<\/td>\n<td class=\"Table4-C\" style=\"padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\"><span style=\"color: #000000;\">Smaller teeth than <em>Homo habilis<\/em><\/span><\/p>\n<\/td>\n<\/tr>\n<tr class=\"Table4-R\" style=\"height: 36pt;\">\n<td class=\"Table4-C\" style=\"padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\"><span style=\"color: #000000;\"><strong>Cranial features<\/strong><\/span><\/p>\n<\/td>\n<td class=\"Table4-C\" style=\"padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\"><span style=\"color: #000000;\">Long, low skull with robust features including thick cranial vault bones and large brow ridge, sagittal keel, and occipital torus<\/span><\/p>\n<\/td>\n<\/tr>\n<tr class=\"Table4-R\" style=\"height: 36pt;\">\n<td class=\"Table4-C\" style=\"padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\"><span style=\"color: #000000;\"><strong>Postcranial features<\/strong><\/span><\/p>\n<\/td>\n<td class=\"Table4-C\" style=\"padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\"><span style=\"color: #000000;\">Larger body size compared to <em>Homo habilis<\/em>; body proportions (longer legs and shorter arms) similar to <em>Homo sapiens<\/em><\/span><\/p>\n<\/td>\n<\/tr>\n<tr class=\"Table4-R\" style=\"height: 23pt;\">\n<td class=\"Table4-C\" style=\"padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\"><span style=\"color: #000000;\"><strong>Culture<\/strong><\/span><\/p>\n<\/td>\n<td class=\"Table4-C\" style=\"padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\"><span style=\"color: #000000;\">Acheulean tools (in Africa); evidence of increased hunting and meat-eating; use of fire; migration out of Africa<\/span><\/p>\n<\/td>\n<\/tr>\n<tr class=\"Table4-R\" style=\"height: 23pt;\">\n<td class=\"Table4-C\" style=\"padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\"><span style=\"color: #000000;\"><strong>Other<\/strong><\/span><\/p>\n<\/td>\n<td class=\"Table4-C\" style=\"padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\"><span style=\"color: #000000;\">N\/A<\/span><\/p>\n<\/td>\n<\/tr>\n<tr>\n<td><\/td>\n<td><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<div class=\"textbox shaded\">\n<h2 class=\"import-Normal\"><span style=\"color: #000000;\">Review Questions<strong><br \/>\n<\/strong><\/span><\/h2>\n<ul>\n<li><span style=\"color: #000000;\">Describe the climate during the early Pleistocene. Explain why climate is important for understanding the evolution of early <em>Homo<\/em>.<\/span><\/li>\n<li><span style=\"color: #000000;\">List the key anatomical characteristics that are generally agreed to define the genus <em>Homo<\/em>.<\/span><\/li>\n<li><span style=\"color: #000000;\">Why has classification of early<em> Homo <\/em>fossils proved difficult? What are some explanations for the variability seen in these fossils?<\/span><\/li>\n<li><span style=\"color: #000000;\">Compare and contrast the Oldowan and Acheulean tool industries<em>.<\/em><\/span><\/li>\n<li><span style=\"color: #000000;\">Name some specific behaviors associated with <em>Homo erectus<\/em> in the areas of tool use, subsistence practices, migration patterns, and other cultural innovations.<\/span><\/li>\n<\/ul>\n<\/div>\n<\/div>\n<h2 class=\"__UNKNOWN__\"><span style=\"color: #000000;\">Key Terms<\/span><\/h2>\n<div class=\"__UNKNOWN__\">\n<p class=\"import-Normal\"><span style=\"color: #000000;\"><strong>Acheulean<\/strong>: Tool industry characterized by teardrop-shaped stone handaxes flaked on both sides. <\/span><\/p>\n<p class=\"import-Normal\"><span style=\"color: #000000;\"><strong>Developmental plasticity<\/strong>: The capability of an organism to modify its phenotype during development in response to environmental cues.<\/span><\/p>\n<p class=\"import-Normal\"><span style=\"color: #000000;\"><strong>Human behavioral ecology<\/strong>: The study of human behavior from an evolutionary and ecological perspective.<\/span><\/p>\n<p class=\"import-Normal\"><span style=\"color: #000000;\"><strong>Life history<\/strong>: The broad pattern of a species\u2019 life cycle, including development, reproduction, and longevity.<\/span><\/p>\n<p class=\"import-Normal\"><span style=\"color: #000000;\"><strong>Mosaic evolution<\/strong>: Different characteristics evolve at different rates and appear at different stages. <\/span><br style=\"clear: both;\" \/><br style=\"clear: both;\" \/><span style=\"color: #000000;\"><strong>Occipital torus<\/strong>: A ridge on the occipital bone in the back of the skull.<\/span><\/p>\n<p class=\"import-Normal\"><span style=\"color: #000000;\"><strong>Oldowan<\/strong>: Earliest stone-tool industry consisting of simple flakes and choppers.<\/span><br style=\"clear: both;\" \/><span style=\"color: #000000;\"><strong><br style=\"clear: both;\" \/>Perikymata<\/strong>: Microscopic ridges on the surface of tooth enamel that serve as markers of tooth development.<\/span><\/p>\n<p class=\"import-Normal\"><span style=\"color: #000000;\"><strong>Pleistocene<\/strong>: Geological epoch dating from 2.6 million years ago to about 11,000 years ago.<\/span><\/p>\n<p class=\"import-Normal\"><span style=\"color: #000000;\"><strong>Pliocene:<\/strong> Geological epoch dating from 5.3 to 2.6 million years ago.<\/span><\/p>\n<p class=\"import-Normal\"><span style=\"color: #000000;\"><strong>Prognathism<\/strong>: Condition where the lower face and jaw protrude forward from a vertical plane.<\/span><\/p>\n<p class=\"import-Normal\"><span style=\"color: #000000;\"><strong>Sagittal keel<\/strong>: A thickened area along the top of the skull.<\/span><\/p>\n<h2 class=\"import-Normal\"><span style=\"color: #000000;\">About the Author<strong><br \/>\n<\/strong><\/span><\/h2>\n<p class=\"import-Normal\"><span style=\"color: #000000;\"><img class=\"alignleft\" src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image14-3.jpg\" alt=\"A woman with long black hair smiles at the camera.\" width=\"222\" height=\"333\" \/><\/span><\/p>\n<h2 class=\"import-Normal\"><strong><span style=\"color: #000000;\">Bonnie Yoshida-Levine, Ph.D.<\/span><\/strong><\/h2>\n<p class=\"import-Normal\"><span style=\"color: #000000;\">Grossmont College, <a class=\"rId108\" style=\"color: #000000;\" href=\"mailto:bonnie.yoshida@gcccd.edu\">bonnie.yoshida@gcccd.edu<\/a><\/span><\/p>\n<p class=\"import-Normal\"><span style=\"color: #000000;\">Bonnie Yoshida-Levine is an instructor of anthropology at Grossmont College, where she teaches biological anthropology and archaeology. She received her bachelor\u2019s degree in history from the University of California, Los Angeles, and her M.A. and Ph.D. degrees in anthropology from the University of California, Santa Barbara. Her dissertation research focused on the bioarchaeology of early civilizations in north coastal Peru. Bonnie has also collaborated on archaeological field projects in Bolivia and coastal California.<\/span><\/p>\n<\/div>\n<p><span style=\"color: #000000; font-family: Raleway, sans-serif; font-size: 1.5em;\">FOR FURTHER EXPLORATION<\/span><\/p>\n<div class=\"__UNKNOWN__\">\n<p class=\"import-Normal\" style=\"margin-left: 0pt; margin-right: -36pt; text-indent: 0pt;\"><span style=\"color: #000000;\">Boaz, Noel Thomas, and Russell L. Ciochon. 2004. <em>Dragon Bone Hill: An Ice-Age Saga of <\/em>Homo erectus. New York: Oxford University Press.<\/span><\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; margin-right: -36pt; text-indent: 0pt;\"><span style=\"color: #000000;\"><a href=\"https:\/\/humanorigins.si.edu\/\">Human Evolution by the Smithsonian Institution<\/a>.\u00a0Produced by the Smithsonian National Museum of Natural History, this website covers many aspects of human evolution including 3-D models of hominin fossils.<\/span><\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; margin-right: -36pt; text-indent: 0pt;\"><span style=\"color: #000000;\">Lewin, Roger, and Robert A. Foley. 2004. <em>Principles of Human Evolution<\/em>. Oxford, UK: Blackwell Publishing.<\/span><\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\"><span style=\"color: #000000;\">Mutu, Kari. \u201cHonour Finds Kenya\u2019s Oldest Fossil Hunter Kamoya Kimeu.\u201d <em>The East African<\/em>, July 19, 2021.<\/span><\/p>\n<p class=\"import-Normal\"><span style=\"color: #000000;\">Nordling, Linda. \u201cRaising Up African Paleoanthropologists.\u201d <em>SAPIENS, <\/em>September 28, 2021. Accessed February 24, 2023. <a class=\"rId110\" style=\"color: #000000;\" href=\"https:\/\/www.sapiens.org\/biology\/african-paleoanthropologists\/\"><em>https:\/\/www.sapiens.org\/biology\/african-paleoanthropologists\/<\/em><\/a>.<\/span><\/p>\n<p class=\"import-Normal\"><span style=\"color: #000000;\">Risen, Clay. \u201cKamoya Kimeu, Fossil-Hunting \u2018Legend\u2019 in East Africa Is Dead.\u201d<em> New York Times<\/em>, August 11, 2022. Accessed February 24, 2023. https:\/\/www.nytimes.com\/2022\/08\/11\/science\/kamoya-kimeu-dead.html\/.<\/span><\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\"><span style=\"color: #000000;\">Stoneking, Mark. 2015. \u201cOf Lice and Men: The Molecular Evolution of Human Lice.\u201d Lecture, Center for Academic Research &amp; Training in Anthropogeny, San Diego, California, October 16, 2015. Accessed February 24, 2023. <a class=\"rId111\" style=\"color: #000000;\" href=\"https:\/\/carta.anthropogeny.org\/events\/unique-features-human-skin\">https:\/\/carta.anthropogeny.org\/events\/unique-features-human-skin<\/a>.<\/span><\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; margin-right: -36pt; text-indent: 0pt;\"><span style=\"color: #000000;\">Tarlach, Gemma. 2015. \u201cThe First Humans to Know Winter.\u201d <em>Discover<\/em>, February 26. https:\/\/www.discovermagazine.com\/planet-earth\/the-first-humans-to-know-winter<\/span><\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\"><span style=\"color: #000000;\">Ungar, Peter S. 2017. <em>Evolution's Bite: A Story of Teeth, Diet, and Human Origins<\/em>. Princeton, NJ: Princeton University Press.<strong><br style=\"clear: both;\" \/><\/strong><\/span><\/p>\n<h2 class=\"import-Normal\" style=\"margin-left: 0pt; margin-right: -36pt; text-indent: 0pt;\"><span style=\"color: #000000;\">References<\/span><\/h2>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; margin-right: -36pt; text-indent: 0pt;\"><span style=\"color: #000000;\">Aiello, Leslie C., and Peter Wheeler. 1995. \u201cThe Expensive-Tissue Hypothesis.\u201d <em>Current Anthropology<\/em> 36 (2): 199\u2013221.<\/span><\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; margin-right: -36pt; text-indent: 0pt;\"><span style=\"color: #000000;\">Anton, Susan C., Richard Potts, and Leslie C. Aiello. 2014. \u201cEvolution of Early <em>Homo<\/em>: An Integrated Biological Perspective.\u201d <em>Science<\/em> 345 (6192) doi: 10.1126\/science.1236828.<\/span><\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; margin-right: -36pt; text-indent: 0pt;\"><span style=\"color: #000000;\">Anton, Susan C., and J. Josh Snodgrass. 2012. \u201cOrigins and Evolution of Genus <em>Homo<\/em>: New Perspectives.\u201d <em>Current Anthropology<\/em> 53 (S6): S479\u2013S496.<\/span><\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; margin-right: -36pt; text-indent: 0pt;\"><span style=\"color: #000000;\">Ashton, Nick, Simon G. Lewis, Isabelle De Groote, Sarah M. Duffy, Martin Bates, Richard Bates, Peter Hoare, et al. 2014. \u201cHominin Footprints from Early Pleistocene Deposits at Happisburgh, UK.\u201d <em>PLOS ONE<\/em> 9 (2): e88329.<\/span><\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; margin-right: -36pt; text-indent: 0pt;\"><span style=\"color: #000000;\">Belmaker, Miriam. 2010. \u201cEarly Pleistocene Faunal Connections between Africa and Eurasia: An Ecological Perspective.\u201d In <em>Out of Africa I: The First Hominin Colonization of Eurasia<\/em>, edited by John G. Fleagle, John J. Shea, Frederick E. Grine, Andrea L. Baden, and Richard E. Leakey, 183\u2013205. Dordrecht: Springer Netherlands.<\/span><\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\"><span style=\"color: #000000;\">Blumenschine, Robert, Henry T. Bunn, Valerius Geist, Fumiko Ikawa-Smith, Curtis W. Marean, Anthony G. Payne, John Tooby, J. Nikolaas, and Van Der Merwe. 1987. \u201cCharacteristics of an Early Hominid Scavenging Niche [and Comments and Reply].\u201d <em>Current Anthropology<\/em> 28 (4): 383\u2013407.<\/span><\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; margin-right: -36pt; text-indent: 0pt;\"><span style=\"color: #000000;\">Bower, Bruce. 2004. \u201cEvolution\u2019s Buggy Ride.\u201d <em>Science News<\/em> 166 (15): 230\u2013230.<\/span><\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; margin-right: -36pt; text-indent: 0pt;\"><span style=\"color: #000000;\">Bramble, Dennis M., and Daniel E. Lieberman. 2004. \u201cEndurance Running and the Evolution of <em>Homo<\/em>.\u201d <em>Nature<\/em> 432 (7015): 345\u2013352.<\/span><\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; margin-right: -36pt; text-indent: 0pt;\"><span style=\"color: #000000;\">Coolidge, Frederick L., and Thomas Grant Wynn. 2017. <em>The Rise of Homo Sapiens: The Evolution of Modern Thinking<\/em>. New York: Oxford University Press.<\/span><\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; margin-right: -36pt; text-indent: 0pt;\"><span style=\"color: #000000;\">Dean, M. Christopher, and B. Holly Smith. 2009. \u201cGrowth and Development of the Nariokotome Youth, KNM-WT 15000.\u201d In <em>The First Humans\u2013Origin and Early Evolution of the Genus Homo: Contributions from the Third Stony Brook Human Evolution Symposium and Workshop October 3<\/em>\u2013<em>7, 2006<\/em>, edited by Frederick E. Grine, John G. Fleagle, and Richard E. Leakey, 101\u2013120. Dordrecht: Springer Netherlands.<\/span><\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; margin-right: -36pt; text-indent: 0pt;\"><span style=\"color: #000000;\">deMenocal, Peter B. 2014. \u201cClimate Shocks.\u201d <em>Scientific American<\/em> 311 (3): 48\u201353.<\/span><\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; margin-right: -36pt; text-indent: 0pt;\"><span style=\"color: #000000;\">Dennell, Robin, and Wil Roebroeks. 2005. \u201cAn Asian Perspective on Early Human Dispersal from Africa.\u201d <em>Nature<\/em> 438 (7071): 1099\u20131104.<\/span><\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; margin-right: -36pt; text-indent: 0pt;\"><span style=\"color: #000000;\">Hawkes, Kristen, James F. O\u2019Connell, Nicholas G. Blurton Jones, Helen Alvarez, and Eric L. Charnov. 1998. \u201cGrandmothering, Menopause, and the Evolution of Human Life\u2009Histories.\u201d <em>Proceedings of the National Academy of Sciences<\/em> 95 (3): 1336\u20131339.<\/span><\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; margin-right: -36pt; text-indent: 0pt;\"><span style=\"color: #000000;\">Herries, A. I. R., J. M. Martin, A. B. Leece, J. W. Adams, G. Boschian, R. Joannes-Boyau, T. R. Edwards, et al. 2020. \"Contemporaneity of <em>Australopithecus<\/em>, <em>Paranthropus<\/em>, and early <em>Homo erectus<\/em> in South Africa.\" <em>Science<\/em> 368 (6486). https:\/\/doi.org\/10.1126\/science.aaw7293<\/span><\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; margin-right: -36pt; text-indent: 0pt;\"><span style=\"color: #000000;\">Hill, Kim, and Hillard Kaplan. 1999. \u201cLife History Traits in Humans: Theory and Empirical Studies.\u201d <em>Annual Review of Anthropology<\/em> 28: 397\u2013430.<\/span><\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; margin-right: -36pt; text-indent: 0pt;\"><span style=\"color: #000000;\">Hlubik, Sarah, Francesco Berna, Craig Feibel, David Braun, and John W. K. Harris. 2017. \u201cResearching the Nature of Fire at 1.5 Mya on the Site of FxJj20 AB, Koobi Fora, Kenya, Using High-Resolution Spatial Analysis and FTIR Spectrometry.\u201d <em>Current Anthropology<\/em> 58 (S16): S243\u2013S257.<\/span><\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; margin-right: -36pt; text-indent: 0pt;\"><span style=\"color: #000000;\">Jablonski, Nina G. 2010. \u201cThe Naked Truth.\u201d <em>Scientific American<\/em> 302 (2): 42\u201349.<\/span><\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; margin-right: -36pt; text-indent: 0pt;\"><span style=\"color: #000000;\">Kamberov, Yana G., Elinor K. Karlsson, Gerda L. Kamberova, Daniel E. Lieberman, Pardis C. Sabeti, Bruce A. Morgan, and Clifford J. Tabin. 2015. \u201cA Genetic Basis of Variation in Eccrine Sweat Gland and Hair Follicle Density.\u201d <em>Proceedings of the National Academy of Sciences<\/em> 112 (32): 9932\u20139937.<\/span><\/p>\n<p class=\"import-Normal\" style=\"background-color: #ffffff; color: #ffffff; margin-left: 0pt; margin-right: 4pt; text-indent: 0pt;\"><span style=\"color: #000000;\">Kittler, R., M. Kayser, and M. Stoneking. 2003. \"Molecular Evolution of Pediculus Humanus and the Origin of Clothing.\" <em>Current Biology<\/em> 13 (16): 1414\u20131417.<\/span><\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; margin-right: -36pt; text-indent: 0pt;\"><span style=\"color: #000000;\">Leakey, Louis S. B., Phillip V. Tobias, and John R. Napier. 1964. \u201cA New Species of Genus <em>Homo<\/em> from Olduvai Gorge.\u201d <em>Nature<\/em> 202: 308\u2013312.<\/span><\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; margin-right: -36pt; text-indent: 0pt;\"><span style=\"color: #000000;\">Lemorini, Cristina, Thomas W. Plummer, David R. Braun, Alyssa N. Crittenden, Peter W. Ditchfield, Laura C. Bishop, Fritz Hertel, et al. 2014. \u201cOld Stones\u2019 Song: Use-Wear Experiments and Analysis of the Oldowan Quartz and Quartzite Assemblage from Kanjera South (Kenya).\u201d <em>Journal of Human Evolution<\/em> 72: 10\u201325.<\/span><\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; margin-right: -36pt; text-indent: 0pt;\"><span style=\"color: #000000;\">Lisiecki, Lorraine E., and Maureen E. Raymo. 2005. \"A Pliocene-Pleistocene stack of 57 globally distributed benthic \u03b418O records.\" <em>Paleoceanography<\/em> 20 (1)<\/span><\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; margin-right: -36pt; text-indent: 0pt;\"><span style=\"color: #000000;\">Lordkipanidze, David, Marcia S. Ponce de Le\u00f3n, Ann Margvelashvili, Yoel Rak, G. Philip Rightmire, Abesalom Vekua, and Christoph P. E. Zollikofer. 2013. \u201cA Complete Skull from Dmanisi, Georgia, and the Evolutionary Biology of Early <em>Homo<\/em>.\u201d <em>Science<\/em> 342 (6156): 326\u2013333.<\/span><\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; margin-right: -36pt; text-indent: 0pt;\"><span style=\"color: #000000;\">Matsu'ura, S., M. Kondo, T. Danhara, S. Sakata, H. Iwano, T. Hirata, I. Kurniawan, et al. 2020. \"Age Control of the First Appearance Datum for Javanese <em>Homo erectus<\/em> in the Sangiran Area.\" <em>Science<\/em> 367 (6474): 210\u2013214.<\/span><\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; margin-right: -36pt; text-indent: 0pt;\"><span style=\"color: #000000;\">Qiu, Jane. 2016. \u201cHow China Is Rewriting the Book on Human Origins.\u201d <em>Nature<\/em> 535: 22\u201325.<\/span><\/p>\n<p class=\"import-Normal\" style=\"background-color: #ffffff; color: #ffffff; margin-left: 0pt; margin-right: 4pt; text-indent: 0pt;\"><span style=\"color: #000000;\">Reed, David L., Jessica E. Light, Julie M. Allen, and Jeremy J. Kirchman. 2007. \"Pair of Lice Lost or Parasites Regained: The Evolutionary History of Anthropoid Primate Lice.\" <em>BMC Biology<\/em> 5 (1): 7. doi: 10.1186\/1741-7007-5-7.<\/span><\/p>\n<p class=\"import-Normal\" style=\"background-color: #ffffff; color: #ffffff; margin-left: 0pt; margin-right: 4pt; text-indent: 0pt;\"><span style=\"color: #000000;\">Rizal, Y., K. E. Westaway, Y. Zaim, G. D. van den Bergh, E. A. Bettis, 3rd, M. J. Morwood, O. F. Huffman, R. Gr\u00fcn, et al. 2020. \"Last Appearance of <em>Homo erectus<\/em> at Ngandong, Java, 117,000\u2013108,000 Years Ago.\" <em>Nature<\/em> 577 (7790): 381\u2013385.<\/span><\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; margin-right: -36pt; text-indent: 0pt;\"><span style=\"color: #000000;\">Roche, Helene, Robert J. Blumenschine, and John J. Shea. 2009. \u201cOrigins and Adaptations of Early <em>Homo<\/em>: What Archeology Tells Us.\u201d In <em>The First Humans: Origin and Early Evolution of the Genus Homo<\/em>, edited by Frederick E. Grine, John G. Fleagle, and Richard E. Leakey, 135\u2013147. New York: Springer.<\/span><\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\"><span style=\"color: #000000;\">Rogers, Alan R., David Iltis, and Stephen Wooding. 2004. \u201cGenetic Variation at the MC1R l Locus and the Time since Loss of Human Body Hair.\u201d <em>Current Anthropology<\/em> 45 (1): 105\u2013108.<\/span><\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; margin-right: -36pt; text-indent: 0pt;\"><span style=\"color: #000000;\">Ruff, Christopher. 2009. \u201cRelative Limb Strength and Locomotion in <em>Homo<\/em><em>habilis<\/em>.\u201d <em>American Journal of Physical Anthropology<\/em> 138 (1): 90\u2013100.<\/span><\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; margin-right: -36pt; text-indent: 0pt;\"><span style=\"color: #000000;\">Shipton, Ceri, James Blinkhorn, Paul S. Breeze, Patrick Cuthbertson, Nick Drake, Huw S. Groucutt, Richard P. Jennings, et al. 2018. \u201cAcheulean Technology and Landscape Use at Dawadmi, Central Arabia.\u201d <em>PloS one<\/em> 13 (7): e0200497\u2013e0200497.<\/span><\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; margin-right: -36pt; text-indent: 0pt;\"><span style=\"color: #000000;\">Simpson, Scott W., Jay Quade, Naomi E. Levin, Robert Butler, Guillaume Dupont-Nivet, Melanie Everett, and Sileshi Semaw. 2008. \u201cA Female <em>Homo<\/em><em>erectus<\/em> Pelvis from Gona, Ethiopia.\u201d <em>Science<\/em> 322 (5904): 1089\u20131092.<\/span><\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; margin-right: -36pt; text-indent: 0pt;\"><span style=\"color: #000000;\">Ungar, Peter S., and Robert S. Scott. 2009. \u201cDental Evidence for Diets of Early <em>Homo<\/em>.\u201d In <em>The First Humans: Origin and Early Evolution of the Genus Homo<\/em>, edited by Frederick E. Grine, John G. Fleagle, and Richard E. Leakey, 121\u2013134. New York: Springer.<\/span><\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; margin-right: -36pt; text-indent: 0pt;\"><span style=\"color: #000000;\">Villmoare, Brian, William H. Kimbel, Chalachew Seyoum, Christopher J. Campisano, Erin N. DiMaggio, John Rowan, David R. Braun, J. Ram\u00f3n Arrowsmith, and Kaye E. Reed. 2015. \u201cEarly <em>Homo<\/em> at 2.8 Ma From Ledi-Geraru, Afar, Ethiopia.\u201d <em>Science<\/em> 347 (6228): 1352\u20131355.<\/span><\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; margin-right: -36pt; text-indent: 0pt;\"><span style=\"color: #000000;\">Wood, Bernard. 2014. \u201cHuman Evolution: Fifty Years after <em>Homo<\/em><em>habilis<\/em>.\u201d <em>Nature<\/em> 508 (7494): 31\u201333.<\/span><\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; margin-right: -36pt; text-indent: 0pt;\"><span style=\"color: #000000;\">Wood, Bernard, and Mark Collard. 1999. \u201cThe Changing Face of Genus <em>Homo<\/em>.\u201d <em>Evolutionary Anthropology<\/em> 8 (6): 195\u2013207.<\/span><\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\"><span style=\"color: #000000;\">Wrangham, Richard. 2009. <em>Catching Fire: How Cooking Made Us Human<\/em>. New York: Basic Books.<\/span><\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; margin-right: -36pt; text-indent: 0pt;\"><span style=\"color: #000000;\">Zhu, Zhaoyu, Robin Dennell, Weiwen Huang, Yi Wu, Shifan Qiu, Shixia Yang, and Zhiguo Rao. 2018. \u201cHominin Occupation of the Chinese Loess Plateau Since about 2.1 Million Years Ago.\u201d <em>Nature<\/em> 559: 608\u2013612.<\/span><\/p>\n<h2 class=\"import-Normal\"><span style=\"color: #000000;\">Acknowledgments<br \/>\n<\/span><\/h2>\n<p class=\"import-Normal\"><span style=\"color: #000000;\">The author gratefully acknowledges funding from the California Community Colleges Chancellor\u2019s Office Zero Textbook Cost Degree Grant Program\u2014Implementation Phase 2.<\/span><\/p>\n<\/div>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_281_1691\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_281_1691\"><div tabindex=\"-1\"><div class=\"__UNKNOWN__\">\n<p class=\"import-Normal\">Amanda Wolcott Paskey, M.A., Cosumnes River College<\/p>\n<p class=\"import-Normal\">AnnMarie Beasley Cisneros, M.A., American River College<\/p>\n<p class=\"import-Normal\"><em>This chapter is a revision from \"<\/em><a class=\"rId7\" href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/chapter\/__unknown__-16\/\"><em>Chapter 11: Archaic Homo<\/em><\/a><em>\u201d by Amanda Wolcott Paskey and AnnMarie Beasley Cisneros. In <\/em><a class=\"rId8\" href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/\"><em>Explorations: An Open Invitation to Biological Anthropology, first edition<\/em><\/a><em>, edited by Beth Shook, Katie Nelson, Kelsie Aguilera, and Lara Braff, which is licensed under <\/em><a class=\"rId9\" href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\"><em>CC BY-NC 4.0<\/em><\/a><em>. <\/em><\/p>\n<div class=\"textbox textbox--learning-objectives\">\n<header class=\"textbox__header\">\n<h2 class=\"textbox__title\"><span style=\"color: #ffffff;\">Learning Objectives<\/span><\/h2>\n<\/header>\n<div class=\"textbox__content\">\n<ul>\n<li class=\"import-Normal\">Identify the main groupings of Archaic <em>Homo sapiens<\/em>, such as Neanderthals.<\/li>\n<li class=\"import-Normal\">Explain how shifting environmental conditions required flexibility of adaptations, both anatomically and behaviorally.<\/li>\n<li class=\"import-Normal\">Describe the unique anatomical and cultural characteristics of Archaic <em>Homo sapiens, <\/em>including Neanderthals, in contrast to other hominins.<\/li>\n<li class=\"import-Normal\">Articulate how Middle Pleistocene hominin fossils fit into evolutionary trends including cranial capacity (brain size) development, cultural innovations, and migration patterns.<\/li>\n<li class=\"import-Normal\">Identify the shared traits, regional variations, and local adaptations among Archaic <em>Homo sapiens.<\/em><\/li>\n<li class=\"import-Normal\">Detail the increased complexity and debates surrounding the classification of hominins in light of transitional species, species admixture, etc.<\/li>\n<\/ul>\n<\/div>\n<\/div>\n<h2 class=\"import-Normal\">Breaking the Stigma of the \"Caveman\"<\/h2>\n<p class=\"import-Normal\">What do you think of when you hear the word \u201ccaveman\u201d? Perhaps you imagine a character from a film such as <em>The Croods<\/em>, <em>Tarzan<\/em>, and <em>Encino Man<\/em> or from the cartoon <em>The Flintstones<\/em>. Maybe you picture the tennis-playing, therapy-going hairy Neanderthals from Geico Insurance commercials. Or perhaps you imagine characters from <em>The Far Side<\/em> or <em>B.C.<\/em> comics. Whichever you picture, the character in your mind is likely stooped over with a heavy brow, tangled long locks and other body hair, and clothed in animal skins, if anything. They might be holding a club with a confused look on their face, standing at the entrance to a cave or dragging an animal carcass to a fire for their next meal (see Figure 11.1). You might have even signed up to take this course because of what you knew\u2014or expected to learn\u2014about \u201ccavemen.\u201d<\/p>\n<figure style=\"width: 224px\" class=\"wp-caption alignleft\"><img class=\"\" src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/06\/image4-3.png\" alt=\"Cartoon Homo sapien has a bone piercing his nose and is scratching his head.\" width=\"224\" height=\"255\" \/><figcaption class=\"wp-caption-text\">Figure 11.1: Popular perceptions of human ancestors at the transition to modern Homo sapiens often take the form of the stereotypical, and inaccurate, \u201ccaveman.\u201d Credit: <a href=\"https:\/\/www.maxpixel.net\/Big-Head-Primitive-Caveman-Nose-Man-Bone-Cave-1460898\">Big head primitive caveman nose man bone cave<\/a> at <a href=\"https:\/\/www.maxpixel.net\/\">Max Pixel<\/a> has been designated to the <a href=\"https:\/\/creativecommons.org\/share-your-work\/public-domain\/cc0\/\">public domain (CC0)<\/a>.<\/figcaption><\/figure>\n<p class=\"import-Normal\">These images have long been the stigma and expectation about our ancestors at the transition to modern <em>Homo sapiens<\/em>. Tracing back to works as early as Carl Linnaeus, scientists once propagated and advanced this imagery, creating a clear picture in the minds of early scholars that informed the general public, even through today, that Archaic <em>Homo sapiens<\/em>, \u201ccavemen,\u201d were somehow fundamentally different and much less intelligent than we are now. Unfortunately, this view is overly simplistic, misleading, and incorrect. Understanding what Archaic <em>Homo sapiens<\/em> were actually like requires a much more complex and nuanced picture, one that comes into sharper focus as continuing research uncovers more about the lives of our not-too-distant (and not-too-different) ancestors.<\/p>\n<p class=\"import-Normal\">The first characterizations of Archaic <em>Homo sapiens<\/em> were formed from limited fossil evidence in a time when <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_1582\">ethnocentric<\/a><\/strong> and species-centric perspectives (<strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_1583\">anthropocentrism<\/a><\/strong>) were more widely accepted and entrenched in both society and science. Today, scientists are working from a more complete fossil record from three continents (Africa, Asia, and Europe), and genetic evidence informs their analyses and conclusions. The existence of Archaic <em>Homo sapiens<\/em> marks an exciting point in our lineage\u2014a point at which many modern traits had emerged and key refinements were on the horizon. Anatomically, humans today are not that much different from Archaic <em>Homo sapiens<\/em>.<\/p>\n<p class=\"import-Normal\"><span style=\"background-color: #ff99cc;\">This chapter will examine how the environment with which Archaic <em>Homo sapiens<\/em> had to contend shaped their biological and cultural evolution. It will also examine the key anatomical traits that define this group of fossils, focusing on the most well-known of them, including Neanderthals. The chapter will describe cultural innovations that aided their adaptation to the changing environment, as well as their geographic distribution and regional variations. Additionally, exciting new research is examined that suggests even greater nuance and complexity during this time period.<\/span><\/p>\n<h2 class=\"import-Normal\">The Changing Environment<\/h2>\n<p class=\"import-Normal\">While modern climate change is of critical concern today due to its cause (human activity) and pace (unprecedentedly rapid), the existence of global climate change itself is not a recent phenomenon. The focus of this chapter, the Middle Pleistocene (roughly between 780 kya and 125 kya), is the time period in which Archaic <em>Homo sapiens <\/em>appears in the fossil record\u2014a time that witnessed some of the most drastic climatic changes in human existence. During this time period, there were 15 major and 50 minor glacial events in Europe, alone.<\/p>\n<p class=\"import-Normal\">What exactly is <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_1635\">glaciation<\/a><\/strong>? When scientists talk about glacial events, they are referring to the climate being in an ice age. This means that the ocean levels were much lower than today, because much of the earth\u2019s water was tied up in large glaciers or ice sheets. Additionally, the average temperature would have been much cooler, which would have better supported an Arctic or tundra-adapted plant-and-animal ecosystem in northern latitudes. The most interesting and relevant features of Middle Pleistocene glacial events are the sheer number of them and their repeated bouts: this era alternated between glacial periods and warmer periods, known as<strong> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_1636\">interglacials<\/a><\/strong>. In other words, the planet wasn\u2019t in an ice age the whole time.<\/p>\n<p class=\"import-Normal\">You can see the dramatic and increasing fluctuations in temperature, recorded through <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_906\">foraminifera<\/a><\/strong>, in Figure 11.2. The distance between highs and lows demonstrates the severity of temperature shifts. Much as the Richter scale represents more intense earthquakes with more dramatic peaks, so too does this chart, which uses dramatic peaks to demonstrate intense temperature swings.<\/p>\n<figure id=\"attachment_347\" aria-describedby=\"caption-attachment-347\" style=\"width: 1753px\" class=\"wp-caption alignnone\"><img class=\"size-full wp-image-330\" src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/All_palaeotemps.png\" alt=\"The graph shows changes in Earth\u2019s temperature for the last 540 My.\" width=\"1753\" height=\"565\" \/><figcaption id=\"caption-attachment-347\" class=\"wp-caption-text\">Figure 11.2: The Geologic Timescale and corresponding temperature shifts. Wide and rapid shifts took place during the Pleistocene (the second box from the right). More dramatic fluctuations depict greater severity of temperature shift. The Eocene, Pliocene, and Holocene epochs had more stable temperatures. Credit: <a href=\"https:\/\/commons.wikimedia.org\/wiki\/File:All_palaeotemps.png\">All paleotemps<\/a> by Glen Fergus is under a <a href=\"https:\/\/creativecommons.org\/licenses\/by-sa\/3.0\/legalcode\">CC BY-SA 3.0 License<\/a>.<\/figcaption><\/figure>\n<p class=\"import-Normal\">Glacial periods are defined by Earth\u2019s average temperature being lower. Worldwide, temperatures are reduced, with cold areas becoming even colder. Huge portions of the landscape may have become inaccessible during glacial events due to the formation of glaciers and massive ice sheets. In Europe, the Scandinavian continental glacier covered what is today Ireland, England, Sweden, Norway, Denmark, and some of continental Europe. Plant and animal communities shifted to lower latitudes along the periphery of ice sheets. Additionally, some new land was opened during glacials. Evaporation with little runoff reduced sea levels by as much as almost 150 meters, shifting coastlines outward by in some instances as much as almost 100 kilometers. Additionally, land became exposed that connected what were previously unconnected continents such as Africa into Yemen at the Gulf of Aden.<\/p>\n<p class=\"import-Normal\">Glacial periods also affected equatorial regions and other regions that are today thought of as warmer or at least more temperate parts of the globe, including Africa. While these areas were not covered with glaciers, increased global glaciation resulted in lower sea levels and expanded coastlines. Cooler temperatures were accompanied by the drying of the climate, which caused significantly reduced rainfall, increased aridity, and the expansion of deserts. It is an interesting question to consider whether the same plants and animals that lived in these regions prior to the ice ages would be able to survive and thrive in this new climate. Plant and animal communities shifted in response to the changing climate, whenever possible.<\/p>\n<h2 class=\"import-Normal\">Surviving During the Middle Pleistocene<\/h2>\n<p class=\"import-Normal\">Rather than a single selective force, the Middle Pleistocene was marked by periods of fluctuation, not just cold periods. Interglacials interrupted glaciations, reversing trends in sea level, coastline, temperature, precipitation, and aridity, as well as glacier size and location. Interglacials are marked by increased rainfall and a higher temperature, which causes built-up ice in glaciers to melt. This leads to glacial retreat, which is the shrinking of glaciers and the movement of the glaciers back toward the poles, as we\u2019ve seen in our lifetime. During interglacials, sea levels increase, flooding some previously exposed coastlines and continental connections. In addition, plant and animal communities shift accordingly, often finding more temperate climates to the north and less arid and more humid climates in the tropics (Van Andel and Tzedakis 1996).<\/p>\n<p class=\"import-Normal\">Scientists have found that the Olorgesailie region in southern Kenya was at various times in the Middle Pleistocene a deep lake, a drought-dried lakebed with an area criss-crossed by small streams, and a grassland. While various animal species would have moved in and out of the area as the climate shifted, some animal species went extinct, and new, often related, species took up residence. The trend, scientists noted, was that animals with more specialized features went extinct and animals with more generalized features, such as animals we see today, survived in this changing climatic time period. For example, a zebra with specialized teeth for eating grass was ultimately replaced by a zebra that could eat both grass and other types of vegetation. If this small, localized example shows such a dramatic change in terms of the environment and the plant and animal biocommunities, what would have been the impact on humans?<\/p>\n<p class=\"import-Normal\">There is no way humans could have escaped the effects of Middle Pleistocene climate change, no matter what region of the world they were living in. As noted earlier, and as evidenced by what was seen in the other biotic communities, humans would have faced changing food sources as previous sources of food may have gone extinct or moved to a different latitude. Depending on where they were living, fresh water may have been limited. Durial glacials, lower sea levels would have given humans more land to live on, while the interglacials would have reduced the available land through the increase in rainfall and associated sea level rise. Dry land connections between the continents would have made movement from one continent to another by foot easier at times than today, although these passageways were not consistently available through the Middle Pleistocene due to the glacial\/interglacial cycle. Finally, as evidenced by the Olorgesailie region in Kenya, during the Middle Pleistocene animal species that were overly specialized to one particular type of environment were less likely to survive when compared to their more generalized counterparts. Evidence suggests that this same pattern may have held true for Archaic <em>Homo sapiens<\/em>, in terms of their ability to survive this dramatic period of climate change.<\/p>\n<h2 class=\"import-Normal\">Defining Characteristics of Archaic <em>Homo sapiens<\/em><\/h2>\n<p class=\"import-Normal\">Archaic <em>Homo sapiens<\/em> share our species name but are distinguished by the term \u201cArchaic\u201d as a way of recognizing both the long period of time between their appearance and ours, as well as the way in which human traits have continued to evolve over time\u2014making Archaic <em>Homo sapiens <\/em>look slightly different from us today, despite being considered the same species. Living throughout Africa, and the Middle East during the Middle Pleistocene, Archaic <em>Homo sapiens <\/em>are considered, in many ways, transitional between <em>Homo <\/em><em>erectus<\/em> and modern <em>Homo sapiens <\/em>(see Figure 11.3). Archaic<em> Homo sapiens<\/em> share the defining trait of an increased brain size of at least 1,100 cc and averaging 1,200 cc, although there are significant regional and temporal (time) variations. Because of these variations, scientists disagree on whether these fossils represent a single, variable species or multiple, closely related species (sometimes called <em>Homo antecessor<\/em>,<em> Homo bodoensis, Homo heidelbergensis<\/em>,<em> Homo georgicus<\/em>,<em> Homo neanderthalensis<\/em>, and <em>Homo rhodesiensis<\/em>).<\/p>\n<p class=\"import-Normal\">An active area of scholarship in the discipline involves reconciling the diversity of species from this time period and establishing the phylogenetic relationships between them. The term \u201cArchaic <em>Homo sapiens\u201d <\/em>can mean different things to different scholars within the discipline. The intent of this chapter is to provide an understanding of the diversity of this time period and provide data used to make interpretations from among the most likely possibilities. Although we recognize that some anthropologists split many of these fossils into separate species, until the issue is resolved at the discipline level, this chapter will rely on the widely used naming conventions that refer to many fossils from this time period as Archaic <em>Homo sapiens<\/em>. We will discuss these contemporaneous fossils as a unit<em>, <\/em>with the exception of a particularly unique population living in Europe and West Asia known as the Neanderthals, which we will examine separately.<\/p>\n<div style=\"text-align: left;\">\n<table class=\"aligncenter\" style=\"width: 468pt;\">\n<caption>Figure 11.3: A comparison of Homo erectus, Archaic Homo sapiens, and anatomically modern Homo sapiens. This table compares key traits of the crania and postcrania that distinguish these three hominins. Credit: <a href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/chapter\/__unknown__-16\/\">Homo erectus, Archaic Homo sapiens, and anatomically modern Homo sapiens table (Figure 11.3)<\/a> original to <a href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\">Explorations: An Open Invitation to Biological Anthropology<\/a> by Amanda Wolcott Paskey and AnnMarie Beasley Cisneros is under a <a href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/\">CC BY-NC 4.0 License<\/a>.<\/caption>\n<thead>\n<tr style=\"height: 0;\">\n<td class=\"Table1-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\"><strong>Trait<\/strong><\/p>\n<\/td>\n<td class=\"Table1-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\"><strong><em>Homo <\/em><\/strong><strong><em>erectus<\/em><\/strong><\/p>\n<\/td>\n<td class=\"Table1-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\"><strong>Archaic <\/strong><strong><em>Homo sapiens <\/em><\/strong><strong>(including Neaderthals)<\/strong><\/p>\n<\/td>\n<td class=\"Table1-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\"><strong>Anatomically Modern <\/strong><strong><em>Homo sapiens<\/em><\/strong><\/p>\n<\/td>\n<\/tr>\n<\/thead>\n<tbody>\n<tr class=\"Table1-R\" style=\"height: 0;\">\n<td class=\"Table1-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\"><strong>Time<\/strong><\/p>\n<\/td>\n<td class=\"Table1-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\">1.8 mya\u2013200,000 ya<\/p>\n<\/td>\n<td class=\"Table1-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\">600,000\u201340,000 ya<\/p>\n<\/td>\n<td class=\"Table1-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\">315,000 ya\u2013today<\/p>\n<\/td>\n<\/tr>\n<tr class=\"Table1-R\" style=\"height: 0;\">\n<td class=\"Table1-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\"><strong>Brain size<\/strong><\/p>\n<\/td>\n<td class=\"Table1-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\">900 cc<\/p>\n<\/td>\n<td class=\"Table1-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\">1,200 cc (1,500 cc when including Neanderthals)<\/p>\n<\/td>\n<td class=\"Table1-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\">1,400 cc<\/p>\n<\/td>\n<\/tr>\n<tr class=\"Table1-R\" style=\"height: 0;\">\n<td class=\"Table1-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\"><strong>Skull Shape<\/strong><\/p>\n<\/td>\n<td class=\"Table1-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\">Long and low,<\/p>\n<p class=\"import-Normal\">angular<\/p>\n<\/td>\n<td class=\"Table1-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\">Intermediate<\/p>\n<\/td>\n<td class=\"Table1-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\">Short and high, <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_1643\">globular<\/a><\/strong><\/p>\n<\/td>\n<\/tr>\n<tr class=\"Table1-R\" style=\"height: 0;\">\n<td class=\"Table1-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\"><strong>Forehead<\/strong><\/p>\n<\/td>\n<td class=\"Table1-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\">Absent<\/p>\n<\/td>\n<td class=\"Table1-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\">Emerging<\/p>\n<\/td>\n<td class=\"Table1-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\">Present<\/p>\n<\/td>\n<\/tr>\n<tr class=\"Table1-R\" style=\"height: 0;\">\n<td class=\"Table1-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\"><strong>Nasal Region<\/strong><\/p>\n<\/td>\n<td class=\"Table1-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\">Projecting nasal bones (bridge of the nose), no midfacial prognathism<\/p>\n<\/td>\n<td class=\"Table1-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\">Wider nasal aperture and some midfacial prognathism, particularly pronounced among Neanderthals<\/p>\n<\/td>\n<td class=\"Table1-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\">Narrower nasal aperture, no midfacial prognathism<\/p>\n<\/td>\n<\/tr>\n<tr class=\"Table1-R\" style=\"height: 0;\">\n<td class=\"Table1-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\"><strong>Chin<\/strong><\/p>\n<\/td>\n<td class=\"Table1-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\">Absent<\/p>\n<\/td>\n<td class=\"Table1-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\">Absent<\/p>\n<\/td>\n<td class=\"Table1-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\">Present<\/p>\n<\/td>\n<\/tr>\n<tr class=\"Table1-R\" style=\"height: 0;\">\n<td class=\"Table1-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\"><strong>Other Facial Features<\/strong><\/p>\n<\/td>\n<td class=\"Table1-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\">Large brow ridge and large projecting face<\/p>\n<\/td>\n<td class=\"Table1-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\">Intermediate<\/p>\n<\/td>\n<td class=\"Table1-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\">Small brow ridge and<strong> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_1642\">retracted face<\/a><\/strong><\/p>\n<\/td>\n<\/tr>\n<tr class=\"Table1-R\" style=\"height: 0;\">\n<td class=\"Table1-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\"><strong>Other Skull Features<\/strong><\/p>\n<\/td>\n<td class=\"Table1-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\">Nuchal torus, sagittal keel, thick cranial bone<\/p>\n<\/td>\n<td class=\"Table1-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\">Projecting occipital bone, often called occipital bun in Neanderthals; intermediate thickness of cranial bone<\/p>\n<\/td>\n<td class=\"Table1-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\">Small bump on rear of skull, if anything; thin cranial bone<\/p>\n<\/td>\n<\/tr>\n<tr class=\"Table1-R\" style=\"height: 0;\">\n<td class=\"Table1-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\"><strong>Dentition<\/strong><\/p>\n<\/td>\n<td class=\"Table1-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\">Large teeth, especially front teeth<\/p>\n<\/td>\n<td class=\"Table1-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\">Slightly smaller teeth; front teeth still large;<\/p>\n<p class=\"import-Normal\">retromolar gap in Neanderthals<\/p>\n<\/td>\n<td class=\"Table1-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\">Smaller teeth<\/p>\n<\/td>\n<\/tr>\n<tr class=\"Table1-R\" style=\"height: 0;\">\n<td class=\"Table1-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\"><strong>Postcranial Features<\/strong><\/p>\n<\/td>\n<td class=\"Table1-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\">Robust bones of skeleton<\/p>\n<\/td>\n<td class=\"Table1-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\">Robust bones of skeleton<\/p>\n<\/td>\n<td class=\"Table1-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\">More gracile bones of skeleton<\/p>\n<\/td>\n<\/tr>\n<tr>\n<td><\/td>\n<td><\/td>\n<td><\/td>\n<td><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<p class=\"import-Normal\">When comparing <em>Homo <\/em><em>erectus<\/em>, Archaic<em> Homo sapiens, <\/em>and anatomically modern <em>Homo sapiens<\/em>, one can see that Archaic<em> Homo sapiens<\/em> are intermediate in their physical form. For some features, this follows the trends first seen in <em>Homo <\/em><em>erectus<\/em> with other features having early, less developed forms of traits seen in modern <em>Homo sapiens<\/em>. For example, Archaic <em>Homo sapiens<\/em> trended toward less angular and higher skulls than <em>Homo <\/em><em>erectus<\/em><em>. <\/em>However, the archaic skulls were not as short and globular and had less developed foreheads compared to anatomically modern <em>Homo sapiens. <\/em>Archaic <em>Homo sapiens<\/em> had smaller brow ridges and a less-projecting face than <em>Homo <\/em><em>erectus<\/em> and slightly smaller teeth, although incisors and canines were often about as large as those of <em>Homo <\/em><em>erectus<\/em>. Archaic <em>Homo sapiens <\/em>also had a wider <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_1638\">nasal aperture<\/a><\/strong>, or opening for the nose, and a forward-projecting midfacial region, which is later seen more fully developed among Neanderthals and is known as <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_1639\">midfacial prognathism<\/a><\/strong>. The occipital bone often projected and the cranial bone was of intermediate thickness, somewhat reduced from <em>Homo <\/em><em>erectus<\/em> but not nearly as thin as that of anatomically modern <em>Homo sapiens. <\/em>The postcrania remained fairly robust. Identifying a set of features that is unique to Archaic<em> Homo sapiens<\/em> is a challenging task, due to both individual and geographic variation\u2014these developments were not all present to the same degree in all individuals. Neanderthals are the exception, as they had several unique traits that made them notably different from modern <em>Homo sapiens<\/em> as well as their closely related Archaic cousins.<\/p>\n<figure style=\"width: 299px\" class=\"wp-caption alignleft\"><img class=\"\" src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image10-4.png\" alt=\"Archaic Homo sapiens skull cast.\" width=\"299\" height=\"299\" \/><figcaption class=\"wp-caption-text\">Figure 11.4: \u201cBroken Hill Man,\u201d found at Kabwe in Zambia, shows common traits associated with archaic Homo sapiens in Africa, including a large brain, taller cranium, and Homo erectus-like features such as massive brow ridges, a large face, and thick cranial bones. Credit: <a href=\"https:\/\/boneclones.com\/product\/homo-heidelbergensis-skull-broken-hill-1-rhodesian-man-BH-004\">Homo heidelbergensis Cranium Broken Hill 1 (Rhodesian Man)<\/a> by <a href=\"https:\/\/boneclones.com\/\">\u00a9BoneClones<\/a> is used by permission and available here under a <a href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/\">CC BY-NC 4.0 License<\/a>.<\/figcaption><\/figure>\n<p class=\"import-Normal\">The one thing that is clear about Archaic <em>Homo sapiens<\/em> is that, despite general features, there is a lot of regional variation, which is first seen in the different <em>Homo <\/em><em>erectus<\/em> specimens across Asia and Africa. While the general features of Archaic <em>Homo sapiens<\/em>, identified earlier, are present in the fossils of this time period, there are significant regional differences. The majority of this regional variation lies in the degree to which fossils have features more closely aligned with <em>Homo <\/em><em>erectus<\/em> or with anatomically modern <em>Homo sapiens<\/em>.<\/p>\n<figure style=\"width: 244px\" class=\"wp-caption alignright\"><img class=\"\" src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image7-5.png\" alt=\"Side view of the Dali cranium.\" width=\"244\" height=\"213\" \/><figcaption class=\"wp-caption-text\">Figure 11.5: Dali cranium, found at Dali, China, is representative of traits seen in archaic Homo sapiens in Asia, including large and robust features with heavy brow ridges like Homo erectus and a large cranial capacity intermediate between Homo erectus and anatomically modern Homo sapiens. Credit: Dali skull original to Explorations: An Open Invitation to Biological Anthropology (2nd ed.) by <a href=\"https:\/\/marynelsonstudio.com\">Mary Nelson<\/a> is under a <a href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/\">CC BY-NC 4.0 License<\/a>.<\/figcaption><\/figure>\n<p>To illustrate this point, we will examine three exemplary specimens, one from each of the three continents on which Archaic<em> Homo sapiens <\/em>lived. First, in Africa, a specimen from Broken Hill is one of several individuals found in the Kabwe lead mine in Zambia. It had a large brain (1,300 cc) and taller cranium as well as many <em>Homo erectus-<\/em>like skull features, including massive brow ridges, a large face, and thick cranial bones (Figure 11.4). Second, one partial crania from Dali, China, is representative of Archaic<em> Homo sapiens <\/em>in Asia, with large and robust features with heavy brow ridges, akin to what is seen in <em>Homo <\/em><em>erectus<\/em>, and a large cranial capacity intermediate between <em>Homo <\/em><em>erectus<\/em> and anatomically modern <em>Homo sapiens<\/em> (Figure 11.5). Third, an almost-complete skeleton was found in northern Spain at Atapuerca. Atapuerca 5 (Figure 11.6) has thick cranial bone, an enlarged cranial capacity, intermediate cranial height, and a more rounded cranium than seen previously. Additionally, Atapuerca 5 demonstrates features that foreshadow Neanderthals, including increased midfacial prognathism. After examining some of the fossils such as those from Kabwe, Dali, and Atapuerca, the transitional nature of Archaic<em> Homo sapiens <\/em>is clear: their features place them squarely between <em>Homo <\/em><em>erectus<\/em> and modern <em>Homo sapiens<\/em>.<\/p>\n<figure style=\"width: 293px\" class=\"wp-caption alignleft\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image13-4.png\" alt=\"Archaic Homo sapiens skull cast with mandible.\" width=\"293\" height=\"293\" \/><figcaption class=\"wp-caption-text\">Figure 11.6: Atapuerca 5 archaic Homo sapiens, found in northern Spain, is representative of traits seen in archaic Homo sapiens in Europe, including a thick cranial bone, an enlarged cranial capacity, intermediate cranial height, a more rounded cranium, and increased midfacial projection. Credit: <a href=\"https:\/\/boneclones.com\/product\/homo-heidelbergensis-skull-atapuerca-5-BH-022\">Homo heidelbergensis Skull Atapuerca 5<\/a> by <a href=\"https:\/\/boneclones.com\/\">\u00a9BoneClones<\/a> is used by permission and available here under a <a href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/\">CC BY-NC 4.0 License<\/a>.<\/figcaption><\/figure>\n<p class=\"import-Normal\">Due to the transitional nature of Archaic<em> Homo sapiens<\/em>, identifying the time period with which they are associated is problematic and complex. Generally, it is agreed that Archaic<em> Homo sapiens <\/em>lived between 600,000 and 200,000 years ago, with regional variation and overlap between <em>Homo <\/em><em>erectus<\/em> on the early end of the spectrum and modern <em>Homo sapiens <\/em>and Neanderthals on the latter end. The earliest-known Archaic<em> Homo sapiens <\/em>fossils tentatively date to about 600,000 years ago in Africa, to around 300,000 years ago in Asia, and to about 350,000 years ago in Europe (and potentially as early as 600,000 years ago). Determining the end point of Archaic<em> Homo sapiens <\/em>is also problematic since it largely depends upon when the next subspecies of <em>Homo sapiens <\/em>appears and the classification of highly intermediate specimens. For example, in Africa, the end of Archaic<em> Homo sapiens <\/em>is met with the appearance of modern <em>Homo sapiens<\/em>, while in Europe it is the appearance of Neanderthals that is traditionally seen as marking the transition from other Archaic<em> Homo sapiens. <\/em><\/p>\n<p class=\"import-Normal\">It is important to remember that this time period is represented by many branching relationships and assuming an evolutionary trajectory that follows a single linear path would not be correct. Even still, Archaic<em> Homo sapiens <\/em>mark an important chapter in the human lineage, connecting more ancestral forms, such as <em>Homo <\/em><em>erectus<\/em>, to modern <em>Homo sapiens<\/em>. During this period of climatic transition and fluctuation, Archaic <em>Homo sapiens<\/em> mirror the challenges of their environments. Showing increasing regional variation due to the need for local adaptation, there is no single archetype for this group; the defining characteristic seems to be variability.<\/p>\n<h2 class=\"import-Normal\">Neanderthals<\/h2>\n<p class=\"import-Normal\">One well-known population of Archaic <em>Homo sapiens <\/em>are the Neanderthals, named after the site where they were first discovered in the Neander Valley, or \u201cthal\u201d in German, located near Dusseldorf, Germany. Popularly known as the stereotypical \u201ccavemen\u201d examined at the outset of this chapter, recent research is upending long-held beliefs about this group of Archaics. Neanderthal behavior was increasingly complex, far beyond what was exhibited by even other Archaic <em>Homo sapiens<\/em> discussed throughout this chapter. We implore you to forget the image of the iconic caveman and have an open mind when exploring the fossil evidence of the Neanderthals.<\/p>\n<p class=\"import-Normal\">It is important to understand why Neanderthals are separated from other Archaic <em>Homo sapiens<\/em>. Unlike the rest of Archaic <em>Homo sapiens<\/em>, Neanderthals are easily defined and identified in many ways. Evidence suggests the time period when Neanderthals lived was between 150,000 and 40,000 years ago. There is a clear geographic boundary of where Neanderthals lived: western Europe, the Middle East, and western Asia. No Neanderthal fossils have ever been discovered outside of this area, including Africa. This is a bit curious, as other Archaics seem to have adapted in Africa and then migrated elsewhere, but Neanderthals\u2019 regional association makes sense in light of the environment to which they were best adapted: namely, extreme cold weather. Additionally, Neanderthals have a unique and distinct cluster of physical characteristics. While a few aspects of Neanderthals are shared among some Archaic <em>Homo sapiens<\/em>, such as the types of tools, most Neanderthal anatomical and behavioral attributes are unique to them.<\/p>\n<p class=\"import-Normal\">Neanderthals lived during some of the coldest times during the last Ice Age and at far northern latitudes. This means Neanderthals were living very close to the glacial edge, rather than in a more temperate region of the globe like some of their Archaic <em>Homo sapiens<\/em> relatives. While able to survive in arctic conditions, most Neanderthal sites dating to the glacial periods were found farther away from the severe cold, in a steppe tundra-like environment, which would have been more hospitable to Neanderthals, and their food sources, both flora and fauna (Ashton 2002; Nicholson 2017; Richter 2006). Their range likely expanded and contracted along with European glacial events, moving into the Middle East during glacial events when Europe became even cooler, and when the animals they hunted would have moved for the same reason. During interglacials, when Europe warmed a bit, Neanderthals and their prey would have been able to move back into Western Europe. Clearly, the true hallmark of Neanderthals is their adaptation to an unstable environment, shifting between warm and cold, as the climate was in constant flux throughout their existence (Adler et al. 2003; Boettger et al. 2009).<\/p>\n<p class=\"import-Normal\">Many of the Neanderthals\u2019 defining physical features are more extreme and robust versions of traits seen in other Archaic<em> Homo sapiens<\/em>, clustered in this single population. Brain size, namely an enlargement of the cranial capacity, is one such trait. The average Neanderthal brain size is around 1,500 cc, and the range for Neanderthal brains can extend to upwards of 1,700 cc. The majority of the increase in the brain occurs in the occipital region, or the back part of the brain, resulting in a skull that has a large cranial capacity with a distinctly long and low shape that is slightly wider than previous forms at the far back of the skull. Modern humans have a brain size comparable to that of Neanderthals; however, our brain expansion occurred in the frontal region of the brain, not the back, as in Neanderthal brains. This difference is also the main reason why Neanderthals lack the vertical forehead that modern humans possess. They simply did not need an enlarged forehead, because their brain expansion occurred in the rear of their brain. Due to cranial expansion, the back of the Neanderthal skull is less angular (as compared to <em>Homo erectus<\/em>), but not as rounded as <em>Homo sapiens<\/em>, producing an elongated shape, akin to a football.<\/p>\n<p class=\"import-Normal\">Another feature that continues the trend noted in previous hominins is the enlargement of the nasal region, or the nose. Neanderthal noses are large and have a wide nasal aperture, which is the opening for the nose. While the nose is only made up of two bones, the nasals, the true size of the nose can be determined by looking at other facial features, including the nasal aperture, and the angle of the nasal and maxillary, or facial bones. In Neanderthals, these indicate a large, forward-projecting nose that appears to be pulled forward away from the rest of the face. This feature is further emphasized by the backward-sloping nature of the cheekbones, or the zygomatic arches. The unique shape and size of the Neanderthal nose is often characterized by the term <em>midfacial prognathism<\/em>\u2014a jutting out of the middle portion of the face, or nose. This is in sharp contrast to the prognathism exhibited by other hominins, who exhibited prognathism, or the jutting out, of their jaws.<\/p>\n<p class=\"import-Normal\">The teeth of the Neanderthals follow a similar pattern seen in the Archaic <em>Homo sapiens<\/em>, which is an overall reduction in size, especially as compared to the extremely large teeth seen in the genus <em>Australopithecus<\/em>. However, while the teeth continued to reduce, the jaw size did not keep pace, leaving Neanderthals with an oversized jaw for their teeth, and a gap between their final molar and the end of their jaw. This gap is called a <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_1644\">retromolar gap<\/a><\/strong>.<\/p>\n<p class=\"import-Normal\">The projecting occipital bone present in other Archaic<em> Homo sapiens <\/em>is also more prominent in Neanderthals, extending the trend found in Archaics. Among Neanderthals, this projection of bone is easily identified by its bun shape on the back of the skull and is known as an <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_1645\">occipital bun<\/a><\/strong>. This projection appears quite similar to a dinner roll in size and shape. Its purpose, if any, remains unknown.<\/p>\n<p class=\"import-Normal\">Continuing the Archaic<em> Homo sapiens <\/em>trend, Neanderthal brow ridges are prominent but somewhat smaller in size than those of <em>Homo <\/em><em>erectus<\/em> and earlier Archaic<em> Homo sapiens. <\/em>In Neanderthals, the brow ridges are also often slightly less arched than those of other Archaic<em> Homo sapiens<\/em>.<\/p>\n<p class=\"import-Normal\">In addition to extending traits present in Archaic<em> Homo sapiens, <\/em>Neanderthals possess several distinct traits. Neanderthal <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_1646\">infraorbital foramina<\/a><\/strong>, the holes in the maxillae or cheek bones through which blood vessels pass, are notably enlarged compared to other hominins. The Neanderthal postcrania are also unique in that they demonstrate increased robusticity in terms of the thickness of bones and body proportions that show a barrel-shaped chest and short, stocky limbs, as well as increased musculature. These body portions are seen across the spectrum of Neanderthals\u2014in men, women, and children.<\/p>\n<p class=\"import-Normal\">Traditionally, many of the unique traits that Neanderthals possess were seen as adaptations to the extreme cold, dry environments in which they often lived and which exerted strong selective forces. For example, Bergmann\u2019s and Allen\u2019s Rules dictate that an increased body mass and short, stocky limbs are common in animals that live in cold conditions. Neanderthals were said to have matched the predictions of Bergmann\u2019s and Allen\u2019s Rules perfectly (Churchill 2006). In addition, the Neanderthal skull also exhibits adaptations to the cold. Neanderthals\u2019 large infraorbital foramina allow for larger blood vessels, increasing the volume of blood that is found closest to the skin, which helps to keep the skin warmer. Their enlarged noses resulted in longer nasal passages and mucus membranes that warmed and moistened cold air before it reached the lungs. The Neanderthals\u2019 larger nose has long been thought to have acted as a humidifier, easing physical exertion in their climate, although research on this particular trait continues to be studied and debated (Rae et al. 2011).<\/p>\n<p class=\"import-Normal\">New research, however, seems to suggest that these unique skeletal adaptations might not have been strict adaptations to cold weather (Evteev et al. 2017; Pearce et al. 2013). For example, large brow ridges might have served as a way to shade the face from the sun. The increased occipital portion of the brain, some researchers state, was to support a larger visual system present in Neanderthals. This visual system would have given them increased light sensitivity, which would have been useful in higher latitudes that had dark winters. And, while recent modeling of nostril airflow on reconstructed Neanderthal specimens supports the notion that Neanderthals had extensive mucus membranes inside their noses, the data shows that modern <em>Homo sapiens<\/em> are superior to Neanderthals in our ability to use our noses as a way to warm and cool air. However, Neanderthals were able to snort air through their noses better than we can. Why is this important? When combined with the fact that Neanderthals tended to prefer a more temperate, tundra-like environment, and that other physical traits suggest that Neanderthals had huge bodies that needed massive amounts of calories to sustain them, the picture gets clearer. Massive amounts of energy would have been required to power a Neanderthal body, and anything that might have made them more calorically efficient would have been favored. Efficient breathing, through larger noses into large lungs, meaning deeper breaths, would have been favored. To further save energy expenditure, body sizes might have been sacrificed as well. These same types of adaptations are similar to ones seen in children today who are born in high altitudes, not cold climates. Figure 11.7 provides a summary of these unique features of the Neanderthal.<\/p>\n<div style=\"text-align: left;\">\n<table class=\"aligncenter\" style=\"width: 468pt;\">\n<caption>Figure 11.7: Neanderthal distinguishing features. This table outlines key features associated with Neanderthals. Credit: <a href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/chapter\/__unknown__-16\/\">Neanderthal distinguishing features table (Figure 11.6)<\/a> original to <a href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\">Explorations: An Open Invitation to Biological Anthropology<\/a> by Amanda Wolcott Paskey and AnnMarie Beasley Cisneros is under a <a href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/\">CC BY-NC 4.0 License<\/a>.<\/caption>\n<thead>\n<tr style=\"height: 21pt;\">\n<td class=\"Table2-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\" colspan=\"2\">\n<p class=\"import-Normal\" style=\"text-align: center;\"><strong>Distinct Neanderthal Anatomical Features<\/strong><\/p>\n<\/td>\n<\/tr>\n<\/thead>\n<tbody>\n<tr class=\"Table2-R\" style=\"height: 0;\">\n<td class=\"Table2-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\"><strong>Brain Size<\/strong><\/p>\n<\/td>\n<td class=\"Table2-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\">1,500 cc average<\/p>\n<\/td>\n<\/tr>\n<tr class=\"Table2-R\" style=\"height: 0;\">\n<td class=\"Table2-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\"><strong>Skull Shape<\/strong><\/p>\n<\/td>\n<td class=\"Table2-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\">Long and low<\/p>\n<\/td>\n<\/tr>\n<tr class=\"Table2-R\" style=\"height: 0;\">\n<td class=\"Table2-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\"><strong>Brow Ridge Size<\/strong><\/p>\n<\/td>\n<td class=\"Table2-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\">Large<\/p>\n<\/td>\n<\/tr>\n<tr class=\"Table2-R\" style=\"height: 0;\">\n<td class=\"Table2-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\"><strong>Nose Size<\/strong><\/p>\n<\/td>\n<td class=\"Table2-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\">Large, with midfacial prognathism<\/p>\n<\/td>\n<\/tr>\n<tr class=\"Table2-R\" style=\"height: 0;\">\n<td class=\"Table2-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\"><strong>Dentition<\/strong><\/p>\n<\/td>\n<td class=\"Table2-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\">Reduced, but large jaw size, creating retromolar gap<\/p>\n<\/td>\n<\/tr>\n<tr class=\"Table2-R\" style=\"height: 0;\">\n<td class=\"Table2-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\"><strong>Occipital Region<\/strong><\/p>\n<\/td>\n<td class=\"Table2-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\">Enlarged occipital region, occipital bun<\/p>\n<\/td>\n<\/tr>\n<tr class=\"Table2-R\" style=\"height: 0;\">\n<td class=\"Table2-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\"><strong>Other Unique Cranial Features<\/strong><\/p>\n<\/td>\n<td class=\"Table2-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\">Large infraorbital foramina<\/p>\n<\/td>\n<\/tr>\n<tr class=\"Table2-R\" style=\"height: 0;\">\n<td class=\"Table2-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\"><strong>Postcranial Features<\/strong><\/p>\n<\/td>\n<td class=\"Table2-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\">Short and stocky body, increased musculature, barrel-shaped chest<\/p>\n<\/td>\n<\/tr>\n<tr>\n<td><\/td>\n<td><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<p class=\"import-Normal\">A classic example of a Neanderthal with all of the characteristics mentioned above is the nearly complete La Ferrassie 1 Neanderthal, from France. This is a male skeleton, with a brain size of around 1640cc, an extremely large nose and infraorbital foramina, brow ridges that are marked in size, and an overall robust skeleton (Figure 11.8).<\/p>\n<p>&nbsp;<\/p>\n<figure style=\"width: 390px\" class=\"wp-caption aligncenter\"><img class=\"\" src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image1-4.png\" alt=\"A reproduction of a complete Neanderthal skeleton.\" width=\"390\" height=\"689\" \/><figcaption class=\"wp-caption-text\">Figure 11.8: La Ferrassie 1 Neanderthal is representative of many classic Neanderthal features, including a large brain, large nose, large infraorbital foramina, large brow ridges, and robust postcrania. Credit: <a href=\"https:\/\/boneclones.com\/product\/neanderthal-skeleton-articulated-SC-019-A\">Neanderthal Skeleton Articulated<\/a> by <a href=\"https:\/\/boneclones.com\/\">\u00a9BoneClones<\/a> is used by permission and available here under a <a href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/\">CC BY-NC 4.0 License<\/a>.<\/figcaption><\/figure>\n<h3 class=\"import-Normal\"><strong>Neanderthal Culture: Tool Making and Use<\/strong><\/h3>\n<p class=\"import-Normal\">One key Neanderthal adaptation was their cultural innovations, which are an important way that hominins adapt to their environment. As you recall, <em>Homo erectus<\/em>'s tools, Acheulean handaxes, represented an increase in complexity over Oldowan tools, allowing more efficient removal of meat and possibly calculated scavenging. In contrast, Neanderthal tools mark a significant innovation in tool-making technique and use with <strong>Mousterian tools<\/strong> (named after the Le Moustier site in southwest France). These tools were significantly smaller, thinner, and lighter than Acheulean handaxes and formed a true toolkit. The materials used for Mousterian tools were of higher quality, which allowed for both more precise toolmaking and tool reworking when the tools broke or dulled after frequent reuse. The use of higher-quality materials is also indicative of required forethought and planning to acquire them for tool manufacture.<span style=\"background-color: #ffff00;\"> It is noteworthy that the Neanderthals, unlike <em>Homo <\/em><em>erectus<\/em>, saved and reused their tools, rather than making new ones each time a tool was needed.<\/span><\/p>\n<figure style=\"width: 290px\" class=\"wp-caption alignright\"><img class=\"\" src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image3-4.png\" alt=\"Large flakes separated from the core.\" width=\"290\" height=\"159\" \/><figcaption class=\"wp-caption-text\">Figure 11.9: The Levallois technique is used to create Mousterian tools. The multistep process involves preparing the core in a specific way to yield flakes that can be used as tools. Credit: <a href=\"https:\/\/commons.wikimedia.org\/wiki\/File:Nucl%C3%A9us_Levallois_La-Parrilla.png\">Nucl\u00e9us Levallois La-Parrilla<\/a> by Jos\u00e9-Manuel Benito \u00c1lvarez is under a <a href=\"https:\/\/creativecommons.org\/licenses\/by-sa\/2.5\/legalcode\">CC BY-SA 2.5 License<\/a>..<\/figcaption><\/figure>\n<p>Mousterian tools are constructed in a very unique manner, utilizing the <strong>Levallois technique<\/strong> (Figure 11.9), named after the first finds of tools made with this technique, which were discovered in the Levallois-Perret suburb of Paris, France. The Levallois technique is a multistep process that requires preparing the core, or raw material, in a specific way that will yield flakes that are roughly uniform in dimension. The flakes are then turned into individual tools. The preparation of the core is akin to peeling a potato or carrot with a vegetable peeler\u2014when peeling vegetables, you want to remove the skin in long, regular strokes, so that you are taking off the same amount of the vegetable all the way around. In the same way, the Levallois technique requires removing all edges of the <strong>cortex<\/strong>, or outside surface of the raw material, in a circle before removing the lid. The flakes, which will eventually be turned into the individual tools, can then be removed from the core. The potential yield of tools from one core would be many, as seen in Figure 11.10, compared to all previous tool-making processes, in which one core yielded a single tool. This manufacturing process might be considered the ultimate zero-waste tool-making technique (Delpiano et al. 2018).<\/p>\n<p>&nbsp;<\/p>\n<figure style=\"width: 589px\" class=\"wp-caption aligncenter\"><img class=\"\" src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image19-4.png\" alt=\"Levallois core and flakes that are gray in color and various shapes and sizes.\" width=\"589\" height=\"470\" \/><figcaption class=\"wp-caption-text\">Figure 11.10: Levallois core and flakes for tool production. Using this technique, one core is used to produce many flakes, each of which can be turned into a tool. Credit: <a href=\"https:\/\/commons.wikimedia.org\/wiki\/File:NHM_-_Levalloiskern.jpg\">NHM - Levalloiskern<\/a> by <a href=\"https:\/\/commons.wikimedia.org\/wiki\/User:Xenophon\">Wolfgang Sauber<\/a> (user: Xenophon) is under a <a href=\"https:\/\/creativecommons.org\/licenses\/by-sa\/4.0\/legalcode\">CC BY-SA 4.0 License<\/a>.<\/figcaption><\/figure>\n<p class=\"import-Normal\"><span style=\"background-color: #ffff00;\">Neanderthal tools were used for a variety of purposes, including cutting, butchering, woodworking or antler working, and hide working.<\/span> Additionally, because the Mousterian tools were lighter than previous stone tools, Neanderthals could <strong>haft<\/strong>, or attach the tool onto a handle, as the stone would not have been too heavy (Degano et al. 2019). Neanderthals attached small stone blades onto short wood or antler handles to make knives or other small weapons, as well as attached larger blades onto longer shafts to make spears. New research examining tar-covered stones and black lumps at several Neanderthal sites in Europe suggests that Neanderthals may have been making tar by distilling it from birch tree bark, which could have been used to glue the stone tool onto its handle. If Neanderthals were, in fact, manufacturing tar to act as glue, this would predate modern humans in Africa using tree resin or similar adhesives by nearly 100,000 years.<\/p>\n<p class=\"import-Normal\">Evidence shows that raw materials used by Neanderthals came from distances as far away as 100 km. This could indicate a variety of things regarding Neanderthal behavior, including a limited trade network with other Neanderthal groups or simply a large area scoured by Neanderthals when collecting raw materials. While research on specific applications continues, it should be clear from this brief discussion that Neanderthal tool manufacturing was much more complex than previous tool-making efforts, requiring technical expertise, patience, and skills beyond toolmaking to carry out.<\/p>\n<h3 class=\"import-Normal\"><strong>Neanderthal Culture: Hunting and Diet<\/strong><\/h3>\n<p class=\"import-Normal\">With their more sophisticated suite of tools and robust muscular bodies, Neanderthals were better armed for hunting than previous hominins. The animal remains in Neanderthal sites show that, unlike earlier Archaic <em>Homo sapiens<\/em>, Neanderthals were very effective hunters who were able to kill their own prey, rather than relying on scavenging. Though more refined than the tools of earlier hominins, the Neanderthal spear was not the kind of weapon that would have been thrown; rather, it would have been used in a jabbing fashion (Churchill 1998; Kortlandt 2002). This may have required Neanderthals to hunt in groups rather than individually and made it necessary to approach their prey quite closely (Gaudzinski-Windheuser et al. 2018). Remember, the animals living with Neanderthals were very large-bodied due to their adaptations to cold weather; this would have included species of deer, horses, and bovids (relatives of the cow).<\/p>\n<p class=\"import-Normal\">Isotopes from Neanderthal bones show that meat was a significant component of their diet, similar to that seen in carnivores like wolves (Bocherens et al. 1999; Jaouen et al. 2019; Richards et al. 2000). In addition to large prey, their diet included ibex, seals, rabbits, and pigeons. Though red meat was a critical component of the Neanderthal diet, evidence shows that at times they also ate limpets, mussels, and pine nuts. Tartar examined from Neanderthal teeth in Iraq and Belgium reveal that they also ate plant material including wheat, barley, date palms, and tubers, first cooking them to make them palatable (Henry et al. 2010). While Neanderthals\u2019 diet varied according to the specific environment in which they lived, meat comprised up to 80% of their diet (Wi\u1e9ein et al. 2015).<\/p>\n<h3 class=\"import-Normal\"><strong>Neanderthal Culture: Caring for the Injured and Sick<\/strong><\/h3>\n<p class=\"import-Normal\">While the close-range style of hunting used by Neanderthals was effective, it also had some major consequences. Many Neanderthal skeletons have been found with significant injuries, which could have caused paralysis or severely limited their mobility. Many of the injuries are to the head, neck, or upper body. Thomas Berger and Erik Trinkaus (1995) conducted a statistical comparative analysis of Neanderthal injuries compared to those recorded in modern-day workers\u2019 compensation reports and found that the closest match was between Neanderthal injuries and those of rodeo workers. Rodeo professionals have a high rate of head and neck injuries that are similar to the Neanderthals\u2019 injuries. What do Neanderthals and rodeo workers have in common? They were both getting very close to large, strong animals, and at times their encounters went awry.<\/p>\n<p class=\"import-Normal\">The extensive injuries sustained by Neanderthals are evident in many fossil remains. Shanidar 1 (Figure 11.11), an adult male found at the Shanidar site in northern Iraq and dating to 45,000 ya, has a lifetime of injuries recorded in his bones (Stewart 1977). Shanidar 1 sustained\u2014and healed from\u2014an injury to the face that would have likely caused blindness. His lower right arm was missing and the right humerus shows severe atrophy, likely due to disuse. This pattern has been interpreted to indicate a substantial injury that required or otherwise resulted in amputation or wasting away of the lower arm. Additionally, Shanidar 1 suffered from bony growths in the inner ear that would have significantly impaired his hearing and severe arthritis in the feet. He also exhibited extensive anterior tooth wear, matching the pattern of wear found among modern populations who use their teeth as a tool. Rather than an anomaly, the type of injuries evident in Shanidar 1 are similar to those found in many other Neanderthal fossils, revealing injuries likely sustained from hunting large mammals as well as demonstrating a long life of physical activity.<\/p>\n<p>&nbsp;<\/p>\n<p><img class=\"aligncenter\" src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image11-4.png\" alt=\"Neaderthal skull.\" width=\"329\" height=\"329\" \/><\/p>\n<figure style=\"width: 330px\" class=\"wp-caption aligncenter\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image5-4.png\" alt=\"Neaderthal right and left humerus. The right humerus is withered looking.\" width=\"330\" height=\"330\" \/><figcaption class=\"wp-caption-text\">Figure 11.11a-b: a. The Shanidar 1 skull shows an injury to the face that would likely have caused blindness. b. The Shanidar 1 right humerus (on the left side of the image) shows severe atrophy, likely due to disuse. Credit: a. <a href=\"https:\/\/boneclones.com\/product\/shanidar-1-skull-BH-050\">Homo neanderthalensis Shanidar 1 Skull<\/a> by <a href=\"https:\/\/boneclones.com\/\">\u00a9BoneClones<\/a> is used by permission and available here under a <a href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/\">CC BY-NC 4.0 License<\/a>. b. <a href=\"https:\/\/humanorigins.si.edu\/evidence\/human-fossils\/fossils\/shanidar-1\">Shanidar 1<\/a> by Chip Clark, <a href=\"https:\/\/www.si.edu\/\">Smithsonian Institution<\/a> [exhibit: <a href=\"https:\/\/humanorigins.si.edu\/research\">Human Evolution <\/a>Evidence, Human Fossils, Species, Homo neanderthalensis] <a href=\"https:\/\/www.si.edu\/termsofuse\">is used for educational and non-commercial purposes as outlined by the Smithsonian.<\/a><\/figcaption><\/figure>\n<p class=\"import-Normal\">The pattern of injuries is as significant as the fact that Shanidar 1 and other injured Neanderthals show evidence of having <em>survived<\/em> their severe injuries. One of the earliest-known Neanderthal discoveries\u2014the one on whom misinformed analysis shaped the stereotype of the species for nearly a century\u2014is the La Chapelle-aux-Saints Neanderthal (Trinkaus 1985). The La Chapelle Neanderthal had a damaged eye orbit that likely caused blindness and suffered arthritis of the spine (Dawson and Trinkaus 1997). He had also lost most of his teeth, many of which he had lived without for so long that the mandibular and maxillary bones were partially reabsorbed due to lack of use. The La Chapelle Neanderthal was also thought to be at least in his mid-forties at death, an old age for the rough life of the Late Pleistocene\u2014giving rise to his nickname, \u201cthe Old Man.\u201d To have survived so long with so many injuries that obviously precluded successful large game hunting, he must have been taken care of by others. Such caretaking behavior is also evident in the survival of other seriously injured Neanderthals, such as Shanidar 1. Long thought to be a hallmark modern human characteristic, taking care of the injured and elderly, for example preparing or pre-chewing food for those without teeth, indicates strong social ties among Neanderthals.<\/p>\n<h3 class=\"import-Normal\"><strong>Neanderthal Culture: Ritual Life<\/strong><\/h3>\n<p class=\"import-Normal\">Such care practices may have been expressed upon death as well. Nearly complete Neanderthal skeletons are not uncommon in the fossil record, and most are well preserved within apparently deliberate burials that involve deep graves and bodies found in specific, often fetal or <strong>flexed positions<\/strong> (Harrold 1980)<strong>.<\/strong> Discoveries of pollen in a grave at the Shanidar site in the 1960s led scientists to think that perhaps Neanderthals had placed flowering plants in the grave, an indication of ritual ceremony or spirituality so common in modern humans. But more recent investigations have raised some doubt about this conclusion (Pomeroy et al. 2020). The pollen may have been brought in by burrowing rodents. Claims of <strong>grave goods<\/strong> or other ornamentation in burials are similarly debated, although possible.<\/p>\n<p class=\"import-Normal\">Some tantalizing evidence for symbolism, and debatably, ritual, is the frequent occurrence of natural pigments, such as <strong>ochre<\/strong> (red) and manganese dioxide (black) in Neanderthal sites that could have been used for art. However, the actual uses of pigments are unclear, as there is very little evidence of art or paintings in Mousterian sites. One exception may be the recent discovery in Spain of a perforated shell that appears to be painted with an orange pigment, which may be evidence of Neanderthal art and jewelry. However, many pigments also have properties that make them good emulsifiers in adhesive (like for attaching a stone tool to a wooden handle) or useful in tanning hides. So the presence of pigment may or may not be associated with symbolic thought; however, it definitely does show a technological sophistication beyond that of earlier Archaic hominins.<\/p>\n<h3 class=\"import-Normal\"><strong>The Lasting Gift of Neanderthals: Tantalizing New Directions for Resear<\/strong><strong>ch<\/strong><\/h3>\n<p class=\"import-Normal\">Examining the more recent time period in which Neanderthals lived and the extensive excavations completed across Europe allows for a much more complete archaeological record from this time period. Additionally, the increased cultural complexity such as complex tools and ritual behaviors expressed by Neanderthals left a more detailed record than previous hominins. Intentional burials enhanced preservation of the dead and potentially associated ritual behaviors. Such evidence allows for a more complete and nuanced picture of this species.<\/p>\n<figure style=\"width: 424px\" class=\"wp-caption alignleft\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image15-5.png\" alt=\"Museum exhibition of life-sized Neanderthal figure.\" width=\"424\" height=\"469\" \/><figcaption class=\"wp-caption-text\">Figure 11.12: Artistic reconstruction of Neanderthal at The Natural History Museum in Vienna, Austria. Credit: <a href=\"https:\/\/commons.wikimedia.org\/wiki\/File:Homo_neanderthalensis,_The_Natural_History_Museum_Vienna,_20210730_1223_1272.jpg\">Homo neanderthalensis, The Natural History Museum Vienna, 20210730 1223 1272<\/a> by <a href=\"https:\/\/commons.wikimedia.org\/wiki\/User:Jakubhal\">Jakub Ha\u0142un<\/a> is under a <a href=\"https:\/\/creativecommons.org\/licenses\/by\/4.0\/legalcode\">CC BY 4.0 License<\/a>.<\/figcaption><\/figure>\n<p class=\"import-Normal\">Additional analyses are possible on many Neanderthal finds, due to increased preservation of bone, the amount of specimens that have been uncovered, and the recency in which Neanderthals lived. We should be cautious, however, to consider the potential bias of many Neanderthal sites. Overwhelmingly, Neanderthal skeletons are found complete, with injuries or evidence of disease in caves. Does this mean all Neanderthals lived a tough, disease-wrought life? Probably not. It does, however, indicate that the sick were cared for by others, and that they lived in environments that preserved their bodies incredibly well. These additional studies include the examination of dental calculus and even DNA analysis. While limited, samples of Neanderthal DNA have been successfully extracted and analyzed. Research thus far has identified specific genetic markers that show some Neanderthals were light-skinned and probably red-haired with light eyes. Genetic analyses, different from the typical hominin reconstruction done with earlier species, allow scientists to further investigate soft tissue markers of Neanderthals and other more recent hominin species. These studies offer striking conclusions regarding Neanderthal traits, their physical appearance, and their culture, as reflected in these artists\u2019 reconstructions (Figure 11.12).<\/p>\n<figure style=\"width: 258px\" class=\"wp-caption alignright\"><img class=\"\" src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image17-4.png\" alt=\"Photograph of Dr. Svante P\u00e4\u00e4bo in a blue suit and red tie.\" width=\"258\" height=\"368\" \/><figcaption class=\"wp-caption-text\">Figure 11.13: Nobel Prize winner (2022) and pioneer in paleogenomic research, Dr. Svante P\u00e4\u00e4bo. Credit: <a href=\"https:\/\/upload.wikimedia.org\/wikipedia\/commons\/2\/26\/Professor_Svante_Paabo_ForMemRS_%28cropped%29.jpg\">Professor Svante Paabo ForMemRS (cropped)<\/a> by Duncan.Hull is under a <a href=\"https:\/\/creativecommons.org\/licenses\/by-sa\/3.0\/legalcode\">CC BY-SA 3.0 License<\/a>.<\/figcaption><\/figure>\n<p class=\"import-Normal\">Dr. Svante P\u00e4\u00e4bo (Figure 11.13), of the Max Planck Institute for Evolutionary Anthropology, has been at the forefront of much of this new research, largely in the form of genomic studies (The Nobel Prize 2022). Awarded the Nobel Prize for Physiology or Medicine in 2022, P\u00e4\u00e4bo is known primarily for his work with ancient DNA. He has successfully sequenced mitochondrial DNA (mtDNA) as well as the entire Neanderthal genome from nuclear DNA. His genomic work has led to the realization that Denisovans are genetically distinct from Neanderthals, as well as the recent identification of a Neanderthal father and teenage daughter, which he discovered by looking for unique DNA markers in the fossil record. Additionally, P\u00e4\u00e4bo\u2019s genomic work has provided researchers with additional lines of evidence regarding the connections between hominin fossils (such as Neanderthals) and modern people, their time of divergence, and current genetic overlap. The work of P\u00e4\u00e4bo has even formalized a new field of study within anthropology\u2014paleogenomics. To stay up to date with Dr. Svante P\u00e4\u00e4bo\u2019s work, be sure to follow his <a href=\"https:\/\/www.eva.mpg.de\/genetics\/neandertals-and-more\/overview\/\">lab\u2019s website<\/a>.<\/p>\n<h3 class=\"import-Normal\"><strong>Neanderthal Culture: Communicating through Speech<\/strong><\/h3>\n<p class=\"import-Normal\">To successfully live in groups and to foster cultural innovations, Neanderthals would have required at least a basic form of communication in order to function, possibly using a speech-based communication system. The challenge with this line of research is that speech, of course, is not preserved, so indirect evidence must be used to support this conclusion. It is thought that Neanderthals would have possessed some basic speech, as evidenced from a variety of sources, including throat anatomy and genetic evidence (Lieberman 1971). There is only one bone in the human body that could demonstrate if a hominin was able to speak, or produce clear vocalizations like modern humans, and that is the hyoid, a U-shaped bone that is found in the throat and is associated with the ability to precisely control the vocal cords. Very few hyoid bones have been found in the archaeological record; however, a few have been uncovered in Neanderthal burials. The shape of the Neanderthal hyoid is nearly identical to that of modern humans, pointing to the likelihood that they had the same vocal capabilities as modern humans. In addition, geneticists have uncovered a mutation present in both modern humans and Neanderthals\u2014the FOXP2 gene\u2014that is possibly linked to the ability to speak. However, other scientists argue that we cannot make sweeping conclusions that the FOXP2 gene accounts for speech due to small sample size. Finally, scientists have also pointed to the increasingly complex cultural behavior of Neanderthals as a sign that symbolic communication, likely through speech, would have been the only way to pass down the skills needed to make, for example, a Levallois blade or to position a body for intentional burial.<\/p>\n<h3 class=\"import-Normal\"><strong>Neanderthal Intelligence<\/strong><\/h3>\n<p class=\"import-Normal\">One of the enduring questions about Neanderthals centers on their intelligence, specifically in comparison to modern humans. Brain volume indicates that Neanderthals certainly had a large brain, but it continues to be debated if Neanderthals were of equal intelligence to modern humans. Remember, creatures with larger body sizes tend to have larger brains; however, scaling of the brain is not always associated with greater intelligence (Alex 2018). Brain volume (cranial capacity), cultural complexity, tool use, and compassion toward their kind all point to an increase in intellect among Neanderthals when compared to previous hominins.<\/p>\n<p class=\"import-Normal\">Yet, new research is suggesting additional differences between Neanderthal brains and our own. For example, Euluned Pearce and colleagues (2013), from the University of Oxford, noted the frontal lobes of Neanderthals and modern humans are almost identical. However, Neanderthals had a larger visual cortex\u2014the portion of the brain involved in processing visual information. This would have left Neanderthals with less brain tissue for other functions, including those that would have aided them in dealing with large social groupings, one of the differences that has been suggested to exist between Neanderthals and modern humans. Other differences were found when geneticist John Blangero, from the Texas Biomedical Research Institute, compared data from the Neanderthal genome against data from modern study participants. Blangero and his colleagues (Blangero et al. 2014) discovered that some Neanderthal brain components were very different, and smaller, than those in the modern sample. Differences were found in areas associated with the processing of information and controlling emotion and motivation, as well as overall brain connectivity. In short, as Blangero stated, \u201cNeanderthals were certainly cognitively adept,\u201d although their specific abilities may have differed from modern humans\u2019 in key areas (qtd. in Wong 2015). This point has been echoed in other recent genetic studies comparing Neanderthal and anatomically modern human brains (el-Showk 2019).<\/p>\n<p class=\"import-Normal\">Finally, scientists are fairly certain that Neanderthal brain development after birth was not the same as that of modern humans. After birth, anatomically modern <em>Homo sapiens <\/em>babies go through a critical period of brain expansion and cognitive development. It appears that Neanderthal babies\u2019 brains and bodies did not follow the same developmental pattern (Smith et al. 2010; Zollikofer and Ponce de Le\u00f3n 2013). Modern humans enjoy an extended period of childhood, which allows children to engage in imaginative play and develop creativity that fosters cognitive skills. Neanderthals had a more limited childhood, with less development of the creative mind that may have affected their species\u2019 success (Nowell 2016).<\/p>\n<p class=\"import-Normal\">The exact nature of Neanderthal intelligence remains under investigation, however. Some studies disagree with the idea that Neanderthal intelligence had limitations compared to our own, noting the extensive evidence of Neanderthals having limb asymmetry. Their tools also have wear marks indicating that they were hand-dominant. This is further supported by marks on Neanderthal teeth that demonstrate hand dominance. The Neanderthal \u201cstuff-and-cut method\u201d of eating, noted by David Frayer and colleagues (Frayer et al. 2012), would have seen Neanderthals hold a piece of meat in their teeth, while pulling it taut with one hand, and then using the other hand, their dominant one, to cut the meat off of the larger slab being held in their teeth. When looking at 17 Neanderthals and their tooth wear, only two do not show markings associated with a right-hand dominant individual eating in this manner. Further, it has been established that favoring the right hand is a key marker between modern humans and chimpanzees, and that handedness also relates to language development, in the form of bilateral brain development. That Neanderthals likely were hand-dominant suggests they had an indicator of bilateral brain development and a precondition for human speech.<\/p>\n<h2 class=\"import-Normal\">The Middle Stone Age: Neanderthal Contemporaries in Africa<\/h2>\n<p class=\"import-Normal\">While Neanderthals made their home on and adapted to the European and Asian continents, evidence of fossil humans in Africa show they were also adapting to their local environments. These populations in Africa exhibit many more similarities to modern humans than Neanderthals, as well as overall evolutionary success. While the African fossil sample size is smaller and more fragmentary than the number of Neanderthal specimens across Europe and Asia, the African sample is interesting in that it represents a longer time period and larger geographical area. This group of fossils\u2014often represented by the name \u201cMiddle Stone Age,\u201d or MSA\u2014dates to between 300,000 and 30,000 years ago across the entire continent of Africa. As with Archaic <em>Homo sapiens<\/em>, there is much variability seen in this African set of fossils. There are also a few key consistent elements: none of them exhibit Neanderthal skeletal features; instead, they demonstrate features that are increasingly consistent with anatomically modern <em>Homo sapiens<\/em>.<\/p>\n<p class=\"import-Normal\">Similarities to Neanderthals and MSA contemporaries in Africa are seen, however, in their behavioral adaptations, including stone tools and other cultural elements. The tools associated with the specimens living in Africa during this time period are, like their physical features, varied. In some parts of Africa, namely Northern Africa, stone tools from this time so closely resemble Neanderthal tools that they are classified as Mousterian. In sub-Saharan Africa, the stone tools associated with these specimens are labeled as MSA. Some scholars argue that these could also be a type of Mousterian tools, but they are still typically subdivided based on geographical location.<\/p>\n<p class=\"import-Normal\">Recall that Mousterian tools were much more advanced than their Acheulean predecessors in terms of how the stone tools were manufactured, the quality of the stones used, and the ultimate use of the tools that were made. In addition, recent evidence suggests that MSA tools may also have been heat treated\u2014to improve the quality of the stone tool produced (Stolarczyk and Schmidt 2018). Evidence for heat treating is seen not only through advanced analysis of the tool itself but also through the residue of fires from this time period. Fire residues show a shift over time from small, short fires fueled by grasses (probably intended for cooking) to larger, more intensive fires that required the exploitation of dry wood, exactly the type of fire that would have been needed for heat treating stone tools (Esteban et al. 2018).<\/p>\n<p class=\"import-Normal\">Other cultural elements seen with MSA specimens include the use of marine (sea-based) resources for their diet (Parkington 2003), manufacture of bone tools, use of adhesive and compound tools (e.g., hafted tools), shell bead production, engraving, use of pigments (such as ochre), and other more advanced tool-making technology (e.g., microlithics). While many of these cultural elements are also seen to a limited extent among Neanderthals, developments at MSA sites appear more complex. This MSA cultural expansion may have been a response to climate change or an increased use of language, complex communication, and\/or symbolic thought. Others have suggested that the MSA cultural expansion was due to the increase of marine resources in their diet, which included more fatty acids that may have aided their cognitive development. Still others have suggested that the increased cultural complexity was due to increased interaction among groups, which spurred competition to innovate. Recent studies suggest that perhaps the best explanation for the marked cultural complexity of MSA cultural artifacts is best explained by the simple fact that they lived in diverse habitats (Kandel et al. 2015). This would have necessitated a unique set of cultural adaptations for each habitat type (for example, specialized marine tools would have been needed along coastal sites but not at inland locations). Simply put, the most useful adaptation of MSA was their flexibility of behavior and adaptability to their local environment. As noted previously in this chapter, flexibility of behavior and physical traits, rather than specialization, seems to be a feature that was favored in hominin evolution at this time.<\/p>\n<h2 class=\"import-Normal\">Where Did They Go? The End of Neanderthals<\/h2>\n<p class=\"import-Normal\">While MSA specimens were increasingly successful and ultimately transitioned into modern <em>Homo sapiens<\/em>, Neanderthals disappeared from the fossil record by around 40,000 years ago. What happened to them? We know, based on genetics, that modern humans come largely from the modern people who occupied Africa around 300,000 to 100,000 years ago, at the same time that Neanderthals were living in northern Europe and Asia. As you will learn in Chapter 12, modern humans expanded out of Africa around 150,000 years ago, rapidly entering areas of Europe and Asia inhabited by Neanderthals and other Archaic hominins. Despite intense interest and speculation in fictional works about possible interactions between these two groups, there is very little direct evidence of either peaceful coexistence or aggressive encounters. It is clear, though, that these two closely related hominins shared Europe for thousands of years, and recent DNA evidence suggests that they occasionally interbred (Fu et al. 2015). Geneticists have found traces of Neanderthal DNA (as much as 1% to 4%) in modern humans of European and Asian descent not present in modern humans from sub-Saharan Africa. This is indicative of limited regional interbreeding with Neanderthals.<\/p>\n<p class=\"import-Normal\">While some interbreeding likely occurred, as a whole, Neanderthals did not survive. What is the cause for their extinction? This question has fascinated many researchers and several <del>possibilities<\/del> <span style=\"text-decoration: underline;\">(theories)<\/span> have been suggested, including:<\/p>\n<ul>\n<li class=\"import-Normal\">At the time that Neanderthals were disappearing from the fossil record, the climate went through both cooling and warming periods\u2014each of which posed challenges for Neanderthal survival (Defleur and Desclaux 2019; Staubwasser et al. 2018). It has been argued that as temperatures warmed, large-bodied animals, well adapted to cold weather, moved farther north to find colder environments or faced extinction. A shifting resource base could have been problematic for continued Neanderthal existence, especially as additional humans, in the form of modern <em>Homo sapiens<\/em>, began to appear in Europe and compete for a smaller pool of available resources.<\/li>\n<li class=\"import-Normal\">It has been suggested that the eruption of a European volcano 40,000 years ago could have put a strain on available plant resources (Golovanova et al. 2010). The eruption would have greatly affected local microclimates, reducing the overall temperature enough to alter the growing season.<\/li>\n<li class=\"import-Normal\">Possible differences in cognitive development may have limited Neanderthals in terms of their creative problem solving. As much as they were biologically specialized for their environment, the nature of their intelligence might not have offered them the creative problem-solving skills to innovate ways to adapt their culture when faced with a changing environment (Pearce et al. 2013).<\/li>\n<li class=\"import-Normal\">CRISPR gene-editing technology has been used in studies to evaluate potential differences between human and Neanderthal brains, based on differences in the genetic code. Potential differences include a Neanderthal propensity for mutations related to brain development that could account for more rapid brain development, maturation, synapse misfires, and less-orderly neural processes (Mora-Berm\u00fadez et al. 2022; Trujillo et al. 2021). Fundamental differences in brain function at the cellular level may account for the differential survival rates of Neanderthal and modern human populations.<\/li>\n<li class=\"import-Normal\">There is evidence that suggests reproduction may have posed challenges for Neanderthals. Childbirth was thought to have been at least as difficult for female Neanderthals as anatomically modern <em>Homo sapiens<\/em> (Weaver and Hublin 2009). Female Neanderthals may have become sexually mature at an older age, even older than modern humans. This delayed maturation could have kept the Neanderthal population size small. A recent study has further suggested that male Neanderthals might have had a genetic marker on the Y chromosome that could have caused incompatibility between the fetus and mother during gestation; this would have had severe consequences for birth rate and survival (Mendez et al. 2016). Even a small but continuous decrease in fertility would have been enough to result in the extinction of Neanderthals (Degioanni et al. 2019).<\/li>\n<li class=\"import-Normal\">As mentioned above, the end of Neanderthal existence overlaps with modern human expansion into northern Europe and Asia. There is no conclusive direct evidence to indicate that Neanderthals and modern humans lived peacefully side by side, nor that they engaged in warfare, but by studying modern societies and the tendencies of modern humans, it has been suggested that modern humans may not have warmly embraced their close but slightly odd-looking cousins when they first encountered them (Churchill et al. 2009). Nevertheless, direct competition with modern humans for the same resources may have contributed to the Neanderthals\u2019 decline (Gilpin et al. 2016); it may also have exposed them to new diseases, brought by modern humans (Houldcroft and Underdown 2016), which further decimated their population. Estimates of energy expenditures suggest Neanderthals had slightly higher caloric needs than modern humans (Venner 2018). When competing for similar resources, the slightly greater efficiency of modern humans might have helped them experience greater success in the face of competition\u2014at a cost to Neanderthals.<\/li>\n<\/ul>\n<p class=\"import-Normal\"><span style=\"background-color: #ffff00;\">As Neanderthal populations were fairly small to begin with<\/span> (estimated between 5,000 and 70,000 individuals; Bocquet-Appel and Degioanni 2013), one or a combination of these factors could have easily led to their demise. As more research is conducted, we will likely get a better picture of exactly what led to Neanderthal extinction.<\/p>\n<h2 class=\"import-Normal\">Denisovans<\/h2>\n<figure style=\"width: 353px\" class=\"wp-caption alignleft\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image16-4.png\" alt=\"Small fossilized finger bone sitting atop a chalk outline of hand bones.\" width=\"353\" height=\"235\" \/><figcaption class=\"wp-caption-text\">Figure 11.14: Reproduction of Denisovan finger bone. Credit: <a href=\"https:\/\/upload.wikimedia.org\/wikipedia\/commons\/6\/6f\/Denisova_Phalanx_distalis.jpg\">Denisova Phalanx distalis<\/a> (image from Museum of Natural Sciences, Brussels, Belgium) by <a href=\"https:\/\/commons.wikimedia.org\/wiki\/User:Thilo_Parg\">Thilo Parg<\/a> is under a <a href=\"https:\/\/creativecommons.org\/licenses\/by-sa\/3.0\/legalcode\">CC BY-SA 3.0 License<\/a>.<\/figcaption><\/figure>\n<p class=\"import-Normal\">While Neanderthals represent one regionally adapted branch of the Archaic <em>Homo sapiens <\/em>family tree, recent discoveries in Siberia and the Tibetan Plateau surprised paleoanthropologists by revealing yet another population that was contemporary with Archaic <em>Homo sapiens<\/em>, Neanderthals, and modern <em>Homo sapiens<\/em>. The genetic analysis of a child\u2019s finger bone (Figure 11.14) and an adult upper third molar (Figure 11.15) from Denisova Cave in the Altai Mountains in Siberia by a team including Svante P\u00e4\u00e4bo discovered that the mitochondrial and nuclear DNA sequences reflected distinct genetic differences from all known Archaic populations. Dubbed \u201cDenisovans\u201d after the cave in which the bones were found, this population is more closely related to Neanderthals than modern humans, suggesting the two groups shared an ancestor who split from modern humans first, then the Neanderthal-Denisovan line diverged more recently (Reich et al. 2010).<\/p>\n<figure style=\"width: 227px\" class=\"wp-caption alignright\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image6-4-1.png\" alt=\"Molar tooth with wear, large surface area, and large roots.\" width=\"227\" height=\"341\" \/><figcaption class=\"wp-caption-text\">Figure 11.15: Reproduction of Denisovan molar. Credit: <a href=\"https:\/\/commons.wikimedia.org\/wiki\/File:Denisova_Molar.jpg\">Denisova Molar<\/a> by <a href=\"https:\/\/commons.wikimedia.org\/wiki\/User:Thilo_Parg\">Thilo Parg<\/a> is under a <a href=\"https:\/\/creativecommons.org\/licenses\/by-sa\/3.0\/legalcode\">CC BY-SA 3.0 License<\/a>.<\/figcaption><\/figure>\n<p class=\"import-Normal\">Denisovans share up to 5% of their DNA with modern Melanesians, aboriginal Australians, and Polynesians, and 0.2% of their DNA with other modern Asian populations and Native Americans. Additional studies have suggested one (Vernot et al. 2018) or two (Browning et al. 2018) separate points of time when interbreeding occurred between modern humans and Denisovans.<\/p>\n<p class=\"import-Normal\">Genetic analysis reveals that Denisovans (potentially three distinct populations) had adaptations for life at high altitudes that prevented them from developing altitude sickness and hypoxia in extreme environments such as Tibet, where the average annual temperature is close to 0\u2103 and the altitude is more than a kilometer (about 4,000 feet) above sea level. Through protein analysis of a jawbone, one study (Chen et al. 2019) has placed Denisovans in Tibet as early as 160,000 years ago. Genetic evidence of interbreeding has linked modern Tibetan populations with Denisovans 30,000 to 40,000 years ago, which implies that the unique high-altitude adaptations seen in modern Tibetans may have originated with Denisovans (Huerta-Sanchez et al. 2014).<\/p>\n<p class=\"import-Normal\">Other research suggests tantalizing new directions regarding Denisovans. Stone tools similar to those found in Siberia have been uncovered in the Tibetan plateau suggesting a connection between the Denisovan populations in those two areas (Zhang et al. 2018). The molar of a young girl, possibly Denisovan, has been found in Laos and shows strong similarities to specimens from China (Demeter et al. 2022). And DNA sequencing from discoveries in the Denisova Cave have yielded a genome that has been interpreted as the first-generation offspring of a Denisovan father and Neanderthal mother (Slon et al. 2018). While this research is not yet conclusive and is still being interpreted, exciting new possibilities are being revealed. To stay up-to-date with new discoveries, consider following organizations such as the <a href=\"https:\/\/www.facebook.com\/smithsonian.humanorigins\/\">Smithsonian\u2019s Human Origins Program<\/a> on social media.<\/p>\n<h2 class=\"import-Normal\">How Do These Fit In? <em>Homo naledi<\/em> and <em>Homo floresiensis<br \/>\n<\/em><\/h2>\n<p class=\"import-Normal\">Recently, some fossils have been unearthed that have challenged our understanding of the hominin lineage. The fossils of <em>Homo <\/em><em>naledi<\/em> and <em>Homo <\/em><em>floresiensis<\/em> are significant for several reasons but are mostly known for how they don\u2019t fit the previously held patterns of hominin evolution. While we examine information about these species, we ask you to consider the evidence presented in this chapter and others to draw your own conclusions regarding the significance and placement of these two unusual fossil species in the hominin lineage.<\/p>\n<h3 class=\"import-Normal\"><strong>Homo <\/strong><strong>naledi<\/strong><\/h3>\n<figure style=\"width: 347px\" class=\"wp-caption alignleft\"><img class=\"\" src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image12-5.png\" alt=\"A nearly complete skeleton surrounded by off-white bone fragments on a black table.\" width=\"347\" height=\"390\" \/><figcaption class=\"wp-caption-text\">Figure 11.16: A sample of some of the 1,550 bones found representing Homo naledi. Credit: <a href=\"https:\/\/elifesciences.org\/articles\/09560#fig1\">Dinaledi skeletal specimens (Figure 1)<\/a> by <a href=\"https:\/\/elifesciences.org\/articles\/09560\">Berger et al. 2015<\/a> is under a <a href=\"https:\/\/creativecommons.org\/licenses\/by\/4.0\/legalcode\">CC BY 4.0 License<\/a>.<\/figcaption><\/figure>\n<p class=\"import-Normal\">In 2013 recreational spelunkers uncovered a collection of bones deep in a cave network in Johannesburg, South Africa. <span style=\"background-color: #ccffcc;\">The cave system, known as Rising Star, had been well documented by other cavers; however, it appears few people had ever gone as far into the cave as these spelunkers did. Lee Berger, paleoanthropologist at University of Witwatersrand, in Johannesburg, immediately put out a call for what he termed \u201cunderground astronauts\u201d to begin recovery and excavation of the fossil materials. Unlike other excavations, Berger and most other paleoanthropologists would not be able to access the elusive site, as it was incredibly difficult to reach, and at some points there was only eight inches of space through which to navigate. The underground astronauts, all petite, slender female anthropologists, were the only ones who were able to access this remarkable site. Armed with small excavation tools and a video camera, which streamed the footage up to the rest of the team at the surface, the team worked together and uncovered a total of 1,550 bones, representing at least 15 individuals, as seen in Figure 11.16. Later, an additional 131 bones, including an almost-complete cranium, were found in a nearby chamber of the cave, representing three more individuals (Figure 11.17). Berger called in a team of specialists to participate in what was dubbed \u201cPaleoanthropology Summer Camp.\u201d Each researcher specialized in a different portion of the hominin skeleton. With various specialists working simultaneously, more rapid analysis was possible of <em>Homo <\/em><em>naledi<\/em> than most fossil discoveries.<\/span><\/p>\n<p>&nbsp;<\/p>\n<figure style=\"width: 534px\" class=\"wp-caption aligncenter\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image2-4.png\" alt=\"Photograph of four different views of the LES1 Homo naledi skull set against a black background.\" width=\"534\" height=\"599\" \/><figcaption class=\"wp-caption-text\">Figure 11.17: Several angles of the nearly complete LES1 Homo naledi skull. Credit: <a href=\"https:\/\/elifesciences.org\/articles\/24232#fig5\">LES1 Cranium (Figure 5)<\/a> by <a href=\"https:\/\/elifesciences.org\/articles\/24232\">Hawks et al. 2017<\/a> is under a <a href=\"https:\/\/creativecommons.org\/licenses\/by\/4.0\/legalcode\">CC BY 4.0 License<\/a>.<\/figcaption><\/figure>\n<p class=\"import-Normal\"><span style=\"background-color: #ccffcc;\">While access to the site, approximately 80 m from any known cave entrance or opening, was treacherous for researchers, it must have been difficult for <em>Homo <\/em><em>naledi<\/em> as well. The route included moving through a portion that is just 25 cm wide at some points, known as \u201cSuperman\u2019s Crawl.\u201d The only way to get through this section is by crawling on your stomach with one arm by your side and the other raised above your head. Past Superman\u2019s Crawl, a jagged wall known as the Dragon\u2019s Back would have been very difficult to traverse. Below that, a narrow vertical chute would have eventually led down to the area where the fossils were discovered. <\/span>While geology changes over time and the cave system likely has undergone its fair share, it is not likely that these features arose after <em>Homo <\/em><em>naledi<\/em> lived (Dirks et al. 2017). This has made scientists curious as to how the bones ended up in the bottom of the cave system in the first place. It has been suggested that <em>Homo <\/em><em>naledi<\/em> deposited the bones there, one way or another. If <em>Homo <\/em><em>naledi<\/em> did deposit the bones, either through random disposal or intentional burial, this raises questions regarding their symbolic behavior and other cultural traits, including the use of fire, to access a very dark cave system. Another competing idea is that a few individuals may have entered the cave system to escape a predator and then got stuck. To account for the sheer number of fossils, this would have had to happen multiple times.<\/p>\n<p class=\"import-Normal\">The features of <em>Homo <\/em><em>naledi<\/em> are well-documented due to the fairly large sample, which represents individuals of all sexes and a wide range of ages. The skull shape and features are very much like other members of the genus <em>Homo<\/em>\u2014including a sagittal keel and large brow, like <em>Homo <\/em><em>erectus<\/em>, and a well-developed frontal lobe, similar to modern humans\u2014yet the brain size is significantly smaller than its counterparts, at approximately 500 cc (560 cc for males and 465 cc for females). The teeth also exhibit features of later members of the genus <em>Homo<\/em>, such as Neanderthals, including a reduction in overall tooth size. <em>Homo <\/em><em>naledi<\/em> also had unique shoulder anatomy and curved fingers, indicating similarities to tree-dwelling primates, which is very different from any other hominin yet found. Perhaps the greatest shock of all is that <em>Homo <\/em><em>naledi<\/em> has been dated to 335,000 to 236,000 years ago, placing it as a contemporary to modern <em>Homo sapiens,<\/em> despite its very primitive features. An additional specimen of a child, found in 2021, not only shares many of the unique features found in the adult specimen but will also add insight into the growth and development of individuals of this species (Brophy et al. 2021).<\/p>\n<h3 class=\"import-Normal\"><strong>Homo <\/strong><strong>floresiensis<\/strong><\/h3>\n<p class=\"import-Normal\">In a small cave called Liang Bua, on the island of Flores, in Indonesia, a small collection of fossils were discovered beginning in 2003 (Figure 11.18). The fossil fragments represent as many as nine individuals, including a nearly complete female skeleton. The features of the skull are very similar to that of <em>Homo <\/em><em>erectus<\/em>, including the presence of a sagittal keel, an arching brow ridges and nuchal torus, and the lack of a chin (Figure 11.19). <em>Homo <\/em><em>floresiensis<\/em>, as the new species is called, had a brain size that was remarkably small at 400 cc, and recent genetic studies suggest a common ancestor with modern humans that predates <em>Homo <\/em><em>erectus<\/em>.<\/p>\n<p>&nbsp;<\/p>\n<figure style=\"width: 606px\" class=\"wp-caption aligncenter\"><img class=\"\" src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image8-3.png\" alt=\"View from inside a large cave with people standing near a dug-out square of dirt.\" width=\"606\" height=\"403\" \/><figcaption class=\"wp-caption-text\">Figure 11.18: Liang Bua Cave on the island of Flores, in Indonesia, where a collection of Homo floresiensis specimens were discovered. Credit: <a href=\"https:\/\/commons.wikimedia.org\/wiki\/File:Homo_floresiensis_cave.jpg\">Homo floresiensis cave<\/a> by <a href=\"https:\/\/www.flickr.com\/people\/84301190@N00\">Rosino<\/a> is under a <a href=\"https:\/\/creativecommons.org\/licenses\/by-sa\/2.0\/legalcode\">CC BY-SA 2.0 License<\/a>.<\/figcaption><\/figure>\n<figure style=\"width: 584px\" class=\"wp-caption aligncenter\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image9-5.png\" alt=\"Photograph of a gray and off-white cast Homo floresiensis skull.\" width=\"584\" height=\"584\" \/><figcaption class=\"wp-caption-text\">Figure 11.19: Homo floresiensis had a brain that was remarkably small at 400 cc. Recent genetic studies suggest a common ancestor with modern humans that predates Homo erectus. Credit: <a href=\"https:\/\/boneclones.com\/product\/homo-floresiensis-skull-BH-033-2\">Homo floresiensis Skull (Flores Skull LB1)<\/a> by <a href=\"https:\/\/boneclones.com\/\">\u00a9BoneClones<\/a> is used by permission and available here under a <a href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/\">CC BY-NC 4.0 License<\/a>.<\/figcaption><\/figure>\n<p class=\"import-Normal\">The complete female skeleton, who was an adult, was approximately a meter tall and would have weighed just under 30 kg, which is significantly shorter and just a few kilograms more than the average, modern, young elementary-aged child. A reconstructed comparison between an anatomically modern human and <em>Homo <\/em><em>floresiensis<\/em> can be seen in Figure 11.20. The small size of the fossil has earned the species the nickname \u201cthe Hobbit.\u201d Many questions have been asked about the stature of this species, as all of the specimens found also show evidence of diminutive stature and small brain size. Some explanations include pathology; however, this seems unlikely as all fossils found thus far demonstrate the same pattern. Another possible explanation lies in a biological phenomena seen in other animal species also found on the island, which date to a similar time period. This phenomenon, called <strong>insular dwarfing<\/strong>, is due to limited food resources on an island, which can create a selective pressure for large-bodied species to be selected for smaller size, as an island would not have been able to support their larger-bodied cousins for a long period of time. This phenomenon is the cause of other unique species known to have lived on the island at the same time, including the miniature stegodon, a dwarf elephant species.<\/p>\n<figure style=\"width: 448px\" class=\"wp-caption aligncenter\"><img class=\"\" src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image18-4.png\" alt=\"Black-and-white drawing of a large nude woman and a much smaller man.\" width=\"448\" height=\"611\" \/><figcaption class=\"wp-caption-text\">Figure 11.20: A reconstructed comparison between an anatomically modern human and Homo floresiensis. As an adult, Homo floresiensis was approximately 1 meter tall and would have weighed under 30 kg. Credit: <a href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/chapter\/__unknown__-16\/\">Anatomically modern human and Homo floresiensis (Figure 11.19)<\/a> original to <a href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\">Explorations: An Open Invitation to Biological Anthropology<\/a> by Mary Nelson is under a <a href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/\">CC BY-NC 4.0 License<\/a>.<\/figcaption><\/figure>\n<p class=\"import-Normal\">There is ongoing research and debate regarding <em>Homo floresiensis<\/em>\u2019 dates of existence, with some researchers concluding that they lived on Flores until perhaps as recently as 17,000 years ago, although they are more often dated to 100,000 to 60,000 years ago. Stone tools from that time period uncovered at the site are similar to other hominin stone tools found on the island of Flores. <em>Homo <\/em><em>floresiensis<\/em> would have hunted a wide range of animals, including the miniature stegodon, giant rats, and other large rodents. Other animals on the island that could have threatened them include the giant komodo dragon. An interesting note about this island chain is that ancestors of <em>Homo <\/em><em>floresiensis<\/em> would have had to traverse the open ocean in order to get there, as the nearest island is almost 10 km away, and there is little evidence to support that a land bridge connecting mainland Asia or Australia to the island would have been present. This separation from the mainland would also have limited the number of other animals, including predators and human species, that would have had access to the island. Anatomically modern <em>Homo sapiens<\/em> arrived on the island around 30,000 years ago and, if some researchers\u2019 later dates for <em>Homo <\/em><em>floresiensis<\/em> are correct, both species may have lived on Flores at the same time. The modern population living on the island of Flores today believes that their ancestors came from the Liang Bua cave; however, recent genetic studies have determined they are not related to <em>Homo <\/em><em>floresiensis<\/em> (Tucci et al. 2018).<\/p>\n<h2 class=\"import-Normal\"><span style=\"background-color: #ff99cc;\">Conclusion<\/span><\/h2>\n<p class=\"import-Normal\"><span style=\"background-color: #ff99cc;\">Research presented in the chapter contributes to why scientists have taken to nicknaming this time period \u201cthe muddle in the middle.\u201d We know that the Middle Pleistocene picks up from <em>Homo erectus <\/em>and ends with the appearance of anatomically modern <em>Homo sapiens<\/em>. While the start and the end are clear, it\u2019s the middle that is messy. As more research is conducted and more data is collected, rather than clarifying our understanding of the hominin lineage during this time period, it only inspires more questions, particularly about the relationships between hominins during this time period, including the oft-misunderstood Neanderthal. Research is painting a more detailed picture of Neanderthal intelligence and both biological and behavioral adaptations. At the same time, their relationship to other Middle Pleistocene hominins, including Denisovans, as well as modern humans, remains unclear.<\/span><\/p>\n<p class=\"import-Normal\"><span style=\"background-color: #ff99cc;\"><em>Homo<\/em> <em>naledi<\/em> and <em>Homo <\/em><em>floresiensis<\/em> are clear outliers when compared to their contemporary hominin species. Each has surprised paleoanthropologists for both their archaic traits in relatively modern times and their unique combination of traits seen in archaic species and modern humans. While these finds have been exciting, they have also completely upended the assumed trajectory of the human lineage, causing scientists to re-examine assumptions about hominin evolution and what it means to be modern. Add this to the developments being made using ancient DNA, other new fossil discoveries, and other innovations in paleoanthropology, and you see that our understanding of Archaic <em>Homo sapiens<\/em> and others living during this time period is rapidly developing and changing. This is a true testament to the nature of science and the scientific method.<\/span><\/p>\n<p class=\"import-Normal\"><span style=\"background-color: #ff99cc;\">Clearly, hominins of the Middle Pleistocene are distinct from our species today. Yet, understanding the hominins that directly preceded our species and clarifying the evolutionary relationships between us is important to better understanding our own place in nature.<\/span><\/p>\n<h2 class=\"import-Normal\" style=\"background-color: #ffffff; color: #ffffff;\"><span style=\"color: #000000;\">Hominin Species Summaries<\/span><\/h2>\n<div style=\"text-align: left;\">\n<table class=\"aligncenter\" style=\"width: 468pt;\">\n<tbody>\n<tr class=\"Table3-R\" style=\"height: 0;\">\n<td class=\"Table3-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\"><strong>Hominin<\/strong><\/p>\n<\/td>\n<td class=\"Table3-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\">Archaic <em>Homo sapiens<\/em><\/p>\n<\/td>\n<\/tr>\n<tr class=\"Table3-R\" style=\"height: 0;\">\n<td class=\"Table3-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\"><strong>Dates<\/strong><\/p>\n<\/td>\n<td class=\"Table3-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\">600,000\u2013200,000 years ago (although some regional variation)<\/p>\n<\/td>\n<\/tr>\n<tr class=\"Table3-R\" style=\"height: 0;\">\n<td class=\"Table3-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\"><strong>Region(s)<\/strong><\/p>\n<\/td>\n<td class=\"Table3-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\">Africa, Europe, and Asia<\/p>\n<\/td>\n<\/tr>\n<tr class=\"Table3-R\" style=\"height: 0;\">\n<td class=\"Table3-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\"><strong>Famous discoveries<\/strong><\/p>\n<\/td>\n<td class=\"Table3-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\">Broken Hill (Zambia), Atapuerca (Spain)<\/p>\n<\/td>\n<\/tr>\n<tr class=\"Table3-R\" style=\"height: 0;\">\n<td class=\"Table3-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\"><strong>Brain size<\/strong><\/p>\n<\/td>\n<td class=\"Table3-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\">1,200 cc average<\/p>\n<\/td>\n<\/tr>\n<tr class=\"Table3-R\" style=\"height: 0;\">\n<td class=\"Table3-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\"><strong>Dentition<\/strong><\/p>\n<\/td>\n<td class=\"Table3-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\">Slightly smaller teeth in back of mouth, larger front teeth<\/p>\n<\/td>\n<\/tr>\n<tr class=\"Table3-R\" style=\"height: 0;\">\n<td class=\"Table3-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\"><strong>Cranial features<\/strong><\/p>\n<\/td>\n<td class=\"Table3-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\">Emerging forehead, no chin, projecting occipital region<\/p>\n<\/td>\n<\/tr>\n<tr class=\"Table3-R\" style=\"height: 0;\">\n<td class=\"Table3-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\"><strong>Postcranial features<\/strong><\/p>\n<\/td>\n<td class=\"Table3-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\">Robust skeleton<\/p>\n<\/td>\n<\/tr>\n<tr class=\"Table3-R\" style=\"height: 0;\">\n<td class=\"Table3-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\"><strong>Culture<\/strong><\/p>\n<\/td>\n<td class=\"Table3-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\">Varied regionally, but some continue to use Acheulean handaxe, others adopt Mousterian tool culture<\/p>\n<\/td>\n<\/tr>\n<tr class=\"Table3-R\" style=\"height: 0;\">\n<td class=\"Table3-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\"><strong>Other <\/strong><\/p>\n<\/td>\n<td class=\"Table3-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\">Lots of regional variation in this species<\/p>\n<\/td>\n<\/tr>\n<tr>\n<td><\/td>\n<td><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<div style=\"text-align: left;\">\n<table class=\"aligncenter\" style=\"width: 468pt;\">\n<tbody>\n<tr class=\"Table4-R\" style=\"height: 0;\">\n<td class=\"Table4-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\"><strong>Species<\/strong><\/p>\n<\/td>\n<td class=\"Table4-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\"><em>Homo <\/em><em>naledi<\/em><\/p>\n<\/td>\n<\/tr>\n<tr class=\"Table4-R\" style=\"height: 0;\">\n<td class=\"Table4-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\"><strong>Dates<\/strong><\/p>\n<\/td>\n<td class=\"Table4-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\">335,000\u2013236,000 years ago<\/p>\n<\/td>\n<\/tr>\n<tr class=\"Table4-R\" style=\"height: 0;\">\n<td class=\"Table4-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\"><strong>Region(s)<\/strong><\/p>\n<\/td>\n<td class=\"Table4-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\">South Africa<\/p>\n<\/td>\n<\/tr>\n<tr class=\"Table4-R\" style=\"height: 0;\">\n<td class=\"Table4-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\"><strong>Famous discoveries<\/strong><\/p>\n<\/td>\n<td class=\"Table4-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\">Rising Star Cave<\/p>\n<\/td>\n<\/tr>\n<tr class=\"Table4-R\" style=\"height: 0;\">\n<td class=\"Table4-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\"><strong>Brain size<\/strong><\/p>\n<\/td>\n<td class=\"Table4-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\">500 cc average<\/p>\n<\/td>\n<\/tr>\n<tr class=\"Table4-R\" style=\"height: 0;\">\n<td class=\"Table4-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\"><strong>Dentition<\/strong><\/p>\n<\/td>\n<td class=\"Table4-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\">Reduced tooth size<\/p>\n<\/td>\n<\/tr>\n<tr class=\"Table4-R\" style=\"height: 0;\">\n<td class=\"Table4-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\"><strong>Cranial features<\/strong><\/p>\n<\/td>\n<td class=\"Table4-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\">Sagittal keel, large brow, well-developed frontal region<\/p>\n<\/td>\n<\/tr>\n<tr class=\"Table4-R\" style=\"height: 0;\">\n<td class=\"Table4-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\"><strong>Postcranial features<\/strong><\/p>\n<\/td>\n<td class=\"Table4-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\">Suspensory shoulder<\/p>\n<\/td>\n<\/tr>\n<tr class=\"Table4-R\" style=\"height: 0;\">\n<td class=\"Table4-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\"><strong>Culture<\/strong><\/p>\n<\/td>\n<td class=\"Table4-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\">unknown<\/p>\n<\/td>\n<\/tr>\n<tr class=\"Table4-R\" style=\"height: 0;\">\n<td class=\"Table4-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\"><strong>Other<\/strong><\/p>\n<\/td>\n<td class=\"Table4-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\">N\/A<\/p>\n<\/td>\n<\/tr>\n<tr>\n<td><\/td>\n<td><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<div style=\"text-align: left;\">\n<table class=\"aligncenter\" style=\"width: 468pt;\">\n<tbody>\n<tr class=\"Table5-R\" style=\"height: 0;\">\n<td class=\"Table5-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\"><strong>Hominin<\/strong><\/p>\n<\/td>\n<td class=\"Table5-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\">Neanderthals<\/p>\n<\/td>\n<\/tr>\n<tr class=\"Table5-R\" style=\"height: 0;\">\n<td class=\"Table5-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\"><strong>Dates<\/strong><\/p>\n<\/td>\n<td class=\"Table5-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\">150,000\u201340,000 years ago<\/p>\n<\/td>\n<\/tr>\n<tr class=\"Table5-R\" style=\"height: 0;\">\n<td class=\"Table5-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\"><strong>Region(s)<\/strong><\/p>\n<\/td>\n<td class=\"Table5-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\">Western Europe, Middle East, and Western Asia only<\/p>\n<\/td>\n<\/tr>\n<tr class=\"Table5-R\" style=\"height: 0;\">\n<td class=\"Table5-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\"><strong>Famous discoveries<\/strong><\/p>\n<\/td>\n<td class=\"Table5-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\">Shanidar (Iraq), La Chapelle-aux-Saints (France)<\/p>\n<\/td>\n<\/tr>\n<tr class=\"Table5-R\" style=\"height: 0;\">\n<td class=\"Table5-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\"><strong>Brain size<\/strong><\/p>\n<\/td>\n<td class=\"Table5-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\">1500 cc average<\/p>\n<\/td>\n<\/tr>\n<tr class=\"Table5-R\" style=\"height: 0;\">\n<td class=\"Table5-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\"><strong>Dentition<\/strong><\/p>\n<\/td>\n<td class=\"Table5-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\">Retromolar gap<\/p>\n<\/td>\n<\/tr>\n<tr class=\"Table5-R\" style=\"height: 0;\">\n<td class=\"Table5-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\"><strong>Cranial features<\/strong><\/p>\n<\/td>\n<td class=\"Table5-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\">Large brow ridge, midfacial prognathism, large infraorbital foramina, occipital bun<\/p>\n<\/td>\n<\/tr>\n<tr class=\"Table5-R\" style=\"height: 0;\">\n<td class=\"Table5-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\"><strong>Postcranial features<\/strong><\/p>\n<\/td>\n<td class=\"Table5-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\">Robust skeleton with short and stocky body, increased musculature, barrel chest<\/p>\n<\/td>\n<\/tr>\n<tr class=\"Table5-R\" style=\"height: 0;\">\n<td class=\"Table5-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\"><strong>Culture<\/strong><\/p>\n<\/td>\n<td class=\"Table5-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\">Mousterian tools often constructed using the Levallois technique<\/p>\n<\/td>\n<\/tr>\n<tr class=\"Table5-R\" style=\"height: 0;\">\n<td class=\"Table5-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\"><strong>Other<\/strong><\/p>\n<\/td>\n<td class=\"Table5-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\">N\/A<\/p>\n<\/td>\n<\/tr>\n<tr>\n<td><\/td>\n<td><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<div style=\"text-align: left;\">\n<table class=\"aligncenter\" style=\"width: 468pt;\">\n<tbody>\n<tr class=\"Table6-R\" style=\"height: 0;\">\n<td class=\"Table6-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\"><strong>Species<\/strong><\/p>\n<\/td>\n<td class=\"Table6-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\"><em>Homo <\/em><em>floresiensis<\/em><\/p>\n<\/td>\n<\/tr>\n<tr class=\"Table6-R\" style=\"height: 0;\">\n<td class=\"Table6-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\"><strong>Dates<\/strong><\/p>\n<\/td>\n<td class=\"Table6-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\">100,000\u201360,000 years ago, perhaps as recently as 17,000 years ago<\/p>\n<\/td>\n<\/tr>\n<tr class=\"Table6-R\" style=\"height: 0;\">\n<td class=\"Table6-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\"><strong>Region(s)<\/strong><\/p>\n<\/td>\n<td class=\"Table6-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\">Liang Bua, island of Flores, Indonesia<\/p>\n<\/td>\n<\/tr>\n<tr class=\"Table6-R\" style=\"height: 0;\">\n<td class=\"Table6-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\"><strong>Famous discoveries<\/strong><\/p>\n<\/td>\n<td class=\"Table6-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\">\u201cThe Hobbit\u201d<\/p>\n<\/td>\n<\/tr>\n<tr class=\"Table6-R\" style=\"height: 0;\">\n<td class=\"Table6-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\"><strong>Brain size<\/strong><\/p>\n<\/td>\n<td class=\"Table6-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\">400 cc average<\/p>\n<\/td>\n<\/tr>\n<tr class=\"Table6-R\" style=\"height: 0;\">\n<td class=\"Table6-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\"><strong>Dentition<\/strong><\/p>\n<\/td>\n<td class=\"Table6-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\">unknown<\/p>\n<\/td>\n<\/tr>\n<tr class=\"Table6-R\" style=\"height: 0;\">\n<td class=\"Table6-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\"><strong>Cranial features<\/strong><\/p>\n<\/td>\n<td class=\"Table6-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\">Sagittal keel, arching brow ridges, nuchal torus, no chin<\/p>\n<\/td>\n<\/tr>\n<tr class=\"Table6-R\" style=\"height: 0;\">\n<td class=\"Table6-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\"><strong>Postcranial features<\/strong><\/p>\n<\/td>\n<td class=\"Table6-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\">Very short stature (approximately 3.5 ft.)<\/p>\n<\/td>\n<\/tr>\n<tr class=\"Table6-R\" style=\"height: 0;\">\n<td class=\"Table6-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\"><strong>Culture<\/strong><\/p>\n<\/td>\n<td class=\"Table6-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\">Tools similar to other tools found on the island of Flores<\/p>\n<\/td>\n<\/tr>\n<tr class=\"Table6-R\" style=\"height: 0;\">\n<td class=\"Table6-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\"><strong>Other<\/strong><\/p>\n<\/td>\n<td class=\"Table6-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\">N\/A<\/p>\n<\/td>\n<\/tr>\n<tr>\n<td><\/td>\n<td><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<div style=\"text-align: left;\">\n<table class=\"aligncenter\" style=\"width: 468pt;\">\n<tbody>\n<tr class=\"Table7-R\" style=\"height: 0;\">\n<td class=\"Table7-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\"><strong>Hominin<\/strong><\/p>\n<\/td>\n<td class=\"Table7-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\">Denisovans<\/p>\n<\/td>\n<\/tr>\n<tr class=\"Table7-R\" style=\"height: 0;\">\n<td class=\"Table7-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\"><strong>Dates<\/strong><\/p>\n<\/td>\n<td class=\"Table7-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\">100,000\u201330,000 years ago<\/p>\n<\/td>\n<\/tr>\n<tr class=\"Table7-R\" style=\"height: 0;\">\n<td class=\"Table7-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\"><strong>Region(s)<\/strong><\/p>\n<\/td>\n<td class=\"Table7-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\">Siberia<\/p>\n<\/td>\n<\/tr>\n<tr class=\"Table7-R\" style=\"height: 0;\">\n<td class=\"Table7-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\"><strong>Famous discoveries<\/strong><\/p>\n<\/td>\n<td class=\"Table7-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\">Child\u2019s finger bone and adult molar<\/p>\n<\/td>\n<\/tr>\n<tr class=\"Table7-R\" style=\"height: 0;\">\n<td class=\"Table7-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\"><strong>Brain size<\/strong><\/p>\n<\/td>\n<td class=\"Table7-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\">unknown<\/p>\n<\/td>\n<\/tr>\n<tr class=\"Table7-R\" style=\"height: 0;\">\n<td class=\"Table7-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\"><strong>Dentition<\/strong><\/p>\n<\/td>\n<td class=\"Table7-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\">Large molars (from limited evidence)<\/p>\n<\/td>\n<\/tr>\n<tr class=\"Table7-R\" style=\"height: 0;\">\n<td class=\"Table7-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\"><strong>Cranial features<\/strong><\/p>\n<\/td>\n<td class=\"Table7-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\">unknown<\/p>\n<\/td>\n<\/tr>\n<tr class=\"Table7-R\" style=\"height: 0;\">\n<td class=\"Table7-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\"><strong>Postcranial features<\/strong><\/p>\n<\/td>\n<td class=\"Table7-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\">unknown<\/p>\n<\/td>\n<\/tr>\n<tr class=\"Table7-R\" style=\"height: 0;\">\n<td class=\"Table7-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\"><strong>Culture<\/strong><\/p>\n<\/td>\n<td class=\"Table7-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\">unknown<\/p>\n<\/td>\n<\/tr>\n<tr class=\"Table7-R\" style=\"height: 0;\">\n<td class=\"Table7-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\"><strong>Other <\/strong><\/p>\n<\/td>\n<td class=\"Table7-C\" style=\"background-color: transparent; padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\">Closely related to Neanderthals (genetically)<\/p>\n<\/td>\n<\/tr>\n<tr>\n<td><\/td>\n<td><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<div class=\"textbox shaded\">\n<h2 class=\"import-Normal\">Review Questions<\/h2>\n<ul>\n<li>What physical and cultural features are unique to Archaic<em> Homo sapiens<\/em>? How are Archaic<em> Homo sapiens<\/em> different in both physical and cultural characteristics from <em>Homo <\/em><em>erectus<\/em>?<\/li>\n<li>Describe the specific changes to the brain and skull first seen in Archaic<em> Homo sapiens<\/em>. Why does the shape of the skull change so dramatically from <em>Homo <\/em><em>erectus<\/em>?<\/li>\n<li>What role did the shifting environment play in the adaptation of Archaic <em>Homo sapiens<\/em>, including Neanderthals? Discuss at least one physical feature and one cultural feature that would have assisted these groups in surviving the changing environment.<\/li>\n<li>What does the regional variation in Archaic <em>Homo sapiens<\/em> represent in terms of the broader story of our species\u2019 evolution?<\/li>\n<li>Describe the issues raised by the discoveries of <em>Homo <\/em><em>naledi<\/em> and <em>Homo <\/em><em>floresiensis<\/em> in the understanding of the story of the evolution of <em>Homo sapiens<\/em>.<\/li>\n<\/ul>\n<\/div>\n<\/div>\n<h2 class=\"__UNKNOWN__\">Key Terms<\/h2>\n<div class=\"__UNKNOWN__\">\n<p><strong>Allele<\/strong>: Each of two or more alternative forms of a gene that arise by mutation and are found at the same place on a chromosome.<\/p>\n<p class=\"import-Normal\"><strong>Anthropocentrism<\/strong>: A way of thinking that assumes humans are the most important species and leads to interpreting the world always through a human lens. Species-centric science and thought.<\/p>\n<p class=\"import-Normal\"><strong>Cortex<\/strong>: The outside, or rough outer covering, of a rock. Usually the cortex is removed during the process of stone tool creation.<\/p>\n<p class=\"import-Normal\"><strong>Ethnocentric<\/strong>: Applying negative judgments to other cultures based on comparison to one\u2019s own.<\/p>\n<p class=\"import-Normal\"><strong>Exogenous DNA<\/strong>: DNA that originates from sources outside of the specimen you are trying to sequence.<\/p>\n<p class=\"import-Normal\"><strong>Flexed position<\/strong>: Fetal position, in which the legs are drawn up to the middle of the body and the arms are drawn toward the body center. Intentional burials are often found in the flexed body position.<\/p>\n<p class=\"import-Normal\"><strong>Foraminifera<\/strong>: Microscopic single-celled organisms with a shell that are common in all marine environments. The fossil record of foraminifera extends back well over 500 million years.<\/p>\n<p class=\"import-Normal\"><strong>Glaciation<\/strong>: A glacial period, or time when a large portion of the world is covered by glaciers and ice sheets.<\/p>\n<p class=\"import-Normal\"><strong>Globular<\/strong>: Round-shaped, like a globe.<\/p>\n<p class=\"import-Normal\"><strong>Grave goods<\/strong>: Items included with a body at burial. Items may signify occupation or hobbies, social status, or level of importance in the community, or they may be items believed necessary for the afterlife.<\/p>\n<p class=\"import-Normal\"><strong>Haft<\/strong>: A handle. Also used as a verb\u2014to attach a handle to an item, such as a stone tool.<\/p>\n<p class=\"import-Normal\"><strong>Infraorbital foramina<\/strong>: Small holes on the maxilla bone of the face that allows nerves and blood to reach the skin.<\/p>\n<p class=\"import-Normal\"><strong>Insular dwarfing<\/strong>: A form of dwarfism that occurs when a limited geographic region, such as an island, causes a large-bodied animal to be selected for a smaller body size.<\/p>\n<p class=\"import-Normal\"><strong>Interglacial<\/strong>: A warmer period between two glacial time periods.<\/p>\n<p class=\"import-Normal\"><strong>Levallois technique<\/strong>: A distinctive technique of stone tool manufacturing used by Archaic <em>Homo sapiens<\/em>, including Neanderthals. The technique involves the preparation of a core and striking edges off in a regular fashion around the core. Then a series of similarly sized pieces can be removed, which can then be turned into different tools.<\/p>\n<p class=\"import-Normal\"><strong>Midfacial prognathism<\/strong>: A forward projection of the nose or the middle facial region. Usually associated with Neanderthals.<\/p>\n<p class=\"import-Normal\"><strong>Mousterian tools<\/strong>: The stone tool industry of Neanderthals and their contemporaries in Africa and Western Asia. Mousterian tools are known for a diverse set of flake tools, which is different from the large bifacial tools of the Acheulean industry.<\/p>\n<p class=\"import-Normal\"><strong>Nasal aperture<\/strong>: The opening for the nose visible on a skull. Often pear- or heart-shaped.<\/p>\n<p class=\"import-Normal\"><strong>Occipital bun<\/strong>: A prominent bulge or projection on the back of the skull, specifically the occipital bone. This is a feature present only on Neanderthal skulls.<\/p>\n<p class=\"import-Normal\"><strong>Ochre<\/strong>: A natural clay pigment mixed with ferric oxide and clay and sand. Ranges in color from brown to red to orange.<\/p>\n<p class=\"import-Normal\"><strong>Retracted face<\/strong>: A face that is flatter.<\/p>\n<p class=\"import-Normal\"><strong>Retromolar gap<\/strong>: A space behind the last molar and the end of the jaw. This is a feature present only on Neanderthals. It also occurs through cultural modification in modern humans who have had their third molars, or wisdom teeth, removed.<\/p>\n<h2 class=\"import-Normal\">About the Authors<\/h2>\n<h3 class=\"import-Normal\"><img class=\"alignleft wp-image-348\" src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/apaskey09.jpg\" alt=\"Headshot of author Amanda Wolcott Paskey.\" width=\"194\" height=\"271\" \/><strong>Amanda Wolcott Paskey, M.A.<\/strong><\/h3>\n<p class=\"import-Normal\">Cosumnes River College, <a class=\"rId98\" href=\"mailto:paskeya@crc.losrios.edu\">paskeya@crc.losrios.edu<\/a><\/p>\n<p class=\"import-Normal\">Amanda Wolcott Paskey is an anthropology professor at Cosumnes River College in Sacramento, California. She earned her B.A. and M.A. in anthropology from the University of California, Davis. Her speciality in anthropology is archaeology; however, she was trained in a holistic program and most of her teaching load is in biological anthropology. She is currently working on analyzing a post\u2013gold rush era archaeological site, in Sacramento, with colleagues and students. This project has given her many opportunities to engage in sharing archaeology with a public audience, including local school children and Sacramentans interested in local history.<\/p>\n<h3 class=\"import-Normal\"><img class=\"wp-image-349 alignleft\" src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/ABeasley-Photo.jpg\" alt=\"Headshot of author AnneMarie Beasley Cisneros.\" width=\"192\" height=\"255\" \/><strong>AnnMarie Beasley Cisneros, M.A.<\/strong><\/h3>\n<p class=\"import-Normal\">American River College, <a class=\"rId99\" href=\"mailto:beaslea@arc.losrios.edu\">beaslea@arc.losrios.edu<\/a><\/p>\n<p class=\"import-Normal\">AnnMarie Beasley Cisneros is an anthropology professor at American River College in Sacramento, California. Trained as a four-field anthropologist, she earned her B.A. and M.A. in anthropology from California State University, Sacramento. She regularly teaches biological anthropology, among other courses, and is currently engaged in applied anthropology work in community development with historically underserved communities. She most recently has particularly enjoyed facilitating her students\u2019 involvement in projects serving Sacramento\u2019s Latino and immigrant Mexican populations.<\/p>\n<h2 class=\"import-Normal\">For Further Exploration<\/h2>\n<p><a href=\"https:\/\/www.amnh.org\/exhibitions\/permanent-exhibitions\/anne-and-bernard-spitzer-hall-of-human-origins\">Anne and Bernard Spitzer Hall of Human Origins<\/a>\u2014American Museum of Natural History.<\/p>\n<p>\u201cDawn of Humanity,\u201d PBS documentary, 2015<\/p>\n<p><a href=\"https:\/\/www.ted.com\/talks\/svante_paeaebo_dna_clues_to_our_inner_neanderthal?language=en\">\u201cDNA Clues to Our Inner Neanderthal,\u201d<\/a> TED Talk by Svante P\u00e4\u00e4bo, 2011.<\/p>\n<p>\u201cThe Dirt\u201d Podcast, Episode 30, <a href=\"https:\/\/thedirtpod.com\/episodes\/\/episode-30-the-human-family-tree-shrub-crabgrass-tumbleweed-part-3\">\u201cThe Human Family Tree (Shrub? Crabgrass? Tumbleweed?), Part 3: Very Humany Indeed\u201d<\/a>.<\/p>\n<p class=\"import-Normal\"><a href=\"https:\/\/www.efossils.org\/page\/games-and-activities\">eFossil Games and Activities<\/a><\/p>\n<p>Frank, Rebecca. 2021. \u201cThe Genus Homo.\u201d In <a href=\"https:\/\/explorations.americananthro.org\/index.php\/lab-and-activities-manual\/\"><em>Explorations: Lab and Activity Manual, <\/em><\/a>edited by Beth Shook, Katie Nelson, Kelsie Aguilera, and Lara Braff. Arlington, VA: American Anthropological Association.<\/p>\n<p><a href=\"https:\/\/humanorigins.si.edu\/research\/asian-research-projects\/hobbits-flores-indonesia.\">Hobbits on Flores, Indonesia<\/a> - Smithsonian Human Origins.<\/p>\n<p><a href=\"https:\/\/evolution.berkeley.edu\/evo-news\/lumping-or-splitting-in-the-fossil-record\/\">Lumping or Splitting in the Fossil Record<\/a> - UC Berkeley Understanding Evolution.<\/p>\n<p><a href=\"https:\/\/www.eva.mpg.de\/genetics\/neandertals-and-more\/overview\/\">Neandertals and More<\/a>\u00a0- Max Planck Institute for Evolutionary Anthropology.<\/p>\n<p><a href=\"https:\/\/www.sapiens.org\/biology\/neanderthal-anatomy\/?fbclid=IwAR2Bcff1GVkTLnbCR58JAWiJzkk-Ell7zL0FUddf1HNAX6RDAZxbqh1zWoI\">Neanderthals: Body of Evidence<\/a> - SAPIENS.<\/p>\n<p>Perash, Rose L., and Kristen A. Broehl. 2021. \u201cHominin Review: Evolutionary Trends.\u201d In <a href=\"https:\/\/explorations.americananthro.org\/index.php\/lab-and-activities-manual\/.\"><em>Explorations: Lab and Activity Manual<\/em><\/a>, edited by Beth Shook, Katie Nelson, Kelsie Aguilera, and Lara Braff. Arlington, VA: American Anthropological Association.<\/p>\n<p>Perkl, Bradley. \u201cBrain, Language, Lithics.\u201d In <a href=\"https:\/\/explorations.americananthro.org\/index.php\/lab-and-activities-manual\/.\"><em>Explorations: Lab and Activity Manual<\/em><\/a>, edited by<em>.<\/em> Beth Shook, Katie Nelson, Kelsie Aguilera, and Lara Braff. CC BY-NC. Arlington, VA: American Anthropological Association.<\/p>\n<p><a href=\"https:\/\/humanorigins.si.edu\/evidence\/human-fossils\/shanidar-3-neanderthal-skeleton\">Shanidar 3 - Neanderthal Skeleton<\/a> - Smithsonian Human Origins.<\/p>\n<p><a href=\"https:\/\/humanorigins.si.edu\/evidence\/human-fossils\/species\">Species<\/a> - Smithsonian Human Origins.<\/p>\n<p><a href=\"https:\/\/www.facebook.com\/smithsonian.humanorigins\/\">Smithsonian Human Origins Program Facebook page<\/a> (@smithsonian.humanorigins).<\/p>\n<p><a href=\"https:\/\/www.smithsonianmag.com\/science-nature\/bringing-human-evolution-life-180951155\/\">Paleoartist Brings Human Evolution to Life<\/a> - Elisabeth Dayn\u00e9s.<\/p>\n<h2 class=\"import-Normal\">References<\/h2>\n<p class=\"import-Normal\">Adler, Daniel S., Timothy J. Prindiville, and Nicholas J. Conard. 2003. \u201cPatterns of Spatial Organization and Land Use During the Eemian Interglacial in the Rhineland: New Data from Wallertheim, Germany.\u201d Eurasian Prehistory 1(2): 25\u201378.<\/p>\n<p class=\"import-Normal\">Alex, Bridget. 2018. \u201cNeanderthal Brains: Bigger, Not Necessarily Better.\u201d Discover, September 21, 2018. <a class=\"rId115\" href=\"https:\/\/www.discovermagazine.com\/planet-earth\/neanderthal-brains-bigger-not-necessarily-better\">https:\/\/www.discovermagazine.com\/planet-earth\/neanderthal-brains-bigger-not-necessarily-better<\/a>.<\/p>\n<p class=\"import-Normal\">Ashton, Nick M. 2002. \u201cAbsence of Humans in Britain during the Last Interglacial Period (Oxygen Isotope Stage 5e).\u201d <em>Publications du CERP<\/em> 8: 93\u2013103.<\/p>\n<p class=\"import-Normal\">Berger, Lee R., John Hawks, Darryl J. de Ruiter, Steven E. Churchill, Peter Schmid, Lucas K. Delezene, Tracy L. Kivell, et al. 2015. \u201c<em>Homo <\/em><em>naledi<\/em>, a New Species of the Genus <em>Homo<\/em> from the Dinaledi Chamber, South Africa.\u201d eLife 4:e09560. <a class=\"rId116\" href=\"https:\/\/doi.org\/10.7554\/eLife.09560\">https:\/\/doi.org\/<\/a><a class=\"rId117\" href=\"https:\/\/doi.org\/10.7554\/eLife.09560\">10.7554\/eLife.09560<\/a><a class=\"rId118\" href=\"https:\/\/doi.org\/10.7554\/eLife.09560\">.<\/a><\/p>\n<p class=\"import-Normal\">Berger, Thomas D., and Erik Trinkaus. 1995. \u201cPatterns of Trauma among the Neanderthals.\u201d <em>Journal of Archaeological Science <\/em>22 (6): 841\u2013852.<\/p>\n<p class=\"import-Normal\">Blangero, J., E.E. Quillen, M.A. Almeida, D.R. McKay, J.M. Peralta, S. Williams-Blangero, J.E. Curran, R. Duggirala, D.C. Glahn. 2014. \u201cGenomic Reconstruction of Neandertal Brain Structure and Function.\u201d Paper presented at the American Association of Physical Anthropologists Annual Meeting, Calgary, Alberta, Canada, 12 April 2014.<\/p>\n<p class=\"import-Normal\">Bocherens, Herv\u00e9, Daniel Billiou, Andr\u00e9 Mariotti, Maryl\u00e8ne Patou-Mathis, Marcel Otte, Dominique Bonjean, and Michel Toussaint. 1999. \u201cPalaeoenvionmental and Palaeodietary Implications of Isotopic Biogeochemistry of Last Interglacial Neanderthal and Mammal Bones in Scladina Cave (Belgium).\u201d <em>Journal of Archaeological Science<\/em> 26 (6): 599\u2013607.<\/p>\n<p class=\"import-Normal\">Bocquet-Appel, Jean-Pierre and Anna Degioanni. 2013. \u201cNeanderthal Demographic Estimates.\u201d <em>Current Anthropology<\/em> 54 (S8): S202\u2013S213.<\/p>\n<p class=\"import-Normal\">Boettger, Tatjana, Elena Yu. Novenko, Andrej A. Velichko, Olga K. Borisova, Konstantin V. Kremenetski, Stefan Knetsch, and Frank W. Junge. 2009. \u201cInstability of Climate and Vegetation Dynamics in Central and Eastern Europe during the Final Stage of the Last Interglacial (Eemian, Mikulino) and Early Glaciation.\u201d <em>Quaternary International<\/em> 207 (1-2): 137\u2013144. <a class=\"rId119\" href=\"https:\/\/doi.org\/10.1016\/j.quaint.2009.05.006.\">https:\/\/doi.org\/<\/a><a class=\"rId120\" href=\"https:\/\/doi.org\/10.1016\/j.quaint.2009.05.006.\">10.1016\/j.quaint.2009.05.006.<\/a><\/p>\n<p class=\"import-Normal\">Brophy, Juliet K., Marina C. Elliott, Darryl J. De Ruiter, Debra R. Bolter, Steven E. Churchill, Christopher S. Walker, John Hawks, and Lee R. Berger. 2021. \u201cImmature Hominin Craniodental Remains from a New Locality in the Rising Star Cave System, South Africa.\u201d <em>PaleoAnthropology <\/em>1: 1\u201314. <a class=\"rId121\" href=\"https:\/\/doi.org\/10.48738\/2021.iss1.64.\">https:\/\/doi.org\/<\/a><a class=\"rId122\" href=\"https:\/\/doi.org\/10.48738\/2021.iss1.64.\">10.48738\/2021.iss1.64.<\/a><\/p>\n<p class=\"import-Normal\">Browning, Sharon R., Brian L. Browning, Ying Zhou, Serena Tucci, and Josh M. Akey. 2018. \u201cAnalysis of Human Sequence Data Reveals Two Pulses of Archaic Denisovan Admixture.\u201d <em>Cell<\/em> 173 (1): 53\u201361.<\/p>\n<p class=\"import-Normal\">Chen, Fahu, Frido Welker, Chuan-Chou Shen, Shara E. Bailey, Inga Bergmann, Simon Davis, Huan Xia, et al. 2019. \u201cA Late Middle Pleistocene Denisovan Mandible from the Tibetan Plateau.\u201d <em>Nature<\/em> 569: 409\u2013412. <a class=\"rId123\" href=\"https:\/\/doi.org\/10.1038\/s41586-019-1139-x.\">https:\/\/doi.org\/10.1038\/s41586-019-1139-x.<\/a><\/p>\n<p class=\"import-Normal\">Churchill, Steven E. 1998. \u201cCold Adaptations, Heterochrony, and Neanderthals.\u201d <em>Evolutionary Anthropology<\/em> 7 (2): 46\u201360.<\/p>\n<p class=\"import-Normal\">Churchill, Steven E. 2006. \u201cBioenergetic Perspective on Neanderthal Thermoregulatory and Activity Budgets.\u201d In <em>Neanderthals Revisited: New Approaches and Perspectives<\/em>, edited by K. Havarti and T. Harrison, pp. 113\u2013134. Dordrecht, Germany: Springer.<\/p>\n<p class=\"import-Normal\">Churchill, Steven E., Robert G. Franciscus, Hilary A. McKean-Peraza, Julie A. Daniel, and Brittany R. Warren. 2009. \u201cShanidar 3 Neanderthal Rib Puncture Wound and Paleolithic Weaponry.\u201d <em>Journal of Human Evolution<\/em> 57 (2): 163\u2013178.<\/p>\n<p class=\"import-Normal\">Cook, Rebecca W., Antonio Vazzana, Rita Sorrentino, Stefano Benazzi, Amanda L. Smith, David S. Strait, and Justin A. Ledogar. 2021. \u201cThe Cranial Biomechanics and Feeding Performance of <em>Homo <\/em><em>floresiensis<\/em>.\u201d <em>Interface Focus<\/em> 11 (5). <a class=\"rId124\" href=\"https:\/\/doi.org\/10.1098\/rsfs.2020.0083.\">https:\/\/doi.org\/<\/a><a class=\"rId125\" href=\"https:\/\/doi.org\/10.1098\/rsfs.2020.0083.\">10.1098\/rsfs.2020.0083.<\/a><\/p>\n<p class=\"import-Normal\">Dawson, James E., and Erik Trinkaus. 1997. \u201cVertebral Osteoarthritis of La Chapelle-Aux-Saints Neanderthal.\u201d <em>Journal of Archaeological Science <\/em>24 (11): 1015-1021. <a class=\"rId126\" href=\"https:\/\/doi.org\/10.1006\/jasc.1996.0179.\">https:\/\/doi.org\/10.1006\/jasc.1996.0179.<\/a><\/p>\n<p class=\"import-Normal\">Defleur, Alban R., and Emmanuel Desclaux. 2019. \u201cImpact of the Last Interglacial Climate Change on Ecosystems and Neanderthals Behavior at Baume Moula-Guercy, Ard\u00e8che, France.\u201d <em>Journal of Archaeological Science<\/em> 104: 114\u2013124. <a class=\"rId127\" href=\"https:\/\/doi.org\/10.1016\/j.jas.2019.01.002.\">https:\/\/doi.org\/10.1016\/j.jas.2019.01.002.<\/a><\/p>\n<p class=\"import-Normal\">Degano, Ilaria, Sylvain Soriano, Paola Villa, Luca Pollarolo, Jeannette J. Lucejko, Zenobia Jacobs, Katerina Douka, Silvana Vitagliano, and Carlo Tozzi. 2019. \u201cHafting of Middle Paleolithic Tools in Latium (Central Italy): New Data from Fossellone and Sant\u2019Agostino Caves.\u201d <em>PLoS ONE<\/em> 14(10): 1\u201329. <a class=\"rId128\" href=\"https:\/\/doi.org\/10.1371\/journal.pone.0213473.\">https:\/\/doi.org\/<\/a><a class=\"rId129\" href=\"https:\/\/doi.org\/10.1371\/journal.pone.0213473.\">10.1371\/journal.pone.0213473.<\/a><\/p>\n<p class=\"import-Normal\">Degioanni Anna, Chritophe Bonenfant, Sandrine Cabut, and Silvana Condemi. 2019. Living on the Edge: Was Demographic Weakness the Cause of Neanderthal Demise? <em>PLoS ONE<\/em> 14 (5): e0216742.<br style=\"clear: both;\" \/><a class=\"rId130\" href=\"https:\/\/doi.org\/10.1371\/journal.pone.0216742.\">https:\/\/doi.org\/<\/a><a class=\"rId131\" href=\"https:\/\/doi.org\/10.1371\/journal.pone.0216742.\">10.1371\/journal.pone.0216742.<\/a><\/p>\n<p class=\"import-Normal\">Delpiano, Davide, Kristin Heasley, and Marci Peresani. 2018. \u201cAssessing Neanderthal Land Use and Lithic Raw Material Management in Discoid Technology.\u201d <em>Journal of Anthropological Sciences<\/em> 96: 89\u2013110. <a class=\"rId132\" href=\"https:\/\/doi.org\/10.4436\/jass.96006.\">https:\/\/doi.org\/<\/a><a class=\"rId133\" href=\"https:\/\/doi.org\/10.4436\/jass.96006.\">10.4436\/jass.96006.<\/a><\/p>\n<p class=\"import-Normal\">Demeter, Fabrice, Cl\u00e9ment Zanolli, Kira E. Westaway, Renaud Joannes-Boyau, Phillippe Duringer, Mike W. Morley, Frido Welker, et al. 2022. \u201cA Middle Pleistocene Denisovan Molar from the Annamite Chain of Northern Laos.\u201d <em>Nature Communications<\/em> 13 (1): 2557. <a class=\"rId134\" href=\"https:\/\/doi.org\/10.7554\/eLife.24231.\">https:\/\/doi.org\/10.7554\/eLife.24231.<\/a><\/p>\n<p class=\"import-Normal\">Dirks, Paul H. G. M., Eric M. Roberts, Hannah Hilbert-Wolf, Jan D. Kramers, John Hawks, Anthony Dosseto, Mathieu Duval, et al. 2017. \u201cThe Age of <em>Homo <\/em><em>naledi<\/em> and Associated Sediments in the Rising Star Cave, South Africa.\u201d <em>eLife<\/em> 6: e24231. <a class=\"rId135\" href=\"https:\/\/doi.org\/10.7554\/eLife.24231.\">https:\/\/doi.org\/<\/a><a class=\"rId136\" href=\"https:\/\/doi.org\/10.7554\/eLife.24231.\">10.7554\/eLife.24231. <\/a><\/p>\n<p class=\"import-Normal\">el-Showk, Sedeer. 2019. \u201cNeanderthal Clues to Brain Evolution in Humans.\u201d Nature 571: S10\u2013S11. <a class=\"rId137\" href=\"https:\/\/doi.org\/10.1038\/d41586-019-02210-6.\">https:\/\/doi.org\/<\/a><a class=\"rId138\" href=\"https:\/\/doi.org\/10.1038\/d41586-019-02210-6.\">10.1038\/<\/a><a class=\"rId139\" href=\"https:\/\/doi.org\/10.1038\/d41586-019-02210-6.\">d41586-019-02210-6<\/a><a class=\"rId140\" href=\"https:\/\/doi.org\/10.1038\/d41586-019-02210-6.\">.<\/a><\/p>\n<p class=\"import-Normal\">Esteban, Irene, Curtis W. Marean, Erich C. Fisher, Panagiotis Karkanas, Dan Carbanes, and Rosa M. Albert. 2018. \u201cPhytoliths as an Indicator of Early Modern Humans\u2019 Plant-Gathering Strategies, Fire, Fuel, and Site-Occupation Intensity During the Middle Stone Age at Pinnacle Point 5-6 (South Coast, South Africa).\u201d <em>PLoS One<\/em> 13 (6): 1\u201333.<\/p>\n<p class=\"import-Normal\">Evteev, Andrej A., Alla A. Movsesian, and Alexandra N. Grosheva. 2017. \u201cThe Association between Mid-facial Morphology and Climate in Northeast Europe Differs from That in North Asia: Implications for Understanding the Morphology of Late Pleistocene <em>Homo sapiens<\/em>.\u201d <em>Journal of Human Evolution<\/em> 107: 36\u201348. <a class=\"rId141\" href=\"https:\/\/doi.org\/10.1016\/j.jhevol.2017.02.008.\">https:\/\/doi.org\/<\/a><a class=\"rId142\" href=\"https:\/\/doi.org\/10.1016\/j.jhevol.2017.02.008.\">10.1016\/j.jhevol.2017.02.008.<\/a><\/p>\n<p class=\"import-Normal\">Frayer, David W., Marina Lozano, Jose M. Bermudez de Castro, Eudald Carbonell, Juan-Luis Arsuaga, Jakov Radovcic, Ivana Fiore, and Luca Bondioli. 2012. \u201cMore Than 500,000 Years of Right-handedness in Europeans.\u201d <em>Laterality<\/em> 17 (1): 51\u201369. <a class=\"rId143\" href=\"https:\/\/doi.org\/10.1080\/1357650X.2010.529451.\">https:\/\/doi.org\/10.1080\/1357650X.2010.529451.<\/a><\/p>\n<p class=\"import-Normal\">Fu, Qiaomei, Mateja Hajdinjak, Oana Teodora Moldovan, Silviu Constantin, Swapan Mallick, Pontus Skoglund, Nick Patterson, et al. 2015. \u201cAn Early Modern Human from Romania with a Recent Neanderthal Ancestor.\u201d <em>Nature<\/em> 524 (7564): 216. <a class=\"rId144\" href=\"https:\/\/doi.org\/10.1038\/nature14558.\">https:\/\/doi.org\/10.1038\/nature14558.<\/a><\/p>\n<p class=\"import-Normal\">Gaudzinski-Windheuser, Sabine, Elizabeth S. Noack, Eduard Pop, Constantin Herbst, Johannes Pfleging, Jonas Buchli, Arne Jacob, et al. 2018. \u201cEvidence for Close-Range Hunting by Last Interglacial Neanderthals.\u201d <em>Nature Ecology and Evolution<\/em> 2: 1087\u20131092. <a class=\"rId145\" href=\"https:\/\/doi.org\/10.1038\/s41559-018-0596-1\">https:\/\/doi.org\/<\/a><a class=\"rId146\" href=\"https:\/\/doi.org\/10.1038\/s41559-018-0596-1\">10.1038\/s41559-018-0596-1<\/a>.<\/p>\n<p class=\"import-Normal\">Gilpin, William., Marcus W. Feldman, and Kenichi Aoki. 2016. \u201cAn Ecocultural Model Predicts Neanderthal Extinction through Competition with Modern Humans.\u201d <em>Proceedings of the National Academy of Sciences<\/em> 113 (8): 2134\u20132139. <a class=\"rId147\" href=\"https:\/\/doi.org\/10.1073\/pnas.1524861113.\">https:\/\/doi.org\/10.1073\/pnas.1524861113.<\/a><\/p>\n<p class=\"import-Normal\">Golovanova, Liubov. Vitaliena, Vladimir B. Doronichev, Naomi E. Cleghorn, Marianna A. Koulkova, Tatiana V. Sapelko, and M. Steven Shackley. 2010. \u201cSignificance of Ecological Factors in the Middle to Upper Paleolithic Transition.\u201d <em>Current Anthropology<\/em> 51 (5): 655\u2013691. <a class=\"rId148\" href=\"blank\">https:\/\/doi.org.10.1086\/656185.<\/a><\/p>\n<p class=\"import-Normal\">Harrold, Francis B. 1980. \u201cA Comparative Analysis of Eurasian Paleolithic Burials.\u201d <em>World Archaeology <\/em>12 (2): 195\u2013211.<\/p>\n<p class=\"import-Normal\">Hawks, John, Marina Elliott, Peter Schmid, Steven E. Churchill, Darryl J. de Ruiter, Eric M. Roberts, Hannah Hilbert-Wolf, et al. 2017. \"New Fossil Remains of <em>Homo <\/em><em>naledi<\/em> from the Lesedi Chamber, South Africa.\u201d eLife 6: e24232. <a class=\"rId149\" href=\"https:\/\/doi.org\/10.7554\/eLife.24232.\">https:\/\/doi.org\/<\/a><a class=\"rId150\" href=\"https:\/\/doi.org\/10.7554\/eLife.24232.\">10.7554\/eLife.24232.<\/a><\/p>\n<p class=\"import-Normal\">Henry, Amanda G., Alison S. Brooks, and Dolores R. Piperno. 2010. \u201cMicrofossils and Calculus Demonstrate Consumption of Plants and Cooked Foods in Neanderthal Diets (Shanidar III, Iraq; Spy I and II, Belgium).\u201d <em>Proceedings of the National Academy of Sciences USA<\/em> 108 (2): 486\u2013491. <a class=\"rId151\" href=\"https:\/\/doi.org\/10.1073\/pnas.1016868108.\">https:\/\/doi.org\/10.1073\/pnas.1016868108.<\/a><\/p>\n<p class=\"import-Normal\">Houldcroft, Charlotte J., and Simon J. Underdown. 2016. \u201cNeanderthal Genomics Suggests a Pleistocene Time Frame for the First Epidemiologic Transition.\u201d <em>American Journal of Physical Anthropology<\/em> 160 (3): 379\u2013388.<\/p>\n<p class=\"import-Normal\">Huerta-S\u00e1nchez, Emilia, Xin Jin, Asan, Zhuoma Bianba, Benjamin M. Peter, Nicolas Vinckenbosch, Yu Liang, et al. 2014. \u201cAltitude Adaptation in Tibetans Caused by Introgression of Denisovan-like DNA.\u201d <em>Nature<\/em> 512 (7513): 194-197.<\/p>\n<p class=\"import-Normal\">Jaouen, Klervia, Michael P. Richards, and Adeline Le Cabec. 2019. \u201cExceptionally High \u03b4<sup>15<\/sup>N Values in Collagen Single Amino Acids Confirm Neanderthals as High-Trophic Level Carnivores.\u201d <em>Proceedings of the National Academy of Sciences<\/em> 116 (11): 4928\u20134933. <a class=\"rId152\" href=\"https:\/\/doi.org\/10.1073\/pnas.1814087116.\">https:\/\/doi.org\/10.1073\/pnas.1814087116.<\/a><\/p>\n<p class=\"import-Normal\">Kandel, Andrew W., Michael Bolus, Knut Bretzke, Angela A. Bruch, Miriam N. Haidle, Christine Hertler, and Michael M\u00e4rker. 2015. \u201cIncreasing Behavioral Flexibility? An Integrative Macro-Scale Approach to Understanding the Middle Stone Age of Southern Africa.\u201d<em> Journal of Archaeological Method and Theory<\/em> 23: 623\u2013668. <a class=\"rId153\" href=\"https:\/\/doi.org\/10.1007\/s10816-015-9254-y.\">https:\/\/doi.org\/<\/a><a class=\"rId154\" href=\"https:\/\/doi.org\/10.1007\/s10816-015-9254-y.\">10.1007\/s10816-015-9254-y.<\/a><\/p>\n<p class=\"import-Normal\">Kortlandt, Adriaan. 2002. \u201cNeanderthal Anatomy and the Use of Spears.\u201d <em>Evolutionary Anthropology<\/em> 11 (5): 183\u2013184.<\/p>\n<p class=\"import-Normal\">Kruger, A., P. Randolph-Quinney, and M. Elliott. 2016. \u201cMultimodal Spatial Mapping and Visualization of Dinaledi Chamber and Rising Star Cave.\u201d <em>South African Journal of Science<\/em> 112 (5\u20136). <a class=\"rId155\" href=\"https:\/\/doi.org\/10.17159\/sajs.2016\/20160032.\">https:\/\/doi.org\/<\/a><a class=\"rId156\" href=\"https:\/\/doi.org\/10.17159\/sajs.2016\/20160032.\">10.17159\/sajs.2016\/20160032.<\/a><\/p>\n<p class=\"import-Normal\">Lieberman, Philip, and Edmund S. Crelin. 1971. \u201cOn the Speech of Neanderthal Man.\u201d <em>Linguistic Inquiry<\/em> 2 (2): 203\u2013222.<\/p>\n<p class=\"import-Normal\">Mendez, Fernando L., G. David Poznik, Sergi Castellano, and Carlos D. Bustamante. 2016. \u201cThe Divergence of Neanderthal and Modern Human Y Chromosomes.\u201d <em>American Journal of Human Genetics<\/em> 98 (4): 728\u2013734.<\/p>\n<p class=\"import-Normal\">Mora-Berm\u00fadez, Felipe, Philipp Kanis, Dominik Macak, Jula Peters, Ronald Naumann, Lei Xing, Mihail Sarov, et al. 2022. \u201cLonger Metaphase and Fewer Chromosome Segregation Errors in Modern Human Than Neanderthal Brain Development.\u201d <em>Science Advances<\/em> 8 (30). <a class=\"rId157\" href=\"https:\/\/doi.org\/10.1126\/sciadv.abn7702.\">https:\/\/doi.org\/10.1126\/sciadv.abn7702.<\/a><\/p>\n<p class=\"import-Normal\">Nicholson, Christopher M. 2017. \u201cEemian Paleoclimate Zones and Neanderthal Landscape Use: A GIS Model of Settlement Patterning during the Last Interglacial.\u201d <em>Quaternary International<\/em> 438 (B): 144\u2013157. <a class=\"rId158\" href=\"https:\/\/doi.org\/10.1016\/j.quaint.2017.04.023.\">https:\/\/doi.org\/10.1016\/j.quaint.2017.04.023.<\/a><\/p>\n<p class=\"import-Normal\">Nobel Prize, The. 2022. \u201cPress Release: The Nobel Prize in Physiology or Medicine 2022.\u201d Nobelf\u00f6rsamlingen The Nobel Assembly at Karolinska Institutet. Press release, November 3, 2022. <a class=\"rId159\" href=\"https:\/\/www.nobelprize.org\/prizes\/medicine\/2022\/press-release\/.\">https:\/\/www.nobelprize.org\/prizes\/medicine\/2022\/press-release\/.<\/a><\/p>\n<p class=\"import-Normal\">Nowell, April. 2016. \u201cChildhood, Play and the Evolution of Cultural Capacity in Neanderthals and Modern Humans.\u201d In<em> The Nature of Culture: Based on an Interdisciplinary Symposium \u201cThe Nature of Culture,\u201d T\u00fcbingen, Germany<\/em>, edited by M. N. Haidle, N. J. Conard, and M. Bolus, 87\u201397. Heidelberg, Germany: Springer. <a class=\"rId160\" href=\"blank\">https:\/\/doi.org.10.1007\/978-94-017-7426-0_9<\/a>.<\/p>\n<p class=\"import-Normal\">Parkington, John. 2003. \u201cMiddens and Moderns: Shellfishing and the Middle Stone Age of the Western Cape, South Africa.\u201d <em>South African Journal of Science<\/em> 99 (5\u20136): 243\u2013274.<\/p>\n<p class=\"import-Normal\">Pearce, Eiluned, Chris Stringer, and R. I. M. Dunbar. 2013. \u201cNew Insights into Differences in Brain Organizations between Neanderthals and Anatomically Modern Humans.\u201d <em>Proceedings of the Royal Society B: Biological Sciences<\/em> 280 (1758): 20130168. <a class=\"rId161\" href=\"https:\/\/doi.org\/10.1098\/rspb.2013.0168\">https:\/\/doi.org\/<\/a><a class=\"rId162\" href=\"https:\/\/doi.org\/10.1098\/rspb.2013.0168\">10.1098\/rspb.2013.0168<\/a><a class=\"rId163\" href=\"https:\/\/doi.org\/10.1098\/rspb.2013.0168\">.<\/a><\/p>\n<p class=\"import-Normal\">Pomeroy, Emma, Paul Bennett, Chris O. Hunt, Tim Reynolds, Lucy Farr, Marine Frouin, James Holman, Ross Lane, Charles French, and Graeme Barker. 2020. \u201cNew Neanderthal Remains Associated with the \u2018Flower Burial\u2019 at Shanidar Cave.\u201d <em>Antiquity<\/em> 94 (373): 11\u201326. <a class=\"rId164\" href=\"https:\/\/doi.org\/10.15184\/aqy.2019.207.\">https:\/\/doi.org\/<\/a><a class=\"rId165\" href=\"https:\/\/doi.org\/10.15184\/aqy.2019.207.\">10.15184\/aqy.2019.207.<\/a><\/p>\n<p class=\"import-Normal\">Rae, Todd, Thomas Koppe, and Chris B. Stringer. 2011. \u201cThe Neanderthal Face Is Not Cold-Adapted.\u201d <em>Journal of Human Evolution<\/em> 60 (2): 234\u2013239. <a class=\"rId166\" href=\"https:\/\/doi.org\/10.1016\/j.jhevol.2010.10.003.\">https:\/\/doi.org\/10.1016\/j.jhevol.2010.10.003.<\/a><\/p>\n<p class=\"import-Normal\">Reich, David, Richard E. Green, Martin Kircher, Johannes Krause, Nick Patterson, Eric Y. Durand, Bence Viola, et al. 2010. \u201cGenetic History of an Archaic Hominin Group from Denisova Cave in Siberia.\u201d <em>Nature<\/em> 468: 1053\u20131060. <a class=\"rId167\" href=\"https:\/\/doi.org\/10.1038\/nature09710.\">https:\/\/doi.org\/10.1038\/nature09710.<\/a><\/p>\n<p class=\"import-Normal\">Richards, Michael P., Paul B. Pettit, Erik Trinkaus, Fred H. Smith, Maja Paunovi\u0107, and Ivor Karavani\u0107. 2000. \u201cNeanderthal Diet at Vindija and Neanderthal Predation: The Evidence from Stable Isotopes.\u201d <em>Proceedings of the National Academy of Sciences<\/em> 97 (13): 7663\u20137666.<br style=\"clear: both;\" \/><a class=\"rId168\" href=\"https:\/\/doi.org\/10.1073\/pnas.120178997.\">https:\/\/doi.org\/<\/a><a class=\"rId169\" href=\"https:\/\/doi.org\/10.1073\/pnas.120178997.\">10.1073\/pnas.120178997.<\/a><\/p>\n<p class=\"import-Normal\">Richter, J\u00fcrgen, 2006. \u201cNeanderthals in Their Landscape: Neanderthals in Europe.\u201d In <em>Proceedings of the International Conference held in the Gallo-Roman Museum in Tongeren<\/em>, ERAUL 117, edited by B. Demarsin and M. Otte, 17\u201332. K\u00f6ln: Universit\u00e4t zu K\u00f6ln.<\/p>\n<p class=\"import-Normal\">Roksandic, Mirjana, Predrag Radovic, Xiu-Jie Wu, and Christopher J. Bae. 2021. \u201cResolving the \u2018Muddle in the Middle\u2019: The Case for <em>Homo bodoensis<\/em>.\u201d <em>Evolutionary Anthropology: Issues, News, and Reviews<\/em>, 31 (1). <a class=\"rId170\" href=\"https:\/\/doi.org\/10.1002\/evan.21929.\">https:\/\/doi.org\/<\/a><a class=\"rId171\" href=\"https:\/\/doi.org\/10.1002\/evan.21929.\">10.1002\/evan.21929.<\/a><\/p>\n<p class=\"import-Normal\">Slon, Viviane, Fabrizio Mafessoni, Benjamin Vernot, Cesare de Filippo, Steffi Grote, Bence Viola, Mateja Hajdinjak, et al. 2018. \u201cThe Genome of the Offspring of a Neanderthal Mother and a Denisovan Father.\u201d <em>Nature<\/em> 561 (7721): 113\u2013116.<\/p>\n<p class=\"import-Normal\">Smith, Tanya M., Paul Tafforeau, Donald J. Reid, Joanne Pouech, Vincent Lazzari, John P. Zermeno, Debbi Guatelli-Steinberg, et al. 2010. \u201cDental Evidence for Ontogenetic Differences Between Modern Humans and Neanderthals.\u201d <em>Proceedings for the National Academy of Sciences<\/em> 107 (49): 20923\u201320928.<\/p>\n<p class=\"import-Normal\">Staubwasser, Michael, Virgil Dr\u0103gu\u0282in, Bogdan P. Onac, Sergey Assonov, Vasile Ersek, Dirk L. Hoffman, and Daniel Veres. 2018. \u201cImpact of Climate Change on the Transition of Neanderthals to Modern Humans in Europe.\u201d <em>Proceedings of the National Academy of Sciences<\/em> 115 (37): 9116\u20139121. <a class=\"rId172\" href=\"https:\/\/doi.org\/10.1073\/pnas.1808647115.\">https:\/\/doi.org\/10.1073\/pnas.1808647115.<\/a><\/p>\n<p class=\"import-Normal\">Stewart, T. D. 1977. \u201cThe Neanderthal Skeletal Remains from Shanidar Cave, Iraq: A Summary of Findings to Date.\u201d<em> Proceedings of the American Philosophical Society <\/em>121 (2): 121\u2013165.<\/p>\n<p class=\"import-Normal\">Stolarczyk, Regine E., and Patrick Schmidt. 2018. \u201cIs Early Silcrete Heat Treatment a New Behavioural Proxy in the Middle Stone Age?\u201d <em>PLoS One<\/em> 13 (10): 1\u201321.<\/p>\n<p class=\"import-Normal\">Trinkaus, E. 1985. \u201cPathology and Posture of the La-Chapelle-aux-Saints Neanderthal.\u201d <em>American Journal of Physical Anthropology <\/em>67 (1): 19\u201341.<\/p>\n<p class=\"import-Normal\">Trujillo Cleber A., Edward S. Rice, Nathan K. Schaefer, Isaac A. Chaim, Emily C. Wheeler, Assael A. Madrigal, Justin Buchanan, et al. 2021. \u201cReintroduction of the Archaic Variant of NOVA1 in Cortical Organoids Alters Neurodevelopment.\u201d <em>Science<\/em> 371 (6530): eaax2537. <a class=\"rId173\" href=\"https:\/\/doi.org\/10.1126\/science.aax2537.\">https:\/\/doi.org\/10.1126\/science.aax2537.<\/a><\/p>\n<p class=\"import-Normal\">Tucci, Serena, Samuel H. Vohr, Rajiv C. McCoy, Benjamin Vernot, Matthew R. Robinson, Chiara Barbieri, Brad J. Nelson, et al. 2018. \u201cEvolutionary History and Adaptation of a Human Pygmy Population of Flores Island, Indonesia.\u201d <em>Science<\/em> 361 (6401): 511\u2013516.<\/p>\n<p class=\"import-Normal\">Van Andel, T. H., and P. C. Tzedakis. 1996. \u201cPaleolithic Landscapes of Europe and Environs, 150,000\u201325,000 Years Ago: An Overview.\u201d <em>Quaternary Science Reviews<\/em> 15 (5\u20136): 481\u2013500.<\/p>\n<p class=\"import-Normal\">Venner, Stephen J. 2018. \u201cA New Estimate for Neanderthal Energy Expenditure.\u201d CUNY Academic Works.<\/p>\n<p class=\"import-Normal\">Vernot, Benjamin, Serena Tucci, Janet Kelso, Joshua G. Schraiber, Aaron B. Wolf, Rachel M. Gittelman, Michael Danneman, et al. 2016. \u201cExcavating Neanderthal and Denisovan DNA from the Genomes of Melanesian Individuals.\u201d <em>Science <\/em>352 (6282): 235\u2013239.<\/p>\n<p class=\"import-Normal\">Weaver, T. D., and J. Hublin. 2009. \u201cNeanderthal Birth Canal Shape and the Evolution of Human Childbirth.\u201d <em>Proceedings of the National Academy of Sciences<\/em> 106 (20): 8151\u20138156.<\/p>\n<p class=\"import-Normal\">Wi\u1e9eing, Christoph, H\u00e9l\u00e8ne Rougier, Isabelle Crevecoer, Mietje Germonpr\u00e9, Yuichi Naito, Patrick Semal, and Herv\u00e9 Bocherens. 2015. \u201cIsotopic Evidence for Dietary Ecology of Late Neanderthals in Northwestern Europe.\u201d <em>Quaternary International<\/em> 411 (A): 327\u2013345. <a class=\"rId174\" href=\"https:\/\/doi.org\/10.1016\/j.quaint.2015.09.091.\">https:\/\/doi.org\/<\/a><a class=\"rId175\" href=\"https:\/\/doi.org\/10.1016\/j.quaint.2015.09.091.\">10.1016\/j.quaint.2015.09.091.<\/a><\/p>\n<p class=\"import-Normal\">Wong, Kate. 2015. \u201cNeanderthal Minds.\u201d <em>Scientific American<\/em> (January): 312(2): 36-43. <a class=\"rId176\" href=\"https:\/\/doi.org\/10.1038\/scientificamerican0215-36.\">https:\/\/doi.org\/10.1038\/scientificamerican0215-36.<\/a><\/p>\n<p class=\"import-Normal\">Zhang, X. L., B. B. Ha, S. J. Wang, Z. J. Chen, J. Y. Ge, H. Long, W. He, et al. 2018. \u201cThe Earliest Human Occupation of the High-Altitude Tibetan Plateau 40 Thousand to 30 Thousand Years Ago.\u201d <em>Science<\/em> 362 (6418): 1049\u20131051. <a class=\"rId177\" href=\"https:\/\/doi.org\/10.1126\/sciadv.add5582.\">https:\/\/doi.org\/10.1126\/sciadv.add5582.<\/a><\/p>\n<p class=\"import-Normal\">Zilh\u00e3o Jo\u00e3o, Diego E. Angelucci, Ernestina Badal-Garc\u00eda, Francesco d'Errico, Flor\u00e9al Daniel, Laure Dayet, Katerina Douka, et al. 2010. \u201cSymbolic Use of Marine Shells and Mineral Pigments by Iberian Neandertals.\u201d <em>Proceedings of the National Academy of Sciences<\/em> 107 (3): 1023\u20131028. <a class=\"rId178\" href=\"https:\/\/doi.org\/10.1073\/pnas.0914088107.\">https:\/\/doi.org\/<\/a><a class=\"rId179\" href=\"https:\/\/doi.org\/10.1073\/pnas.0914088107.\">10.1073\/pnas.0914088107.<\/a><\/p>\n<p class=\"import-Normal\">Zollikofer, Christopher Peter Edwards, and Marcia Silvia Ponce de Le\u00f3n. 2013. \u201cPandora\u2019s Growing Box: Inferring the Evolution and Development of Hominin Brains from Endocasts.\u201d Evolutionary Anthropology 22 (1): 20\u201333. <a class=\"rId180\" href=\"https:\/\/doi.org\/10.1002\/evan.21333.\">https:\/\/doi.org\/10.1002\/evan.21333.<\/a><\/p>\n<h2>Acknowledgments<\/h2>\n<p class=\"import-Normal\">The authors would like to extend their thanks to Cassandra Gilmore and Anna Goldfield for thoughtful and insightful suggestions on the first edition of this chapter.<\/p>\n<\/div>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_281_1712\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_281_1712\"><div tabindex=\"-1\"><div class=\"__UNKNOWN__\">\n<p class=\"import-Normal\">Hayley Mann, M.A., Binghamton University<\/p>\n<p class=\"import-Normal\"><em>This chapter is a revision from <\/em><a class=\"rId7\" href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/chapter\/__unknown__-9\/\"><em>\"Chapter 3: Molecular Biology and Genetics\"<\/em><\/a><em> by Hayley Mann, Xazmin Lowman, and Malaina Gaddis. In <\/em><a class=\"rId8\" href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/\"><em>Explorations: An Open Invitation to Biological Anthropology, first edition<\/em><\/a><em>, edited by Beth Shook, Katie Nelson, Kelsie Aguilera, and Lara Braff, which is licensed under <\/em><a class=\"rId9\" href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\"><em>CC BY-NC 4.0<\/em><\/a><em>. <\/em><\/p>\n<div class=\"textbox textbox--learning-objectives\">\n<header class=\"textbox__header\">\n<h2 class=\"textbox__title\"><span style=\"color: #ffffff\">Learning Objectives<\/span><\/h2>\n<\/header>\n<div class=\"textbox__content\">\n<ul>\n<li class=\"import-Normal\">Explain and identify the purpose of both DNA replication and the cell cycle.<\/li>\n<li class=\"import-Normal\">Identify key differences between mitosis and meiosis.<\/li>\n<li class=\"import-Normal\">Outline the process of protein synthesis, including transcription and translation.<\/li>\n<li class=\"import-Normal\">Use principles of Mendelian inheritance to predict genotypes and phenotypes of future generations.<\/li>\n<li class=\"import-Normal\">Explain complexities surrounding patterns of genetic inheritance and polygenic traits.<\/li>\n<li class=\"import-Normal\">Discuss challenges to and bioethical concerns of genetic testing.<\/li>\n<\/ul>\n<\/div>\n<\/div>\n<p class=\"import-Normal\">I [Hayley Mann] started my Bachelor\u2019s degree in 2003, which was the same year the Human Genome Project released its first draft sequence. I initially declared a genetics major because I thought it sounded cool. However, upon taking an actual class, I discovered that genetics was <em>challenging<\/em>. In addition to my genetics major, I signed up for biological anthropology classes and soon learned that anthropology could bring all those molecular lessons to life. For instance, we are composed of cells, proteins, nucleic acids, carbohydrates, and lipids. Anthropologists often include these molecules in their studies to identify how humans vary; if there are meaningful differences, they propose theories to explain them. Anthropologists study biomolecules in both living and ancient individuals. Ancient biomolecules can also be found on artifacts such as stone tools and cooking vessels. Over the years, scientific techniques for studying organic molecules have improved, which has unlocked new insights into the deep human past.<\/p>\n<p class=\"import-Normal\"><span style=\"background-color: #00ff00\">This chapter provides the basics for understanding human variation and how the evolutionary process works. A few advanced genetics topics are also presented because biotechnology is now commonplace in health and society. Understanding the science behind this remarkable field means you will be able to participate in bioethical and anthropological discussions as well as make more informed decisions regarding genetic testing.<\/span><\/p>\n<h2 class=\"import-Normal\">Cells and Molecules<\/h2>\n<h3 class=\"import-Normal\">Molecules of Life<\/h3>\n<p class=\"import-Normal\">All organisms are composed of four basic types of molecules that are essential for cell structure and function: proteins<strong>, <\/strong>lipids<strong>, <\/strong>carbohydrates, and nucleic acids (Figure 3.1). <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_586\">Proteins<\/a> <\/strong>are crucial for cell shape and nearly all cellular tasks, including receiving signals from outside the cell and mobilizing intra-cellular responses. <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_588\">Lipids<\/a> <\/strong>are a class of organic compounds that include fats, oils, and hormones. <span style=\"background-color: #ff00ff\">As discussed later in the chapter, lipids are also responsible for the characteristic phospholipid bilayer structure of the cell membrane.<\/span> <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_590\">Carbohydrates<\/a><\/strong> are sugar molecules and serve as energy to cells in the form of glucose. Lastly, <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_592\">nucleic acids<\/a><\/strong>, including <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_594\">deoxyribonucleic acid (DNA)<\/a><\/strong>, carry genetic information about a living organism.<\/p>\n<table class=\"aligncenter\" style=\"width: 740px;height: 551px\" border=\"1pt solid rgb(0, 0, 0)\" cellpadding=\"5pt\">\n<caption>Figure 3.1: Information about the four biomolecules. Credit: Biomolecules Table original to Explorations: An Open Invitation to Biological Anthropology (2nd ed.) by Hayley Mann is under a <a href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/\">CC BY-NC 4.0 License<\/a>.<\/caption>\n<thead>\n<tr style=\"height: 40px\">\n<td class=\"a-C\" style=\"background-color: transparent;padding: 5pt;border: 1pt solid #000000;width: 125.594px;height: 40px\">\n<p class=\"import-Normal\"><strong>Molecule<\/strong><\/p>\n<\/td>\n<td class=\"a-C\" style=\"background-color: transparent;padding: 5pt;border: 1pt solid #000000;width: 223.906px;height: 40px\">\n<p class=\"import-Normal\" style=\"margin-left: 36pt\"><strong>Definition<\/strong><\/p>\n<\/td>\n<td class=\"a-C\" style=\"background-color: transparent;padding: 5pt;border: 1pt solid #000000;width: 346.562px;height: 40px\">\n<p class=\"import-Normal\" style=\"margin-left: 36pt\"><strong>Example<\/strong><\/p>\n<\/td>\n<\/tr>\n<\/thead>\n<tbody>\n<tr class=\"a-R\" style=\"height: 194px\">\n<td class=\"a-C\" style=\"background-color: transparent;padding: 5pt;border: 1pt solid #000000;width: 125.594px;height: 194px\">\n<p class=\"import-Normal\">Proteins<\/p>\n<\/td>\n<td class=\"a-C\" style=\"background-color: transparent;padding: 5pt;border: 1pt solid #000000;width: 223.906px;height: 194px\">\n<p class=\"import-Normal\">Composed of one or more long chains of amino acids (i.e., basic units of protein)<\/p>\n<p class=\"import-Normal\">Often folded into complex 3D shapes that relate to function<\/p>\n<p class=\"import-Normal\">Proteins interact with other types of proteins and molecules<\/p>\n<\/td>\n<td class=\"a-C\" style=\"background-color: transparent;padding: 5pt;border: 1pt solid #000000;width: 346.562px;height: 194px\">\n<p class=\"import-Normal\">Proteins come in different categories including structural (e.g., collagen, keratin, lactase, hemoglobin, cell membrane proteins), defense proteins (e.g, antibodies), enzymes (e.g., lactase), hormones (e.g., insulin), and motor proteins (e.g., actin)<\/p>\n<\/td>\n<\/tr>\n<tr class=\"a-R\" style=\"height: 137px\">\n<td class=\"a-C\" style=\"background-color: transparent;padding: 5pt;border: 1pt solid #000000;width: 125.594px;height: 137px\">\n<p class=\"import-Normal\">Lipids<\/p>\n<\/td>\n<td class=\"a-C\" style=\"background-color: transparent;padding: 5pt;border: 1pt solid #000000;width: 223.906px;height: 137px\">\n<p class=\"import-Normal\">Insoluble in water due to hydrophilic (water-loving) head and a hydrophobic (water-repelling) tail<\/p>\n<\/td>\n<td class=\"a-C\" style=\"background-color: transparent;padding: 5pt;border: 1pt solid #000000;width: 346.562px;height: 137px\">\n<p class=\"import-Normal\">Fats, such as triglycerides, store energy for your body<\/p>\n<p class=\"import-Normal\">Steroid hormones (e.g., estrogen and testosterone) act as chemical messengers to communicate between cells and tissues, as well as biochemical pathways inside of the cell<\/p>\n<\/td>\n<\/tr>\n<tr class=\"a-R\" style=\"height: 80px\">\n<td class=\"a-C\" style=\"background-color: transparent;padding: 5pt;border: 1pt solid #000000;width: 125.594px;height: 80px\">\n<p class=\"import-Normal\">Carbohydrates<\/p>\n<\/td>\n<td class=\"a-C\" style=\"background-color: transparent;padding: 5pt;border: 1pt solid #000000;width: 223.906px;height: 80px\">\n<p class=\"import-Normal\">Large group of organic molecules that are composed of carbon and hydrogen atoms<\/p>\n<\/td>\n<td class=\"a-C\" style=\"background-color: transparent;padding: 5pt;border: 1pt solid #000000;width: 346.562px;height: 80px\">\n<p class=\"import-Normal\">Starches and sugars, including blood glucose, provide cells with energy<\/p>\n<\/td>\n<\/tr>\n<tr class=\"a-R\" style=\"height: 78px\">\n<td class=\"a-C\" style=\"background-color: transparent;padding: 5pt;border: 1pt solid #000000;width: 125.594px;height: 78px\">\n<p class=\"import-Normal\">Nucleic Acids<\/p>\n<\/td>\n<td class=\"a-C\" style=\"background-color: transparent;padding: 5pt;border: 1pt solid #000000;width: 223.906px;height: 78px\">\n<p class=\"import-Normal\">Carries the genetic information of an organism<\/p>\n<\/td>\n<td class=\"a-C\" style=\"background-color: transparent;padding: 5pt;border: 1pt solid #000000;width: 346.562px;height: 78px\">\n<p class=\"import-Normal\">DNA<\/p>\n<p class=\"import-Normal\">RNA<\/p>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<h3 class=\"import-Normal\">Cells<\/h3>\n<p class=\"import-Normal\">In 1665, Robert Hooke observed slices of plant cork using a microscope. Hooke noted that the microscopic plant structures he saw resembled <em>cella,<\/em> meaning \u201ca small room\u201d in Latin. Approximately two centuries later, biologists recognized the cell as being the most fundamental unit of life and that all life is composed of cells. Cellular organisms can be characterized as two main cell types: <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_596\">prokaryotes<\/a><\/strong> and <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_598\">eukaryotes<\/a> <\/strong>(Figure 3.2).<\/p>\n<figure id=\"attachment_77\" aria-describedby=\"caption-attachment-77\" style=\"width: 468px\" class=\"wp-caption alignleft\"><a href=\"\/part\/figure-3-2\/\" target=\"_blank\" rel=\"noopener\"><img class=\"wp-image-166\" src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/06\/cellsfinal-scaled-1.jpg\" alt=\"Prokaryote and eukaryote cells. A full text description of this image is available using link in the caption.\" width=\"468\" height=\"370\" \/><\/a><figcaption id=\"caption-attachment-77\" class=\"wp-caption-text\">Figure 3.2: Prokaryotic cell and eukaryotic cell. <a href=\"https:\/\/docs.google.com\/document\/d\/1VUDKMBJYS_jNONjLxT04jQN0_z9Ua50BRN6auGSHUuU\/edit\" target=\"_blank\" rel=\"noopener\">A full text description of this image is available.<\/a> Credit: Prokaryote vs. eukaryote original to Explorations: An Open Invitation to Biological Anthropology (2nd ed.) by Mary Nelson is under a <a href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/\">CC BY-NC 4.0 License<\/a>.<\/figcaption><\/figure>\n<p class=\"import-Normal\">Prokaryotes include bacteria and archaea, and they are composed of a single cell. Additionally, their DNA and <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_600\">organelles<\/a><\/strong> are not surrounded by individual membranes. Thus, no compartments separate their DNA from the rest of the cell (see Figure 3.2). It is well known that some bacteria can cause illness in humans. For instance, <em>Escherichia coli<\/em> (<em>E. coli<\/em>) and <em>Salmonella<\/em> contamination can result in food poisoning symptoms. Pneumonia and strep throat are caused by <em>Streptococcal<\/em> bacteria. <em>Neisseria gonorrhoeae<\/em> is a sexually transmitted bacterial disease. Although bacteria are commonly associated with illness, not all bacteria are harmful. For example, researchers are studying the relationship between the <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_602\">microbiome<\/a> <\/strong>and human health. The bacteria that are part of the healthy human microbiome perform beneficial roles, such as digesting food, boosting the immune system, and even making vitamins (e.g., B12 and K).<\/p>\n<p class=\"import-Normal\">Eukaryotes can be single-celled or multi-celled in their body composition. In contrast to prokaryotes, eukaryotes possess membranes that surround their DNA and organelles. An example of a single-celled eukaryote is the microscopic algae found in ponds (phytoplankton), which can produce oxygen from the sun. Yeasts are also single-celled, and fungi can be single- or multicellular. Plants and animals are all multicellular.<\/p>\n<p class=\"import-Normal\">Although plant and animal cells have a surprising number of similarities, there are some key differences (Figure 3.3). For example, plant cells possess a thick outer cell membrane made of a fibrous carbohydrate called cellulose. Animal and plant cells also have different <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_604\">tissues<\/a><\/strong>. <span style=\"background-color: #ff00ff\">A tissue is an aggregation of cells that are morphologically similar and perform the same task.<\/span> For most plants, the outermost layer of cells forms a waxy cuticle that helps to protect the cells and to prevent water loss. Humans have skin, which is the outermost cell layer that is predominantly composed of a tough protein called keratin. Overall, humans have a diversity of tissue types (e.g., cartilage, brain, and heart).<\/p>\n<p>&nbsp;<\/p>\n<figure id=\"attachment_77\" aria-describedby=\"caption-attachment-77\" style=\"width: 2560px\" class=\"wp-caption aligncenter\"><img class=\"wp-image-459 size-full\" src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/3.x3ai-01-scaled-1.jpg\" alt=\"Plant and animal cells. A full text description of this image is available using link in the caption.\" width=\"2560\" height=\"1162\" \/><figcaption id=\"caption-attachment-77\" class=\"wp-caption-text\">Figure 3.3: Plant cell compared to an animal cell. <a href=\"https:\/\/docs.google.com\/document\/d\/1VUDKMBJYS_jNONjLxT04jQN0_z9Ua50BRN6auGSHUuU\/edit\" target=\"_blank\" rel=\"noopener\">A full text description of this image is available.<\/a> Credit: <a href=\"https:\/\/commons.wikimedia.org\/wiki\/File:Simple_plant_and_animal_cell.svg\">Simple plant and animal cell<\/a> by <a href=\"https:\/\/commons.wikimedia.org\/wiki\/User:Nefronus\">Tom\u00e1\u0161 Kebert<\/a> &amp; <a href=\"https:\/\/www.umimeto.org\/\">umimeto.org<\/a> has been modified (labels added) and is under a <a href=\"https:\/\/creativecommons.org\/licenses\/by-nc-sa\/4.0\/\">CC BY-NC-SA 4.0 License<\/a>.<\/figcaption><\/figure>\n<h3 class=\"import-Normal\"><strong>Animal Cell Organelles<\/strong><\/h3>\n<p class=\"import-Normal\">An animal cell is surrounded by a double membrane called the <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_606\">phospholipid bilayer<\/a> <\/strong>(Figure 3.4). A closer look reveals that this protective barrier is made of lipids and proteins that provide structure and function for cellular activities, such as regulating the passage of molecules and ions (e.g., H<sub>2<\/sub>O and sodium) into and out of the cell. <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_608\">Cytoplasm<\/a><\/strong> is the jelly-like matrix inside of the cell membrane. Part of the cytoplasm comprises organelles, which perform different specialized tasks for the cell (Figure 3.5). An example of an organelle is the <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_610\">nucleus<\/a><\/strong>, where the cell\u2019s DNA is located.<\/p>\n<p>&nbsp;<\/p>\n<figure style=\"width: 555px\" class=\"wp-caption aligncenter\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image1.png\" alt=\"Cell wall of a phospholipid bilayer with embedded channels, carbohydrates, and proteins.\" width=\"555\" height=\"270\" \/><figcaption class=\"wp-caption-text\">Figure 3.4: A phospholipid bilayer with membrane-bound carbohydrates and proteins. <a href=\"https:\/\/docs.google.com\/document\/d\/1VUDKMBJYS_jNONjLxT04jQN0_z9Ua50BRN6auGSHUuU\/edit\" target=\"_blank\" rel=\"noopener\">A full text description of this image is available.<\/a> Credit: <a href=\"https:\/\/openstax.org\/books\/anatomy-and-physiology\/pages\/3-1-the-cell-membrane#fig-ch03_01_03\">Cell Membrane (Anatomy &amp; Physiology, Figure 3.4)<\/a> by<a href=\"https:\/\/openstax.org\/\"> OpenStax<\/a> is under a<a href=\"https:\/\/creativecommons.org\/licenses\/by\/4.0\/\"> CC BY 4.0 License<\/a>.<\/figcaption><\/figure>\n<figure style=\"width: 547px\" class=\"wp-caption aligncenter\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image1-1.png\" alt=\"Animal cell with various organelles labeled.\" width=\"547\" height=\"415\" \/><figcaption class=\"wp-caption-text\">Figure 3.5: An animal cell with membrane-enclosed organelles. <a href=\"https:\/\/docs.google.com\/document\/d\/1VUDKMBJYS_jNONjLxT04jQN0_z9Ua50BRN6auGSHUuU\/edit\" target=\"_blank\" rel=\"noopener\">A full text description of this image is available.<\/a> Credit: <a href=\"https:\/\/www.genome.gov\/genetics-glossary\/Organelle?id=147\">Organelle<\/a> by<a href=\"https:\/\/www.genome.gov\/\"> NIH National Human Genome Research Institute<\/a> is in the<a href=\"https:\/\/www.genome.gov\/about-nhgri\/Policies-Guidance\/Copyright\"> public domain<\/a>.<\/figcaption><\/figure>\n<p class=\"import-Normal\">Another organelle is the <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_612\">mitochondrion<\/a><\/strong>. Mitochondria are often referred to as \u201cpowerhouse centers\u201d because they produce energy for the cell in the form of <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_616\">adenosine triphosphate (ATP)<\/a><\/strong>. Depending on the species and tissue type, multicellular eukaryotes can have hundreds to thousands of mitochondria in each of their cells. Scientists have determined that mitochondria were once <em>symbiotic<\/em> prokaryotic organisms (i.e., helpful bacteria) that transformed into cellular organelles over time. This evolutionary explanation helps explain why mitochondria also have their own DNA, called <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_618\">mitochondrial DNA (mtDNA)<\/a><\/strong>. All organelles have important physiological functions and disease can occur when organelles do not perform their role optimally. Figure 3.6 lists other organelles found in the cell and their specialized cellular roles.<\/p>\n<table class=\"aligncenter\" style=\"width: 399pt\" border=\"1pt solid rgb(0, 0, 0)\" cellpadding=\"5pt\">\n<caption>Figure 3.6: This table depicts the names of organelles and their cellular functions. Credit: <a href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/chapter\/__unknown__-9\/\">Cell Structure table (Figure 3.11)<\/a> original to <a href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/\">Explorations: An Open Invitation to Biological Anthropology<\/a> by Hayley Mann, Xazmin Lowman, and Malaina Gaddis is under a <a href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/\">CC BY-NC 4.0 License<\/a>.<\/caption>\n<thead>\n<tr>\n<td class=\"a0-C\" style=\"background-color: transparent;padding: 5pt 5pt 5pt 5pt;border: solid #000000 1pt\">\n<p class=\"import-Normal\"><strong>Cell structure<\/strong><\/p>\n<\/td>\n<td class=\"a0-C\" style=\"background-color: transparent;padding: 5pt 5pt 5pt 5pt;border: solid #000000 1pt\">\n<p class=\"import-Normal\"><strong>Description<\/strong><\/p>\n<\/td>\n<\/tr>\n<\/thead>\n<tbody>\n<tr class=\"a0-R\" style=\"height: 36pt\">\n<td class=\"a0-C\" style=\"background-color: transparent;padding: 5pt 5pt 5pt 5pt;border: solid #000000 1pt\">\n<p class=\"import-Normal\">Centrioles<\/p>\n<\/td>\n<td class=\"a0-C\" style=\"background-color: transparent;padding: 5pt 5pt 5pt 5pt;border: solid #000000 1pt\">\n<p class=\"import-Normal\">Assist with the organization of mitotic spindles, which extend and contract for the purpose of cellular movement during mitosis and meiosis.<\/p>\n<\/td>\n<\/tr>\n<tr class=\"a0-R\" style=\"height: 36pt\">\n<td class=\"a0-C\" style=\"background-color: transparent;padding: 5pt 5pt 5pt 5pt;border: solid #000000 1pt\">\n<p class=\"import-Normal\">Cytoplasm<\/p>\n<\/td>\n<td class=\"a0-C\" style=\"background-color: transparent;padding: 5pt 5pt 5pt 5pt;border: solid #000000 1pt\">\n<p class=\"import-Normal\">Gelatinous fluid located inside of cell membrane that contains organelles.<\/p>\n<\/td>\n<\/tr>\n<tr class=\"a0-R\" style=\"height: 24pt\">\n<td class=\"a0-C\" style=\"background-color: transparent;padding: 5pt 5pt 5pt 5pt;border: solid #000000 1pt\">\n<p class=\"import-Normal\">Endoplasmic reticulum (ER)<\/p>\n<\/td>\n<td class=\"a0-C\" style=\"background-color: transparent;padding: 5pt 5pt 5pt 5pt;border: solid #000000 1pt\">\n<p class=\"import-Normal\">Continuous membrane with the nucleus that helps transport, synthesize, modify, and fold proteins. Rough ER has embedded ribosomes, whereas smooth ER lacks ribosomes.<\/p>\n<\/td>\n<\/tr>\n<tr class=\"a0-R\" style=\"height: 24pt\">\n<td class=\"a0-C\" style=\"background-color: transparent;padding: 5pt 5pt 5pt 5pt;border: solid #000000 1pt\">\n<p class=\"import-Normal\">Golgi body<\/p>\n<\/td>\n<td class=\"a0-C\" style=\"background-color: transparent;padding: 5pt 5pt 5pt 5pt;border: solid #000000 1pt\">\n<p class=\"import-Normal\">Layers of flattened sacs that receive and transmit messages from the ER to secrete and transport proteins within the cell.<\/p>\n<\/td>\n<\/tr>\n<tr class=\"a0-R\" style=\"height: 24pt\">\n<td class=\"a0-C\" style=\"background-color: transparent;padding: 5pt 5pt 5pt 5pt;border: solid #000000 1pt\">\n<p class=\"import-Normal\">Lysosome<\/p>\n<\/td>\n<td class=\"a0-C\" style=\"background-color: transparent;padding: 5pt 5pt 5pt 5pt;border: solid #000000 1pt\">\n<p class=\"import-Normal\">Located in the cytoplasm; contains enzymes to degrade cellular components.<\/p>\n<\/td>\n<\/tr>\n<tr class=\"a0-R\" style=\"height: 24pt\">\n<td class=\"a0-C\" style=\"background-color: transparent;padding: 5pt 5pt 5pt 5pt;border: solid #000000 1pt\">\n<p class=\"import-Normal\">Microtubule<\/p>\n<\/td>\n<td class=\"a0-C\" style=\"background-color: transparent;padding: 5pt 5pt 5pt 5pt;border: solid #000000 1pt\">\n<p class=\"import-Normal\">Involved with cellular movement including intracellular transport and cell division.<\/p>\n<\/td>\n<\/tr>\n<tr class=\"a0-R\" style=\"height: 24pt\">\n<td class=\"a0-C\" style=\"background-color: transparent;padding: 5pt 5pt 5pt 5pt;border: solid #000000 1pt\">\n<p class=\"import-Normal\">Mitochondrion<\/p>\n<\/td>\n<td class=\"a0-C\" style=\"background-color: transparent;padding: 5pt 5pt 5pt 5pt;border: solid #000000 1pt\">\n<p class=\"import-Normal\">Responsible for cellular respiration, where energy is produced by converting nutrients into ATP.<\/p>\n<\/td>\n<\/tr>\n<tr class=\"a0-R\" style=\"height: 24pt\">\n<td class=\"a0-C\" style=\"background-color: transparent;padding: 5pt 5pt 5pt 5pt;border: solid #000000 1pt\">\n<p class=\"import-Normal\">Nucleolus<\/p>\n<\/td>\n<td class=\"a0-C\" style=\"background-color: transparent;padding: 5pt 5pt 5pt 5pt;border: solid #000000 1pt\">\n<p class=\"import-Normal\">Resides inside of the nucleus and is the site of <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_620\">ribosomal RNA (rRNA)<\/a><\/strong> transcription, processing, and assembly.<\/p>\n<\/td>\n<\/tr>\n<tr class=\"a0-R\" style=\"height: 24pt\">\n<td class=\"a0-C\" style=\"background-color: transparent;padding: 5pt 5pt 5pt 5pt;border: solid #000000 1pt\">\n<p class=\"import-Normal\">Nucleopore<\/p>\n<\/td>\n<td class=\"a0-C\" style=\"background-color: transparent;padding: 5pt 5pt 5pt 5pt;border: solid #000000 1pt\">\n<p class=\"import-Normal\">Pores in the <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_622\">nuclear envelope<\/a><\/strong> that are selectively permeable.<\/p>\n<\/td>\n<\/tr>\n<tr class=\"a0-R\">\n<td class=\"a0-C\" style=\"background-color: transparent;padding: 5pt 5pt 5pt 5pt;border: solid #000000 1pt\">\n<p class=\"import-Normal\">Nucleus<\/p>\n<\/td>\n<td class=\"a0-C\" style=\"background-color: transparent;padding: 5pt 5pt 5pt 5pt;border: solid #000000 1pt\">\n<p class=\"import-Normal\">Contains the cell\u2019s DNA and is surrounded by the nuclear envelope.<\/p>\n<\/td>\n<\/tr>\n<tr class=\"a0-R\">\n<td class=\"a0-C\" style=\"background-color: transparent;padding: 5pt 5pt 5pt 5pt;border: solid #000000 1pt\">\n<p class=\"import-Normal\">Ribosome<\/p>\n<\/td>\n<td class=\"a0-C\" style=\"background-color: transparent;padding: 5pt 5pt 5pt 5pt;border: solid #000000 1pt\">\n<p class=\"import-Normal\">Located in the cytoplasm and also the membrane of the rough endoplasmic reticulum. Messenger RNA (mRNA) binds to ribosomes and proteins are synthesized.<\/p>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<h2 class=\"import-Normal\">Introduction to Genetics<\/h2>\n<p class=\"import-Normal\">Genetics is the study of heredity. Biological parents pass down their genetic traits to their offspring. Although children resemble their parents, genetic traits often vary in appearance or molecular function. For example, two parents with normal color vision can sometimes produce a son with red-green colorblindness. <span style=\"background-color: #ff00ff\">Patterns of genetic inheritance will be discussed in a later section.<\/span> <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_624\">Molecular geneticists<\/a> <\/strong>study the biological mechanisms responsible for creating variation between individuals, such as DNA <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_626\">mutations<\/a><\/strong> (see Chapter 4), cell division, and genetic regulation.<\/p>\n<p class=\"import-Normal\"><strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_628\">Molecular anthropologists<\/a><\/strong> use genetic data to test anthropological questions. Some of these anthropologists utilize <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_630\">ancient DNA (aDNA)<\/a><\/strong>, which is DNA that is extracted from anything once living, including human, animal, and plant remains. Over time, DNA becomes degraded (i.e., less intact), but specialized laboratory techniques can make copies of short degraded aDNA segments, which can then be reassembled to provide more complete DNA information. <span style=\"background-color: #00ff00\">A recent example of an aDNA study is provided in Special Topic: Native American Immunity and European Diseases, and aDNA is also explored in Appendix D.<\/span><\/p>\n<h3 class=\"import-Normal\"><strong>DNA Structure<\/strong><\/h3>\n<p class=\"import-Normal\">The discovery, in 1953, of the molecular structure of deoxyribonucleic acid (DNA) was one of the greatest scientific achievements of all time. Using X-ray crystallography, Rosalind Franklin (Figure 3.7) provided the image that clearly showed the double helix shape of DNA. <span style=\"background-color: #00ff00\">However, due to a great deal of controversy, Franklin\u2019s colleague and outside associates received greater publicity for the discovery. In 1962, James Watson, Francis Crick, and Maurice Wilkins received a Nobel Prize for developing a biochemical model of DNA. Unfortunately, Rosalind Franklin had passed away in 1958 from ovarian cancer. In current times, Franklin\u2019s important contribution and her reputation as a skilled scientist are widely acknowledged<\/span>.<\/p>\n<figure style=\"width: 223px\" class=\"wp-caption alignleft\"><img class=\"\" src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image2-1.png\" alt=\"Historic photo of woman looking into a microscope.\" width=\"223\" height=\"268\" \/><figcaption class=\"wp-caption-text\">Figure 3.7: Chemist and X-ray crystallographer Rosalind Franklin. Credit: <a href=\"https:\/\/commons.wikimedia.org\/wiki\/File:Rosalind_Franklin.jpg\">Rosalind Franklin<\/a> from the personal collection of Jenifer Glynn by MRC Laboratory of Molecular Biology is under a <a href=\"https:\/\/creativecommons.org\/licenses\/by-sa\/4.0\/legalcode\">CC BY-SA 4.0 License<\/a>.<\/figcaption><\/figure>\n<p class=\"import-Normal\">The double helix shape of DNA can be described as a twisted ladder (Figure 3.8). More specifically, DNA is a double-stranded molecule with its two strands oriented in opposite directions (i.e., antiparallel). Each strand is composed of <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_632\">nucleotides<\/a> <\/strong>with a<strong> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_634\">sugar phosphate backbone<\/a><\/strong>. There are four different types of DNA nucleotides: adenine (A), thymine (T), cytosine (C), and guanine (G). The two DNA strands are held together by nucleotide <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_636\">base pairs<\/a><\/strong>, which have chemical bonding rules. The complementary base-pairing rules are as follows: A and T bond with each other, while C and G form a bond. The chemical bonds between A-T and C-G are formed by \u201cweak\u201d hydrogen atom interactions, which means the two strands can be easily separated. A DNA sequence is the order of nucleotide bases (A, T, G, C) along only one DNA strand. If one DNA strand has the sequence CATGCT, then the other strand will have a complementary sequence GTACGA. This is an example of a short DNA sequence. In reality, there are approximately three billion DNA base pairs in human cells.<\/p>\n<figure style=\"width: 341px\" class=\"wp-caption alignright\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image3.jpg\" alt=\"Double helix structure of DNA.\" width=\"341\" height=\"400\" \/><figcaption class=\"wp-caption-text\">Figure 3.8: Structural components that form double-stranded nucleic acid (DNA). Credit: <a href=\"https:\/\/commons.wikimedia.org\/wiki\/File:Difference_DNA_RNA-EN.svg\">Difference DNA RNA-EN<\/a> by <a href=\"https:\/\/commons.wikimedia.org\/wiki\/User:Sponk\">Sponk<\/a> (translation by <a href=\"https:\/\/commons.wikimedia.org\/wiki\/User:Sponk\">Sponk<\/a>, cropped by Katie Nelson) is under a <a href=\"https:\/\/creativecommons.org\/licenses\/by-nc-sa\/4.0\/\">CC BY-NC-SA 4.0 License<\/a>.<\/figcaption><\/figure>\n<h3 class=\"import-Normal\"><strong>DNA Is Highly Organized within the Nucleus<\/strong><\/h3>\n<p class=\"import-Normal\">If you removed the DNA from a single human cell and stretched it out completely, it would measure approximately two meters (about 6.5 feet). Therefore, DNA molecules must be compactly organized in the nucleus. To achieve this, the double helix configuration of DNA undergoes coiling. An analogy would be twisting a string until coils are formed and then continuing to twist so that secondary coils are formed, and so on. To assist with coiling, DNA is first wrapped around proteins called <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_638\">histones<\/a><\/strong>. This creates a complex called <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_640\">chromatin<\/a>,<\/strong> which resembles \u201cbeads on a string\u201d (Figure 3.9). Next, chromatin is further coiled into a <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_642\">chromosome<\/a><\/strong>. Another important feature of DNA is that chromosomes can be altered from tightly coiled (chromatin) to loosely coiled (<strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_644\">euchromatin<\/a><\/strong>). Most of the time, chromosomes in the nucleus remain in a euchromatin state so that DNA sequences are accessible for regulatory processes to occur.<\/p>\n<p>&nbsp;<\/p>\n<figure style=\"width: 558px\" class=\"wp-caption aligncenter\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image1-2.png\" alt=\"Illustrates how chromosomes are made up of various components. \" width=\"558\" height=\"534\" \/><figcaption class=\"wp-caption-text\">Figure 3.9: The hierarchical organization of chromosomes. <a href=\"https:\/\/docs.google.com\/document\/d\/1VUDKMBJYS_jNONjLxT04jQN0_z9Ua50BRN6auGSHUuU\/edit\" target=\"_blank\" rel=\"noopener\">A full text description of this image is available<\/a>.\u00a0Credit: <a href=\"https:\/\/www.genome.gov\/glossary\/index.cfm?id=102\">Histone (2019)<\/a> by<a href=\"https:\/\/www.genome.gov\/\"> NIH National Human Genome Research Institute<\/a> is in the<a href=\"https:\/\/www.genome.gov\/about-nhgri\/Policies-Guidance\/Copyright\"> public domain<\/a>.<\/figcaption><\/figure>\n<figure style=\"width: 256px\" class=\"wp-caption alignleft\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image4-1.png\" alt=\"Chromatid is divided into a short and long arm, bound by a centromere. \" width=\"256\" height=\"296\" \/><figcaption class=\"wp-caption-text\">Figure 3.10: The regions of a chromosome. Credit: <a href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/chapter\/__unknown__-9\/\">Chromosome (Figure 3.16)<\/a> original to <a href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/\">Explorations: An Open Invitation to Biological Anthropology<\/a> by Katie Nelson is under a <a href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/\">CC BY-NC 4.0 License<\/a>.<\/figcaption><\/figure>\n<p>&nbsp;<\/p>\n<\/div>\n<p>&nbsp;<\/p>\n<div class=\"__UNKNOWN__\">\n<p>Human body cells typically have 23 pairs of chromosomes, for a total of 46 chromosomes in each cell\u2019s nucleus. An interesting fact is that the number of chromosomes an organism possesses varies by species, and this figure is not dependent upon the size or complexity of the organism. For instance, chimpanzees have a total of 48 chromosomes, while hermit crabs have 254. Chromosomes also have a distinct physical structure, including <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_646\">centromeres<\/a> <\/strong>(the \u201ccenter\u201d) and <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_648\">telomeres<\/a> <\/strong>(the ends) (Figure 3.10). Because of the centromeric region, chromosomes are described as having two different \u201carms,\u201d where one arm is long and the other is shorter. Centromeres play an important role during cell division, which will be discussed in the next section. Telomeres are located at the ends of chromosomes; they help protect the chromosomes from degradation after every round of cell division.<\/p>\n<\/div>\n<p>&nbsp;<\/p>\n<div class=\"__UNKNOWN__\">\n<div class=\"textbox\">\n<h2 class=\"import-Normal\">Special Topic: <del>Native American<\/del> First Nation\u00a0Immunity and European Diseases\u2014A Study of Ancient DNA<\/h2>\n<figure style=\"width: 300px\" class=\"wp-caption alignleft\"><img class=\"\" src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image5-1.png\" alt=\"A group of people in historic clothing, some with traditional shawls, eat under a tent.\" width=\"300\" height=\"184\" \/><figcaption class=\"wp-caption-text\">Figure 3.11a: Tsimshian Native Americans of the Pacific Northwest Coast. Credit: <a href=\"https:\/\/central.bac-lac.gc.ca\/.redirect?app=fonandcol&amp;id=3368729&amp;lang=eng\">A group of Tsimshian people having a tea party in a tent, Lax Kw'alaams (formerly Port Simpson), B.C., c. 1890<\/a> by unknown photographer is in the <a href=\"https:\/\/creativecommons.org\/share-your-work\/public-domain\/pdm\">Public Domain<\/a>. This image is available from the <a href=\"https:\/\/www.bac-lac.gc.ca\/eng\/Pages\/home.aspx\">Library and Archives Canada<\/a>, item number 3368729.<\/figcaption><\/figure>\n<p>Beginning in the early fifteenth century, First Nations progressively suffered from high mortality rates as the result of colonization from foreign powers. European-borne diseases such as measles, tuberculosis, influenza, and smallpox are largely responsible for the population collapse of Indigenous peoples in the Americas. Many Europeans who immigrated to the Americas had lived in large sedentary populations, which also included coexisting with domestic animals and pests. Although a few prehistoric Indigenous populations can be characterized as large agricultural societies (especially in Mesoamerica), their overall culture, community lifestyle, and subsistence practices were markedly different from that of Europeans. Therefore, because they did not share the same urban living environments as Europeans, it is believed that Indigenous peoples were susceptible to many European diseases.<\/p>\n<figure style=\"width: 459px\" class=\"wp-caption alignright\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image6.jpg\" alt=\"Tsimshian territory on the coast of British Columbia next to the Hecate Strait.\" width=\"459\" height=\"594\" \/><figcaption class=\"wp-caption-text\">Figure 3.11b: Tsimshian territory in present-day British Columbia. Credit: <a href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/chapter\/__unknown__-9\/\">Tsimshian Territory map (Figure 3.12b)<\/a> original to <a href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/\">Explorations: An Open Invitation to Biological Anthropology<\/a> by Elyssa Ebding at<a href=\"https:\/\/www.csuchico.edu\/geop\/geoplace\/index.shtml\"> GeoPlace, California State University, Chico<\/a> is under a<a href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/\"> CC BY-NC 4.0 License<\/a>.<\/figcaption><\/figure>\n<p>In 2016, a <em>Nature<\/em> article published by John Lindo and colleagues was the first to investigate whether pre-contact Indigenous peoples possessed a genetic susceptibility to European diseases. Their study included Tsimshians, a First Nation community from British Columbia (Figure 3.11a-b). DNA from both present-day and ancient individuals (who lived between 500 and 6,000 years ago) was analyzed. The research team discovered that a change occurred in the <em>HLA-DQA1<\/em> gene, which is a member of the major histocompatibility complex (MHC) immune system molecules. MHC molecules are responsible for detecting and triggering an immune response against pathogens. Lindo and colleagues (2016) concluded that <em>HLA-DQA1<\/em> gene helped Indigenous peoples adapt to their local environmental ecology. However, when European-borne epidemics occurred in the Northwest during the 1800s, a certain <em>HLA-DQA1<\/em> <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_650\">DNA sequence<\/a><\/strong> variant (allele) associated with ancient Tsimshian immunity was no longer adaptive. As the result of past selective pressures from European diseases, present-day Tsimshians have different <em>HLA-DQA1<\/em> allele frequencies. The precise role that <em>HLA-DQA1 <\/em>plays in immune adaptation requires further investigation. But overall, this study serves as an example of how studying ancient DNA from the remains of deceased individuals can help provide insight into living human populations and historical events.<\/p>\n<\/div>\n<h2 class=\"import-Normal\">DNA Replication and Cell Division<\/h2>\n<p class=\"import-Normal\">For life to continue and flourish, cells must be able to divide. Tissue growth and cellular damage repair are also necessary to maintain an organism throughout its life. All these rely on the dynamic processes of <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_652\">DNA replication<\/a><\/strong> and the <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_654\">cell cycle<\/a><\/strong>. The mechanisms highlighted in this section are tightly regulated and represent only part of the life cycle of a cell.<\/p>\n<h3 class=\"import-Normal\"><strong>DNA Replication <\/strong><\/h3>\n<p class=\"import-Normal\">DNA replication is the process by which new DNA is copied from an original DNA template. It is one phase of the highly coordinated cell cycle, and it requires a variety of enzymes with special functions. The creation of a complementary DNA strand from a template strand is described as <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_656\">semi-conservative replication<\/a><\/strong>. The result of semi-conservative replication is two separate double-stranded DNA molecules, each of which is composed of an original \u201cparent\u201d template strand and a newly synthesized \u201cdaughter\u201d DNA strand.<\/p>\n<p class=\"import-Normal\">DNA replication progresses in three steps referred to as <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_658\">initiation<\/a><\/strong>, <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_660\">elongation<\/a>,<\/strong> and <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_662\">termination<\/a><\/strong>. During initiation, enzymes are recruited to specific sites along the DNA sequence (Figure 3.12). For example, an initiator enzyme, called <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_664\">helicase<\/a><\/strong>, \u201cunwinds\u201d DNA by breaking the hydrogen bonds between the two parent strands. The unraveling of the helix into two separated strands exposes the strands and creates a fork, which is the active site of DNA replication.<\/p>\n<figure style=\"width: 580px\" class=\"wp-caption aligncenter\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image7.jpg\" alt=\"Helicase enzyme splits apart 2 DNA strands. On each strand DNA polymerase matches free nucleotides.\" width=\"580\" height=\"359\" \/><figcaption class=\"wp-caption-text\">Figure 3.12: DNA replication and the different enzymes associated with it. <a href=\"https:\/\/docs.google.com\/document\/d\/1VUDKMBJYS_jNONjLxT04jQN0_z9Ua50BRN6auGSHUuU\/edit\" target=\"_blank\" rel=\"noopener\">A full text description of this image is available<\/a>. Credit: <a href=\"https:\/\/commons.wikimedia.org\/wiki\/File:0323_DNA_Replication.jpg\">0323 DNA Replication<\/a> by <a href=\"https:\/\/openstax.org\/books\/anatomy-and-physiology\/pages\/1-introduction\">OpenStax<\/a> is under a <a href=\"https:\/\/creativecommons.org\/licenses\/by\/4.0\/legalcode\">CC BY 4.0 License<\/a>.<\/figcaption><\/figure>\n<p class=\"import-Normal\">Elongation is the assembly of new DNA daughter strands from the exposed original parent strands. The two parent strands can further be classified as <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_666\">leading strand<\/a><\/strong> or <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_668\">lagging strand<\/a><\/strong> and are distinguished by the direction of replication. Enzymes called <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_670\">DNA polymerases<\/a><\/strong> read parent template strands in a specific direction. Complementary nucleotides are added, and the newly formed daughter strands will grow. On the leading parent strand, a DNA polymerase will create one continuous strand. The lagging parent strand is created in several disconnected sections and other enzymes fill in the missing nucleotide gaps between these sections.<\/p>\n<p class=\"import-Normal\">Finally, termination refers to the end of DNA replication activity. It is signaled by a stop sequence in the DNA that is recognized by machinery at the replication fork. The end result of DNA replication is that the number of chromosomes are doubled so that the cell can divide into two.<\/p>\n<h3 class=\"import-Normal\"><strong>DNA Mutations<\/strong><\/h3>\n<p class=\"import-Normal\">DNA replication should result in the creation of two identical DNA nucleotide sequences. However, although DNA polymerases are quite precise during DNA replication, copying mistakes are estimated to occur every 10<sup>7<\/sup> DNA nucleotides. Variation from the original DNA sequence is known as a mutation <span style=\"background-color: #00ff00\">(Refer to Chapter 4)<\/span>. <span style=\"background-color: #ff0000\">The different types of mutations will be discussed in greater detail in Chapter 4.<\/span> Briefly, mutations can result in single nucleotide changes, as well as the insertion or deletion of nucleotides and repeated sequences. Depending on where they occur in the genome, mutations can be <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_672\">deleterious<\/a> <\/strong>(harmful). For example, mutations may occur in regions that control cell cycle regulation, which can result in cancer <span style=\"background-color: #ff0000\">(see Special Topic: The Cell Cycle and Immortality of Cancer Cells)<\/span>. Many other types of mutations, however, are not harmful to an organism.<\/p>\n<p class=\"import-Normal\">Regardless of their effect, the cell attempts to reduce the frequency of mutations that occur during DNA replication. To accomplish this, there are polymerases with proofreading capacities that can identify and correct mismatched nucleotides. These safeguards reduce the frequency of DNA mutations so that they only occur every 10<sup>9<\/sup> nucleotides.<\/p>\n<h3 class=\"import-Normal\"><strong>Mitotic Cell Division<\/strong><\/h3>\n<p class=\"import-Normal\">There are two types of cells in the body: <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_674\">germ cells<\/a> <\/strong>(sperm and egg) and <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_676\">somatic cells<\/a><\/strong>. The body and its various tissues comprises somatic cells. Organisms that contain two sets of chromosomes in their somatic cells are called <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_678\">diploid<\/a><\/strong> organisms. Humans have 46 chromosomes and they are diploid because they inherit one set of chromosomes (<em>n <\/em>= 23) from each parent. As a result, they have 23 matching pairs of chromosomes, which are known as <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_680\">homologous chromosomes<\/a><\/strong>. As seen in Figure 3.13, homologous chromosome pairs vary in size and are generally numbered from largest (chromosome 1) to smallest (chromosome 22) with the exception of the 23rd pair, which is made up of the sex chromosomes (X and Y). Typically, the female sex is XX and the male sex is XY. Individuals inherit an X chromosome from their chromosomal mother and an X or Y from their chromosomal father.<\/p>\n<figure id=\"attachment_82\" aria-describedby=\"caption-attachment-82\" style=\"width: 468px\" class=\"wp-caption alignleft\"><img class=\"wp-image-82\" src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/Karyotype.jpg\" alt=\"Karyotype showing pairs of chromosomes organized by size into 23 pairs.\" width=\"468\" height=\"263\" \/><figcaption id=\"caption-attachment-82\" class=\"wp-caption-text\">Figure 3.13: The 23 human chromosome pairs. Credit: Genome (2019) by NIH National Human Genome Research Institute is in the public domain.<\/figcaption><\/figure>\n<p class=\"import-Normal\">To grow and repair tissues, somatic cells must divide. As discussed previously, for cell division to occur, a cell must first replicate its genetic material. During DNA replication, each chromosome produces double the amount of genetic information. The duplicated arms of chromosomes are known as <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_682\">sister chromatids<\/a>,<\/strong> and they are attached at the centromeric region. To elaborate, the number of chromosomes stays the same (<em>n<\/em> = 46); however, the amount of genetic material is doubled in the cell as the result of replication.<\/p>\n<p class=\"import-Normal\"><strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_684\">Mitosis<\/a><\/strong> is the process of somatic cell division that gives rise to two diploid daughter cells. Figure 3.14 includes a brief overview of mitosis. Once DNA and other organelles in the cell have finished replication, mitotic spindle fibers physically align each chromosome at the center of the cell. Next, the spindle fibers divide the sister chromatids and move each one to opposite sides of the cell. At this phase, there are 46 chromosomes on each side of a human cell. The cell can now divide into two fully separated daughter cells.<\/p>\n<\/div>\n<figure id=\"attachment_89\" aria-describedby=\"caption-attachment-89\" style=\"width: 569px\" class=\"wp-caption aligncenter\"><img class=\"wp-image-83\" src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/mitosismeiosisNEW.jpg\" alt=\"The stages of mitosis and meiosis.\" width=\"569\" height=\"521\" \/><figcaption id=\"caption-attachment-89\" class=\"wp-caption-text\">Figure 3.14: The steps of mitotic cell division and meiotic cell division. Credit: Mitosis and meiosis original to Explorations: An Open Invitation to Biological Anthropology (2nd ed.) by Katie Nelson is a collective work under a CC BY-NC 4.0 License. [Includes Mitosis (Figure 3.20) and Meiosis (Figure 3.21) by Mary Nelson; CC BY-NC 4.0 License.]<\/figcaption><\/figure>\n<div class=\"__UNKNOWN__\">\n<h3 class=\"import-Normal\"><strong>Meiotic Cell Division<\/strong><\/h3>\n<p class=\"import-Normal\">Gametogenesis is the production of <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_686\">gametes<\/a><\/strong> (sperm and egg cells); it involves two rounds of cell division called <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_688\">meiosis<\/a><\/strong>. Similar to mitosis, the parent cell in meiosis is diploid. However, meiosis has a few key differences, including the number of daughter cells produced (four cells, which require two rounds of cell division to produce) and the number of chromosomes each daughter cell has (see Figure 3.14).<\/p>\n<p class=\"import-Normal\">During the first round of division (known as meiosis I), each chromosome (<em>n<\/em> = 46) replicates its DNA so that sister chromatids are formed. Next, with the help of spindle fibers, homologous chromosomes align near the center of the cell and sister chromatids physically swap genetic material. In other words, the sister chromatids of matching chromosomes cross over with each other at matching DNA nucleotide positions. The occurrence of homologous chromosomes crossing over, swapping DNA, and then rejoining segments is called <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_690\">genetic recombination<\/a><\/strong>. The \u201cgenetic shuffling\u201d that occurs in gametes increases organismal genetic diversity by creating new combinations of genes on chromosomes that are different from the parent cell. Genetic mutations can also arise during recombination. For example, there may be an unequal swapping of genetic material that occurs between the two sister chromatids, which can result in deletions or duplications of DNA nucleotides. Once genetic recombination is complete, homologous chromosomes are separated and two daughter cells are formed.<\/p>\n<p class=\"import-Normal\">The daughter cells after the first round of meiosis are <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_692\">haploid<\/a><\/strong>, meaning they only have one set of chromosomes (<em>n <\/em>= 23). During the second round of cell division (known as meiosis II), sister chromatids are separated and two additional haploid daughter cells are formed. Therefore, the four resulting daughter cells have one set of chromosomes (<em>n<\/em> = 23), and they also have a genetic composition that is not identical to the parent cells nor to each other.<\/p>\n<p class=\"import-Normal\">Although both sperm and egg gamete production undergo meiosis, they differ in the final number of viable daughter cells. In the case of spermatogenesis, four mature sperm cells are produced. Although four egg cells are also produced in oogenesis, only one of these egg cells will result in an ovum (mature egg). During fertilization, an egg cell and sperm cell fuse, which creates a diploid cell that develops into an embryo. The ovum also provides the cellular organelles necessary for embryonic cell division. This includes mitochondria, which is why humans, and most other multicellular eukaryotes, have the same mtDNA sequence as their mothers.<\/p>\n<h3 class=\"import-Normal\"><strong>Chromosomal Disorders: Aneuploidies<\/strong><\/h3>\n<p class=\"import-Normal\">During mitosis or meiosis, entire deletions or duplications of chromosomes can occur due to error. For example, homologous chromosomes may fail to separate properly, so one daughter cell may end up with an extra chromosome while the other daughter cell has one less. Cells with an unexpected (or abnormal) number of chromosomes are known as <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_694\">aneuploid<\/a><\/strong>. Adult or embryonic cells can be tested for chromosome number (<strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_696\">karyotyping<\/a><\/strong>). Aneuploid cells are typically detrimental to a dividing cell or developing embryo, which can lead to a loss of pregnancy. However, the occurrence of individuals being born with three copies of the 21st chromosome is relatively common; this genetic condition is known as Down Syndrome. Moreover, individuals can also be born with aneuploid sex chromosome conditions such as XXY, XXX, and XO (referring to only one X chromosome).<\/p>\n<div class=\"textbox\">\n<h2 class=\"import-Normal\">Special Topic: The Cell Cycle and Immortality of Cancer Cells<\/h2>\n<p class=\"import-Normal\">DNA replication is part of a series of preparatory phases that a cell undergoes prior to cell division, collectively known as <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_698\">interphase<\/a> <\/strong>(Figure 3.15). During interphase, the cell not only doubles its chromosomes through DNA replication, but it also increases its metabolic capacity to provide energy for growth and division. Transition into each phase of the cell cycle is tightly controlled by proteins that serve as checkpoints. If a cell fails to pass a checkpoint, then DNA replication and\/or cell division will not continue. Some of the reasons why a cell may fail at a checkpoint is DNA damage, lack of nutrients to continue the process, or insufficient size. In turn, a cell may undergo <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_700\">apoptosis<\/a><\/strong>, which is a mechanism for cell death.<\/p>\n<figure style=\"width: 617px\" class=\"wp-caption aligncenter\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image11.png\" alt=\"The cell cycle is mostly cell growth and DNA synthesis (interphase), followed by the mitotic phase (mitosis and cytokinesis).\" width=\"617\" height=\"433\" \/><figcaption class=\"wp-caption-text\">Figure 3.15: The phases and checkpoints of the cell cycle. <a href=\"https:\/\/docs.google.com\/document\/d\/1VUDKMBJYS_jNONjLxT04jQN0_z9Ua50BRN6auGSHUuU\/edit\" target=\"_blank\" rel=\"noopener\">A full text description of this image is available.<\/a> Credit: <a href=\"https:\/\/cnx.org\/contents\/jVCgr5SL@15.43:SeU_rWbd@14\/10-2-The-Cell-Cycle\">Cell cycle (Biology 2e, Figure 10.5)<\/a> by<a href=\"https:\/\/openstax.org\/\"> OpenStax<\/a> is under a<a href=\"https:\/\/creativecommons.org\/licenses\/by\/4.0\/\"> CC BY 4.0 License<\/a>.<\/figcaption><\/figure>\n<p>&nbsp;<\/p>\n<p class=\"import-Normal\">Unchecked cellular growth is a distinguishing hallmark of cancer. In other words, as cancer cells grow and proliferate, they acquire the capacity to avoid death and replicate indefinitely. This uncontrolled and continuous cell division is also known as \u201cimmortality.\u201d As previously mentioned, most cells lose the ability to divide due to shortening of telomeres on the ends of chromosomes over time. One way in which cancer cells retain replicative immortality is that the length of their telomeres is continuously protected. Chemotherapy, often used to treat cancer, targets the cell cycle (especially cell division) to halt the propagation of genetically abnormal cells. Another therapeutic approach that continues to be investigated is targeting telomere activity to stop the division of cancer cells.<\/p>\n<figure style=\"width: 296px\" class=\"wp-caption alignleft\"><img class=\"\" src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image12-1.png\" alt=\"Microscope image of irregularly shaped cells with bright nuclei.\" width=\"296\" height=\"223\" \/><figcaption class=\"wp-caption-text\">Figure 3.16: A microscopic slide of HeLa cancer cells. Credit: <a href=\"https:\/\/commons.wikimedia.org\/wiki\/File:HeLa-III.jpg\">HeLa-III<\/a> by National Institutes of Health (NIH) is in the <a href=\"https:\/\/en.wikipedia.org\/wiki\/Public_domain\">public domain<\/a>.<\/figcaption><\/figure>\n<p>Researchers have exploited the immortality of cancer cells for molecular research. The oldest immortal cell line is HeLa cells (Figure 3.16), which were harvested from Henrietta Lacks, an African American woman diagnosed with cervical cancer in 1955. At that time, extracted cells frequently died during experiments, but surprisingly HeLa cells continued to replicate. Propagation of Lacks\u2019s cell line has significantly contributed to medical research, including contributing to ongoing cancer research and helping to test the polio vaccine in the 1950s. However, Lacks had not given her consent for her tumor biopsy to be used in cell culture research. Moreover, her family was unaware of the extraction and remarkable application of her cells for two decades. The history of HeLa cell origin was first revealed in 1976. The controversy voiced by the Lacks family was included in an extensive account of HeLa cells published in Rebecca Skloot\u2019s 2010 book, <em>The Immortal Life of Henrietta Lacks<\/em>. A film based on the book was also released in 2017 (Wolfe 2017).<\/p>\n<\/div>\n<h2 class=\"import-Normal\"><span style=\"text-align: initial;font-size: 1em\">Protein Synthesis<\/span><\/h2>\n<p class=\"import-Normal\">At the beginning of the chapter, we defined <em>proteins<\/em> as strings of <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_702\">amino acids<\/a><\/strong> that fold into complex 3-D shapes. There are 20 standard amino acids that can be strung together in different combinations in humans, and the result is that proteins can perform an impressive amount of different functions. For instance, muscle fibers are proteins that help facilitate movement. A special class of proteins (immunoglobulins) help protect the organism by detecting disease-causing pathogens in the body. Protein hormones, such as insulin, help regulate physiological activity. Blood hemoglobin is a protein that transports oxygen throughout the body. <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_704\">Enzymes<\/a> <\/strong>are also proteins, and they are catalysts for biochemical reactions that occur in the cell (e.g., metabolism). Larger-scale protein structures can be visibly seen as physical features of an organism (e.g., hair and nails).<\/p>\n<h3 class=\"import-Normal\"><strong>Transcription and Translation <\/strong><\/h3>\n<figure style=\"width: 272px\" class=\"wp-caption alignleft\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image13.jpg\" alt=\"From DNA, transcription creates pre-mRNA, is processed to mature mRNA, translated to an amino acid chain (protein)\" width=\"272\" height=\"336\" \/><figcaption class=\"wp-caption-text\">Figure 3.17: The major steps of protein synthesis. <a href=\"https:\/\/docs.google.com\/document\/d\/1VUDKMBJYS_jNONjLxT04jQN0_z9Ua50BRN6auGSHUuU\/edit\" target=\"_blank\" rel=\"noopener\">A full text description of this image is available.<\/a> Credit: Protein synthesis original to Explorations: An Open Invitation to Biological Anthropology (2nd ed.) by Mary Nelson is under a <a href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/\">CC BY-NC 4.0 License<\/a>.<\/figcaption><\/figure>\n<p>Nucleotides in our DNA provide the coding instructions on how to make proteins. Making proteins, also known as <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_706\">protein synthesis<\/a><\/strong>, can be broken down into two main steps referred to as <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_708\">transcription<\/a><\/strong> and <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_710\">translation<\/a><\/strong>. The purpose of transcription, the first step, is to make an <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_712\">ribonucleic acid (RNA)<\/a><\/strong> copy of our genetic code. Although there are many different types of RNA molecules that have a variety of functions within the cell, we will mainly focus on <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_714\">messenger RNA (mRNA)<\/a><\/strong>. Transcription concludes with the processing (<strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_716\">splicing<\/a><\/strong>) of the mRNA. The second step, translation, uses mRNA as the instructions for chaining together amino acids into a new protein molecule (Figure 3.17).<\/p>\n<figure style=\"width: 340px\" class=\"wp-caption alignright\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image14.jpg\" alt=\"Single stranded RNA is composed of 4 types of nucleobases: cytosine, guanine, adenine, and uracil.\" width=\"340\" height=\"461\" \/><figcaption class=\"wp-caption-text\">Figure 3.18: Structural components that form ribonucleic acid (RNA). <a href=\"https:\/\/docs.google.com\/document\/d\/1VUDKMBJYS_jNONjLxT04jQN0_z9Ua50BRN6auGSHUuU\/edit\" target=\"_blank\" rel=\"noopener\">A full text description of this image is available.<\/a> Credit: <a href=\"https:\/\/commons.wikimedia.org\/wiki\/File:Difference_DNA_RNA-EN.svg\">Difference DNA RNA-EN<\/a> by <a href=\"https:\/\/commons.wikimedia.org\/wiki\/User:Sponk\">Sponk<\/a> (translation by <a href=\"https:\/\/commons.wikimedia.org\/wiki\/User:Sponk\">Sponk<\/a>, cropped by Katie Nelson) is under a <a href=\"https:\/\/creativecommons.org\/licenses\/by-nc-sa\/4.0\/\">CC BY-NC-SA 4.0 License<\/a>.<\/figcaption><\/figure>\n<p class=\"import-Normal\">Unlike double-stranded DNA, RNA molecules are single-stranded nucleotide sequences (Figure 3.18). Additionally, while DNA contains the nucleotide thymine (T), RNA does not\u2014instead its fourth nucleotide is uracil (U). Uracil is complementary to (or can pair with) adenine (A), while cytosine (C) and guanine (G) continue to be complementary to each other.<\/p>\n<p>For transcription to proceed, a <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_718\">gene<\/a><\/strong> must first be turned \u201con\u201d by the cell. A gene is a segment of DNA that codes for RNA, and genes can vary in length from a few hundred to as many as two million base pairs in length. The double-stranded DNA is then separated, and one side of the DNA is used as a coding template that is read by <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_720\">RNA polymerase<\/a>.<\/strong> Next, complementary free-floating RNA nucleotides are linked together (Figure 3.19) to form a single-stranded mRNA. For example, if a DNA template is TACGGATGC, then the newly constructed mRNA sequence will be AUGCCUACG.<\/p>\n<p>Genes contain segments called <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_722\">introns<\/a> <\/strong>and <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_724\">exons<\/a><\/strong>. Exons are considered \u201ccoding\u201d while introns are considered \u201cnoncoding\u201d\u2014meaning the information they contain will not be needed to construct proteins. When a gene is first transcribed into pre-mRNA, introns and exons are both included (Figure 3.20). However, once transcription is finished, introns are removed in a process called splicing. During splicing, a protein\/RNA complex attaches itself to the pre-mRNA. Next, introns are removed and the remaining exons are connected, thus creating a shorter mature mRNA that serves as a template for building proteins.<\/p>\n<figure style=\"width: 1846px\" class=\"wp-caption alignnone\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image15.jpg\" alt=\"DNA strands pulled apart making space for RNA polymerase to form mRNA using 1 DNA template strand.\" width=\"1846\" height=\"473\" \/><figcaption class=\"wp-caption-text\">Figure 3.19: RNA polymerase catalyzing DNA transcription. <a href=\"https:\/\/docs.google.com\/document\/d\/1VUDKMBJYS_jNONjLxT04jQN0_z9Ua50BRN6auGSHUuU\/edit\" target=\"_blank\" rel=\"noopener\">A full text description of this image is available.<\/a> Credit: <a href=\"https:\/\/www.genome.gov\/glossary\/index.cfm?id=197\">Transcription (2019)<\/a>\u00a0by<a href=\"https:\/\/www.genome.gov\/\"> NIH National Human Genome Research Institute<\/a> has been modified (cropped and labels changed by Katie Nelson) and is under a <a href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/\">CC BY-NC 4.0 License<\/a>.<\/figcaption><\/figure>\n<\/div>\n<figure id=\"attachment_89\" aria-describedby=\"caption-attachment-89\" style=\"width: 1900px\" class=\"wp-caption aligncenter\"><img class=\"wp-image-89 size-full\" src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/4.20.jpg\" alt=\"Pre mRNA contains transcriptions of exons and introns. Mature mRNA only contains spliced exon mRNA.\" width=\"1900\" height=\"700\" \/><figcaption id=\"caption-attachment-89\" class=\"wp-caption-text\">Figure 3.20: RNA processing is the modification of RNA, including the removal of introns, called splicing, between transcription and translation. <a href=\"https:\/\/docs.google.com\/document\/d\/1VUDKMBJYS_jNONjLxT04jQN0_z9Ua50BRN6auGSHUuU\/edit\" target=\"_blank\" rel=\"noopener\">A full text description of this image is available.<\/a> Credit: <a href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/chapter\/__unknown__-9\/\">Protein synthesis (Figure 3.23)<\/a> original to <a href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/\">Explorations: An Open Invitation to Biological Anthropology<\/a> by Mary Nelson is under a <a href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/\">CC BY-NC 4.0 License<\/a>.<\/figcaption><\/figure>\n<div class=\"__UNKNOWN__\">\n<p class=\"import-Normal\">As described above, the result of transcription is a single-stranded mRNA copy of a gene<strong>. <\/strong>Translation is the process by which amino acids are chained together to form a new protein. During translation, the mature mRNA is transported outside of the nucleus, where it is bound to a <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_726\">ribosome<\/a> <\/strong>(Figure 3.21). The nucleotides in the mRNA are read in triplets, which are called <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_728\">codons<\/a><\/strong>. Each mRNA codon corresponds to an amino acid, which is carried to the ribosome by a <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_730\">transfer RNA<\/a> <\/strong>(tRNA). Thus, tRNAs is the link between the mRNA molecule and the growing amino acid chain.<\/p>\n<figure style=\"width: 651px\" class=\"wp-caption aligncenter\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image17.jpg\" alt=\"Ribosome and tRNA read mRNA and help join amino acids to a growing polypeptide chain.\" width=\"651\" height=\"366\" \/><figcaption class=\"wp-caption-text\">Figure 3.21: Translation of mRNA into a polypeptide chain composed of the twenty different types of amino acids. <a href=\"https:\/\/docs.google.com\/document\/d\/1VUDKMBJYS_jNONjLxT04jQN0_z9Ua50BRN6auGSHUuU\/edit\" target=\"_blank\" rel=\"noopener\">A full text description of this image is available.<\/a> Credit: <a href=\"https:\/\/www.genome.gov\/genetics-glossary\/Amino-Acids?id=5\">Amino Acids<\/a> by<a href=\"https:\/\/www.genome.gov\/\"> NIH National Human Genome Research Institute<\/a> is in the<a href=\"https:\/\/www.genome.gov\/about-nhgri\/Policies-Guidance\/Copyright\"> public domain<\/a>.<\/figcaption><\/figure>\n<p class=\"import-Normal\">Continuing with our mRNA sequence example from above, the mRNA sequence AUG-CCU-ACG codes for three amino acids. Using a codon table (Figure 3.22), AUG is a codon for methionine (Met), CCU is proline (Pro), and ACG is threonine (Thr). Therefore, the protein sequence is Met-Pro-Thr. Methionine is the most common \u201cstart codon\u201d (AUG) for the initiation of protein translation in eukaryotes. As the ribosome moves along the mRNA, the growing amino acid chain exits the ribosome and folds into a protein. When the ribosome reaches a \u201cstop\u201d codon (UAA, UAG, or UGA), the ribosome stops adding any new amino acids, detaches from the mRNA, and the protein is released. Depending upon the amino acid sequence, a linear protein may undergo additional \u201cfolding.\u201d The final three-dimensional protein shape is integral to completing a specific structural or functional task.<\/p>\n<div class=\"textbox shaded\">\n<h2 class=\"import-Normal\">Dig Deeper: Protein Synthesis<\/h2>\n<p class=\"import-Normal\">To see protein synthesis in animation, please check out the\u00a0 <a href=\"https:\/\/www.yourgenome.org\/video\/from-dna-to-protein\/\">From DNA to Protein<\/a> video on YourGenome.org.<\/p>\n<\/div>\n<figure style=\"width: 550px\" class=\"wp-caption aligncenter\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image18-1.png\" alt=\"A circle labeled with letters for mRNA nucleotides.\" width=\"550\" height=\"541\" \/><figcaption class=\"wp-caption-text\">Figure 3.22: This table can be used to identify which mRNA codons (sequence of three nucleotides) correspond with each of the 20 different amino acids. For each mRNA codon, you work in the 5\u2019 to 3\u2019 direction (inside the circle to outside). For example, if the mRNA codon is CAU, you look at the inner circle for the \u201cC,\u201d the middle circle for \u201cA,\u201d and outside circle for \u201cU,\u201d indicating that the CAU codon corresponds with the amino acid \u201chistidine\u201d (abbreviated \u201cHis\u201d or \u201cH\u201d). The table also indicates that the \u201cstart codon\u201d (AUG) correlates with Methionine, and the three \u201cstop\u201d codons are UAA, UAG, and UGA. <a href=\"https:\/\/docs.google.com\/document\/d\/1AKB8mx6Ih-V-1DJ_zxTbf9Jn4puHRCPEhG1rGOlojNc\/edit?usp=sharing\" target=\"_blank\" rel=\"noopener\">An accessible full text RNA codon to amino acid table is available.<\/a> Credit: <a href=\"https:\/\/commons.wikimedia.org\/wiki\/File:Aminoacids_table.svg\">Aminoacids table<\/a> by <a href=\"https:\/\/commons.wikimedia.org\/wiki\/User:Mouagip\">Mouagip<\/a> has been designated to the <a href=\"https:\/\/creativecommons.org\/share-your-work\/public-domain\/cc0\/\">public domain (CC0)<\/a>.<\/figcaption><\/figure>\n<div class=\"textbox\">\n<h2 class=\"import-Normal\"><span style=\"background-color: #ff9900\">Special Topic: Genetic Regulation of the Lactase (LCT) Gene <\/span><span style=\"text-decoration: underline\">(chapter 14)<\/span><\/h2>\n<p class=\"import-Normal\">The <em>LCT<\/em> gene codes for a protein called lactase, an enzyme produced in the small intestine. It is responsible for breaking down the sugar \u201clactose,\u201d which is found in milk. Lactose intolerance occurs when not enough lactase enzyme is produced and, in turn, digestive symptoms occur. To avoid this discomfort, individuals may take lactase supplements, drink lactose-free milk, or avoid milk products altogether.<\/p>\n<p class=\"import-Normal\">The <em>LCT <\/em>gene is a good example of how cells regulate protein synthesis. The <strong>promoter<\/strong> region of the <em>LCT <\/em>gene helps regulate whether it is transcribed or not transcribed (i.e., turned \u201con\u201d or \u201coff,\u201d respectively). Lactase production is initiated when a regulatory protein known as a <strong>transcription factor<\/strong> binds to a site on the <em>LCT <\/em>promoter. RNA polymerases are then recruited; they read DNA and string together nucleotides to make RNA molecules. An <em>LCT<\/em> pre-mRNA is synthesized (made) in the nucleus, and further chemical modifications flank the ends of the mRNA to ensure the molecule will not be degraded in the cell. Next, a spliceosome complex removes the introns from the <em>LCT<\/em> pre-mRNA and connects the exons to form a mature mRNA. Translation of the <em>LCT<\/em> mRNA occurs and the growing protein then folds into the lactase enzyme, which can break down lactose.<\/p>\n<p class=\"import-Normal\">Most animals lose their ability to digest milk as they mature due to the decreasing transcriptional \u201csilence\u201d of the <em>LCT<\/em> gene over time. However, some humans have the ability to digest lactose into adulthood (also known as \u201clactase persistence\u201d). This means they have a genetic mutation that leads to continuous transcriptional activity of <em>LCT<\/em>. Lactase persistence mutations are common in populations with a long history of pastoral farming, such as northern European and North African populations. It is believed that lactase persistence evolved because the ability to digest milk was nutritionally beneficial. More information about lactase persistence will be covered in Chapter 14.<\/p>\n<\/div>\n<h2 class=\"import-Normal\">Mendelian Genetics<\/h2>\n<figure style=\"width: 183px\" class=\"wp-caption alignleft\"><img class=\"\" src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image19.png\" alt=\"Stone statue of a robed monk.\" width=\"183\" height=\"239\" \/><figcaption class=\"wp-caption-text\">Figure 3.23: Statue of Mendel located at the Mendel Museum, located at Masaryk University in Brno, Czech Republic. Credit: \u00a0<a href=\"https:\/\/commons.wikimedia.org\/wiki\/File:Mendel%C2%B4s_statue.JPG\">Mendel\u00b4s statue<\/a> by <a href=\"https:\/\/commons.wikimedia.org\/wiki\/User:Coeli\">Coeli<\/a> has been designated to the <a href=\"https:\/\/creativecommons.org\/share-your-work\/public-domain\/cc0\/\">public domain (CC0)<\/a>.<\/figcaption><\/figure>\n<p>Gregor Johann Mendel (1822\u20131884) is often described as the \u201cFather of Genetics.\u201d Mendel was a monk who conducted pea plant breeding experiments in a monastery located in the present-day Czech Republic (Figure 3.23). After several years of experiments, Mendel presented his work to a local scientific community in 1865 and published his findings the following year. Although his meticulous effort was notable, the importance of his work was not recognized for another 35 years. One reason for this delay in recognition is that his findings did not agree with the predominant scientific viewpoints on inheritance at the time. For example, it was believed that parental physical traits \u201cblended\u201d together and offspring inherited an intermediate form of that trait. In contrast, Mendel showed that certain pea plant physical traits (e.g., flower color) were passed down separately to the next generation in a statistically predictable manner. Mendel also observed that some parental traits disappeared in offspring but then reappeared in later generations. He explained this occurrence by introducing the concept of \u201cdominant\u201d and \u201crecessive\u201d traits. Mendel established a few fundamental laws of inheritance, and this section reviews some of these concepts. Moreover, the study of traits and diseases that are controlled by a single gene is commonly referred to as <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_732\">Mendelian genetics<\/a><\/strong>.<\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<figure style=\"width: 738px\" class=\"wp-caption aligncenter\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image20.png\" alt=\"Pea plant variation: round\/wrinkled, yellow\/ green pods, white\/purple flowers, tall\/short stem.\" width=\"738\" height=\"304\" \/><figcaption class=\"wp-caption-text\">Figure 3.24: Various phenotypic characteristics of pea plants resulting from different genotypes. Credit: <a href=\"https:\/\/commons.wikimedia.org\/wiki\/File:Mendels_peas.png\">Mendels peas<\/a> by Mariana Ruiz <a href=\"https:\/\/commons.wikimedia.org\/wiki\/User:LadyofHats\">LadyofHats<\/a> has been designated to the <a href=\"https:\/\/creativecommons.org\/share-your-work\/public-domain\/cc0\/\">public domain (CC0 1.0)<\/a>.<\/figcaption><\/figure>\n<p>The physical appearance of a trait is called an organism\u2019s <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_734\">phenotype<\/a><\/strong>. Figure 3.24 shows pea plant (<em>Pisum sativum<\/em>) phenotypes that were studied by Mendel, and in each of these cases the physical traits are controlled by a single gene. In the case of Mendelian genetics, a phenotype is determined by an organism\u2019s <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_736\">genotype<\/a><\/strong>. A genotype consists of two gene copies, wherein one copy was inherited from each parent. Gene copies are also known as <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_738\">alleles<\/a><\/strong> (Figure 3.25), which means they are found in the same gene location on homologous chromosomes. Alleles have a nonidentical DNA sequence, which means their phenotypic effect can be different. In other words, although alleles code for the same trait, different phenotypes can be produced depending on which two alleles (i.e., genotypes) an organism possesses. For example, Mendel\u2019s pea plants all have flowers, but their flower color can be purple or white. Flower color is therefore dependent upon which two color alleles are present in a genotype.<\/p>\n<figure style=\"width: 771px\" class=\"wp-caption aligncenter\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image21.jpeg\" alt=\"Four pairs of chromosomes. Each chromosome is labeled with an allele, either capital B or lowercase b.\" width=\"771\" height=\"315\" \/><figcaption class=\"wp-caption-text\">Figure 3.25: Homozygous refers to having the same alleles (e.g. two capital Bs or two lowercase bs). Heterozygous refers to having two different alleles (e.g. one capital B and one lowercase b). Credit: <a href=\"https:\/\/www.genome.gov\/genetics-glossary\/homozygous\">Homozygous<\/a> by<a href=\"https:\/\/www.genome.gov\/\"> NIH National Human Genome Research Institute<\/a> is in the<a href=\"https:\/\/www.genome.gov\/about-nhgri\/Policies-Guidance\/Copyright\"> public domain<\/a>.<\/figcaption><\/figure>\n<p class=\"import-Normal\">A Punnett square is a diagram that can help visualize Mendelian inheritance patterns. For instance, when parents of known genotypes mate, a Punnett square can help predict the ratio of Mendelian genotypes and phenotypes that their offspring would possess. When discussing genotype, biologists use upper and lower case letters to denote the different allele copies. Figure 3.26 is a Punnett square that includes two <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_740\">heterozygous<\/a><\/strong> parents for flower color (Bb). A heterozygous genotype means there are two different alleles for the same gene. Therefore, a pea plant that is heterozygous for flower color has one purple allele and one white allele. When an organism is <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_742\">homozygous<\/a><\/strong> for a specific trait, it means their genotype consists of two copies of the same allele. Using the Punnett square example, the two heterozygous pea plant parents can produce offspring with two different homozygous genotypes (BB or bb) or offspring that are heterozygous (Bb).<\/p>\n<figure style=\"width: 220px\" class=\"wp-caption alignleft\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image22.png\" alt=\"Pollen and Pistol (each with one capital B and one lower case b allele) merge in different combinations.\" width=\"220\" height=\"220\" \/><figcaption class=\"wp-caption-text\">Figure 3.26: Punnett square depicting the possible genetic combinations of offspring from two heterozygous parents. <a href=\"https:\/\/docs.google.com\/document\/d\/1VUDKMBJYS_jNONjLxT04jQN0_z9Ua50BRN6auGSHUuU\/edit\" target=\"_blank\" rel=\"noopener\">A full text description of this image is available.<\/a> Credit: <a href=\"https:\/\/commons.wikimedia.org\/wiki\/File:Punnett_square_mendel_flowers.svg\">Punnett square mendel flowers<\/a> by Madeleine Price Ball (<a href=\"https:\/\/commons.wikimedia.org\/wiki\/User:Madprime\">Madprime<\/a>) is under a <a href=\"https:\/\/creativecommons.org\/licenses\/by-sa\/3.0\/legalcode\">CC BY-SA 3.0 License<\/a>.<\/figcaption><\/figure>\n<p class=\"import-Normal\">A pea plant with purple flowers could be heterozygous (Bb) or homozygous (BB). This is because the purple color allele (B) is <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_744\">dominant<\/a> <\/strong>to the white color allele (b), and therefore it only needs one copy of that allele to phenotypically express purple flowers. Because the white flower allele is <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_746\">recessive<\/a><\/strong>, a pea plant must be homozygous for the recessive allele in order to have a white color phenotype (bb). As seen by the Punnett square example (Figure 3.26), three of four offspring will have purple flowers and the other one will have white flowers.<\/p>\n<p class=\"import-Normal\">The Law of Segregation was introduced by Mendel to explain why we can predict the ratio of genotypes and phenotypes in offspring. As discussed previously, a parent will have two alleles for a certain gene (with each copy on a different homologous chromosome). The Law of Segregation states that the two copies will be segregated from each other and will each be distributed to their own gamete. We now know that the process where that occurs is meiosis.<\/p>\n<p class=\"import-Normal\">Offspring are the products of two gametes combining, which means the offspring inherits one allele from each gamete for most genes. When multiple offspring are produced (like with pea plant breeding), the predicted phenotype ratios are more clearly observed. The pea plants Mendel studied provide a simplistic model to understand single-gene genetics. While many traits anthropologists are interested in have a more complicated inheritance (e.g., are informed by many genes), there are a few known Mendelian traits in humans. Additionally, some human diseases also follow a Mendelian pattern of inheritance (Figure 3.27). Because humans do not have as many offspring as other organisms, we may not recognize Mendelian patterns as easily. However, understanding these principles and being able to calculate the probability that an offspring will have a Mendelian phenotype is still important.<\/p>\n<\/div>\n<div align=\"left\">\n<table class=\"grid aligncenter\" style=\"width: 422px;height: 420px\">\n<caption>Figure 3.27: Examples of human diseases with their gene names that follow a Mendelian pattern of inheritance.<\/caption>\n<thead>\n<tr style=\"height: 30px\">\n<td style=\"width: 432.598px;height: 30px\"><strong>Mendelian disorder<\/strong><\/td>\n<td style=\"width: 89.9414px;height: 30px\"><strong>Gene\u00a0<\/strong><\/td>\n<\/tr>\n<\/thead>\n<tbody>\n<tr style=\"height: 30px\">\n<td style=\"width: 432.598px;height: 30px\">Alpha Thalassemia<\/td>\n<td style=\"width: 89.9414px;height: 30px\">HBA1<\/td>\n<\/tr>\n<tr style=\"height: 30px\">\n<td style=\"width: 432.598px;height: 30px\">Cystic Fibrosis<\/td>\n<td style=\"width: 89.9414px;height: 30px\">CFTR<\/td>\n<\/tr>\n<tr style=\"height: 30px\">\n<td style=\"width: 432.598px;height: 30px\">Fragile X Syndrome<\/td>\n<td style=\"width: 89.9414px;height: 30px\">FMR1<\/td>\n<\/tr>\n<tr style=\"height: 30px\">\n<td style=\"width: 432.598px;height: 30px\">Glucose-6-Phosphate Dehydrogenase Deficiency<\/td>\n<td style=\"width: 89.9414px;height: 30px\">G6PD<\/td>\n<\/tr>\n<tr style=\"height: 30px\">\n<td style=\"width: 432.598px;height: 30px\">Hemophilia A<\/td>\n<td style=\"width: 89.9414px;height: 30px\">F8<\/td>\n<\/tr>\n<tr style=\"height: 30px\">\n<td style=\"width: 432.598px;height: 30px\">Huntington disease<\/td>\n<td style=\"width: 89.9414px;height: 30px\">HTT<\/td>\n<\/tr>\n<tr style=\"height: 30px\">\n<td style=\"width: 432.598px;height: 30px\">Mitochondrial DNA Depletion Syndrome<\/td>\n<td style=\"width: 89.9414px;height: 30px\">TYMP<\/td>\n<\/tr>\n<tr style=\"height: 30px\">\n<td style=\"width: 432.598px;height: 30px\">Oculocutaneous Albinism: Type 1<\/td>\n<td style=\"width: 89.9414px;height: 30px\">TYR<\/td>\n<\/tr>\n<tr style=\"height: 30px\">\n<td style=\"width: 432.598px;height: 30px\">Polycystic Kidney Disease<\/td>\n<td style=\"width: 89.9414px;height: 30px\">PKHD1<\/td>\n<\/tr>\n<tr style=\"height: 30px\">\n<td style=\"width: 432.598px;height: 30px\">Sickle-cell anemia<\/td>\n<td style=\"width: 89.9414px;height: 30px\">HBB<\/td>\n<\/tr>\n<tr style=\"height: 30px\">\n<td style=\"width: 432.598px;height: 30px\">Spinal Muscular Atrophy: SMN1 Linked<\/td>\n<td style=\"width: 89.9414px;height: 30px\">SMN1<\/td>\n<\/tr>\n<tr style=\"height: 30px\">\n<td style=\"width: 432.598px;height: 30px\">Tay-Sachs Disease<\/td>\n<td style=\"width: 89.9414px;height: 30px\">HEXA<\/td>\n<\/tr>\n<tr style=\"height: 30px\">\n<td style=\"width: 432.598px;height: 30px\">Wilson Disease<\/td>\n<td style=\"width: 89.9414px;height: 30px\">ATP7B<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<div class=\"__UNKNOWN__\">\n<h3 class=\"import-Normal\"><strong>Example of Mendelian Inheritance: The ABO Blood Group System<\/strong><\/h3>\n<p class=\"import-Normal\">In 1901, Karl Landsteiner at the University of Vienna published his discovery of ABO blood groups. While conducting blood immunology experiments in which he combined the blood of individuals who possess different blood cell types, he observed an agglutination (clotting) reaction. The presence of agglutination implies there is an incompatible immunological reaction; no agglutination will occur in individuals with the same blood type. This work was clearly important because it resulted in a higher survival rate of patients who received blood transfusions. Blood transfusions from someone with a different type of blood causes agglutinations, and the resulting coagulated blood can not easily pass through blood vessels, resulting in death. Landsteiner received the Nobel Prize (1930) for his discovery and explaination of the ABO blood group system.<\/p>\n<p class=\"import-Normal\">Blood <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_748\">cell surface antigens<\/a><\/strong> are proteins that coat the surface of red blood cells, and<strong> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_750\">antibodies<\/a> <\/strong>are specifically \u201cagainst\u201d or \u201canti\u201d to the antigens from other blood types. Thus, antibodies are responsible for causing agglutination between incompatible blood types. Understanding the interaction of antigens and antibodies helps to determine ABO compatibility amongst blood donors and recipients. To better comprehend blood phenotypes and ABO compatibility, blood cell antigens and plasma antibodies are presented in Figure 3.28. Individuals that are blood type A have A antigens on the red blood cell surface, and anti-B antibodies, which will bind to B antigens should they come in contact. Alternatively, individuals with blood type B have B antigens and anti-A antibodies. Individuals with blood type AB have both A and B antigens but do not produce antibodies for the ABO system. This does not mean type AB does not have any antibodies present, just that specifically anti-A and anti-B antibodies are not produced. Individuals who are blood type O have nonspecific antigens and produce both anti-A and anti-B antibodies.<\/p>\n<p>&nbsp;<\/p>\n<figure style=\"width: 713px\" class=\"wp-caption aligncenter\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image23-1.png\" alt=\"ABO (A, B, AB, and O), and Rhesus (Rh+ and Rh-) blood cells, antigens, and antibodies are drawn.\" width=\"713\" height=\"357\" \/><figcaption class=\"wp-caption-text\">Figure 3.28: The different ABO and Rhesus blood types with their associated antibodies and antigens. <a href=\"https:\/\/docs.google.com\/document\/d\/1VUDKMBJYS_jNONjLxT04jQN0_z9Ua50BRN6auGSHUuU\/edit\" target=\"_blank\" rel=\"noopener\">A full text description of this image is available.<\/a> Credit: <a href=\"https:\/\/commons.wikimedia.org\/wiki\/File:Different_Blood_Types.png\">Different Blood Types<\/a> by <a href=\"https:\/\/commons.wikimedia.org\/wiki\/User:Michael540170\">Michael540170<\/a> has been modified (antibodies images swapped) and is under a <a href=\"https:\/\/creativecommons.org\/licenses\/by-nc-sa\/4.0\/\">CC BY-NC-SA 4.0 License<\/a>.<\/figcaption><\/figure>\n<p class=\"import-Normal\">Figure 3.29 shows a table of the ABO allele system, which has a Mendelian pattern of inheritance. Both the A and B alleles function as dominant alleles, so the A allele always codes for the A antigen, and the B allele codes for the B antigen. The O allele differs from A and B, because it codes for a nonfunctional antigen protein, which means there is no antigen present on the cell surface of O blood cells. To have blood type O, two copies of the O allele must be inherited, one from each parent, thus the O allele is considered recessive. Therefore, someone who is a heterozygous AO genotype is phenotypically blood type A, and a genotype of BO is blood type B. The ABO blood system also provides an example of <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_752\">codominance<\/a><\/strong>, which is when both alleles are observed in the phenotype. This is true for blood type AB: when an individual inherits both the A and B alleles, then both A and B antigens will be present on the cell surface.<\/p>\n<figure style=\"width: 425px\" class=\"wp-caption alignleft\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image24.jpg\" alt=\"A table showing the genotypes that can occur from combinations of A, B, and O alleles.\" width=\"425\" height=\"177\" \/><figcaption class=\"wp-caption-text\">Figure 3.29: The different combinations of ABO blood alleles (A, B, and O) to form ABO blood genotypes. <a href=\"https:\/\/docs.google.com\/document\/d\/1VUDKMBJYS_jNONjLxT04jQN0_z9Ua50BRN6auGSHUuU\/edit\" target=\"_blank\" rel=\"noopener\">A full text description of this image is available<\/a>. Credit: <a href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/chapter\/__unknown__-9\/\">ABO Blood Genotypes (Figure 3.33)<\/a> original to <a href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/\">Explorations: An Open Invitation to Biological Anthropology<\/a> by Katie Nelson is under a <a href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/\">CC BY-NC 4.0 License<\/a>.<\/figcaption><\/figure>\n<p class=\"import-Normal\">Also found on the surface of red blood cells is the rhesus group antigen, known as \u201cRh factor.\u201d In reality, there are several antigens on red blood cells independent from the ABO blood system, however, the Rh factor is the second most important antigen to consider when determining blood donor and recipient compatibility. Rh antigens must also be considered when a pregnant mother and her baby have incompatible Rh factors. In such cases, a doctor can administer necessary treatment steps to prevent pregnancy complications and hemolytic disease, which is when the mother\u2019s antibodies break down the newborn\u2019s red blood cells.<\/p>\n<p class=\"import-Normal\">An individual can possess the Rh antigen (be Rh positive) or lack the Rh antigen (be Rh negative). The Rh factor is controlled by a single gene and is inherited independently of the ABO alleles. Therefore, all blood types can either be positive (O+, A+, B+, AB+) or negative (O-, A-, B-, AB-).<\/p>\n<p class=\"import-Normal\">Individuals with O+ red blood cells can donate blood to A+, B+, AB+, and O+ blood type recipients. Because O- individuals do not have AB or Rh antigens, they are compatible with all blood cell types and are referred to as \u201cuniversal donors.\u201d Individuals that are AB+ are considered to be \u201cuniversal recipients\u201d because they do not possess antibodies against other blood types.<\/p>\n<h3 class=\"import-Normal\"><strong>Mendelian Patterns of Inheritance and Pedigrees<\/strong><\/h3>\n<p class=\"import-Normal\">A <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_754\">pedigree<\/a><\/strong> can be used to investigate a family\u2019s medical history by determining if a health issue is inheritable and will possibly require medical intervention. A pedigree can also help determine if it is a Mendelian recessive or dominant genetic condition. Figure 3.30 is a pedigree example of a family with Huntington\u2019s disease, which has a Mendelian dominant pattern of inheritance. In a standard pedigree, males are represented by a square and females are represented by a circle. Biological family members are connected to a horizontal line, with biological parents above and offspring below. When an individual is affected with a certain condition, the square or circle is filled in as a solid color. With a dominant condition, at least one of the parents will have the disease and an offspring will have a 50% chance of inheriting the affected chromosome. Therefore, dominant genetic conditions tend to be present in every generation. In the case of Huntington\u2019s, some individuals may not be diagnosed until later in adulthood, so parents may unknowingly pass this dominantly inherited disease to their children.<\/p>\n<figure style=\"width: 389px\" class=\"wp-caption alignleft\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image25.png\" alt=\"A three-generation pedigree with about half the individuals shaded in. Please see text discussion for details.\" width=\"389\" height=\"189\" \/><figcaption class=\"wp-caption-text\">Figure 3.30: A pedigree depicting an example of dominant Mendelian inheritance like Huntington\u2019s. Offspring with the trait will have at least one parent with the same trait. Credit: <a href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/chapter\/__unknown__-9\/\">Mendelian dominant pattern of inheritance (Figure 3.34)<\/a> original to <a href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/\">Explorations: An Open Invitation to Biological Anthropology<\/a> by Beth Shook is under a <a href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/\">CC BY-NC 4.0 License<\/a>.<\/figcaption><\/figure>\n<p class=\"import-Normal\">Because the probability of inheriting a disease-causing recessive allele is more rare, recessive medical conditions can skip generations. Figure 3.31 is an example of a family that carries a recessive cystic fibrosis mutation. A parent that is heterozygous for the cystic fibrosis allele has a 50% chance of passing down their affected chromosome to the next generation. If a child has a recessive disease, then it means both of their parents are <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_756\">carriers<\/a><\/strong> (heterozygous) for that condition. In most cases, carriers for recessive conditions show no serious medical symptoms. Individuals whose family have a known medical history for certain conditions sometimes seek family planning services (see the Genetic Testing section).<\/p>\n<\/div>\n<div><\/div>\n<div class=\"__UNKNOWN__\">\n<figure style=\"width: 392px\" class=\"wp-caption alignright\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image26.png\" alt=\"A three-generation pedigree with three individuals with the trait shaded in. Please see text discussion for details.\" width=\"392\" height=\"215\" \/><figcaption class=\"wp-caption-text\">Figure 3.31: A pedigree depicting an example of recessive Mendelian inheritance like cystic fibrosis. Individuals may have a trait not observed in the previous generation. Credit: <a href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/chapter\/__unknown__-9\/\">Mendelian recessive pattern of inheritance (Figure 3.35)<\/a> original to <a href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/\">Explorations: An Open Invitation to Biological Anthropology<\/a> by Beth Shook is under a <a href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/\">CC BY-NC 4.0 License<\/a>.<\/figcaption><\/figure>\n<p class=\"import-Normal\">Pedigrees can also help distinguish if a health issue has either an <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_758\">autosomal<\/a> <\/strong>or <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_760\">X-linked<\/a><\/strong> pattern of inheritance. As previously discussed, there are 23 pairs of chromosomes and 22 of these pairs are known as autosomes. The provided pedigree examples (Figure 3.30\u201331) are autosomally linked genetic diseases. This means the genes that cause the disease are on one of the chromosomes numbered 1 to 22. The conditions caused by genes located on the X chromosome are referred to as X-linked diseases.<\/p>\n<p class=\"import-Normal\">Figure 3.32 depicts a family in which the mother is a carrier for the X-linked recessive disease Duchenne Muscular Dystrophy (DMD). The mother is a carrier for DMD, so daughters and sons will have a 50% chance of inheriting the <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_762\">pathogenic<\/a><\/strong> <em>DMD<\/em> allele. Because females have two X chromosomes, females who inherit only one copy will not have the disease (although in rare cases, female carriers may show some symptoms of the disease). On the other hand, males who inherit a copy of an X-linked pathogenic <em>DMD<\/em> allele will typically be affected with the condition. Thus, males are more susceptible to X-linked conditions because they only have one X chromosome. Therefore, when evaluating a pedigree, if a higher proportion of males are affected with the disease, this could suggest the disease is X-linked recessive. <br style=\"clear: both\" \/><br style=\"clear: both\" \/>Compared to the X chromosome, the Y chromosome is smaller with only a few genes. Y-linked traits are therefore rare and can only be passed from a chromosomal father to a biological XY child.<\/p>\n<figure style=\"width: 407px\" class=\"wp-caption alignleft\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image27.jpg\" alt=\"A three-generation pedigree with four males and one female with the trait. Please see text discussion for details.\" width=\"407\" height=\"236\" \/><figcaption class=\"wp-caption-text\">Figure 3.32: A pedigree depicting an example of X-linked Mendelian inheritance like Duchenne Muscular Dystrophy (DMD). Credit: <a href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/chapter\/__unknown__-9\/\">X-linked recessive pattern of inheritance (Figure 3.36)<\/a> original to <a href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/\">Explorations: An Open Invitation to Biological Anthropology<\/a> by Beth Shook is under a <a href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/\">CC BY-NC 4.0 License<\/a>.<\/figcaption><\/figure>\n<h2 class=\"import-Normal\">Other Patterns of Inheritance<\/h2>\n<h3 class=\"import-Normal\"><strong>Complexity Surrounding Mendelian Inheritance<\/strong><\/h3>\n<p class=\"import-Normal\">Pea plant trait genetics are relatively simple compared to what we know about genetic inheritance today. The vast majority of genetically controlled traits are not strictly dominant or recessive, so the relationship among alleles and predicting phenotype is often more complicated. For example, traits that exhibit<strong> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_764\">incomplete dominance<\/a><\/strong> occur when a heterozygote exhibits a phenotype that is an intermediate phenotype of both alleles. In snapdragon flowers, the red flower color (R) is dominant and white is recessive (r). Therefore, the homozygous dominant RR is red and homozygous recessive rr is white. However, because the R allele is not completely dominant, the heterozygote Rr is a blend of red and white, which results in a pink flower (Figure 3.33).<\/p>\n<figure style=\"width: 302px\" class=\"wp-caption alignright\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image28.png\" alt=\"Snapdragon flowers in many hues.\" width=\"302\" height=\"188\" \/><figcaption class=\"wp-caption-text\">Figure 3.33: Snap dragons with different genotypes resulting in different flower color phenotypes. Credit: <a href=\"https:\/\/commons.wikimedia.org\/wiki\/File:Antirrhinum_aka_Snap_dragon_at_lalbagh_7112.JPG\">Antirrhinum a.k.a. Snap dragon at lalbagh 7112<\/a> by <a href=\"https:\/\/commons.wikimedia.org\/wiki\/User:Rameshng\">Rameshng<\/a> is under a <a href=\"https:\/\/creativecommons.org\/licenses\/by-sa\/3.0\/legalcode\">CC BY-SA 3.0 License<\/a>.<\/figcaption><\/figure>\n<p class=\"import-Normal\">An example of incomplete dominance in humans is the enzyme \u03b2-hexosaminidase A (Hex A), which is encoded by the gene <em>HEXA<\/em>. Patients with two dysfunctional <em>HEXA <\/em>alleles are unable to metabolize a specific lipid-sugar molecule (GM2 ganglioside); because of this, the molecule builds up and causes damage to nerve cells in the brain and spinal cord. This condition is known as Tay-Sachs disease, and it usually appears in infants who are three to six months old. Most children with Tay-Sachs do not live past early childhood. Individuals who are heterozygous for the functional type <em>HEXA<\/em> allele and one dysfunctional allele have reduced Hex A activity. However, the amount of enzyme activity is still sufficient, so carriers do not exhibit any neurological phenotypes and appear healthy.<\/p>\n<p class=\"import-Normal\">Some genes and alleles can also have higher <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_766\">penetrance<\/a><\/strong> than others. Penetrance can be defined as the proportion of individuals who have a certain allele and also express an expected phenotype. If a genotype always produces an expected phenotype, then those alleles are said to be fully penetrant. However, in the case of incomplete (or reduced) penetrance, an expected phenotype may not occur even if an individual possesses the alleles that are known to control a trait or cause a disease.<\/p>\n<p class=\"import-Normal\">A well-studied example of genetic penetrance is the cancer-related genes <em>BRCA1<\/em> and <em>BRCA2<\/em>. Mutations in these genes can affect crucial processes such as DNA repair, which can lead to breast and ovarian cancers. Although <em>BRCA1<\/em> and <em>BRCA2<\/em> mutations have an autosomal dominant pattern of inheritance, it does not mean an individual will develop cancer if they inherit a pathogenic allele. Several lifestyle and environmental factors can also influence the risk for developing cancer. Regardless, if a family has a history of certain types of cancers, then it is often recommended that genetic testing be performed for individuals who are at risk. Moreover, publically available genetic testing companies are now offering health reports that include <em>BRCA1<\/em> and <em>BRCA2<\/em> allele testing (see the Genetic Testing section).<\/p>\n<h3 class=\"import-Normal\"><strong>Polygenic Traits<\/strong><\/h3>\n<p class=\"import-Normal\">While Mendelian traits tend to be influenced by a single gene, the vast majority of human phenotypes are <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_768\">polygenic traits<\/a><\/strong>. The term <em>polygenic<\/em> means \u201cmany genes.\u201d Therefore, a polygenic trait is influenced by many genes that work together to produce the phenotype. Human phenotypes such as hair color, eye color, height, and weight are examples of polygenic traits. Hair color, for example, is largely determined by the type and quantity of a pigment called melanin, which is produced by a specialized cell type within the skin called melanocytes.The quantity and ratio of melanin pigments determine black, brown, blond, and red hair colors. <em>MC1R<\/em> is a well-studied gene that encodes a protein expressed on the surface of melanocytes that is involved in the production of eumelanin pigment. Typically, people with two functional copies of <em>MC1R <\/em>have brown hair. People with reduced functioning <em>MC1R<\/em> allele copies tend to produce pheomelanin, which results in blond or red hair. However, <em>MC1R <\/em>alleles have variable penetrance, and studies are continually identifying new genes (e.g., <em>TYR<\/em>, <em>TYRP1<\/em>, <em>SLC24A5<\/em>, and <em>KITLG<\/em>) that also influence hair color. Individuals with two nonfunctioning copies of the gene <em>TYR<\/em> have a condition called oculocutaneous albinism\u2014their melanocytes are unable to produce melanin so these individuals have white hair, light eyes, and pale skin.<\/p>\n<p class=\"import-Normal\">In comparison to Mendelian diseases, <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_770\">complex diseases<\/a><\/strong> (e.g., Type II diabetes, coronary heart disease, Alzheimer's, and schizophrenia) are more prevalent in humans. Complex diseases are polygenic, but their development is also influenced by physical, environmental, sociocultural, and individual lifestyle factors. Families can be more predisposed to certain diseases; however, complex diseases often do not have a clear pattern of inheritance.<\/p>\n<p class=\"import-Normal\">Although research of complex traits and diseases continue, geneticists may not know all of the genes involved with a given complex disease. Additionally, how much genetic versus nongenetic determinants contribute to a disease phenotype can be difficult to decipher. Therefore, predicting individual medical risk and risk across different human populations is often a significant challenge. For instance, cardiovascular diseases (CVDs) continue to be one of the leading causes of death around the world. Development of CVDs has been linked to nutrient exposure during fetal development, high fat and sedentary lifestyles, drug usage, adverse socioeconomic conditions, and various genes. Human environments are diverse, and public health research including the field of Human Biology can help identify risk factors and behaviors associated with chronic diseases. Large-scale clinical genetic studies with powerful bioinformatic approaches can also help elucidate some of these complex relationships.<\/p>\n<h2 class=\"import-Normal\">Genomics and Epigenetics<\/h2>\n<p class=\"import-Normal\">A <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_772\">genome<\/a><\/strong> is all of the genetic material of an organism. In the case of humans, this includes 46 chromosomes and mtDNA. The human genome contains approximately three billion base pairs of DNA and has regions that are both noncoding and coding. Scientists now estimate that the human genome contains 20,000\u201325,000 protein-coding genes, with each chromosome containing a few hundred to a few thousand genes. As our knowledge of heredity increases, researchers have begun to realize the importance of <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_774\">epigenetics<\/a><\/strong>, or changes in gene expression that do not result in a change of the underlying DNA sequence. Epigenetics research is also crucial for unraveling gene regulation, which involves complex interactions between DNA, RNA, proteins, and the environment.<\/p>\n<h3 class=\"import-Normal\"><strong>Genomics<\/strong><\/h3>\n<p class=\"import-Normal\">The vast majority of the human genome is noncoding, meaning there are no instructions to make a protein or RNA product in these regions. Historically, noncoding DNA was referred to as \u201cjunk DNA\u201d because these vast segments of the genome were thought to be irrelevant and nonfunctional. However, continual improvement of DNA <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_776\">sequencing<\/a><\/strong> technology along with worldwide scientific collaborations and consortia have contributed to our increased understanding of how the genome functions. Through these technological advances and collaborations, we have since discovered that many of these noncoding DNA regions are involved in dynamic genetic regulatory processes.<\/p>\n<p class=\"import-Normal\">Genomics is a diverse field of molecular biology that focuses on genomic evolution, structure, and function; gene mapping; and <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_778\">genotyping<\/a> <\/strong>(determining the alleles present). Evolutionary genomics determined that humans share about 98.8% percent of their DNA with chimpanzees. Given the phenotypic differences between humans and chimpanzees, having a DNA sequence difference of 1.2% seems surprising. However, a lot of genomics research is also focused on understanding how noncoding genomic regions influence how individual genes are turned \u201con\u201d and \u201coff\u201d (i.e., regulated). Therefore, although DNA sequences are identical, regulatory differences in noncoding genetic regions (e.g., promoters) are believed to be largely responsible for the physical differences between humans and chimpanzees.<\/p>\n<p class=\"import-Normal\">Further understanding of genomic regulatory elements can lead to new therapies and personalized treatments for a broad range of diseases. For example, targeting the regulatory region of a pathogenic gene to \u201cturn off\u201d its expression can prevent its otherwise harmful effects. Such molecular targeting approaches can be personalized based on an individual\u2019s genetic makeup. Genome-wide association studies (GWAS), which seek to determine genes that are linked to complex traits and diseases, typically require significant computational efforts. This is because millions of DNA sequences must be analyzed and GWAS sometimes include thousands of participants. During the beginning of the genomics field, most of the large-scale genomics studies only included North American, European, and East Asian participants and patients. Researchers are now focusing on increasing ethnic diversity in genomic studies and databases. In turn, accuracy of individual disease risk across all human populations will be improved and more rare disease\u2013causing alleles will be identified.<\/p>\n<h3 class=\"import-Normal\"><strong>Epigenetics<\/strong><\/h3>\n<p class=\"import-Normal\">All cells within your body have the same copy of DNA. For example, a brain neuron has the same DNA blueprint as does a skin cell on your arm. Although these cells have the same genetic information, they are considered specialized. The reason all cells within the body have the same DNA but different morphologies and functions is that different subsets of genes are turned \u201con\u201d and \u201coff\u201d within the different cell types. A more precise explanation is that there is differential expression of genes among different cell types. In the case of neuronal cells, a unique subset of genes are active that allow them to grow axons to send and receive messages. This subset of genes will be inactive in non-neuronal cell types such as skin cells. Epigenetics is a branch of genetics that studies how these genes are regulated through mechanisms that do not change the underlying DNA sequence. \u201cSpecial Topics: Epigenetics and X Chromosome Inactivation\u201d details a well-known example of epigenetics regulation.<\/p>\n<p class=\"import-Normal\">The prefix <em>epi-<\/em> means \u201con, above, or near,\u201d and epigenetic mechanisms such as <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_780\">DNA methylation<\/a><\/strong> and histone modifications occur on, above, or near DNA. The addition of a methyl group (\u2014 CH\u2083) to DNA is known as DNA methylation (Figure 3.34). DNA methylation and other modifications made to the histones around which DNA are wrapped are thought to make chromatin more compact. This DNA is inaccessible to transcription factors and RNA polymerases, thus preventing genes from being turned on (i.e., transcribed). Other histone modifications have the opposite effect by loosening chromatin, which makes genes accessible to transcription factors.<\/p>\n<figure style=\"width: 510px\" class=\"wp-caption aligncenter\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image29.png\" alt=\"Epigenetic histone tail modifications that can tighten and loosen the chromatin of DNA. \" width=\"510\" height=\"395\" \/><figcaption class=\"wp-caption-text\">Figure 3.34: Different types of epigenetic histone tail modifications that can tighten (top) and loosen (bottom) the chromatin of DNA. <a href=\"https:\/\/docs.google.com\/document\/d\/1VUDKMBJYS_jNONjLxT04jQN0_z9Ua50BRN6auGSHUuU\/edit\" target=\"_blank\" rel=\"noopener\">A full text description of this image is available.<\/a> Credit: <a href=\"https:\/\/cnx.org\/contents\/jVCgr5SL@15.43:5cz8bfb2@10\/16-3-Eukaryotic-Epigenetic-Gene-Regulation\">Epigenetic Control (Biology 2e, Figure 16.7)<\/a> by<a href=\"https:\/\/openstax.org\/\"> OpenStax<\/a> is under a<a href=\"https:\/\/creativecommons.org\/licenses\/by\/4.0\/\"> CC BY 4.0 License<\/a>.<\/figcaption><\/figure>\n<p class=\"import-Normal\">It is important to note that environmental factors can alter DNA methylation and histone modifications and also that these changes can be passed from generation to generation. For example, someone\u2019s <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_782\">epigenetic profile<\/a><\/strong> can be altered during a stressful time (e.g., natural disasters, famine, etc.), and those regulatory changes can be inherited by the next generation. Moreover, our epigenetic expression profile changes as we age. For example, certain places in our genome become \u201chyper\u201d or \u201chypo\u201d methylated over time. Identical twins also have epigenetic profiles that become more different as they age. Researchers are only beginning to understand what all of these genome-wide epigenetic changes mean. Scientists have also discovered that changes in epigenetic modifications can alter gene expression in ways that contribute to diseases. It is also important to note that, unlike DNA mutations (which permanently change the nucleotide sequence), epigenetic changes can be easily reversed. A lot of research now focuses on how drugs can alter or modulate changes in DNA methylation and histone modifications to treat diseases such as cancer.<\/p>\n<div class=\"textbox\">\n<h2 class=\"import-Normal\"><span style=\"background-color: #ccffcc\">Special Topic: Epigenetics and X Chromosome Inactivation\u00a0\u00a0<\/span><\/h2>\n<figure style=\"width: 181px\" class=\"wp-caption alignleft\"><img class=\"\" src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image30.jpg\" alt=\"A cat that has a multicolored coat pattern in colors of black, orange, and white.\" width=\"181\" height=\"201\" \/><figcaption class=\"wp-caption-text\">Figure 3.35: A multicolored coat pattern as the result of X chromosome inactivation during development. Credit: \u201cRue\u201d the calico cat by Hayley Mann is under a<a href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/\"> CC BY-NC 4.0 License<\/a>.<\/figcaption><\/figure>\n<p>Mary Lyon was a British geneticist who presented a hypothesis for X chromosome inactivation (called the <em>Lyon hypothesis<\/em>) based on her work and other studies of the day. Females inherit two X chromosomes, one from each parent. Males have one functional X chromosome; however, this does not mean females have more active genes than males. During the genetic embryonic development of many female mammals, one of the X chromosomes is inactivated at random, so females have one functional X chromosome. The process of X chromosome inactivation in females occurs through epigenetic mechanisms, such as DNA methylation and histone modifications. Recent studies have analyzed the role of a long noncoding RNA called X-inactive specific transcript (XIST), which is largely responsible for the random silencing of one of the X chromosomes. The presence of two X chromosomes is the signal for XIST RNA to be expressed so that one X chromosome can be inactivated. However, some cells may have an active paternal X chromosome while other cells may have an active maternal X chromosome. This phenomenon is easily seen in calico and tortoiseshell cats (Figure 3.35). In cats, the gene that controls coat color is found on the X chromosome. During early embryo development, random inactivation of X chromosomes gives rise to populations of cells that express black or orange, which results in the unique coat patterning. Therefore, calico cats are typically always female.<\/p>\n<\/div>\n<h2 class=\"import-Normal\">Genetic Testing<\/h2>\n<p class=\"import-Normal\">To assist with public health efforts, newborn screening for genetic diseases has been available in the United States for over 50 years. One of the first available genetic tests was to confirm a phenylketonuria (PKU) diagnosis in infants, which is easily treatable with a dietary change. Currently, each state decides what genes are included on newborn screening panels and some states even have programs to help with infant medical follow-ups.<\/p>\n<p class=\"import-Normal\">There are now hundreds of laboratories that provide testing for a few thousand different genes that can inform medical decisions for infants and adults. What has made this industry possible are the advancements in technology and decreased cost to patients. Moreover, genetic testing has been made available publicly to anyone without the assistance of medical professionals.<\/p>\n<h3 class=\"import-Normal\"><strong>Clinical Testing<\/strong><\/h3>\n<p class=\"import-Normal\">Clinical genetics tests assist patients with making medically informed decisions about family planning and health. Applications of this technology include assistance with<em> in vitro<\/em> fertilization (IVF) procedures, embryo genetic screening, and personalized medicine such as matching patients to cancer therapies. To ensure accuracy of patient genetic screening, it is important that all clinical laboratories are regulated. The Clinical Laboratory Improvement Amendments (CLIA) are United States federal standards that all human laboratory testing clinics must follow. A major benefit provided by some clinical genetic testing companies is access to genetic counselors, who have specialized education and training in medical genetics and counseling. For individuals with a family history of genetic disease, a physician may recommend genetic carrier screening to see if there is a risk for passing on a disease to a child. Genetic counselors provide expertise with interpretation of genetic testing results, as well as help guide and support patients when making impactful medical decisions.<\/p>\n<h3 class=\"import-Normal\"><strong>Direct-to-Consumer (DTC) Genetic Testing <\/strong><\/h3>\n<p class=\"import-Normal\">Genetic testing that is performed without the guidance of medical professionals is called direct-to-consumer (DTC) genetic testing. Companies that sell affordable genome sequencing products to the public continue to increase in popularity. These companies have marketing campaigns typically based on the notion of personal empowerment, which can be achieved by knowing more about your DNA. For example, if you are identified as having a slightly increased risk for developing celiac disease (Figure 3.36), then you may be motivated to modify your dietary consumption by removing gluten from your diet. Another scenario is that you could test positive for a known pathogenic <em>BRCA1<\/em> or <em>BRCA2<\/em> cancer-predisposing allele. In this case, you may want to follow up with a physician and obtain additional clinical testing, which could lead to life-altering decisions. DNA sequencing products for entertainment and lifestyle purposes are also available. For example, some DTC companies offer customized genetic reports for health and fitness, wherein recommendations for optimal exercise workout and meal plans are provided.<\/p>\n<figure style=\"width: 711px\" class=\"wp-caption aligncenter\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image31.png\" alt=\"Genetic testing result: 1 variant detected in the HLA-DQB1 gene\" width=\"711\" height=\"258\" \/><figcaption class=\"wp-caption-text\">Figure 3.36: A positive result for a genetic allele associated with an increased risk for celiac disease. Credit: Positive carrier result for celiac disease allele by Hayley Mann is under a<a href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/\"> CC BY-NC 4.0 License<\/a>.<\/figcaption><\/figure>\n<figure style=\"width: 320px\" class=\"wp-caption alignleft\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image32.png\" alt=\"A genetic test result: European: 91.6%, East Asian &amp; Native American 7.8%, South Asian 0.2%, etc. \" width=\"320\" height=\"716\" \/><figcaption class=\"wp-caption-text\">Figure 3.37: An example of ancestry percentage results provided to customers. Credit: DNA ancestry percentage test results by Hayley Mann is under a<a href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/\"> CC BY-NC 4.0 License<\/a>.<\/figcaption><\/figure>\n<p>DTC testing typically lacks genetic counselor services to consumers, and regulations for nonclinical laboratories are not as strict. This has led to some controversies regarding company genetic products that provide health information. The company 23andMe was the first on the market to offer DTC health testing, and in 2013, the U.S. Food and Drug Administration (FDA) intervened. 23andMe worked toward complying with FDA regulations and then gained approval to offer testing on a few medically related genes. In 2017, 23andMe offered a \u201cLate-Onset Alzheimer's Disease\u201d genetic risk report. Such offerings have been criticized because customers could receive results they may not fully be able to interpret without professional assistance and advice. In turn, this could increase the stress of participants (sometimes called the \u201cburden of knowing\u201d) and could lead to unnecessary medical intervention.To address this issue, 23andMe now provides disclaimers and also interactive learning modules that customers must complete if they wish to view certain genotyping results. However, individuals who tested positive for a disease-causing allele have also been able to successfully seek medical help. The potential for harm and the proposed benefits of DTC testing continue to be a topic of debate and investigation.<\/p>\n<p class=\"import-Normal\">Ancestry percentage tests are also widely popular (Figure 3.37). Customers are genotyped and their alleles are assigned to different groups from around the world (Chapter 4 will discuss human biological variation in further detail). However, the scientific significance and potential harm of ancestry percentage tests have been called into question. For example, most alleles tested are not exclusive to one population, and populations may be defined differently depending on the testing companies. If an allele is assigned to the \u201cIrish\u201d population, there is a good chance that the allele may have evolved in a different cultural group or region that pre-dates the formation of the country Ireland. In other words, genetic variation often pre-dates the origins of the population and geographical names of the region used by genetic testing companies. Another critique is that someone\u2019s identity need not include biological relationships. In using the tests, customers have the option to find and connect online with other individuals with whom they share portions of their genome, which has resulted in both positive and negative personal experiences. Another interesting development in this field is that law enforcement is currently developing forensic techniques that involve mining DTC genomic databases for the purpose of identifying suspects linked to crimes. Regardless of these various considerations, there are now millions of individuals worldwide who have \u201cunlocked the secrets\u201d of their DNA, and the multibillion-dollar genomics market only continues to grow.<\/p>\n<p class=\"import-Normal\">As you have seen in this chapter, DNA provides instructions to our cells, which results in the creation and regulation of proteins. Understanding these fundamental mechanisms is important to being able to understand how the evolutionary process works (see Chapter 4) and how humans vary from one another (see Chapters 13 and 14). In addition, advancement in genetic technologies\u2014including ancient DNA studies, genomics, and epigenetics\u2014has led to new anthropological understandings about our biological relationships to other living (extant) and extinct primates. Many of these genetic discoveries will be covered in the chapters to come.<\/p>\n<div class=\"textbox\">\n<h2 class=\"import-Normal\">Special Topic: Genetic Biotechnology<\/h2>\n<h3 class=\"import-Normal\"><strong>Polymerase Chain Reaction (PCR) and Sanger Sequencing<\/strong><\/h3>\n<p class=\"import-Normal\">One of the most important inventions in the genetics field was <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_784\">polymerase chain reaction (PCR)<\/a><\/strong>. In order for researchers to visualize and therefore analyze DNA, the concentration must meet certain thresholds. In 1985, Kary Mullis developed PCR, which can amplify millions of copies of DNA from a very small amount of template DNA (Figure 3.38). For example, a trace amount of DNA at a crime scene can be amplified and tested for a DNA match. Also, aDNA is typically degraded, so a few remaining molecules of DNA can be amplified to reconstruct ancient genomes. The PCR assay uses similar biochemical reactions to our own cells during DNA replication.<\/p>\n<p class=\"import-Normal\">In <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_786\">Sanger sequencing<\/a><\/strong>, PCR sequences can be analyzed at the nucleotide level with the help of fluorescent labeling. Several different types of alleles and genetic changes can be detected in DNA by using this analysis. Figure 3.39 shows someone who is heterozygous for a single nucleotide allele. These methods continue to be used extensively alongside larger-scale genome technologies.<\/p>\n<p>&nbsp;<\/p>\n<figure style=\"width: 575px\" class=\"wp-caption aligncenter\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image33.png\" alt=\"UV light iridescence highlights DNA samples, appearing as many small bands on a gray gel background.\" width=\"575\" height=\"197\" \/><figcaption class=\"wp-caption-text\">Figure 3.38: Gel electrophoresis is used to analyze DNA after PCR amplification. DNA is loaded into wells at the top, and an electric current applied to pull negatively charged DNA through the gel. Small DNA fragments move more quickly, separating DNA by size. Credit: PCR electrophoresis gel by Hayley Mann is under a<a href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/\"> CC BY-NC 4.0 License<\/a>.<\/figcaption><\/figure>\n<figure style=\"width: 531px\" class=\"wp-caption aligncenter\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image34.png\" alt=\"DNA sequencing printout with color bases (A, C, G, T) printed above color corresponding peaks.\" width=\"531\" height=\"263\" \/><figcaption class=\"wp-caption-text\">Figure 3.39: Sanger sequencing results showing a heterozygous DNA nucleotide. The sequencer detected the presence of both G (black) and C (blue) bases, as seen in the peaks at the bottom. The software records the base as N (undetermined) since both C and G bases are present. Credit: Sanger sequencing with heterozygous result by Hayley Mann is under a<a href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/\"> CC BY-NC 4.0 License<\/a>.<\/figcaption><\/figure>\n<p class=\"import-Normal\">Genetic innovations are transforming the healthcare industry. However, the different types of technology and the results of these tests often include a learning curve for patients, the public, and medical practitioners. <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_788\">Microarray technology<\/a><\/strong>, by which DNA samples are genotyped (or \u201cscreened\u201d) for specific alleles, has been available for quite some time (Figure 3.40). Presently, microarray chips can include hundreds of alleles that are known to be associated with various diseases. The microarray chip only binds with a DNA sample if it is \u201cpositive\u201d for that particular allele and a fluorescent signal is emitted, which can be further analyzed.<\/p>\n<figure style=\"width: 435px\" class=\"wp-caption alignleft\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image35.jpg\" alt=\"Black background with hundreds of flourescent dots in rows and columns.\" width=\"435\" height=\"216\" \/><figcaption class=\"wp-caption-text\">Figure 3.40: Microarray chip with fluorescent labeled probes that hybridize with DNA to detect homozygous and heterozygous nucleotides throughout the genome. Credit: <a href=\"https:\/\/commons.wikimedia.org\/wiki\/File:Cdnaarray.jpg\">Cdnaarray<\/a> by Mangapoco (cropped from www.sgn.cornell.edu) is under a <a href=\"https:\/\/creativecommons.org\/licenses\/by-sa\/3.0\/legalcode\">CC BY-SA 3.0 License<\/a>.<\/figcaption><\/figure>\n<p class=\"import-Normal\"><strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_790\">Next-generation sequencing (NGS)<\/a><\/strong> is a newer technology that can screen the entire genome by analyzing millions of sequences within a single machine run. If a patient is suspected of having a rare genetic condition that cannot be easily diagnosed or the diagnosis is entirely unknown, whole genome sequencing may be recommended by a doctor. However, sequencing the entire genome is still not a cost-effective healthcare approach. Therefore, clinical NGS genetic testing typically only includes a smaller subset of the genome known to have pathogenic disease-causing mutations (i.e., the gene-coding, or \u201cexonic,\u201d regions of the genome). Sequencing cancer tumor genomes is another significant application of this technology. To better understand how genetic mutations affect gene expression patterns, tumor genomic analysis also often involves RNA sequencing (known as the \u201ctranscriptome\u201d). The primary goal of this complex \u201cmulti-omics\u201d analysis is to provide personalized medicine, where patient outcome can be improved by administering tailored targeted therapies.<\/p>\n<\/div>\n<div class=\"textbox shaded\">\n<h2 class=\"import-Normal\">Review Questions<\/h2>\n<ul>\n<li class=\"import-Normal\">What is the purpose of DNA replication? Explain in a few sentences what happens during DNA replication. When do DNA mutations happen? And how does this create phenotypic variation (i.e., different phenotypes of the same physical trait)?<\/li>\n<li class=\"import-Normal\">Using your own words, what are homologous chromosomes and sister chromatids? What are the key differences between mitosis and meiosis?<\/li>\n<li class=\"import-Normal\">Determine if the pedigree diagram below (Figure 3.41) represents an autosomal dominant, autosomal recessive, or X-linked recessive pattern of inheritance. You should write the genotype (i.e., AA, Aa, or aa) above each square to help you (note: there may sometimes be two possible answers for a square\u2019s genotype). Please also explain why you concluded a particular pattern of inheritance.<\/li>\n<\/ul>\n<p>&nbsp;<\/p>\n<figure style=\"width: 247px\" class=\"wp-caption aligncenter\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image36.png\" alt=\"Pedigree where 6 of 15 individuals have the trait. On 2 separate branches parents without the trait have a biological child who does.\" width=\"247\" height=\"214\" \/><figcaption class=\"wp-caption-text\">Figure 3.41: A four generation pedigree depicting a trait with an undetermined inheritance pattern. Credit: <a href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/chapter\/__unknown__-9\/\">X-linked recessive pattern of inheritance (Figure 3.46)<\/a> original to <a href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/\">Explorations: An Open Invitation to Biological Anthropology<\/a> by Beth Shook is under a <a href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/\">CC BY-NC 4.0 License<\/a>.<\/figcaption><\/figure>\n<ul>\n<li class=\"import-Normal\">Use base pairing rules to transcribe the following DNA template sequence into mRNA: GTAAAGGTGCTGGCCATC. Next, use the protein codon table (see Figure 3.21) to translate the sequence. In regard to transcription, explain what the significance is of the first and last codon\/protein in the sequence.<\/li>\n<li class=\"import-Normal\">In your opinion, what do you think the benefits are of direct-to-consumer (DTC) genetic testing? What are the drawbacks and\/or greater ethical concerns? Do you think benefits outweigh concerns?<\/li>\n<li class=\"import-Normal\">Imagine that you submit your DNA sample to a genetic testing company and among the various diseases for which they test, there is an allele that is associated with late-onset Alzheimer\u2019s disease. You have the option to view your Alzheimer\u2019s result or to not view your result. What do you do and why?<\/li>\n<\/ul>\n<\/div>\n<h2 class=\"import-Normal\">Key Terms<\/h2>\n<p class=\"import-Normal\"><strong>Adenosine triphosphate (ATP)<\/strong>: A high-energy compound produced by mitochondria that powers cellular processes.<\/p>\n<p class=\"import-Normal\"><strong>Allele<\/strong>: A nonidentical DNA sequence found in the same gene location on a homologous chromosome, or gene copy, that codes for the same trait but produces a different phenotype.<\/p>\n<p class=\"import-Normal\"><strong>Amino acids<\/strong>: Organic molecules that are the building blocks of protein. Each of the 20 different amino acids have their own unique chemical property. Amino acids are chained together to form proteins.<\/p>\n<p class=\"import-Normal\"><strong>Ancient DNA (aDNA)<\/strong>: DNA that is extracted from organic remains and that often dates from hundreds to thousands of years ago. Also, aDNA is typically degraded (i.e., damaged) due to exposure to the elements such as heat, acidity, and humidity.<\/p>\n<p class=\"import-Normal\"><strong>Aneuploid<\/strong>: A cell with an unexpected amount of chromosomes. The loss or gain of chromosomes can occur during mitotic or meiotic division.<\/p>\n<p class=\"import-Normal\"><strong>Antibodies<\/strong>: Immune-related proteins that can detect and bind to foreign substances in the blood such as pathogens.<\/p>\n<p class=\"import-Normal\"><strong>Apoptosis<\/strong>: A series of molecular steps that is activated leading to cell death. Apoptosis can be activated when a cell fails checkpoints during the cell cycle; however, cancer cells have the ability to avoid apoptosis.<\/p>\n<p class=\"import-Normal\"><strong>Autosomal<\/strong>: Refers to a pattern of inheritance in which an allele is located on an autosome (non sex chromosome).<\/p>\n<p class=\"import-Normal\"><strong>Base pairs<\/strong>: Chemical bonding between nucleotides. In DNA, adenine (A) pairs with thymine (T) and cytosine (C) pairs with guanine (G); in RNA, adenine (A) always pairs with uracil (U).<\/p>\n<p class=\"import-Normal\"><strong>Carbohydrate<\/strong>: Molecules composed of carbon and hydrogen atoms that can be broken down to supply energy.<\/p>\n<p class=\"import-Normal\"><strong>Carrier<\/strong>: An individual who has a heterozygous genotype that is typically associated with a disease.<\/p>\n<p class=\"import-Normal\"><strong>Cell cycle<\/strong>: A cycle the cell undergoes with checkpoints between phases to ensure that DNA replication and cell division occur properly.<\/p>\n<p class=\"import-Normal\"><strong>Cell surface antigen<\/strong>: A protein that is found on a red blood cell\u2019s surface.<\/p>\n<p class=\"import-Normal\"><strong>Centromere<\/strong>: A structural feature that is defined as the \u201ccenter\u201d of a chromosome and that creates two different arm lengths. This term also refers to the region of attachment for microtubules during mitosis and meiosis.<\/p>\n<p class=\"import-Normal\"><strong>Chromatin<\/strong>: DNA wrapped around histone complexes. During cell division, chromatin becomes a condensed chromosome.<\/p>\n<p class=\"import-Normal\"><strong>Chromosome<\/strong>: DNA molecule that is wrapped around protein complexes, including histones.<\/p>\n<p class=\"import-Normal\"><strong>Codominance<\/strong>: The effects of both alleles in a genotype can be seen in the phenotype.<\/p>\n<p class=\"import-Normal\"><strong>Codons<\/strong>: A sequence that comprises three DNA nucleotides that together code for a protein.<\/p>\n<p class=\"import-Normal\"><strong>Complex diseases<\/strong>: A category of diseases that are polygenic and are also influenced by environment and lifestyle factors.<\/p>\n<p class=\"import-Normal\"><strong>Cytoplasm<\/strong>: The \u201cjelly-like\u201d matrix inside of the cell that contains many organelles and other cellular molecules.<\/p>\n<p class=\"import-Normal\"><strong>Deleterious<\/strong>: A mutation that increases an organism\u2019s susceptibility to disease.<\/p>\n<p class=\"import-Normal\"><strong>Deoxyribonucleic acid (DNA)<\/strong>: A molecule that carries the hereditary information passed down from parents to offspring. DNA can be described as a \u201cdouble helix\u201d\u2019 shape. It includes two chains of nucleotides held together by hydrogen bonds with a sugar phosphate backbone.<\/p>\n<p class=\"import-Normal\"><strong>Diploid<\/strong>: Refers to an organism or cell with two sets of chromosomes.<\/p>\n<p class=\"import-Normal\"><strong>DNA methylation<\/strong>: Methyl groups bind DNA, which modifies the transcriptional activity of a gene by turning it \u201con\u201d or \u201coff.\u201d<\/p>\n<p class=\"import-Normal\"><strong>DNA polymerase<\/strong>: Enzyme that adds nucleotides to existing nucleic acid strands during DNA replication. These enzymes can be distinguished by their processivity (e.g., DNA replication).<\/p>\n<p class=\"import-Normal\"><strong>DNA replication<\/strong>: Cellular process in which DNA is copied and doubled.<\/p>\n<p class=\"import-Normal\"><strong>DNA sequence<\/strong>: The order of nucleotide bases. A DNA sequence can be short, long, or representative of entire chromosomes or organismal genomes.<\/p>\n<p class=\"import-Normal\"><strong>Dominant<\/strong>: Refers to an allele for which one copy is sufficient to be visible in the phenotype.<\/p>\n<p class=\"import-Normal\"><strong>Elongation<\/strong>: The assembly of new DNA from template strands with the help of DNA polymerases.<\/p>\n<p class=\"import-Normal\"><strong>Enzymes<\/strong>: Proteins responsible for catalyzing (accelerating) various biochemical reactions in cells.<\/p>\n<p class=\"import-Normal\"><strong>Epigenetic profile<\/strong>: The methylation pattern throughout a genome\u2014that is, which genes (and other genomic sites) are methylated and unmethylated.<\/p>\n<p class=\"import-Normal\"><strong>Epigenetics<\/strong>: Changes in gene expression that do not result in a change of the underlying DNA sequence. These changes typically involve DNA methylation and histone modifications. These changes are reversible and can also be inherited by the next generation.<\/p>\n<p class=\"import-Normal\"><strong>Euchromatin<\/strong>: Loosely coiled chromosomes found within the nucleus that are accessible for regulatory processing of DNA.<\/p>\n<p class=\"import-Normal\"><strong>Eukaryote<\/strong>: Single-celled or multicelled organism characterized by a distinct nucleus, with each organelle surrounded by its own membrane.<\/p>\n<p class=\"import-Normal\"><strong>Exon<\/strong>: Protein-coding segment of a gene.<\/p>\n<p class=\"import-Normal\"><strong>Gametes<\/strong>: Haploid cells referred to as an egg and sperm that will fuse together during sexual reproduction to form a diploid organism.<\/p>\n<p class=\"import-Normal\"><strong>Gene<\/strong>: Segment of DNA that contains protein-coding information and various regulatory (e.g., promoter) and noncoding (e.g., introns) regions.<\/p>\n<p class=\"import-Normal\"><strong>Genetic recombination<\/strong>: A cellular process that occurs during meiosis I in which homologous chromosomes pair up and sister chromatids on different chromosomes physically swap genetic information.<\/p>\n<p class=\"import-Normal\"><strong>Genome<\/strong>: All the genetic information of an organism.<\/p>\n<p class=\"import-Normal\"><strong>Genotype<\/strong>: The combination of two alleles that code for or are associated with the same gene.<\/p>\n<p class=\"import-Normal\"><strong>Genotyping<\/strong>: A molecular procedure that is performed to test for the presence of certain alleles or to discover new ones.<\/p>\n<p class=\"import-Normal\"><strong>Germ cells<\/strong>: Specialized cells that form gametes (egg and sperm cells).<\/p>\n<p class=\"import-Normal\"><strong>Haploid<\/strong>: Cell or organism with one set of chromosomes (<em>n<\/em> = 23).<\/p>\n<p class=\"import-Normal\"><strong>Helicase<\/strong>: A protein that breaks the hydrogen bonds that hold double-stranded DNA together.<\/p>\n<p class=\"import-Normal\"><strong>Heterozygous<\/strong>: Genotype that consists of two different alleles.<\/p>\n<p class=\"import-Normal\"><strong>Histones<\/strong>: Proteins that DNA wraps around to assist with DNA organization within the nucleus.<\/p>\n<p class=\"import-Normal\"><strong>Homologous chromosomes<\/strong>: A matching pair of chromosomes wherein one chromosome is maternally inherited and the other is paternally inherited.<\/p>\n<p class=\"import-Normal\"><strong>Homozygous<\/strong>: Genotype that consists of two identical alleles.<\/p>\n<p class=\"import-Normal\"><strong>Incomplete dominance<\/strong>: Heterozygous genotype that produces a phenotype that is a blend of both alleles.<\/p>\n<p class=\"import-Normal\"><strong>Initiation<\/strong>: The recruitment of proteins to separate DNA strands and begin DNA replication.<\/p>\n<p class=\"import-Normal\"><strong>Interphase<\/strong>: Preparatory period of the cell cycle when increased metabolic demand allows for DNA replication and doubling of the cell prior to cell division.<\/p>\n<p class=\"import-Normal\"><strong>Introns<\/strong>: Segment of DNA that does not code for proteins.<\/p>\n<p class=\"import-Normal\"><strong>Karyotyping<\/strong>: The microscopic procedure wherein the number of chromosomes in a cell is determined.<\/p>\n<p class=\"import-Normal\"><strong>Lagging strand<\/strong>: DNA template strand that is opposite to the leading strand during DNA replication. This strand is created in several disconnected sections and other enzymes fill in the missing nucleotide gaps between these sections.<\/p>\n<p class=\"import-Normal\"><strong>Leading strand<\/strong>: DNA template strand in which replication proceeds continuously.<\/p>\n<p class=\"import-Normal\"><strong>Lipids<\/strong>: Fatty acid molecules that serve various purposes in the cell, including energy storage, cell signaling, and structure.<\/p>\n<p class=\"import-Normal\"><strong>Meiosis<\/strong>: The process that gametes undergo to divide. The end of meiosis results in four haploid daughter cells.<\/p>\n<p class=\"import-Normal\"><strong>Mendelian genetics<\/strong>: A classification given to phenotypic traits that are controlled by a single gene.<\/p>\n<p class=\"import-Normal\"><strong>Messenger RNA (mRNA)<\/strong>: RNA molecule that is transcribed from DNA. Its tri-nucleotide codons are \u201cread\u201d by a ribosome to build a protein.<\/p>\n<p class=\"import-Normal\"><strong>Microarray technology<\/strong>: A genotyping procedure that utilizes a microarray chip, which is a collection of thousands of short nucleotide sequences attached to a solid surface that can probe genomic DNA.<\/p>\n<p class=\"import-Normal\"><strong>Microbiome<\/strong>: The collective genomes of the community of microorganisms that humans have living inside of their bodies.<\/p>\n<p class=\"import-Normal\"><strong>Mitochondrial DNA (mtDNA)<\/strong>: Circular DNA segment found in mitochondria that is inherited maternally.<\/p>\n<p class=\"import-Normal\"><strong>Mitochondrion<\/strong>: Specialized cellular organelle that is the site for energy production. It also has its own genome (mtDNA).<\/p>\n<p class=\"import-Normal\"><strong>Mitosis<\/strong>: The process that somatic cells undergo to divide. The end of mitosis results in two diploid daughter cells.<\/p>\n<p class=\"import-Normal\"><strong>Molecular anthropologists<\/strong>: Individuals who use molecular techniques (primarily genetics) to compare ancient and modern populations and to study living populations of humans and nonhuman primates.<\/p>\n<p class=\"import-Normal\"><strong>Molecular geneticists<\/strong>: Biologists that study the structure and function of genes.<\/p>\n<p class=\"import-Normal\"><strong>Mutation<\/strong>: A nucleotide sequence variation from the template DNA strand that can occur during replication. Mutations can also happen during recombination.<\/p>\n<p class=\"import-Normal\"><strong>Next-generation sequencing<\/strong>: A genotyping technology that involves producing millions of nucleotide sequences (from a single DNA sample) that are then read with a sequencing machine. It can be used for analyzing entire genomes or specific regions and requires extensive program-based applications.<\/p>\n<p class=\"import-Normal\"><strong>Nuclear envelope<\/strong>: A double-layered membrane that encircles the nucleus.<\/p>\n<p class=\"import-Normal\"><strong>Nucleic acid<\/strong>: A complex structure (like DNA or RNA) that carries genetic information about a living organism.<\/p>\n<p class=\"import-Normal\"><strong>Nucleotide<\/strong>: The basic structural component of nucleic acids, which includes DNA (A, T, C, and G) and RNA (A, U, C, and G).<\/p>\n<p class=\"import-Normal\"><strong>Nucleus<\/strong>: Double-membrane cellular organelle that helps protect DNA and also regulates nuclear activities.<\/p>\n<p class=\"import-Normal\"><strong>Organelle<\/strong>: A structure within a cell that performs specialized tasks that are essential for the cell. There are different types of organelles, each with its own function.<\/p>\n<p class=\"import-Normal\"><strong>Pathogenic<\/strong>: A genetic mutation (i.e., allele) that has a harmful phenotypic disease-causing effect.<\/p>\n<p class=\"import-Normal\"><strong>Pedigree<\/strong>: A diagram of family relationships that indicates which members may have or carry certain genetic and\/or phenotypic traits.<\/p>\n<p class=\"import-Normal\"><strong>Penetrance<\/strong>: The proportion of how often the possession of an allele results in an expected phenotype. Some alleles are more penetrant than others.<\/p>\n<p class=\"import-Normal\"><strong>Phenotype<\/strong>: The physical appearance of a given trait.<\/p>\n<p class=\"import-Normal\"><strong>Phospholipid bilayer<\/strong>: Two layers of lipids that form a barrier due to the properties of a hydrophilic (water-loving) head and a hydrophobic (water-repelling) tail.<\/p>\n<p class=\"import-Normal\"><strong>Polygenic trait<\/strong>: A phenotype that is controlled by two or more genes.<\/p>\n<p class=\"import-Normal\"><strong>Polymerase chain reaction (PCR)<\/strong>: A molecular biology procedure that can make copies of genomic DNA segments. A small amount of DNA is used as a starting template and is then used to make millions of copies.<\/p>\n<p class=\"import-Normal\"><strong>Prokaryote<\/strong>: A single-celled organism characterized by the lack of a nucleus and membrane-enclosed organelles.<\/p>\n<p class=\"import-Normal\"><strong>Promoter<\/strong>: The region of a gene that initiates transcription. Transcription factors can bind and DNA methylation may occur at a promoter site, which can modify the transcriptional activities of a gene.<\/p>\n<p class=\"import-Normal\"><strong>Protein<\/strong>: Chain of amino acids that folds into a three-dimensional structure that allows a cell to function in a variety of ways.<\/p>\n<p class=\"import-Normal\"><strong>Protein synthesis<\/strong>: A multi-step process by which amino acids are strung together by RNA machinery read from a DNA template.<\/p>\n<p class=\"import-Normal\"><strong>Recessive<\/strong>: Refers to an allele whose effect is not normally seen unless two copies are present in an individual\u2019s genotype.<\/p>\n<p class=\"import-Normal\"><strong>Ribonucleic acid (RNA)<\/strong>: Single-stranded nucleic acid molecule.There are different RNAs found within cells and they perform a variety of functions, such as cell signaling and involvement in protein synthesis.<\/p>\n<p class=\"import-Normal\"><strong>Ribosomal RNA (rRNA)<\/strong>: A ribosome-bound molecule that is used to correctly assemble amino acids into proteins.<\/p>\n<p class=\"import-Normal\"><strong>Ribosome<\/strong>: An organelle in the cell found in the cytoplasm or endoplasmic reticulum. It is responsible for reading mRNA and protein assemblage.<\/p>\n<p class=\"import-Normal\"><strong>RNA polymerase<\/strong>: An enzyme that catalyzes the process of making RNA from a DNA template.<\/p>\n<p class=\"import-Normal\"><strong>Sanger-sequencing<\/strong>: A process that involves the usage of fluorescently labeled nucleotides to visualize DNA (PCR fragments) at the nucleotide level.<\/p>\n<p class=\"import-Normal\"><strong>Semi-conservative replication<\/strong>: DNA replication in which new DNA is replicated from an existing DNA template strand.<\/p>\n<p class=\"import-Normal\"><strong>Sequencing<\/strong>: A molecular laboratory procedure that produces the order of nucleotide bases (i.e., sequences).<\/p>\n<p class=\"import-Normal\"><strong>Sister chromatids<\/strong>: During DNA replication, sister chromatids are produced on the chromosome. In cell division, sister chromatids are pulled apart so that two cells can be formed. In meiosis, sister chromatids are also the sites of genetic recombination.<\/p>\n<p class=\"import-Normal\"><strong>Somatic cells<\/strong>: Diploid cells that comprise body tissues and undergo mitosis for maintenance and repair of tissues.<\/p>\n<p class=\"import-Normal\"><strong>Splicing<\/strong>: The process by which mature mRNAs are produced. Introns are removed (spliced) and exons are joined together.<\/p>\n<p class=\"import-Normal\"><strong>Sugar phosphate backbone<\/strong>: A biochemical structural component of DNA. The \u201cbackbone\u201d consists of deoxyribose sugars and phosphate molecules.<\/p>\n<p class=\"import-Normal\"><strong>Telomere<\/strong>: A compound structure located at the ends of chromosomes to help protect the chromosomes from degradation after every round of cell division.<\/p>\n<p class=\"import-Normal\"><strong>Termination<\/strong>: The halt of DNA replication activity that occurs when a DNA sequence \u201cstop\u201d codon is encountered.<\/p>\n<p class=\"import-Normal\"><strong>Tissue<\/strong>: A cluster of cells that are morphologically similar and perform the same task.<\/p>\n<p class=\"import-Normal\"><strong>Transcription<\/strong>: The process by which DNA nucleotides (within a gene) are copied, which results in a messenger RNA molecule.<\/p>\n<p class=\"import-Normal\"><strong>Transcription factors<\/strong>: Proteins that bind to regulatory regions of genes (e.g., promoter) and increase or decrease the amount of transcriptional activity of a gene, including turning them \u201con\u201d or \u201coff.\u201d<\/p>\n<p class=\"import-Normal\"><strong>Transfer RNA (tRNA)<\/strong>: RNA molecule involved in translation. Transfer RNA transports amino acids from the cell\u2019s cytoplasm to a ribosome.<\/p>\n<p class=\"import-Normal\"><strong>Translation<\/strong>: The process by which messenger RNA codons are read and amino acids are \u201cchained together\u201d to form proteins.<\/p>\n<p class=\"import-Normal\"><strong>X-linked<\/strong>: Refers to a pattern of inheritance where the allele is located on the X or Y chromosome.<\/p>\n<h2 class=\"import-Normal\">About the Author<\/h2>\n<p class=\"import-Normal\"><img class=\"alignleft\" src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image37.png\" alt=\"Headshot of author with long brown hair and brown eyes, wearing blue and black.\" width=\"165\" height=\"214\" \/><\/p>\n<p class=\"import-Normal\">Hayley Mann, M.A.<\/p>\n<p class=\"import-Normal\">Binghamton University, <a class=\"rId159\" href=\"mailto:hmann3@binghamton.edu\">hmann3@binghamton.edu<\/a><\/p>\n<p class=\"import-Normal\">Hayley Mann received her bachelor\u2019s degree in Genetics from the University of California, Davis, and continued her graduate studies in Biological and Molecular Anthropology at the California State University, Sacramento. She is currently a Ph.D. candidate at Binghamton University, where her dissertation focus is on studying genetic variation of Pacific Islanders (Republic of Vanuatu) and also changes in health as the result of colonization. Hayley also works in clinical molecular carrier screening and specializes in DNA-sequencing procedures.<\/p>\n<h2 class=\"import-Normal\">For Further Exploration<\/h2>\n<p class=\"import-Normal\"><a href=\"https:\/\/www.genome.gov\/\">National Human Genome Research Institute<\/a><\/p>\n<p class=\"import-Normal\"><a href=\"https:\/\/ghr.nlm.nih.gov\/\">Genetics Home Reference<\/a><\/p>\n<p class=\"import-Normal\"><a href=\"https:\/\/knowgenetics.org\/\">Genetics Generation<\/a><\/p>\n<p class=\"import-Normal\"><a href=\"https:\/\/www.yourgenome.org\/\">yourgenome<\/a><\/p>\n<p class=\"import-Normal\">NOVA. 2018. Gene Sequencing Speeds Diagnosis of Deadly Newborn Diseases. NOVA, March 7, 2018. Accessed January 31, 2023. <a class=\"rId164\" href=\"https:\/\/www.pbs.org\/wgbh\/nova\/next\/body\/newborn-gene-sequencing\/\">https:\/\/www.pbs.org\/wgbh\/nova\/next\/body\/newborn-gene-sequencing\/<\/a>.<\/p>\n<p class=\"import-Normal\">Zimmer, Carl. N.d. \u201cCarl Zimmer\u2019s Game of Genomes.\u201d STATnews. Accessed January 31, 2023. <a class=\"rId165\" href=\"https:\/\/www.statnews.com\/feature\/game-of-genomes\/season-one\/\">https:\/\/www.statnews.com\/feature\/game-of-genomes\/season-one\/<\/a>.<\/p>\n<p class=\"import-Normal\">Illumina. 2016. \u201cIllumina Sequencing by Synthesis.\u201d YouTube.com, October 5, 2016. Accessed January 31, 2023. <a class=\"rId166\" href=\"https:\/\/www.youtube.com\/watch?v=fCd6B5HRaZ8\">https:\/\/www.youtube.com\/watch?v=fCd6B5HRaZ8<\/a>.<\/p>\n<h2 class=\"import-Normal\">References<\/h2>\n<p class=\"import-Normal\">Aartsma-Rus, Annemieke, Ieke B. Ginjaar, and Kate Bushby. 2016. \u201cThe Importance of Genetic Diagnosis for Duchenne Muscular Dystrophy.\u201d Journal of Medical Genetics 53 (3): 145\u2013151.<\/p>\n<p class=\"import-Normal\">Acuna-Hidalgo, Rocio, Joris A. Veltman, and Alexander Hoischen. 2016. \u201cNew Insights into the Generation and Role of De Novo Mutations in Health and Disease.\u201d Genome Biology 17 (241): 1\u201319.<\/p>\n<p class=\"import-Normal\">Albert, Benjamin, Susanna Tomassetti, Yvonne Gloor, Daniel Dilg, Stefano Mattarocci, Slawomir Kubik, Lukas Hafner, and David Shore. 2019. \"Sfp1 Regulates Transcriptional Networks Driving Cell Growth and Division through Multiple Promoter-Binding Modes.\" Genes &amp; Development 33 (5\u20136): 288\u2013293.<\/p>\n<p class=\"import-Normal\">Almathen, Faisal, Haitham Elbir, Hussain Bahbahani, Joram Mwacharo, and Olivier Hanotte. 2018. \u201cPolymorphisms in Mc1r and Asip Genes Are Associated with Coat Color Variation in the Arabian Camel.\u201d Journal of Heredity 109 (6): 700\u2013706.<\/p>\n<p class=\"import-Normal\">Ballester, Leomar Y., Rajyalakshmi Luthra, Rashmi Kanagal-Shamanna, and Rajesh R. Singh. 2016. \u201cAdvances in Clinical Next-Generation Sequencing: Target Enrichment and Sequencing Technologies.\u201d Expert Review of Molecular Diagnostics 16 (3): 357\u2013372.<\/p>\n<p class=\"import-Normal\">Baranovskiy, Andrey G., Vincent N. Duong, Nigar D. Babayeva, Yinbo Zhang, Youri I. Pavlov, Karen S. Anderson, and Tahir H. Tahirov. 2018. \u201cActivity and Fidelity of Human DNA Polymerase Alpha Depend on Primer Structure.\u201d Journal of Biological Chemistry 293 (18): 6824\u20136843.<\/p>\n<p class=\"import-Normal\">Brezina, Paulina R., Raymond Anchan, and William G. Kearns. 2016. \u201cPreimplantation Genetic Testing for Aneuploidy: What Technology Should You Use and What Are the Differences?\u201d Journal of Assisted Reproduction and Genetics 33 (7): 823\u2013832.<\/p>\n<p class=\"import-Normal\">Bultman, Scott J. 2017. \u201cInterplay Between Diet, Gut Microbiota, Epigenetic Events, and Colorectal Cancer.\" Molecular Nutrition &amp; Food Research 61 (1):1\u201312.<\/p>\n<p class=\"import-Normal\">Cutting, Garry R. 2015. \u201cCystic Fibrosis Genetics: From Molecular Understanding to Clinical Application.\u201d Nature Reviews Genetics 16 (1): 45\u201356.<\/p>\n<p class=\"import-Normal\">D'Alessandro, Giuseppina., and Fabrizio d'Adda di Fagagna. 2017. \u201cTranscription and DNA Damage: Holding Hands or Crossing Swords?\u201d Journal of Molecular Biology 429 (21): 3215\u20133229.<\/p>\n<p class=\"import-Normal\">De Craene, Johan-Owen, Dimitri L. Bertazzi, S\u00e9verine Bar, and Sylvie Friant. 2017. \u201cPhosphoinositides, Major Actors in Membrane Trafficking and Lipid Signaling Pathways.\u201d International Journal of Molecular Sciences 18 (3): 1\u201320.<\/p>\n<p class=\"import-Normal\">Deng, Lian, and Shuhua Xu. 2018. \u201cAdaptation of Human Skin Color in Various Populations.\u201d Hereditas 155 (1): 1\u201312.<\/p>\n<p class=\"import-Normal\">Dever, Thomas E., Terri G. Kinzy, and Graham D. Pavitt. 2016. \u201cMechanism and Regulation of Protein Synthesis in Saccharomyces Cerevisiae.\u201d Genetics 203 (1): 65\u2013107.<\/p>\n<p class=\"import-Normal\">Eme, Laura, Anja Spang, Jonathan Lombard, Courtney W. Stairs, and Thijs J. G. Ettema. 2017. \u201cArchaea and the Origin of Eukaryotes.\u201d Nature Reviews Microbiology 15 (12): 711\u2013723.<\/p>\n<p class=\"import-Normal\">Gomez-Carballa, Alberto, Jacobo Pardo-Seco, Stefania Brandini, Alessandro Achilli, Ugo A. Perego, Michael D. Coble, Toni M. Diegoli, et al. 2018. \u201cThe Peopling of South America and the Trans-Andean Gene Flow of the First Settlers.\u201d Genome Research 28 (6): 767\u2013779.<\/p>\n<p class=\"import-Normal\">Gvozdenov, Zlata, Janhavi Kolhe, and Brian C. Freeman. 2019. \u201cThe Nuclear and DNA-Associated Molecular Chaperone Network.\u201d Cold Spring Harbor Perspectives in Biology 11 (10): a034009.<\/p>\n<p class=\"import-Normal\">Harkins, Kelly M., and Anne C. Stone. 2015. \u201cAncient Pathogen Genomics: Insights into Timing and Adaptation.\u201d Journal of Human Evolution 79: 137\u2013149.<\/p>\n<p class=\"import-Normal\">Jackson, Maria, Leah Marks, Gerhard H. W. May, and Joanna B. Wilson. 2018. \u201cThe Genetic Basis of Disease.\u201d Essays in Biochemistry 62 (5): 643\u2013723.<\/p>\n<p class=\"import-Normal\">Lenormand, Thomas, Jan Engelstadter, Susan E. Johnston, Erik Wijnker, and Christopher R. Haag. 2016. \u201cEvolutionary Mysteries in Meiosis.\u201d Philosophical Transactions of the Royal Society B 371: 1\u201314.<\/p>\n<p class=\"import-Normal\">Levy, Shawn E., and Richard M. Myers. 2016. \u201cAdvancements in Next-Generation Sequencing.\u201d Annual Review of Genomics and Human Genetics 17: 95\u2013115.<\/p>\n<p class=\"import-Normal\">Lindo, John, Emilia Huerta-S\u00e1nchez, Shigeki Nakagome, Morten Rasmussen, Barbara Petzelt, Joycelynn Mitchell, Jerome S. Cybulski, et al. 2016. \"A Time Transect of Exomes from a Native American Population Before and After European Contact.\" Nature Communications 7: 1\u201311. https:\/\/doi.org\/10.1038\/ncomms13175.<\/p>\n<p class=\"import-Normal\">Lu, Mengfei, Cathryn M. Lewis, and Matthew Traylor. 2017. \u201cPharmacogenetic Testing through the Direct-to-Consumer Genetic Testing Company 23andme.\u201d BMC Medical Genomics 10 (47): 1\u20138.<\/p>\n<p class=\"import-Normal\">Ly, Lundi, Donovan Chan, Mahmoud Aarabi, Mylene Landry, Nathalie A. Behan, Amanda J. MacFarlane, and Jacquetta Trasler. 2017. \u201cIntergenerational Impact of Paternal Lifetime Exposures to Both Folic Acid Deficiency and Supplementation on Reproductive Outcomes and Imprinted Gene Methylation.\u201d Molecular Human Reproduction 23 (7): 461\u2013477.<\/p>\n<p class=\"import-Normal\">Ma, Wenxiu, Giancarlo Bonora, Joel B. Berletch, Xinxian Deng, William S. Noble, and Christine M. Disteche. 2018. \u201cX-Chromosome Inactivation and Escape from X Inactivation in Mouse.\u201d Methods in Molecular Biology 1861: 205\u2013219.<\/p>\n<p class=\"import-Normal\">Machiela, Mitchell J., Weiyin Zhou, Eric Karlins, Joshua N. Sampson, Neal D. Freedman, Qi Yang, Belynda Hicks, et al. 2016. \u201cFemale Chromosome X Mosaicism Is Age-Related and Preferentially Affects the Inactivated X Chromosome.\u201d Nature Communications 7: 1\u20139. https:\/\/doi.org\/10.1038\/ncomms11843.<\/p>\n<p class=\"import-Normal\">Mahdavi, Morteza, Mohammadreza Nassiri, Mohammad M. Kooshyar, Masoume Vakili-Azghandi, Amir Avan, Ryan Sandry, Suja Pillai, Alfred K. Lam, and Vinod Gopalan. 2019. \u201cHereditary Breast Cancer; Genetic Penetrance and Current Status with BRCA.\u201d Journal of Cellular Physiology 234 (5): 5741\u20135750.<\/p>\n<p class=\"import-Normal\">McDade, Thomas W., Calen P. Ryan, Meaghan J. Jones, Morgan K. Hoke, Judith Borja, Gregory E. Miller, Christopher W. Kuzawa, and Michael S. Kobor. 2019. \u201cGenome-Wide Analysis of DNA Methylation in Relation to Socioeconomic Status During Development and Early Adulthood.\u201d American Journal of Physical Anthropology 169 (1): 3\u201311.<\/p>\n<p class=\"import-Normal\">Migeon, Barbara R. 2017. \u201cChoosing the Active X: The Human Version of X Inactivation.\u201d Trends in Genetics 33 (12): 899\u2013909.<\/p>\n<p class=\"import-Normal\">Myerowitz, Rachel. 1997. \u201cTay-Sachs Disease-Causing Mutations and Neutral Polymorphisms in the Hex A Gene.\u201d Human Mutation 9 (3): 195\u2013208.<\/p>\n<p class=\"import-Normal\">Onufriev, Alexey V., and Helmut Schiessel. 2019. \u201cThe Nucleosome: From Structure to Function through Physics.\u201d Current Opinion in Structural Biology 56: 119\u2013130.<\/p>\n<p class=\"import-Normal\">Quillen, Ellen E., Heather L. Norton, Esteban J. Parra, Frida Lona-Durazo, Khai C. Ang, Florin M. Illiescu, Laurel N. Pearson, et al. 2019. \u201cShades of Complexity: New Perspectives on the Evolution and Genetic Architecture of Human Skin.\u201d American Journal of Physical Anthropology 168 (67): 4\u201326.<\/p>\n<p class=\"import-Normal\">Raspelli, Erica, and Roberta Fraschini. 2019. \u201cSpindle Pole Power in Health and Disease.\u201d Current Genetics 65 (4): 851\u2013855.<\/p>\n<p class=\"import-Normal\">Ravinet, M., R. Faria, R. K. Butlin, J. Galindo, N. Bierne, M. Rafajlovic, M. A. F. Noor, B. Mehlig, and A. M. Westram. 2017. \u201cInterpreting the Genomic Landscape of Speciation: A Road Map for Finding Barriers to Gene Flow.\u201d Journal of Evolutionary Biology 30 (8): 1450\u20131477.<\/p>\n<p class=\"import-Normal\">Regev, Aviv, Sarah A. Teichmann, Eric S. Lander, Ido Amit, Christophe Benoist, Ewan Birney, Bernd Bodenmiller, et al. 2017. \u201cThe Human Cell Atlas.\u201d Elife 6e27041: 1\u201330. https:\/\/doi.org\/10.7554.eLife.27041.<\/p>\n<p class=\"import-Normal\">Roberts, Andrea L., Nicole Gladish, Evan Gatev, Meaghan J. Jones, Ying Chen, Julia L. MacIsaac, Shelley S. Tworoger, et al. 2018. \u201cExposure to Childhood Abuse Is Associated with Human Sperm DNA Methylation.\u201d Translational Psychiatry 8 (194): 1\u201311.<\/p>\n<p class=\"import-Normal\">Roger, Andrew J., Sergio A. Mu\u00f1oz-G\u00f3mez, and Ryoma Kamikawa. 2017. \u201cThe Origin and Diversification of Mitochondria.\u201d Current Biology 27 (21): R1177\u2013R1192. https:\/\/www.sciencedirect.com\/science\/article\/pii\/S096098221731179X?via%3Dihub#!<\/p>\n<p class=\"import-Normal\">S\u00e9gurel, Laure, and C\u00e9line Bon. 2017. \u201cOn the Evolution of Lactase Persistence in Humans.\u201d Annual Review of Genomics and Human Genetics 18: 297\u2013319.<\/p>\n<p class=\"import-Normal\">Sheth, Bhavisha P., and Vrinda S. Thaker. 2017. \u201cDNA Barcoding and Traditional Taxonomy: An Integrated Approach for Biodiversity Conservation.\u201d Genome 60 (7): 618\u2013628.<\/p>\n<p class=\"import-Normal\">Skloot, Rebecca. 2010. The Immortal Life of Henrietta Lacks. New York: Crown Publishing Group.<\/p>\n<p class=\"import-Normal\">Snedeker, Jonathan, Matthew Wooten, and Xin Chen. 2017. \u201cThe Inherent Asymmetry of DNA Replication.\u201d Annual Review of Cell and Developmental Biology 33: 291\u2013318.<\/p>\n<p class=\"import-Normal\">Sullivan-Pyke, Chantae, and Anuja Dokras. 2018. \u201cPreimplantation Genetic Screening and Preimplantation Genetic Diagnosis.\u201d Obstetrics and Gynecology Clinics of North America 45 (1): 113\u2013125.<\/p>\n<p class=\"import-Normal\">Szostak, Jack W. 2017. \u201cThe Narrow Road to the Deep Past: In Search of the Chemistry of the Origin of Life.\u201d Angewandte Chemie International Edition 56 (37): 11037\u201311043.<\/p>\n<p class=\"import-Normal\">Tessema, Mathewos, Ulrich Lehmann, and Hans Kreipe. 2004. \u201cCell Cycle and No End.\u201d Virchows Archiv European Journal of Pathology 444 (4): 313\u2013323.<\/p>\n<p class=\"import-Normal\">Tishkoff, Sarah A., Floyd A. Reed, Alessia Ranciaro, Benjamin F. Voight, Courtney C. Babbitt, Jesse S. Silverman, Kweli Powell, et al. 2007. \u201cConvergent Adaptation of Human Lactase Persistence in Africa and Europe.\u201d Nature Genetics 39 (1): 31\u201340.<\/p>\n<p class=\"import-Normal\">Visootsak, Jeannie, and John M. Graham, Jr. 2006. \u201cKlinefelter Syndrome and Other Sex Chromosomal Aneuploidies.\u201d Orphanet Journal of Rare Diseases 1:42. https:\/\/doi.org\/10.1186\/1750-1172-1-42.<\/p>\n<p class=\"import-Normal\">Wolfe, George C., dir. 2017. The Immortal Life of Henrietta Lacks. HBO Films, April 22, 2017. TV Movie.<\/p>\n<p class=\"import-Normal\">Yamamoto, Fumi-ichiro, Henrik Clausen, Thayer White, John Marken, and Sen-itiroh Hakomori. 1990. \u201cMolecular Genetic Basis of the Histo-Blood Group ABO System.\u201d Nature 345 (6272): 229\u2013233.<\/p>\n<p class=\"import-Normal\">Zlotogora, Jo\u00ebl. 2003. \u201cPenetrance and Expressivity in the Molecular Age.\u201d Genetics in Medicine 5 (5): 347\u2013352.<\/p>\n<p class=\"import-Normal\">Zorina-Lichtenwalter, Katerina, Ryan N. Lichtenwalter, Dima V. Zaykin, Marc Parisien, Simon Gravel, Andrey Bortsov, and Luda Diatchenko. 2019. \u201cA Study in Scarlet: MC1R as the Main Predictor of Red Hair and Exemplar of the Flip-Flop Effect.\u201d Human Molecular Genetics 28 (12): 2093-2106.<\/p>\n<p class=\"import-Normal\">Zwart, Haeh. 2018. \u201cIn the Beginning Was the Genome: Genomics and the Bi-Textuality of Human Existence.\u201d New Bioethics 24 (1): 26\u201343.<\/p>\n<\/div>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_281_1713\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_281_1713\"><div tabindex=\"-1\"><p>This is where you can add appendices or other back matter.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_281_1711\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_281_1711\"><div tabindex=\"-1\"><\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_281_1714\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_281_1714\"><div tabindex=\"-1\"><div class=\"__UNKNOWN__\"><span style=\"font-size: 1em\">Jason M. Organ, Ph.D., Indiana University School of Medicine<\/span><\/div>\n<div class=\"__UNKNOWN__\">\n<div>\n<div><\/div>\n<div>\n<div class=\"__UNKNOWN__\">Jessica N. Byram, Ph.D., Indiana University School of Medicine<\/div>\n<\/div>\n<\/div>\n<p><em>This chapter is a revision from \"<\/em><a class=\"rId7\" href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/chapter\/osteology\/\"><em>Appendix A: Osteology<\/em><\/a><em>'' by<\/em><em> Jason M. Organ and Jessica N. Byram. In <\/em><a class=\"rId8\" href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/\"><em>Explorations: An Open Invitation to Biological Anthropology, first edition<\/em><\/a><em>, edited by <\/em><em>Beth Shook, Katie Nelson, Kelsie Aguilera, and Lara Braff<\/em><em>, which is licensed under <\/em><a class=\"rId9\" href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\"><em>CC BY-NC 4.0<\/em><\/a><em>. <\/em><\/p>\n<\/div>\n<div class=\"__UNKNOWN__\">\n<div class=\"textbox textbox--learning-objectives\">\n<header class=\"textbox__header\">\n<h2 class=\"textbox__title\"><span style=\"color: #ffffff\">Learning Objectives<\/span><\/h2>\n<\/header>\n<div class=\"textbox__content\">\n<ul>\n<li class=\"import-Normal\" style=\"background-color: transparent;text-align: left;text-indent: 0pt\">Identify anatomical position and anatomical planes, and use directional terms to describe relative positions of bones and teeth.<\/li>\n<li class=\"import-Normal\" style=\"background-color: transparent;text-align: left;text-indent: 0pt\">Describe the different regions of the human skeleton and identify (by name) all of the bones within them.<\/li>\n<li class=\"import-Normal\" style=\"background-color: transparent;text-align: left;text-indent: 0pt\">Distinguish major bony features of the human skeleton like muscle attachment sites and passages for nerves and\/or arteries and veins.<\/li>\n<li class=\"import-Normal\" style=\"background-color: transparent;text-align: left;text-indent: 0pt\">Identify the bony features relevant to estimating age and sex in forensic and bioarchaeological contexts.<\/li>\n<\/ul>\n<\/div>\n<\/div>\n<h2>Introduction to Osteology<\/h2>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Osteology<\/strong>, or the study of bones, is central to biological anthropology because every person\u2019s skeleton tells a story of how that person has lived. Bones from archaeological sites can be used to understand what animals people ate, how stressful and strenuous their lives were, and how they died\u2014by natural or unnatural causes. This appendix introduces the basics of anatomical terminology and describes the different regions and bones of the skeleton. It also highlights some skeletal features that are used frequently by forensic anthropologists to estimate the age and sex of recovered remains. The authors note that sex is not binary but exists on a spectrum based on influences of chromosomes, genes, and hormones. These biological influences affect the size and shape of bone, which is sometimes useful in classifying skeletal remains into one of the two most common sex categories: female and male.<\/p>\n<h3 class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Bone Structure and Function<\/strong><\/h3>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\">Bone is a composite of organic collagen and an inorganic mineral (hydroxyapatite, a calcium phosphate salt), which help make it strong enough to support the body under the force of gravity without collapsing. When bone is mature (fully mineralized as in adults), it comprises an outer dense region of bone called <strong>cortical (or compact) bone<\/strong> and an inner spongy region of bone called <strong>cancellous (or trabecular) bone<\/strong> (Figure A.1).<\/p>\n<figure style=\"width: 380px\" class=\"wp-caption aligncenter\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/06\/image19-6.png\" alt=\"A femur with parts of bone cut away to show regions.\" width=\"380\" height=\"642\" \/><figcaption class=\"wp-caption-text\">Figure A.1: A typical long bone shows the gross anatomical characteristics of bone. <a href=\"https:\/\/docs.google.com\/document\/d\/1VUDKMBJYS_jNONjLxT04jQN0_z9Ua50BRN6auGSHUuU\/edit\">A full text description of this image is available<\/a>. Credit: <a href=\"https:\/\/openstax.org\/books\/anatomy-and-physiology\/pages\/6-3-bone-structure#fig-ch06_03_01\">Anatomy of\u00a0 a Long Bone (Anatomy &amp; Physiology, Figure 6.7)<\/a> by <a href=\"https:\/\/openstax.org\/\">OpenStax<\/a> has been modified (some labels modified or removed) and is under a <a href=\"https:\/\/creativecommons.org\/licenses\/by\/4.0\/\">CC BY 4.0 License<\/a>.<\/figcaption><\/figure>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\">Bone performs both metabolic and mechanical functions for the body. On the metabolic side, bone is required to maintain mineral (i.e., calcium) homeostasis and for the production of red and white blood cells (Figure A.2), which develop in the diaphyseal marrow cavity and the cancellous region of the metaphysis and epiphysis. But it is undeniable that the mechanical functions of bone are primary because bone is critically responsible for protecting internal organs, providing support against the force of gravity, and serving as a network of rigid levers for muscles to act upon during movement.<\/p>\n<figure style=\"width: 515px\" class=\"wp-caption aligncenter\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image1-11.png\" alt=\"Skeleton with six panels representing functions.\" width=\"515\" height=\"629\" \/><figcaption class=\"wp-caption-text\">Figure A.2: Functions of the skeletal system include support and protection, storage and release of fat, production of red blood cells, storage and release of calcium and phosphates, and facilitating movement. <a href=\"https:\/\/docs.google.com\/document\/d\/1VUDKMBJYS_jNONjLxT04jQN0_z9Ua50BRN6auGSHUuU\/edit\">A full text description of this image is available<\/a>. Credit: <a href=\"https:\/\/open.oregonstate.education\/app\/uploads\/sites\/157\/2019\/07\/mineral_storage_revised.png\">Functions of the Skeletal System (Anatomy &amp; Physiology, Figure 6.1.1)<\/a> by <a href=\"https:\/\/open.oregonstate.education\/aandp\/\">Open Oregon State<\/a> is under a <a href=\"https:\/\/creativecommons.org\/licenses\/by\/4.0\/\">CC BY 4.0 License<\/a>.<\/figcaption><\/figure>\n<h3 class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Bone Shape<\/strong><\/h3>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\">Bones have different shapes that largely relate to their specific function within the skeletal system. Additionally, the ratio of cortical to cancellous bone, and which muscles are attached to the bone and how, affect the shape of the whole bone. Generally there are five recognized bone shapes: long bones, short bones, flat bones, sesamoid bones, and irregular bones. <strong>Long bones <\/strong>are longer than they are wide and consist of three sections: diaphysis, epiphysis, and metaphysis (see Figure A.1). The <strong>diaphysis<\/strong> of a long bone is simply the shaft of the bone, and it comprises mostly cortical bone with a thin veneer of internal cancellous bone lining a <strong>medullary cavity<\/strong>. At both the proximal and distal ends of every long bone, there is an <strong>epiphysis<\/strong>, which consists of a thin shell of cortical bone surrounding a high concentration of cancellous bone. The epiphysis is usually coated with cartilage to facilitate joint articulation with other bones. The junction between diaphysis and epiphysis is the <strong>metaphysis<\/strong>, which has a more equal ratio of cortical to cancellous bone. Examples of long bones are the humerus, the femur, and the metacarpals and metatarsals.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\">The other three bone shapes are simpler. <strong>Short<\/strong> <strong>bones<\/strong> are defined as being equal in length and width, and they possess a mix of cortical and cancellous bone (Figure A.3). They are usually involved in forming movable joints with adjacent bones and therefore often have surfaces covered with cartilage. Examples of short bones are the carpals of the wrist and the tarsals of the ankle. <strong>Flat<\/strong> <strong>bones<\/strong> are flat and consist of two layers of thick cortical bone with an intermediate layer of cancellous bone referred to as diplo\u00eb. Most of the bones of the skull are flat bones, such as the frontal and parietal bones, as well as all parts of the sternum (Figure A.3). Sometimes bones develop within the tendon of a muscle in order to reduce friction on the joint surface and to increase leverage of the muscle to move a joint. These types of bones are called <strong>sesamoid bones<\/strong>, and these include the patella (or knee cap) and the pisiform (a bone of the wrist). <strong>Irregular<\/strong> <strong>bones<\/strong> are bones that don\u2019t fit into any of the other four categories. The shapes of these bones are often more complex than the others, and examples include the vertebrae and certain bones of the skull, like the ethmoid and sphenoid bones (Figure A.3).<\/p>\n<figure style=\"width: 619px\" class=\"wp-caption aligncenter\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image29-1-1.jpg\" alt=\"Skeleton with arrows showing different bone types.\" width=\"619\" height=\"717\" \/><figcaption class=\"wp-caption-text\">Figure A.3: Bones are classified according to their shape and include long, short, flat, sesamoid, and irregular bones. <a href=\"https:\/\/docs.google.com\/document\/d\/1VUDKMBJYS_jNONjLxT04jQN0_z9Ua50BRN6auGSHUuU\/edit\">A full text description of this image is available<\/a>. Credit: <a href=\"https:\/\/openstax.org\/books\/anatomy-and-physiology\/pages\/6-2-bone-classification#fig-ch06_02_01\">Classifications of Bones (Anatomy &amp; Physiology, Figure 6.6)<\/a> by <a href=\"https:\/\/openstax.org\/\">OpenStax<\/a> is under a <a href=\"https:\/\/creativecommons.org\/licenses\/by\/4.0\/\">CC BY 4.0 License<\/a>.<\/figcaption><\/figure>\n<div class=\"textbox\">\n<h2 class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\">Dig Deeper: Bone Functional Adaptation<\/h2>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\">Each time we move our muscles, we bend, twist, compress, and tense our bones, and this causes them to develop microscopic cracks that weaken them. These may even lead to a bone fracture. Bone cells called <strong>osteocytes <\/strong>can sense when these microcracks form. Osteocytes then signal <strong>osteoclasts<\/strong> to remove the cracked bone and <strong>osteoblasts<\/strong> to lay down new bone\u2014a process known as skeletal remodeling. <strong>Osteogenic cells<\/strong> are stem cells that are able to differentiate into osteoblasts and osteocytes (Figure A.4).<\/p>\n<figure style=\"width: 423px\" class=\"wp-caption aligncenter\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image10-6.jpg\" alt=\"A bone section with arrows pointing to types of bone cells.\" width=\"423\" height=\"297\" \/><figcaption class=\"wp-caption-text\">Figure A.4: Four types of cells are found within bone tissue. Osteogenic cells are stem cells that develop into osteoblasts. Osteoblasts lay down new bone while osteoclasts remove bone. Osteoblasts that get trapped in calcified matrix become osteocytes. <a href=\"https:\/\/docs.google.com\/document\/d\/1VUDKMBJYS_jNONjLxT04jQN0_z9Ua50BRN6auGSHUuU\/edit\">A full text description of this image is available<\/a>. Credit: <a class=\"rId29\" href=\"https:\/\/openstax.org\/books\/anatomy-and-physiology\/pages\/6-3-bone-structure#fig-ch06_03_01\">Bone Cells (Anatomy &amp; Physiology, Figure 6.11)<\/a> by <a class=\"rId31\" href=\"https:\/\/openstax.org\/\">OpenStax<\/a> is under a <a class=\"rId33\" href=\"https:\/\/creativecommons.org\/licenses\/by\/4.0\/\">CC BY 4.0 License<\/a>.<\/figcaption><\/figure>\n<\/div>\n<div class=\"textbox\">\n<h2 class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\">Did Deeper: How Do Bones Develop?<\/h2>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\">Bones develop via one of two mechanisms: intramembranous or endochondral bone formation. During <strong>intramembranous bone formation<\/strong> connective tissue (mesenchymal) stem cells form a tissue layer and then differentiate into osteoblasts, which begin to synthesize new bone along the tissue layer (Figure A.5). Only a few bones develop through intramembranous bone formation, mostly bones of the skull and the clavicle (collar bone). In <strong>endochondral bone formation<\/strong>, instead of developing directly from connective tissue stem cells, osteoblasts develop from an intermediate cartilage \u201cmodel\u201d that is then replaced by synthesized new bone (Figure A.6). Most bones of the skeleton develop through endochondral bone formation (Burr and Organ 2017).<\/p>\n<figure style=\"width: 573px\" class=\"wp-caption aligncenter\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image32-2.png\" alt=\"Four panels show stages of intramembranous ossification.\" width=\"573\" height=\"400\" \/><figcaption class=\"wp-caption-text\">Figure A.5: Intramembranous ossification begins when mesenchymal stem cells group into clusters. These clusters contain osteoblasts, which lay down the initial trabecular bone. Compact bone develops superficial to the trabecular bone, and the initial structure of the bone is complete. <a href=\"https:\/\/docs.google.com\/document\/d\/1VUDKMBJYS_jNONjLxT04jQN0_z9Ua50BRN6auGSHUuU\/edit\">A full text description of this image is available<\/a>. Credit: <a class=\"rId35\" href=\"https:\/\/openstax.org\/books\/anatomy-and-physiology\/pages\/6-4-bone-formation-and-development#fig-ch06_04_01\">Intramembranous Ossification (Anatomy &amp; Physiology, Figure 6.16)<\/a> by <a class=\"rId37\" href=\"https:\/\/openstax.org\/\">OpenStax<\/a> has been modified (some labels modified or removed) and is under a <a class=\"rId39\" href=\"https:\/\/creativecommons.org\/licenses\/by\/4.0\/\">CC BY 4.0 License<\/a>.<\/figcaption><\/figure>\n<figure style=\"width: 592px\" class=\"wp-caption aligncenter\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image39-2.png\" alt=\"The phases of endochondral ossification.\" width=\"592\" height=\"790\" \/><figcaption class=\"wp-caption-text\">Figure A.6: Endochondral ossification begins when mesenchymal cells differentiate into cartilage cells, which lay down a cartilage model of the future bony skeleton. Cartilage is then replaced by bone, except at the (epiphyseal) growth plates (which fuse at the end of postnatal growth) and the hyaline (articular) cartilage on the joint surface. <a href=\"https:\/\/docs.google.com\/document\/d\/1VUDKMBJYS_jNONjLxT04jQN0_z9Ua50BRN6auGSHUuU\/edit\">A full text description of this image is available<\/a>. Credit: <a class=\"rId41\" href=\"https:\/\/openstax.org\/books\/anatomy-and-physiology\/pages\/6-4-bone-formation-and-development#fig-ch06_04_01\">Endochondral Ossification (Anatomy &amp; Physiology, Figure 6.17)<\/a> by <a class=\"rId43\" href=\"https:\/\/openstax.org\/\">OpenStax<\/a> has been modified (some labels modified or removed) and is under a <a class=\"rId45\" href=\"https:\/\/creativecommons.org\/licenses\/by\/4.0\/\">CC BY 4.0 License<\/a>.<\/figcaption><\/figure>\n<\/div>\n<h2 class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\">Anatomical Terminology<\/h2>\n<h3 class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Anatomical Planes<\/strong><\/h3>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\">A body in <strong>anatomical position<\/strong>  is situated as if the individual is standing upright; with head, eyes, and feet pointing forward; and with arms at the side and palms facing forward. In anatomical position, the bones of the forearm are not crossed (Figure A.7).<\/p>\n<\/div>\n<figure id=\"attachment_503\" aria-describedby=\"caption-attachment-503\" style=\"width: 497px\" class=\"wp-caption aligncenter\"><img class=\"wp-image-503\" src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/man.jpg\" alt=\"Front and back views with lines showing body regions.\" width=\"497\" height=\"439\" \/><figcaption id=\"caption-attachment-503\" class=\"wp-caption-text\">Figure A.7: A human body is shown in anatomical position in an (left) anterior view and a (right) posterior view. <a href=\"https:\/\/docs.google.com\/document\/d\/1VUDKMBJYS_jNONjLxT04jQN0_z9Ua50BRN6auGSHUuU\/edit\">A full text description of this image is available<\/a>. Credit: <a class=\"rId47\" href=\"https:\/\/openstax.org\/books\/anatomy-and-physiology\/pages\/1-6-anatomical-terminology\">Regions of the Human Body (Anatomy &amp; Physiology, Figure 1.12)<\/a> by <a class=\"rId49\" href=\"https:\/\/openstax.org\/\">OpenStax<\/a> has been modified (labels removed) and is under a <a class=\"rId51\" href=\"https:\/\/creativecommons.org\/licenses\/by\/4.0\/\">CC BY 4.0 License<\/a>.<\/figcaption><\/figure>\n<div class=\"__UNKNOWN__\">\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\">In anatomical position, specific organs are situated within specific anatomical planes (Figure A.8). These imaginary planes divide the body into equal or subequal halves, depending on which plane is described. <strong>C<\/strong><strong>oronal (frontal) planes<\/strong> divide the body vertically into anterior (front) and posterior (back) halves. <strong>Transverse planes<\/strong> divide the body horizontally into superior (upper) and inferior (lower) halves. <strong>Sagittal planes<\/strong> divide the body vertically into left and right halves. The plane that divides the body vertically into equal left and right halves is called the <strong>midsagittal plane<\/strong>. The midsagittal plane is also called the median plane because it is in the midline of the body. Every other sagittal plane divides the body into unequal right and left halves; these planes are called <strong>parasagittal planes<\/strong>.<\/p>\n<p>&nbsp;<\/p>\n<figure style=\"width: 416px\" class=\"wp-caption aligncenter\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image5-10.png\" alt=\"Person with panels showing anatomical planes.\" width=\"416\" height=\"427\" \/><figcaption class=\"wp-caption-text\">Figure A.8: The three planes most commonly used in anatomical and medical imaging are the sagittal, coronal (or frontal), and transverse planes. <a href=\"https:\/\/docs.google.com\/document\/d\/1VUDKMBJYS_jNONjLxT04jQN0_z9Ua50BRN6auGSHUuU\/edit\">A full text description of this image is available<\/a>. <a href=\"https:\/\/docs.google.com\/document\/d\/1VUDKMBJYS_jNONjLxT04jQN0_z9Ua50BRN6auGSHUuU\/edit\">A full text description of this image is available<\/a>. Credit: <a class=\"rId53\" href=\"https:\/\/openstax.org\/books\/anatomy-and-physiology\/pages\/1-6-anatomical-terminology\">Planes of the Body (Anatomy &amp; Physiology, Figure 1.14)<\/a> by <a class=\"rId55\" href=\"https:\/\/openstax.org\/\">OpenStax<\/a> has been modified (some labels modified) and is under a <a class=\"rId57\" href=\"https:\/\/creativecommons.org\/licenses\/by\/4.0\/\">CC BY 4.0 License<\/a>.<\/figcaption><\/figure>\n<h3 class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Directional Terms<\/strong><\/h3>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\">An anatomical feature that is <strong>anterior (or ventral)<\/strong> is located toward the front of the body, and a bone that is <strong>posterior (or dorsal)<\/strong> is located toward the back of the body (Figure A.9). For example, the sternum (breastbone) is anterior to the vertebral column (\u201cbackbone\u201d). A feature that is <strong>medial<\/strong> is located closer to the midline (midsagittal plane) than a feature that is <strong>lateral<\/strong>, or located further from the midline. For example, the thumb is lateral to the index finger. A structure that is <strong>proximal<\/strong> is closer to the trunk of the body (usually referring to limb bones) than a <strong>distal<\/strong> structure, which is further from the trunk of the body. For example, the femur (thigh bone) is proximal to the tibia (leg bone). Finally, a structure that is <strong>superior (or cranial)<\/strong> is located closer to the head than a structure that is <strong>inferior (or caudal)<\/strong>. For example, the rib cage is superior to the pelvis, and the foot is inferior to the knee.<\/p>\n<figure style=\"width: 618px\" class=\"wp-caption aligncenter\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image4-7.jpg\" alt=\"Front and side view of person; arrows show directional terms.\" width=\"618\" height=\"627\" \/><figcaption class=\"wp-caption-text\">Figure A.9: Paired directional terms are shown as applied to a human body. <a href=\"https:\/\/docs.google.com\/document\/d\/1VUDKMBJYS_jNONjLxT04jQN0_z9Ua50BRN6auGSHUuU\/edit\">A full text description of this image is available<\/a>. Credit: <a class=\"rId59\" href=\"https:\/\/openstax.org\/books\/anatomy-and-physiology\/pages\/1-6-anatomical-terminology\">Directional Terms Applied to the Human Body (Anatomy &amp; Physiology, Figure 1.13)<\/a> by <a class=\"rId61\" href=\"https:\/\/openstax.org\/\">OpenStax<\/a> is under a <a class=\"rId63\" href=\"https:\/\/creativecommons.org\/licenses\/by\/4.0\/\">CC BY 4.0 License<\/a>.<\/figcaption><\/figure>\n<h2 class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\">Human Skeletal System<\/h2>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\">The skeletal system is divided into two regions: axial and appendicular (Figure A.10). The <strong>axial skeleton<\/strong> consists of the skull, vertebral column, and the thoracic cage formed by the ribs and sternum (breastbone). The <strong>appendicular skeleton<\/strong> comprises the pectoral girdle, the pelvic girdle, and all the bones of the upper and lower limbs.<\/p>\n<figure style=\"width: 607px\" class=\"wp-caption aligncenter\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image42-1-1.jpg\" alt=\"Appendicular skeleton in green and axial skeleton in tan.\" width=\"607\" height=\"617\" \/><figcaption class=\"wp-caption-text\">Figure A.10: The axial skeleton consists of the skull, vertebral column, and the thoracic cage. The appendicular skeleton is made up of all bones of the upper and lower limbs. <a href=\"https:\/\/docs.google.com\/document\/d\/1VUDKMBJYS_jNONjLxT04jQN0_z9Ua50BRN6auGSHUuU\/edit\">A full text description of this image is available<\/a>. Credit: <a class=\"rId65\" href=\"https:\/\/cnx.org\/contents\/FPtK1zmh@12.17:PU5JkR5b@6\/Divisions-of-the-Skeletal-System#fig-ch07_01_01\">Axial and Appendicular Skeleton (Anatomy &amp; Physiology, Figure 7.2)<\/a> by <a class=\"rId67\" href=\"https:\/\/openstax.org\/\">OpenStax<\/a> is under a <a class=\"rId69\" href=\"https:\/\/creativecommons.org\/licenses\/by\/4.0\/\">CC BY 4.0 License<\/a>.<\/figcaption><\/figure>\n<h3 class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Axial Skeleton<\/strong><\/h3>\n<h4 class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><em>Skull<\/em><\/h4>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\">The skull comprises numerous bones (some paired and others that are unpaired) and is divided into two major portions: the <strong>mandible<\/strong> (or lower jaw) and the <strong>cranium<\/strong> (the remainder of the skull). The cranium is further subdivided into the <strong>neurocranium<\/strong> (or cranial vault), which houses the brain, and the <strong>viscerocranium<\/strong> (or facial skeleton; Figure A.11), which houses the organs responsible for special senses like sight, smell, taste, hearing, and balance.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\">Where two bones of the cranium come together, they form articulations called <strong>cranial sutures<\/strong>, which fuse (or close) with increasing age. Degree of suture closure can be used to broadly estimate age at death (Boldsen et al. 2002; Meindl and Lovejoy 1985).<\/p>\n<figure style=\"width: 589px\" class=\"wp-caption aligncenter\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image7-12.png\" alt=\"Lateral view of skull.\" width=\"589\" height=\"451\" \/><figcaption class=\"wp-caption-text\">Figure A.11: The skull consists of the cranium and the mandible (jawbone). The cranium is further divided into the neurocranium and viscerocranium. <a href=\"https:\/\/docs.google.com\/document\/d\/1VUDKMBJYS_jNONjLxT04jQN0_z9Ua50BRN6auGSHUuU\/edit\">A full text description of this image is available<\/a>. Credit: <a class=\"rId71\" href=\"https:\/\/openstax.org\/books\/anatomy-and-physiology\/pages\/7-2-the-skull#fig-ch07_02_01\">Parts of the Skull (Anatomy &amp; Physiology, Figure 7.3)<\/a> by <a class=\"rId73\" href=\"https:\/\/openstax.org\/\">OpenStax<\/a> has been modified (some labels modified or removed) and is under a <a class=\"rId75\" href=\"https:\/\/creativecommons.org\/licenses\/by\/4.0\/\">CC BY 4.0 License<\/a>.<\/figcaption><\/figure>\n<h5 class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\">Bones and Some Features of the Neurocranium<\/h5>\n<p class=\"import-Normal\" style=\"background-color: transparent;text-align: left;margin-left: 0pt;margin-right: 0pt;text-indent: 0pt\"><strong>Frontal bone<\/strong><strong>: <\/strong>an unpaired bone consisting of two parts: a superior, vertically oriented portion called the squama and an inferior, horizontally oriented portion that forms the roof of the <strong>orbit<\/strong> (eye socket; Figures A.12 and A.13).<\/p>\n<p class=\"import-Normal\" style=\"background-color: transparent;text-align: left;margin-left: 0pt;margin-right: 0pt;text-indent: 0pt\">The <strong>c<\/strong><strong>oronal suture<\/strong> is the articulation between the frontal bone and the two parietal bones posterior and lateral to the frontal.<\/p>\n<p class=\"import-Normal\" style=\"background-color: transparent;text-align: left;margin-left: 0pt;margin-right: 0pt;text-indent: 0pt\">The frontal bone develops initially as two separate bones that fuse together during growth. Occasionally this fusion is incomplete, resulting in a <strong>metopic suture<\/strong> that persists between the two halves (left and right) of the frontal bone (Cunningham, Scheuer, and Black 2017).<\/p>\n<p class=\"import-Normal\" style=\"background-color: transparent;text-align: left;margin-left: 0pt;margin-right: 0pt;text-indent: 0pt\">The <strong>g<\/strong><strong>labella<\/strong> is a bony projection between the brow ridges. The glabella in females tends to be flat while it is more rounded and protruding in males (Walker 2008).<\/p>\n<p class=\"import-Normal\" style=\"background-color: transparent;text-align: left;margin-left: 0pt;margin-right: 0pt;text-indent: 0pt\">The <strong>supraorbital margin<\/strong> is the upper edge of the orbit. The thickness of the edge may be used as an indicator of sex. The border tends to be thin and sharp in females and blunt and thick in males.<\/p>\n<p>&nbsp;<\/p>\n<figure style=\"width: 603px\" class=\"wp-caption aligncenter\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image37-2-1.png\" alt=\"Front view of skull with colors representing bones.\" width=\"603\" height=\"510\" \/><figcaption class=\"wp-caption-text\">Figure A.12: Anterior view of the skull. <a href=\"https:\/\/docs.google.com\/document\/d\/1VUDKMBJYS_jNONjLxT04jQN0_z9Ua50BRN6auGSHUuU\/edit\">A full text description of this image is available<\/a>. Credit: <a class=\"rId77\" href=\"https:\/\/cnx.org\/contents\/FPtK1zmh@12.17:1w-m01MB@7\/The-Skull#fig-ch07_02_02\">Anterior View of Skull (Anatomy &amp; Physiology, Figure 7.4)<\/a> by <a class=\"rId79\" href=\"https:\/\/openstax.org\/\">OpenStax<\/a> has been modified (some labels removed) and is under a <a class=\"rId81\" href=\"https:\/\/creativecommons.org\/licenses\/by\/4.0\/\">CC BY 4.0 License<\/a>.<\/figcaption><\/figure>\n<figure style=\"width: 579px\" class=\"wp-caption aligncenter\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image27-6.png\" alt=\"Side view of skull with colors representing bones.\" width=\"579\" height=\"398\" \/><figcaption class=\"wp-caption-text\">Figure A.13: The lateral view of the skull. Credit: <a class=\"rId83\" href=\"https:\/\/cnx.org\/contents\/FPtK1zmh@12.17:1w-m01MB@7\/The-Skull#fig-ch07_02_02\">Lateral View of Skull (Anatomy &amp; Physiology, Figure 7.5)<\/a> by <a class=\"rId85\" href=\"https:\/\/openstax.org\/\">OpenStax<\/a> has been modified (some labels removed) and is under a <a class=\"rId87\" href=\"https:\/\/creativecommons.org\/licenses\/by\/4.0\/\">CC BY 4.0 License<\/a>.<\/figcaption><\/figure>\n<p class=\"import-Normal\" style=\"background-color: transparent;text-align: left;margin-left: 0pt;margin-right: 0pt;text-indent: 0pt\"><strong>Parietal bone:<\/strong> Paired bones that form the majority of the roof and sides of the neurocranium (Figures A.12 and A.13).<\/p>\n<p class=\"import-Normal\" style=\"background-color: transparent;text-align: left;margin-left: 0pt;margin-right: 0pt;text-indent: 0pt\">The <strong>s<\/strong><strong>agittal suture<\/strong> is the articulation between the right and left parietal bones. It extends from the coronal suture to the lambdoidal suture, which separates the parietal bones from the occipital bone posteriorly.<\/p>\n<p class=\"import-Normal\" style=\"background-color: transparent;text-align: left;margin-left: 0pt;margin-right: 0pt;text-indent: 0pt\">Each parietal bone is marked by two <strong>temporal lines<\/strong> (superior and inferior), which are anterior-posterior arching lines that serve as attachment sites for a major chewing muscle (temporalis) and its associated connective tissue.<\/p>\n<p class=\"import-Normal\" style=\"background-color: transparent;text-align: left;margin-left: 0pt;margin-right: 0pt;text-indent: 0pt\"><strong>Temporal bone:<\/strong> Paired bones on the lateral side of the neurocranium that are divided into two portions: squamous (or flat) portion that forms the lateral side of the neurocranium and the petrous (or rock-like) portion that houses the special sense organs of the ear for hearing and balance as well as the three tiny bones of the middle ear: incus, malleus, and stapes (Figures A.13, A.14, and A.15).<\/p>\n<p class=\"import-Normal\" style=\"background-color: transparent;text-align: left;margin-left: 0pt;margin-right: 0pt;text-indent: 0pt\">The <strong>s<\/strong><strong>quamosal suture<\/strong> is the articulation between the squamous portion of the temporal bone and the inferior border of the parietal bone.<\/p>\n<p class=\"import-Normal\" style=\"background-color: transparent;text-align: left;margin-left: 0pt;margin-right: 0pt;text-indent: 0pt\">The <strong>m<\/strong><strong>astoid process<\/strong> is a prominent muscle attachment site for several muscles including the large sternocleidomastoid muscle. Males tend to have longer and wider mastoid processes compared to females (Walker 2008).<\/p>\n<p class=\"import-Normal\" style=\"background-color: transparent;text-align: left;margin-left: 0pt;margin-right: 0pt;text-indent: 0pt\">The <strong>styloid process<\/strong> is a thin, pointed, inferior projection of the temporal bone that serves as an attachment site for several muscles and a ligament of the throat.<\/p>\n<p class=\"import-Normal\" style=\"background-color: transparent;text-align: left;margin-left: 0pt;margin-right: 0pt;text-indent: 0pt\">The <strong>zygomatic process of the temporal bone <\/strong>is a long thin, arch-like process that originates from the squamous portion of the temporal bone. The zygomatic process articulates with the temporal process of the zygomatic bone to form the <strong>zygomatic arch<\/strong> (or cheekbone).<\/p>\n<p class=\"import-Normal\" style=\"background-color: transparent;text-align: left;margin-left: 0pt;margin-right: 0pt;text-indent: 0pt\">The <strong>mandibular<\/strong><strong> fossa<\/strong> is the depression in the temporal bone where the mandibular condyle (see below, under mandible) articulates to form the temporomandibular (or jaw) joint.<\/p>\n<figure style=\"width: 520px\" class=\"wp-caption aligncenter\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image36-2.png\" alt=\"Temporal bone with parts labeled.\" width=\"520\" height=\"373\" \/><figcaption class=\"wp-caption-text\">Figure A.14: A lateral view of the isolated temporal bone shows the squamous portion. <a href=\"https:\/\/docs.google.com\/document\/d\/1VUDKMBJYS_jNONjLxT04jQN0_z9Ua50BRN6auGSHUuU\/edit\">A full text description of this image is available<\/a>. Credit: <a class=\"rId89\" href=\"https:\/\/openstax.org\/books\/anatomy-and-physiology\/pages\/7-2-the-skull#fig-ch07_02_06\">Temporal Bone (Anatomy &amp; Physiology, Figure 7.7)<\/a> by <a class=\"rId91\" href=\"https:\/\/openstax.org\/\">OpenStax<\/a> has been modified (some labels removed) and is under a <a class=\"rId93\" href=\"https:\/\/creativecommons.org\/licenses\/by\/4.0\/\">CC BY 4.0 License<\/a>.<\/figcaption><\/figure>\n<figure style=\"width: 584px\" class=\"wp-caption aligncenter\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image16-4.jpg\" alt=\"Base and internal cranium views colored to represent bones.\" width=\"584\" height=\"792\" \/><figcaption class=\"wp-caption-text\">Figure A.15a\u2013b: a. The base of the cranium. b. The floor of the cranial cavity. <a href=\"https:\/\/docs.google.com\/document\/d\/1VUDKMBJYS_jNONjLxT04jQN0_z9Ua50BRN6auGSHUuU\/edit\">A full text description of this image is available<\/a>. Credit: <a class=\"rId95\" href=\"https:\/\/openstax.org\/books\/anatomy-and-physiology\/pages\/7-2-the-skull#fig-ch07_02_06\">External and Internal Views of Base of Skull (Anatomy &amp; Physiology, Figure 7.8)<\/a> by <a class=\"rId97\" href=\"https:\/\/openstax.org\/\">OpenStax<\/a> has been modified (some labels modified or removed) and is under a <a class=\"rId99\" href=\"https:\/\/creativecommons.org\/licenses\/by\/4.0\/\">CC BY 4.0 License<\/a>.<\/figcaption><\/figure>\n<p class=\"import-Normal\" style=\"background-color: transparent;text-align: left;margin-left: 0pt;margin-right: 0pt;text-indent: 0pt\"><strong>Occipital bone: <\/strong>Unpaired bone that forms the posterior and inferior portions of the neurocranium (see Figures A.13 and A.15).<\/p>\n<p class=\"import-Normal\" style=\"background-color: transparent;text-align: left;margin-left: 0pt;margin-right: 0pt;text-indent: 0pt\">The <strong>lambdoidal suture<\/strong> is the articulation between the occipital bone and the two parietal bones. It resembles the shape of the Greek letter lambda.<\/p>\n<p class=\"import-Normal\" style=\"background-color: transparent;text-align: left;margin-left: 0pt;margin-right: 0pt;text-indent: 0pt\">The <strong>external occipital protuberance<\/strong> (EOP) is a bump along the posterior margin of the occipital bone where the nuchal ligament attaches.<\/p>\n<p class=\"import-Normal\" style=\"background-color: transparent;text-align: left;margin-left: 0pt;margin-right: 0pt;text-indent: 0pt\">The <strong>nuchal lines<\/strong> are parallel ridges that meet on the midline at the EOP and serve as attachment sites for neck muscles. Nuchal lines are usually more pronounced in males.<\/p>\n<p class=\"import-Normal\" style=\"background-color: transparent;text-align: left;margin-left: 0pt;margin-right: 0pt;text-indent: 0pt\">The occipital bone contains a large circular opening called the <strong>foramen magnum<\/strong>, which provides a space for passage of the brainstem\/spinal cord from the neurocranium into the vertebral canal of the spine.<\/p>\n<p class=\"import-Normal\" style=\"background-color: transparent;text-align: left;margin-left: 0pt;margin-right: 0pt;text-indent: 0pt\"><strong>Sphenoid bone:<\/strong> Unpaired, butterfly-shaped bone that forms the central portion of the bottom of the neurocranium. The sphenoid is divided into several regions, including the body, greater wings, lesser wings, and pterygoid processes (with pterygoid plates; see Figures A.15 and A.16). This bone is critical to supporting the brain and several nerves and blood vessels supplying this region.<\/p>\n<p class=\"import-Normal\" style=\"background-color: transparent;text-align: left;margin-left: 0pt;margin-right: 0pt;text-indent: 0pt\"><strong>Pterygoid plates<\/strong> are flat projections of the pterygoid processes that serve as attachment sites for chewing muscles and muscles of the throat.<\/p>\n<figure style=\"width: 512px\" class=\"wp-caption aligncenter\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image26-5.png\" alt=\"Sphenoid with labels.\" width=\"512\" height=\"663\" \/><figcaption class=\"wp-caption-text\">Figure A.16: Shown in isolation in (a) superior and (b) posterior views, the sphenoid forms the central portion of the neurocranium. The sphenoid has multiple openings for the passage of nerves and blood vessels. <a href=\"https:\/\/docs.google.com\/document\/d\/1VUDKMBJYS_jNONjLxT04jQN0_z9Ua50BRN6auGSHUuU\/edit\">A full text description of this image is available<\/a>. Credit: <a class=\"rId101\" href=\"https:\/\/openstax.org\/books\/anatomy-and-physiology\/pages\/7-2-the-skull#fig-ch07_02_8\">Sphenoid Bone (Anatomy &amp; Physiology, Figure 7.10)<\/a> by <a class=\"rId103\" href=\"https:\/\/openstax.org\/\">OpenStax<\/a> has been modified (some labels removed) and is under a <a class=\"rId105\" href=\"https:\/\/creativecommons.org\/licenses\/by\/4.0\/\">CC BY 4.0 License<\/a>.<\/figcaption><\/figure>\n<p class=\"import-Normal\" style=\"background-color: transparent;text-align: left;margin-left: 0pt;margin-right: 0pt;text-indent: 0pt\"><strong>Ethmoid bone:<\/strong> Unpaired bone consisting of a median vertical plate that forms part of the bony nasal septum and a horizontal plate (cribriform plate) with many small <strong>cribriform f<\/strong><strong>oramina<\/strong>  (holes) that transmit olfactory nerves (special sense of smell; Figure A.17).<\/p>\n<figure style=\"width: 542px\" class=\"wp-caption aligncenter\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image11-10.png\" alt=\"Front view of ethmoid bone.\" width=\"542\" height=\"419\" \/><figcaption class=\"wp-caption-text\">Figure A.17: The unpaired ethmoid bone is located at the midline within the central skull. It forms the upper nasal septum and contains foramina to convey olfactory nerves. <a href=\"https:\/\/docs.google.com\/document\/d\/1VUDKMBJYS_jNONjLxT04jQN0_z9Ua50BRN6auGSHUuU\/edit\">A full text description of this image is available<\/a>. Credit: <a class=\"rId107\" href=\"https:\/\/openstax.org\/books\/anatomy-and-physiology\/pages\/7-2-the-skull#fig-ch07_02_10\">Ethmoid Bone (Anatomy &amp; Physiology, Figure 7.12)<\/a> by <a class=\"rId109\" href=\"https:\/\/openstax.org\/\">OpenStax<\/a> has been modified (some labels removed) and is under a <a class=\"rId111\" href=\"https:\/\/creativecommons.org\/licenses\/by\/4.0\/\">CC BY 4.0 License<\/a>.<\/figcaption><\/figure>\n<h5 class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\">Bones of the Viscerocranium<\/h5>\n<p class=\"import-Normal\" style=\"background-color: transparent;text-align: left;margin-left: 0pt;margin-right: 0pt;text-indent: 0pt\"><strong>Maxilla<\/strong><strong> bone<\/strong><strong>:<\/strong> Paired bones that form the upper jaw, support the upper teeth, and form the inferior margin of the cheek (Figures A.12, A.15, and A.18).<\/p>\n<p class=\"import-Normal\" style=\"background-color: transparent;text-align: left;margin-left: 0pt;margin-right: 0pt;text-indent: 0pt\">The <strong>nasal spine<\/strong> is a thin projection on the midline at the inferior border of the nasal aperture.<\/p>\n<p class=\"import-Normal\" style=\"background-color: transparent;text-align: left;margin-left: 0pt;margin-right: 0pt;text-indent: 0pt\">The <strong>zygomatic process of the maxilla<\/strong> is the portion of the bone that articulates with the zygomatic bone to form the anterior portion of the zygomatic arch.<\/p>\n<figure style=\"width: 616px\" class=\"wp-caption aligncenter\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image17-9.png\" alt=\"Right side view of isolated maxilla.\" width=\"616\" height=\"472\" \/><figcaption class=\"wp-caption-text\">Figure A.18: The maxilla forms the upper jaw and supports the upper teeth. <a href=\"https:\/\/docs.google.com\/document\/d\/1VUDKMBJYS_jNONjLxT04jQN0_z9Ua50BRN6auGSHUuU\/edit\">A full text description of this image is available<\/a>. Credit: <a class=\"rId113\" href=\"https:\/\/cnx.org\/contents\/FPtK1zmh@12.17:1w-m01MB@7\/The-Skull#fig-ch07_02_12\">Maxillary Bone (Anatomy &amp; Physiology, Figure 7.14)<\/a> by <a class=\"rId115\" href=\"https:\/\/openstax.org\/\">OpenStax<\/a> has been modified (some labels modified or removed) and is under a <a class=\"rId117\" href=\"https:\/\/creativecommons.org\/licenses\/by\/4.0\/\">CC BY 4.0 License<\/a>.<\/figcaption><\/figure>\n<p class=\"import-Normal\" style=\"background-color: transparent;text-align: left;margin-left: 0pt;margin-right: 0pt;text-indent: 0pt\"><strong>Nasal bone:<\/strong> Small, paired, flat, rectangular bones that form the bridge of the nose (Figure A.19).<\/p>\n<p class=\"import-Normal\" style=\"background-color: transparent;text-align: left;margin-left: 0pt;margin-right: 0pt;text-indent: 0pt\"><strong>Nasal aperture<\/strong> is the anterior opening into the nasal cavity.<\/p>\n<p class=\"import-Normal\" style=\"background-color: transparent;text-align: left;margin-left: 0pt;margin-right: 0pt;text-indent: 0pt\"><strong>Zygomatic bone:<\/strong> Paired bones that form the anterolateral portion of the cheekbone and contribute to the lateral and inferior wall of the orbit (Figure A.19).<\/p>\n<p class=\"import-Normal\" style=\"background-color: transparent;text-align: left;margin-left: 0pt;margin-right: 0pt;text-indent: 0pt\">The<strong> temporal process of the zygomatic bone<\/strong> is the portion of the bone that articulates with the temporal bone to form the anterior portion of the zygomatic arch.<\/p>\n<p class=\"import-Normal\" style=\"background-color: transparent;text-align: left;margin-left: 0pt;margin-right: 0pt;text-indent: 0pt\"><strong>Palatine bone:<\/strong> Paired L-shaped bones that form the posterior portion of the roof of the mouth, floor of the orbit, and the floor and lateral walls of the nasal cavity (Figures A.15 and A.19).<\/p>\n<p class=\"import-Normal\" style=\"background-color: transparent;text-align: left;margin-left: 0pt;margin-right: 0pt;text-indent: 0pt\"><strong>Lacrimal b<\/strong><strong>one<\/strong><strong>:<\/strong> Small, flat, paired bones that form the anterior portion of the medial wall of the orbit (Figure A.19).<\/p>\n<figure style=\"width: 598px\" class=\"wp-caption aligncenter\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image2-10.png\" alt=\"Half of face with bones shaded in different colors. \" width=\"598\" height=\"283\" \/><figcaption class=\"wp-caption-text\">Figure A.19: Seven skull bones contribute to the walls of the orbit: frontal, zygomatic, maxilla, lacrimal, ethmoid, palatine, and sphenoid. <a href=\"https:\/\/docs.google.com\/document\/d\/1VUDKMBJYS_jNONjLxT04jQN0_z9Ua50BRN6auGSHUuU\/edit\">A full text description of this image is available<\/a>. Credit: <a class=\"rId119\" href=\"https:\/\/openstax.org\/books\/anatomy-and-physiology\/pages\/7-2-the-skull#fig-ch07_02_14\">Bones of the Orbit (Anatomy &amp; Physiology, Figure 7.16)<\/a> by <a class=\"rId121\" href=\"https:\/\/openstax.org\/\">OpenStax<\/a> has been modified (some labels removed) and is under a <a class=\"rId123\" href=\"https:\/\/creativecommons.org\/licenses\/by\/4.0\/\">CC BY 4.0 License<\/a>.<\/figcaption><\/figure>\n<p class=\"import-Normal\" style=\"background-color: transparent;text-align: left;margin-left: 0pt;margin-right: 0pt;text-indent: 0pt\"><strong>Vomer<\/strong><strong> bone<\/strong><strong>:<\/strong> Unpaired thin bone that forms the inferior portion of the bony nasal septum. It articulates with the ethmoid superiorly (Figure A.20).<\/p>\n<p class=\"import-Normal\" style=\"background-color: transparent;text-align: left;margin-left: 0pt;margin-right: 0pt;text-indent: 0pt\"><strong>Inferior nasal concha<\/strong><strong> bone<\/strong><strong>:<\/strong> Paired bones that project and curl like a scroll from the lateral wall of the nasal cavity (Figure A.21).<\/p>\n<figure style=\"width: 496px\" class=\"wp-caption aligncenter\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image13-9.png\" alt=\"Nasal cavity with bones shaded in different colors.\" width=\"496\" height=\"334\" \/><figcaption class=\"wp-caption-text\">Figure A.20: The nasal septum is formed by the perpendicular plate of the ethmoid bone and the vomer bone. <a href=\"https:\/\/docs.google.com\/document\/d\/1VUDKMBJYS_jNONjLxT04jQN0_z9Ua50BRN6auGSHUuU\/edit\">A full text description of this image is available<\/a>. Credit: <a class=\"rId125\" href=\"https:\/\/cnx.org\/contents\/FPtK1zmh@12.17:1w-m01MB@7\/The-Skull#fig-ch07_02_14\">Nasal Septum (Anatomy &amp; Physiology, Figure 7.17)<\/a> by <a class=\"rId127\" href=\"https:\/\/openstax.org\/\">OpenStax<\/a> has been modified (some labels modified or removed) and is under a <a class=\"rId129\" href=\"https:\/\/creativecommons.org\/licenses\/by\/4.0\/\">CC BY 4.0 License<\/a>.<\/figcaption><\/figure>\n<figure style=\"width: 546px\" class=\"wp-caption aligncenter\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image28-4.png\" alt=\"Midline view of skull without nasal septum.\" width=\"546\" height=\"422\" \/><figcaption class=\"wp-caption-text\">Figure A.21: Inferior nasal concha scroll from the lateral wall of the nasal cavity. <a href=\"https:\/\/docs.google.com\/document\/d\/1VUDKMBJYS_jNONjLxT04jQN0_z9Ua50BRN6auGSHUuU\/edit\">A full text description of this image is available<\/a>. Credit: <a class=\"rId131\" href=\"https:\/\/cnx.org\/contents\/FPtK1zmh@12.17:1w-m01MB@7\/The-Skull#fig-ch07_02_11\">Lateral Wall of Nasal Cavity (Anatomy &amp; Physiology, Figure 7.13)<\/a> by <a class=\"rId133\" href=\"https:\/\/openstax.org\/\">OpenStax<\/a> has been modified (some labels removed) and is under a <a class=\"rId135\" href=\"https:\/\/creativecommons.org\/licenses\/by\/4.0\/\">CC BY 4.0 License<\/a>.<\/figcaption><\/figure>\n<p class=\"import-Normal\" style=\"background-color: transparent;text-align: left;margin-left: 0pt;margin-right: 0pt;text-indent: 0pt\"><strong>Hyoid bone:<\/strong> Unpaired U-shaped bone that sits in the neck inferior to the mandible. The hyoid is the only bone of the skeleton that does not articulate with another bone. Instead, it is encased in a sling of muscles that move the larynx (voice box), pharynx, and tongue (Figure A.22).<\/p>\n<p>&nbsp;<\/p>\n<figure style=\"width: 306px\" class=\"wp-caption aligncenter\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image20-6.png\" alt=\"Anterior and lateral views of hyoid bone.\" width=\"306\" height=\"476\" \/><figcaption class=\"wp-caption-text\">Figure A.22: The hyoid bone is located in the upper neck and does not join with any other bone. It provides attachments for muscles that move the tongue, larynx, and pharynx. <a href=\"https:\/\/docs.google.com\/document\/d\/1VUDKMBJYS_jNONjLxT04jQN0_z9Ua50BRN6auGSHUuU\/edit\">A full text description of this image is available<\/a>. Credit: <a class=\"rId137\" href=\"https:\/\/cnx.org\/contents\/FPtK1zmh@12.17:1w-m01MB@7\/The-Skull#fig-ch07_02_17\">Hyoid Bone (Anatomy &amp; Physiology, Figure 7.19)<\/a> by <a class=\"rId139\" href=\"https:\/\/openstax.org\/\">OpenStax<\/a> has been modified (some labels removed) and is under a <a class=\"rId141\" href=\"https:\/\/creativecommons.org\/licenses\/by\/4.0\/\">CC BY 4.0 License<\/a>.<\/figcaption><\/figure>\n<p class=\"import-Normal\" style=\"background-color: transparent;text-align: left;margin-left: 0pt;margin-right: 0pt;text-indent: 0pt\"><strong>Mandible:<\/strong> Unpaired bone with a horizontal (and anteriorly arched) body and a vertical ramus that articulates with the mandibular fossa to form the temporomandibular (jaw) joint. The body of the mandible houses the lower teeth (Figure A.13 and A.23).<\/p>\n<p class=\"import-Normal\" style=\"background-color: transparent;text-align: left;margin-left: 0pt;margin-right: 0pt;text-indent: 0pt\">The <strong>mental protuberance (eminence)<\/strong> is the most anteriorly projecting point on the mandible\u2014the so-called \u201cchin.\u201d Males tend to have a more prominent mental protuberance than females (Walker 2008).<\/p>\n<p class=\"import-Normal\" style=\"background-color: transparent;text-align: left;margin-left: 0pt;margin-right: 0pt;text-indent: 0pt\">The <strong>ramus of the mandible<\/strong> projects superiorly from the body of the mandible and ascends to one of two features on the superior aspect: coronoid process or mandibular condyle.<\/p>\n<p class=\"import-Normal\" style=\"background-color: transparent;text-align: left;margin-left: 0pt;margin-right: 0pt;text-indent: 0pt\">The <strong>coronoid process <\/strong>is a bony projection off the anterior and superior aspect of the mandibular ramus. The inferior attachment of the temporalis muscle (a chewing muscle) attaches here.<\/p>\n<p class=\"import-Normal\" style=\"background-color: transparent;text-align: left;margin-left: 0pt;margin-right: 0pt;text-indent: 0pt\">The <strong>mandibular<\/strong> <strong>condyle<\/strong>, a rounded projection off the posterior and superior aspect of the mandibular ramus. It articulates with the temporal (mandibular) fossa of the temporal bone at the temporomandibular (TMJ) joint.<\/p>\n<p class=\"import-Normal\" style=\"background-color: transparent;text-align: left;margin-left: 0pt;margin-right: 0pt;text-indent: 0pt\">The <strong>gonial (or mandibular) angle<\/strong> is the rounded posteroinferior border of the mandible. It tends to be smooth in females with a more obtuse angle but is laterally flared in males and closer to a right angle in shape (Christensen, Passalacqua, and Bartelink 2019).<\/p>\n<figure style=\"width: 566px\" class=\"wp-caption aligncenter\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image12-8.png\" alt=\"Labeled mandible.\" width=\"566\" height=\"434\" \/><figcaption class=\"wp-caption-text\">Figure A.23: Isolated view of the mandible, the only moveable bone of the skull. <a href=\"https:\/\/docs.google.com\/document\/d\/1VUDKMBJYS_jNONjLxT04jQN0_z9Ua50BRN6auGSHUuU\/edit\">A full text description of this image is available<\/a>. Credit: <a class=\"rId143\" href=\"https:\/\/openstax.org\/books\/anatomy-and-physiology\/pages\/7-2-the-skull#fig-ch07_02_13\">Isolated Mandible (Anatomy &amp; Physiology, Figure 7.15)<\/a> by <a class=\"rId145\" href=\"https:\/\/openstax.org\/\">OpenStax<\/a> has been modified (some labels modified or removed) and is under a <a class=\"rId147\" href=\"https:\/\/creativecommons.org\/licenses\/by\/4.0\/\">CC BY 4.0 License<\/a>.<\/figcaption><\/figure>\n<p class=\"import-Normal\" style=\"background-color: transparent;text-align: left;margin-left: 0pt;margin-right: 0pt;text-indent: 0pt\">Teeth: Adults normally have 32 teeth, distributed among four quadrants of the mouth (upper left, upper right, lower left, lower right). In each quadrant, there are eight teeth: two incisors (central and lateral), one canine, two premolars, and three molars. Each of these types of teeth has a different shape that reflects its function during chewing:<\/p>\n<p class=\"import-Normal\" style=\"background-color: transparent;text-align: left;margin-left: 0pt;margin-right: 0pt;text-indent: 0pt\"><strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_1160\">Incisors<\/a><\/strong> are flat and shovel shaped and are used to bite into a food item.<\/p>\n<p class=\"import-Normal\" style=\"background-color: transparent;text-align: left;margin-left: 0pt;margin-right: 0pt;text-indent: 0pt\"><strong>Canines<\/strong> are conical, with a single pointed cusp used to puncture a food item.<\/p>\n<p class=\"import-Normal\" style=\"background-color: transparent;text-align: left;margin-left: 0pt;margin-right: 0pt;text-indent: 0pt\"><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_1350\"><strong>Premolars<\/strong><\/a> have two rounded cusps and are used to grind and mash a food item.<\/p>\n<p class=\"import-Normal\" style=\"background-color: transparent;text-align: left;margin-left: 0pt;margin-right: 0pt;text-indent: 0pt\"><strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_1164\">Molars<\/a><\/strong> have four (upper molars) or five (lower molars) flatter cusps and are used to grind food prior to swallowing.<\/p>\n<p class=\"import-Normal\" style=\"background-color: transparent;text-align: left;margin-left: 0pt;margin-right: 0pt;text-indent: 0pt\">The teeth have their own set of directional terms that help differentiate the different parts of the tooth. For example, the anterior portion of the tooth is called <strong>mesial<\/strong>, while the posterior portion of the tooth is called distal. In the case of teeth in the front of the mouth, mesial refers to the aspect toward the midline of the body; distal refers to the aspect away from the midline. Similarly, the side of the tooth facing the lips is called the <strong>buccal<\/strong> surface and the side facing the tongue is called the <strong>lingual <\/strong>surface. Finally, we can talk about the <strong>occlusal surface<\/strong> of the tooth, which is the surface that comes in contact with food or the teeth from the other jaw when the jaw is closed. Sometimes the occlusal surface of the incisors is called the <strong>incisal surface<\/strong>.<\/p>\n<h4 class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><em>Vertebral Column <\/em><\/h4>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\">The adult vertebral column consists of 32\u201333 individual vertebrae, divided into five regions: cervical, thoracic, lumbar, sacral, and coccygeal.<\/p>\n<h5 class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\">General Structure of a Vertebra<\/h5>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\">A typical vertebra consists of an anteriorly situated <strong>centrum<\/strong> (body)\u2014the main weight-bearing element of the vertebra\u2014and a posteriorly projecting <strong>vertebral arch <\/strong>(Figure A.24). The vertebral arch consists of the paired pedicles and paired laminae. The <strong>pedicle<\/strong> connects the <strong>transverse process<\/strong>\u2014a laterally projecting process that serves as an attachment site for muscles and ligaments\u2014to the vertebral body; the <strong>lamina<\/strong> connects the <strong>spinous process<\/strong>\u2014a posteriorly projecting process that serves as an attachment site for muscles and ligaments\u2014to the transverse process. Projecting inferiorly off the vertebral arch is the <strong>inferior articular process,<\/strong> and projecting superiorly off the vertebral arch is the <strong>superior articular process<\/strong>. Between the vertebral body anteriorly and the vertebral arch posteriorly is an open space called the <strong>vertebral foramen<\/strong>.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\">Vertebrae articulate with one another through two major types of joints: <strong>intervertebral disc joints <\/strong>between adjacent vertebral bodies and <strong>zygapophyseal (facet) joints<\/strong> between the inferior articular process of one vertebra and the superior articular process of the vertebra immediately inferior to it. When all vertebrae are articulated into a column, the adjacent vertebral foramina form the <strong>vertebral canal<\/strong>, through which the spinal cord travels from the foramen magnum of the occipital bone to approximately the level of the second lumbar vertebra. At the level of each vertebra, the spinal cord gives off a pair (left and right) of spinal nerves that exit between vertebrae through the intervertebral foramen formed by adjacent vertebral arches. Even though the spinal cord ends in the lumbar region, the spinal nerves emanating from the spinal cord continue all the way to the sacral (and sometimes coccygeal) region, culminating in a total of 30\u201331 pairs of spinal nerves.<\/p>\n<figure style=\"width: 650px\" class=\"wp-caption aligncenter\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image30-4.png\" alt=\"Superior view of vertebra, and three vertebrae in articulation.\" width=\"650\" height=\"283\" \/><figcaption class=\"wp-caption-text\">Figure A.24: A typical vertebra consists of a body and a vertebral arch. The arch is formed by the paired pedicles and paired laminae. Arising from the vertebral arch are the transverse, spinous, superior articular, and inferior articular processes. The vertebral foramen provides for passage of the spinal cord. Each spinal nerve exits through an intervertebral foramen, located between adjacent vertebrae. <a href=\"https:\/\/docs.google.com\/document\/d\/1VUDKMBJYS_jNONjLxT04jQN0_z9Ua50BRN6auGSHUuU\/edit\">A full text description of this image is available<\/a>. Credit: <a class=\"rId149\" href=\"https:\/\/openstax.org\/books\/anatomy-and-physiology\/pages\/7-3-the-vertebral-column#fig-ch07_03_04\">Parts of a Typical Vertebra (Anatomy &amp; Physiology, Figure 7.23)<\/a> by <a class=\"rId151\" href=\"https:\/\/openstax.org\/\">OpenStax<\/a> has been modified (some labels removed) and is under a <a class=\"rId153\" href=\"https:\/\/creativecommons.org\/licenses\/by\/4.0\/\">CC BY 4.0 License<\/a>.<\/figcaption><\/figure>\n<h5 class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\">Regional Differences in Vertebral Shape<\/h5>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\">In the <strong>cervical region<\/strong> of the vertebral column, there are seven vertebrae (named C1\u2013C7 from superior to inferior; Figure A.25). The first two cervical vertebrae are unique from each other and all other cervical vertebrae, and they get special names: atlas (C1) and axis (C2). The atlas lacks a vertebral body (having only two large articular facets for articulation with the occipital bone of the skull: the <strong>atlanto-occipital joint <\/strong>for nodding the head) and does not have a spinous process. The axis is notable for the superiorly projecting <strong>dens<\/strong>(or<strong>odontoid process<\/strong>), which articulates with the atlas to create the <strong>atlanto-axial<\/strong><strong> joint<\/strong> for head rotation. Otherwise, a typical cervical vertebra has a small vertebral body, a bifid (split) spinous process, a transverse process with a transverse foramen on it for passage of the vertebral artery and vein, and a triangular-shaped vertebral foramen.<\/p>\n<figure style=\"width: 734px\" class=\"wp-caption aligncenter\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image22-8.png\" alt=\"A typical cervical vertebra, C1, C2, and cervical vertebrae in articulation.\" width=\"734\" height=\"841\" \/><figcaption class=\"wp-caption-text\">Figure A.25: A typical cervical vertebra has a small body, a bifid spinous process, transverse processes that have a transverse foramen, and a triangular vertebral foramen. The atlas (C1 vertebra) does not have a body or spinous process. The axis (C2 vertebra) has the upward projecting dens, which articulates with the atlas. <a href=\"https:\/\/docs.google.com\/document\/d\/1VUDKMBJYS_jNONjLxT04jQN0_z9Ua50BRN6auGSHUuU\/edit\">A full text description of this image is available<\/a>. Credit: <a class=\"rId155\" href=\"https:\/\/cnx.org\/contents\/FPtK1zmh@12.17:4CMef3D9@7\/The-Vertebral-Column#fig-ch07_03_06\">Cervical Vertebra (Anatomy &amp; Physiology, Figure 7.25)<\/a> by <a class=\"rId157\" href=\"https:\/\/openstax.org\/\">OpenStax<\/a> has been modified (some labels removed) and is under a <a class=\"rId159\" href=\"https:\/\/creativecommons.org\/licenses\/by\/4.0\/\">CC BY 4.0 License<\/a>.<\/figcaption><\/figure>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\">The vertebrae in the other regions of the spinal column are less variable in shape than the cervical region vertebrae. There are 12 <strong>thoracic region <\/strong>vertebrae (T1\u2013T12), and they can be easily distinguished from the vertebrae in other regions because they have articular facets on their vertebral bodies for articulation with the head of a rib, as well as articular facets on the transverse process for articulation with the rib tubercle (Figure A.26). In particular, the vertebral bodies of T2\u2013T9 have two pairs of articular facets called <strong>demifacets<\/strong> (superior and inferior), for articulation with multiple ribs; T1 and T10\u2013T12 have single facets for articulation with a single rib. All five <strong>lumbar region <\/strong>vertebrae (L1\u2013L5) are distinguished by their large vertebral body and rounded spinous process (Figure A.27). Finally, there is the <strong>sacrum<\/strong>, which is a bone of the pelvis that forms from the fusion of all five sacral region vertebrae (S1\u2013S5), and there is the <strong>coccyx,<\/strong> which comprises three to four fused coccygeal region vertebrae that form the tailbone (Figure A.28).<\/p>\n<figure style=\"width: 437px\" class=\"wp-caption aligncenter\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image34-2.png\" alt=\"Rib articulating at thoracic vertebrae.\" width=\"437\" height=\"329\" \/><figcaption class=\"wp-caption-text\">Figure A.26: Thoracic vertebrae have superior and inferior articular facets on the vertebral body for articulation with the head of a rib, as well as a transverse process facet for articulation with the rib tubercle. <a href=\"https:\/\/docs.google.com\/document\/d\/1VUDKMBJYS_jNONjLxT04jQN0_z9Ua50BRN6auGSHUuU\/edit\">A full text description of this image is available<\/a>. Credit: <a class=\"rId161\" href=\"https:\/\/openstax.org\/books\/anatomy-and-physiology\/pages\/7-3-the-vertebral-column#fig-ch07_03_06\">Rib Articulation in Thoracic Vertebrae (Anatomy &amp; Physiology, Figure 7.27)<\/a> by <a class=\"rId163\" href=\"https:\/\/openstax.org\/\">OpenStax<\/a> has been modified (some labels removed) and is under a <a class=\"rId165\" href=\"https:\/\/creativecommons.org\/licenses\/by\/4.0\/\">CC BY 4.0 License<\/a>.<\/figcaption><\/figure>\n<figure style=\"width: 404px\" class=\"wp-caption aligncenter\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image15-6.jpg\" alt=\"Lumbar vertebrae in articulation.\" width=\"404\" height=\"372\" \/><figcaption class=\"wp-caption-text\">Figure A.27: Lumbar vertebrae are characterized by having a large, thick body and a short, rounded spinous process. <a href=\"https:\/\/docs.google.com\/document\/d\/1VUDKMBJYS_jNONjLxT04jQN0_z9Ua50BRN6auGSHUuU\/edit\">A full text description of this image is available<\/a>. Credit: <a class=\"rId167\" href=\"https:\/\/cnx.org\/contents\/FPtK1zmh@12.17:4CMef3D9@7\/The-Vertebral-Column#fig-ch07_03_09\">Lumbar Vertebrae (Anatomy &amp; Physiology, Figure 7.28)<\/a> by <a class=\"rId169\" href=\"https:\/\/openstax.org\/\">OpenStax<\/a> is under a <a class=\"rId171\" href=\"https:\/\/creativecommons.org\/licenses\/by\/4.0\/\">CC BY 4.0 License<\/a>.<\/figcaption><\/figure>\n<figure style=\"width: 569px\" class=\"wp-caption aligncenter\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image14-8.png\" alt=\"Anterior and posterior views of isolated sacrum.\" width=\"569\" height=\"254\" \/><figcaption class=\"wp-caption-text\">Figure A.28: The sacrum is formed from the fusion of five sacral vertebrae, whose lines of fusion are indicated by the transverse ridges. The coccyx is formed by the fusion of three to four coccygeal vertebrae. <a href=\"https:\/\/docs.google.com\/document\/d\/1VUDKMBJYS_jNONjLxT04jQN0_z9Ua50BRN6auGSHUuU\/edit\">A full text description of this image is available<\/a>. Credit: <a class=\"rId173\" href=\"https:\/\/openstax.org\/books\/anatomy-and-physiology\/pages\/7-3-the-vertebral-column#fig-ch07_03_10\">Sacrum and Coccyx (Anatomy &amp; Physiology, Figure 7.29)<\/a> by <a class=\"rId175\" href=\"https:\/\/openstax.org\/\">OpenStax<\/a> has been modified (some labels removed) and is under a <a class=\"rId177\" href=\"https:\/\/creativecommons.org\/licenses\/by\/4.0\/\">CC BY 4.0 License<\/a>.<\/figcaption><\/figure>\n<h5 class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\">Curvatures of the Vertebral Column<\/h5>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\">The adult spine is curved in the midsagittal plane in four regions of the vertebral column (cervical, thoracic, lumbar, and sacral; Figure A.29). During the fetal period of development, the vertebral column forms an anteriorly concave curvature called a <strong>kyphosis<\/strong>. But during the postnatal period, when an infant learns to hold its head up and then again when it learns to walk, it develops secondary curvatures called lordoses (singular: <strong>lordosis<\/strong>) that are posteriorly concave in the cervical and lumbar vertebral regions, while the kyphoses remain in the thoracic and sacral regions. The end result is an S-shaped curvature to our spine that enables us to keep our head and torso above our center of mass (near our pelvis) while walking around on two legs.<\/p>\n<figure style=\"width: 556px\" class=\"wp-caption aligncenter\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image6-9.png\" alt=\"Person with vertebral column shows curvatures.\" width=\"556\" height=\"531\" \/><figcaption class=\"wp-caption-text\">Figure A.29: The adult vertebral column is curved in the midsagittal plane, with two primary curvatures (thoracic and sacral kyphoses) and two secondary curvatures (cervical and lumbar lordoses). <a href=\"https:\/\/docs.google.com\/document\/d\/1VUDKMBJYS_jNONjLxT04jQN0_z9Ua50BRN6auGSHUuU\/edit\">A full text description of this image is available<\/a>. Credit: <a class=\"rId179\" href=\"https:\/\/openstax.org\/books\/anatomy-and-physiology\/pages\/7-3-the-vertebral-column#fig-ch07_03_01\">Vertebral Column (Anatomy &amp; Physiology, Figure 7.20)<\/a> by <a class=\"rId181\" href=\"https:\/\/openstax.org\/\">OpenStax<\/a> has been modified (some labels modified or removed) and is under a <a class=\"rId183\" href=\"https:\/\/creativecommons.org\/licenses\/by\/4.0\/\">CC BY 4.0 License<\/a>.<\/figcaption><\/figure>\n<h4 class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><em>Thoracic Cage<\/em><\/h4>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\">The thoracic cage is formed from the sternum, the 12 ribs and their cartilages (costal cartilages), and the 12 thoracic vertebrae with which the ribs articulate (Figure A.30). The <strong>sternum<\/strong> comprises the <strong>manubrium<\/strong> (superior portion), the <strong>body of the sternum,<\/strong> and the <strong>xiphoid process<\/strong><\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\">. Each rib has a head and neck (with rib tubercle) at the vertebral end of the rib as well as a flattened shaft that extends to articulate with the sternum. All ribs articulate with the vertebral column at two points: the transverse process facet (<strong>rib tubercle<\/strong>) and vertebral body articular facet (<strong>head of rib<\/strong>). But articulations between the ribs and the sternum vary, where some ribs (1\u20137, the \u201ctrue ribs\u201d) attach directly to the sternum via their costal cartilages, other ribs (8\u201310, the \u201cfalse ribs\u201d) attach indirectly to the sternum via the costal cartilage of the rib above, and some ribs (11\u201312, the \u201cfloating ribs\u201d) do not attach to the sternum at all. With increasing age, the <strong>sternal end of the rib<\/strong> becomes thinner and irregularly shaped compared to the smooth, rounded shape seen in young adults (Hartnett 2010).<\/p>\n<figure style=\"width: 522px\" class=\"wp-caption aligncenter\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image8-7.png\" alt=\"Anterior view of sternum. Thorax skeleton shows articulation of ribs to sternum.\" width=\"522\" height=\"309\" \/><figcaption class=\"wp-caption-text\">Figure A.30: The thoracic cage is formed by the (a) sternum and (b) 12 pairs of ribs with their costal cartilages. The ribs are anchored posteriorly to the 12 thoracic vertebrae. The sternum consists of the manubrium, body, and xiphoid process. The ribs are classified as true ribs (1\u20137) and false ribs (8\u201312). The last two pairs of false ribs are also known as floating ribs (11\u201312). <a href=\"https:\/\/docs.google.com\/document\/d\/1VUDKMBJYS_jNONjLxT04jQN0_z9Ua50BRN6auGSHUuU\/edit\">A full text description of this image is available<\/a>. Credit: <a class=\"rId185\" href=\"https:\/\/openstax.org\/books\/anatomy-and-physiology\/pages\/7-4-the-thoracic-cage\">Thoracic Cage (Anatomy &amp; Physiology, Figure 7.32)<\/a> by <a class=\"rId187\" href=\"https:\/\/openstax.org\/\">OpenStax<\/a> has been modified (some labels modified or removed) and is under a <a class=\"rId189\" href=\"https:\/\/creativecommons.org\/licenses\/by\/4.0\/\">CC BY 4.0 License<\/a>.<\/figcaption><\/figure>\n<h3 class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Appendicular Skeleton<\/strong><\/h3>\n<h4 class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><em>Pectoral Girdle<\/em><\/h4>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\">The pectoral girdle consists of the <strong>clavicle<\/strong> and the <strong>scapula<\/strong>, and it serves as the proximal base of the upper limb as well as the anchor for the upper limb to the axial skeleton. The clavicle is an S-shaped bone, and it forms the strut that connects the scapula to the sternum (Figure A.31). The scapula is a large, flat bone with three angles (superior, inferior, and lateral) and three borders (medial, lateral, and superior). The lateral angle is noteworthy because it serves as the articulation for the head of the humerus of the upper limb at the <strong>glenoid cavity (or fossa) (<\/strong>Figure A.32). The borders and the anterior and posterior surfaces of the scapula are sites of muscle attachment. The scapula also has three important projections for muscle and ligament attachments: the <strong>coracoid process <\/strong>anteriorly and superiorly; the <strong>acromion<\/strong>, which articulates with the lateral end of the clavicle; and the <strong>spine<\/strong> on the posterior aspect of the scapula.<\/p>\n<figure style=\"width: 614px\" class=\"wp-caption aligncenter\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image18-6.png\" alt=\"Anterior and posterior views of pectoral girdle and isolated clavicles.\" width=\"614\" height=\"847\" \/><figcaption class=\"wp-caption-text\">Figure A.31: The pectoral girdle consists of the clavicle and the scapula, which serve to attach the upper limb to the axial skeleton at the sternum. <a href=\"https:\/\/docs.google.com\/document\/d\/1VUDKMBJYS_jNONjLxT04jQN0_z9Ua50BRN6auGSHUuU\/edit\">A full text description of this image is available<\/a>. Credit: <a class=\"rId191\" href=\"https:\/\/openstax.org\/books\/anatomy-and-physiology\/pages\/8-1-the-pectoral-girdle#fig-ch08_01_02\">Pectoral Girdle (Anatomy &amp; Physiology, Figure 8.3)<\/a> by <a class=\"rId193\" href=\"https:\/\/openstax.org\/\">OpenStax<\/a> has been modified (some labels modified or removed) and is under a <a class=\"rId195\" href=\"https:\/\/creativecommons.org\/licenses\/by\/4.0\/\">CC BY 4.0 License<\/a>.<\/figcaption><\/figure>\n<figure style=\"width: 712px\" class=\"wp-caption aligncenter\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image9-11.png\" alt=\"Labeled sketch of a scapula.\" width=\"712\" height=\"469\" \/><figcaption class=\"wp-caption-text\">Figure A.32: The scapula is shown from its anterior (deep) side and its posterior (superficial) side. <a href=\"https:\/\/docs.google.com\/document\/d\/1VUDKMBJYS_jNONjLxT04jQN0_z9Ua50BRN6auGSHUuU\/edit\">A full text description of this image is available<\/a>. Credit: <a class=\"rId197\" href=\"https:\/\/cnx.org\/contents\/FPtK1zmh@12.17:a7_2DvnP@7\/The-Pectoral-Girdle#fig-ch08_01_02\">Scapula (Anatomy &amp; Physiology, Figure 8.4)<\/a> by <a class=\"rId199\" href=\"https:\/\/openstax.org\/\">OpenStax<\/a> has been modified (some labels modified or removed) and is under a <a class=\"rId201\" href=\"https:\/\/creativecommons.org\/licenses\/by\/4.0\/\">CC BY 4.0 License<\/a>.<\/figcaption><\/figure>\n<h4 class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><em>Upper Limb<\/em><\/h4>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\">The bones of the upper limb skeleton include the humerus, radius, ulna, eight carpal (wrist) bones, five metacarpal (hand) bones, and 14 phalanges (finger bones). Each of these bones is described below along with several of the prominent features.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\">The <strong>humerus<\/strong> is the bone of the arm. On the proximal epiphysis of the humerus are attachment sites for muscles of the rotator cuff (<strong>greater tubercle <\/strong>and <strong>lesser tubercle<\/strong>). A major shoulder muscle (deltoid muscle) attaches to the humerus along the lateral aspect of the diaphysis at the <strong>deltoid tuberosity<\/strong>. On the distal epiphysis of the humerus, the medial epicondyle is an attachment site for muscles that flex the forearm, and the lateral epicondyle is an attachment site for muscles that extend the forearm (Figure A.33).<\/p>\n<figure style=\"width: 478px\" class=\"wp-caption aligncenter\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image38-2.png\" alt=\"Anterior and posterior views of the humerus.\" width=\"478\" height=\"603\" \/><figcaption class=\"wp-caption-text\">Figure A.33: The humerus is the single bone of the upper arm region. It articulates with the radius and ulna bones of the forearm to form the elbow joint. <a href=\"https:\/\/docs.google.com\/document\/d\/1VUDKMBJYS_jNONjLxT04jQN0_z9Ua50BRN6auGSHUuU\/edit\">A full text description of this image is available<\/a>. Credit: <a class=\"rId203\" href=\"https:\/\/cnx.org\/contents\/FPtK1zmh@12.17:HYsYjkmm@8\/Bones-of-the-Upper-Limb#fig-ch08_02_01\">Humerus and Elbow Joint (Anatomy &amp; Physiology, Figure 8.5)<\/a> by <a class=\"rId205\" href=\"https:\/\/openstax.org\/\">OpenStax<\/a> has been modified (some labels modified or removed) and is under a <a class=\"rId207\" href=\"https:\/\/creativecommons.org\/licenses\/by\/4.0\/\">CC BY 4.0 License<\/a>.<\/figcaption><\/figure>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\">There are two bones of the forearm, attached to each other by a thick connective tissue interosseous membrane: the radius and the ulna (Figure A.34). The <strong>radius<\/strong> is lateral to the ulna in anatomical position (this is called supination of the forearm), but it crosses over the ulna when the wrist is rotated so that the thumb points medially (this is called pronation of the forearm). On the proximal end of the radius is the <strong>radial tuberosity<\/strong>, an attachment site for the biceps brachii muscle that will help supinate and flex the forearm; on the distal end of the radius is the <strong>styloid process of radius<\/strong>, an attachment site for ligaments of the wrist. The <strong>ulna<\/strong> also has a styloid process (<strong>styloid process of ulna<\/strong>), but unlike the one on the radius it does not have a relevant function. Instead, the important processes on the ulna are located proximally, and they include the <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_1430\">olecranon process<\/a><\/strong> for the attachment of the triceps brachii muscle (a muscle that extends the forearm and arm) and the coronoid process for the attachment of the brachialis muscle (a muscle that flexes the forearm).<\/p>\n<figure style=\"width: 404px\" class=\"wp-caption aligncenter\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image40-2.png\" alt=\"Anterior and posterior views of radius and ulna in articulation.\" width=\"404\" height=\"523\" \/><figcaption class=\"wp-caption-text\">Figure A.34: The ulna is located on the medial side of the forearm, and the radius is on the lateral side. These bones are attached to each other by an interosseous membrane. <a href=\"https:\/\/docs.google.com\/document\/d\/1VUDKMBJYS_jNONjLxT04jQN0_z9Ua50BRN6auGSHUuU\/edit\">A full text description of this image is available<\/a>. Credit: <a class=\"rId209\" href=\"https:\/\/cnx.org\/contents\/FPtK1zmh@12.17:HYsYjkmm@8\/Bones-of-the-Upper-Limb#fig-ch08_02_01\">Ulna and Radius (Anatomy &amp; Physiology, Figure 8.6)<\/a> by <a class=\"rId211\" href=\"https:\/\/openstax.org\/\">OpenStax<\/a> has been modified (some labels removed) and is under a <a class=\"rId213\" href=\"https:\/\/creativecommons.org\/licenses\/by\/4.0\/\">CC BY 4.0 License<\/a>.<\/figcaption><\/figure>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\">There are eight <strong>carpal bones<\/strong> that comprise the wrist, and they are organized into two rows: proximal and distal (Figure A.35). The proximal row of carpals (from lateral to medial) includes the scaphoid, lunate, triquetrum, and pisiform. The distal row (from lateral to medial) includes the trapezium, trapezoid, capitate, and hamate with its distinctive hamulus (hook) for muscle and ligament attachments. Distal to the carpal bones are the digital rays, each of which contains a <strong>metacarpal<\/strong> (hand) bone and three <strong>phalanges <\/strong>(proximal, middle, and distal) or finger bones. The exception to this rule is the thumb, which has fewer phalanges (proximal and distal, but no middle) than the other digits.<\/p>\n<figure style=\"width: 601px\" class=\"wp-caption aligncenter\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image24-4.png\" alt=\"Wrist and hand bones in articulation, in anterior and posterior views.\" width=\"601\" height=\"485\" \/><figcaption class=\"wp-caption-text\">Figure A.35: The eight carpal bones form the base of the hand. These are arranged into proximal and distal rows of four bones each. The five metacarpal bones form the palm of the hand. The thumb and fingers contain a total of 14 phalanges. <a href=\"https:\/\/docs.google.com\/document\/d\/1VUDKMBJYS_jNONjLxT04jQN0_z9Ua50BRN6auGSHUuU\/edit\">A full text description of this image is available<\/a>. Credit: <a class=\"rId215\" href=\"https:\/\/cnx.org\/contents\/FPtK1zmh@12.17:HYsYjkmm@8\/Bones-of-the-Upper-Limb#fig-ch08_02_03\">Bones of the Wrist and Hand (Anatomy &amp; Physiology, Figure 8.7)<\/a> by <a class=\"rId217\" href=\"https:\/\/openstax.org\/\">OpenStax<\/a> has been modified (some labels removed) and is under a <a class=\"rId219\" href=\"https:\/\/creativecommons.org\/licenses\/by\/4.0\/\">CC BY 4.0 License<\/a>.<\/figcaption><\/figure>\n<h4 class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><em>Pelvic Girdle<\/em><\/h4>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\">The pelvic girdle consists of the two <strong>os coxae<\/strong> and the sacrum that articulates with both, and it serves as the proximal base and anchor of the lower limb to the axial skeleton. Each os coxa comprises three bones that fuse together during growth: ilium, ischium, and pubis. These three bones fuse in a region called the <strong>acetabulum<\/strong>, which is the socket for the ball-and-socket hip joint (Figure A.36). The <strong>ilium<\/strong>, the flared superior portion of the pelvis, is the largest bone of the os coxa and serves as a major site of attachments for muscles from the abdomen, back, and lower limb. The ilium has several important features including the <strong>auricular surface<\/strong>, the surface where the ilium articulates with the sacrum. The auricular surface is used to estimate age at death as the surface progressively deteriorates with increasing age to appear coarse and porous. The <strong>greater sciatic notch<\/strong> is a large notch in the ilium that allows for several structures to leave the pelvis and enter the lower extremity, including the sciatic nerve. In females, the notch tends to be symmetrical whereas in males it tends to curve posteriorly (Nawrocki et al. 2018).<\/p>\n<figure style=\"width: 649px\" class=\"wp-caption aligncenter\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image25-6.png\" alt=\"Pelvis bones in articulation viewed from anterior.\" width=\"649\" height=\"442\" \/><figcaption class=\"wp-caption-text\">Figure A.36: The pelvic girdle consists of two os coxae and the sacrum. It serves to anchor the axial skeleton to the lower limb. <a href=\"https:\/\/docs.google.com\/document\/d\/1VUDKMBJYS_jNONjLxT04jQN0_z9Ua50BRN6auGSHUuU\/edit\">A full text description of this image is available<\/a>. Credit: <a class=\"rId221\" href=\"https:\/\/cnx.org\/contents\/FPtK1zmh@12.17:U6HolX6c@6\/The-Pelvic-Girdle-and-Pelvis#fig-ch08_03_01\">Pelvis (Anatomy &amp; Physiology, Figure 8.12)<\/a> by <a class=\"rId223\" href=\"https:\/\/openstax.org\/\">OpenStax<\/a> has been modified (some labels modified or removed) and is under a <a class=\"rId225\" href=\"https:\/\/creativecommons.org\/licenses\/by\/4.0\/\">CC BY 4.0 License<\/a>.<\/figcaption><\/figure>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\">The <strong>ischium<\/strong> forms the posterior and inferior portion of the os coxa. There are two significant projections of note on the ischium: the ischial spine and tuberosity. The <strong>ischial spine<\/strong> is the attachment point for a major pelvic ligament and is located inferior to the greater sciatic notch of the ilium. The <strong>ischial tuberosity<\/strong> is the proximal attachment site for the hamstring muscles of the lower limb.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\">The anterior and medial portions of the os coxa are formed by the <strong>pubis<\/strong>. The pubis is a useful bone with which to sex a skeleton in a forensic context (Bass 2005; Buikstra and Ubelaker 1994). The <strong>body of pubis<\/strong> is the superior and medial portion (Figure A.37). The body tends to be rectangular in cross-section in females and triangular in males. The bony projection that unites the ischium and pubis anteriorly is called the <strong>ischiopubic ramus<\/strong>. Females tend to display a thin and sharp ramus on the medial surface while the surface in males tends to be broad and blunt. The joint that unites the two pubic bones in the front of the pelvis is called the <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_1262\">pubic symphysis<\/a><\/strong>, which is a structure commonly used in age estimation. In young adults, the surface is billowed, but it transitions to being smooth and porous with increasing age (Hartnett 2010). The <strong>sub<\/strong><strong>pubic concavity<\/strong> is a depression inferior to the ischiopubic ramus. Female pelves tend to exhibit this concavity while male pelves tend not to. Finally, the large opening encircled by the pubis and ischium is called the <strong>obturator foramen<\/strong>. The shape of the foramen in females has been described as triangular while it is more likely to appear oval in males (Bass 2005).<\/p>\n<figure style=\"width: 562px\" class=\"wp-caption aligncenter\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image33-2.png\" alt=\"Bones of the os coxa in different colors.\" width=\"562\" height=\"404\" \/><figcaption class=\"wp-caption-text\">Figure A.37: The os coxae consist of three bones that fuse during development. The ilium forms the large, fan-shaped superior portion, the ischium forms the posteroinferior portion, and the pubis forms the anteromedial portion. <a href=\"https:\/\/docs.google.com\/document\/d\/1VUDKMBJYS_jNONjLxT04jQN0_z9Ua50BRN6auGSHUuU\/edit\">A full text description of this image is available<\/a>. Credit: <a class=\"rId227\" href=\"https:\/\/cnx.org\/contents\/FPtK1zmh@12.17:U6HolX6c@6\/The-Pelvic-Girdle-and-Pelvis#fig-ch08_03_01\">The Hip Bone (Anatomy &amp; Physiology, Figure 8.13)<\/a> by <a class=\"rId229\" href=\"https:\/\/openstax.org\/\">OpenStax<\/a> has been modified (some labels removed) and is under a <a class=\"rId231\" href=\"https:\/\/creativecommons.org\/licenses\/by\/4.0\/\">CC BY 4.0 License<\/a>.<\/figcaption><\/figure>\n<h4 class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><em>Lower Limb<\/em><\/h4>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\">The bones of the lower limb skeleton include the femur, patella, tibia, fibula, seven tarsal (ankle) bones, five <strong>metatarsal<\/strong> (foot) bones, and 14 phalanges (toe bones). Each of these bones is described below along with several of the prominent features.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\">The <strong>femur <\/strong>is the bone of the thigh. On the proximal epiphysis of the femur are attachment sites for major hip and thigh muscles on the <strong>greater trochanter<\/strong>,<strong> lesser trochanter<\/strong>, and <strong>gluteal tuberosity <\/strong>(Figure A.38). The raised ridge on the posterior aspect of the femoral diaphysis is called the <strong>linea aspera<\/strong>, and it is a major attachment site for the quadriceps femoris muscles and other muscles, and it terminates distally by splitting into medial and lateral epicondyles, additional sites of muscle attachment. The distal epiphysis of the femur is marked by two rounded condyles that articulate with the proximal part of the tibia. The anterior surface of the distal femur articulates with the <strong>patella<\/strong> (kneecap), a bone that develops within the tendon of the quadriceps femoris muscle to enhance the function of the muscle. The patella does not articulate with the tibia.<\/p>\n<figure style=\"width: 578px\" class=\"wp-caption aligncenter\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image21-8.png\" alt=\"Anterior and posterior views of the bones of the hip, knee, and thigh.\" width=\"578\" height=\"905\" \/><figcaption class=\"wp-caption-text\">Figure A.38: The femur is the bone of the thigh that articulates superiorly with the os coxa at the hip joint and inferiorly with the tibia at the knee joint. The patella only articulates with the distal end of the femur. <a href=\"https:\/\/docs.google.com\/document\/d\/1VUDKMBJYS_jNONjLxT04jQN0_z9Ua50BRN6auGSHUuU\/edit\">A full text description of this image is available<\/a>. Credit: <a class=\"rId233\" href=\"https:\/\/cnx.org\/contents\/FPtK1zmh@12.17:c4okIKQJ@7\/Bones-of-the-Lower-Limb#fig-ch08_04_01\">Femur and Patella (Anatomy &amp; Physiology, Figure 8.16)<\/a> by <a class=\"rId235\" href=\"https:\/\/openstax.org\/\">OpenStax<\/a> has been modified (some labels modified or removed) and is under a <a class=\"rId237\" href=\"https:\/\/creativecommons.org\/licenses\/by\/4.0\/\">CC BY 4.0 License<\/a>.<\/figcaption><\/figure>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\">There are two bones of the leg: <strong>tibia<\/strong> and <strong>fibula<\/strong>. The tibia is the robust, medial bone of the leg, and it is connected to the laterally positioned fibula by an interosseous membrane like in the forearm (Figure A.39). The proximal epiphysis of the tibia has two articular facets called tibial condyles that articulate with the femoral condyles. On the anterior surface of the proximal tibia is a raised projection called the <strong>tibial<\/strong> <strong>tuberosity<\/strong>, where the quadriceps muscle tendon attaches distally after containing the patella. On the distal epiphysis of the tibia is the <strong>medial<\/strong> <strong>malleolus<\/strong>, which articulates with the talus in the ankle joint. The <strong>lateral<\/strong> <strong>malleolus<\/strong> is a feature of the distal end of the fibula; the proximal end of the fibula articulates with the lateral portion of the proximal tibia.<\/p>\n<figure style=\"width: 583px\" class=\"wp-caption aligncenter\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image23-5.jpg\" alt=\"Anterior and posterior views of tibia and fibula in articulation.\" width=\"583\" height=\"721\" \/><figcaption class=\"wp-caption-text\">Figure A.39: The tibia is the larger, weight-bearing bone located on the medial side of the leg. It is connected to the laterally positioned fibula by an interosseous membrane. <a href=\"https:\/\/docs.google.com\/document\/d\/1VUDKMBJYS_jNONjLxT04jQN0_z9Ua50BRN6auGSHUuU\/edit\">A full text description of this image is available<\/a>. Credit: <a class=\"rId239\" href=\"https:\/\/cnx.org\/contents\/FPtK1zmh@12.17:c4okIKQJ@7\/Bones-of-the-Lower-Limb#fig-ch08_04_01\">Tibia and Fibula (Anatomy &amp; Physiology, Figure 8.18)<\/a> by <a class=\"rId241\" href=\"https:\/\/openstax.org\/\">OpenStax<\/a> has been modified (label removed) and is under a <a class=\"rId243\" href=\"https:\/\/creativecommons.org\/licenses\/by\/4.0\/\">CC BY 4.0 License<\/a>.<\/figcaption><\/figure>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\">There are seven <strong>tarsal bones<\/strong> that comprise the ankle (Figure A.40). The <strong>talus<\/strong> is the most superior of the tarsals, and it articulates with the distal tibia and distal fibula superiorly and with the calcaneus inferiorly. The <strong>calcaneus<\/strong> is the heel of the foot; it is the largest of the tarsals. On the posterior-most aspect of the calcaneus is the <strong>calcaneal<\/strong> <strong>tuberosity<\/strong>, which is the attachment site for the Achilles tendon of the posterior leg. Distal to the talus is the medially positioned navicular, the three cuneiform bones (medial, intermediate, and lateral), and the laterally positioned cuboid. Distal to the tarsals are the digital rays, each of which contains a metatarsal (foot) bone and three phalanges (proximal, middle, and distal) or toe bones. The exception to this rule is the big toe, which has fewer phalanges (proximal and distal, but no middle) than the other digits.<\/p>\n<figure style=\"width: 670px\" class=\"wp-caption aligncenter\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image41-1.jpg\" alt=\"Foot bones in articulation, in superior, medial, and lateral views.\" width=\"670\" height=\"493\" \/><figcaption class=\"wp-caption-text\">Figure A.40: The bones of the foot are divided into three groups. The posterior foot is formed by the seven tarsal bones. The mid-foot has the five metatarsal bones. The toes contain 14 phalanges. <a href=\"https:\/\/docs.google.com\/document\/d\/1VUDKMBJYS_jNONjLxT04jQN0_z9Ua50BRN6auGSHUuU\/edit\">A full text description of this image is available<\/a>. Credit: <a class=\"rId245\" href=\"https:\/\/cnx.org\/contents\/FPtK1zmh@12.17:c4okIKQJ@7\/Bones-of-the-Lower-Limb#fig-ch08_04_01\">Bones of the Foot (Anatomy &amp; Physiology, Figure 8.19)<\/a> by <a class=\"rId247\" href=\"https:\/\/openstax.org\/\">OpenStax<\/a> has been modified (some labels modified or removed) and is under a <a class=\"rId249\" href=\"https:\/\/creativecommons.org\/licenses\/by\/4.0\/\">CC BY 4.0 License<\/a>.<\/figcaption><\/figure>\n<div class=\"textbox shaded\">\n<h2 class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\">Review Questions<strong><br \/>\n<\/strong><\/h2>\n<ul>\n<li class=\"import-Normal\" style=\"background-color: transparent;text-align: left;text-indent: 0pt\">Which bony features of the pelvic girdle are relevant to estimating age and\/or sex in forensic and bioarchaeological contexts? Give specific examples of how these features differ among sexes.<\/li>\n<li class=\"import-Normal\" style=\"background-color: transparent;text-align: left;text-indent: 0pt\">What is the mechanistic difference between endochondral and intramembranous bone formation?<\/li>\n<li class=\"import-Normal\" style=\"background-color: transparent;text-align: left;text-indent: 0pt\">Which bones articulate with the calcaneus? Which bones articulate with the humerus?<\/li>\n<li class=\"import-Normal\" style=\"background-color: transparent;text-align: left;text-indent: 0pt\">Which elements of the skeleton belong to the axial skeleton versus the appendicular skeleton?<\/li>\n<\/ul>\n<\/div>\n<h2 class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\">Key Terms<strong><br \/>\n<\/strong><\/h2>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Acetabulum<\/strong>: Shallow cavity of the coxa for articulation of the head of the femur.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Acromion<\/strong>: Lateral projection of the spine of scapula.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Anatomical position<\/strong>: Standing upright, facing forward with arms at the side and palms facing forward.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Anterior (ventral)<\/strong>: Toward the front.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Appendicular skeleton<\/strong>: Part of the skeleton that consists of the bones of the pectoral and pelvic girdls, arms, and legs.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Atlanto-axial joint<\/strong>: Joint between the atlas (C1 vertebrae) and the axis (C2 vertebrae), used for turning the head side to side.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Atlanto-occipital joint<\/strong>: Joint between the atlas (C1 vertebrae) and occipital bone, used for nodding the head.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Auricular surface<\/strong>: Roughened joint surface for articulation of the sacrum.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Axial skeleton<\/strong>: Part of the skeleton that consists of the bones of the head and trunk.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Body of pubis<\/strong>: Superior bar of the pubis.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Body of the sternum<\/strong>: Central portion of the sternum where ribs articulate.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Buccal<\/strong>: Toward the cheek.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Calcaneal tuberosity<\/strong>: Roughened attachment site at the posterior calcaneus.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Calcaneus<\/strong>: Large bone that forms the heel.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Cancellous (or trabecular) bone<\/strong>: Porous bone found at the ends of long bones and within flat and irregular bones.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Canines:<\/strong> Conical teeth with a single pointed cusp used to puncture a food item.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Carpal bones<\/strong>: The 8 bones of the wrist: scaphoid, lunate, triquetrum, pisiform, trapezium, trapezoid, capitate, and hamate.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Centrum<\/strong>: Anterior body of vertebra; the main weight-bearing element of the vertebra.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Cervical region<\/strong>: Neck region that contains 7 vertebrae.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Clavicle<\/strong>: The collarbone, which connects the sternum to the scapula to form the pectoral girdle.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Coccyx<\/strong>: Small triangular bone that projects from the inferior part of sacrum.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Coracoid process<\/strong>: Hook-shaped projection from the anterior surface of the scapula.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Coronal (frontal) plane<\/strong>: An imaginary line that divides the body into anterior and posterior halves.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Coronal suture<\/strong>: Joint that connects the frontal bone to the paired parietal bones.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Coronoid process<\/strong>: Triangular eminence from the superior part of the mandibular ramus.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Coronoid process<\/strong><strong> of ulna<\/strong>: Triangular projection from the anterior surface of proximal ulna.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Cortical (or compact) bone<\/strong>: Dense, outer surface of bone.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Cranial sutures<\/strong>: Fibrous joints that connect bones of the skull and face.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Cranium<\/strong>: Bones of the head that support the brain and face.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Cribriform foramina<\/strong>: Small openings in the superior plate of the ethmoid that transmit olfactory nerves.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Deltoid tuberosity<\/strong>: Lateral projection for attachment of deltoid muscle.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Demifacets<\/strong>: Partial joint surfaces on the lateral surface of the centrum of thoracic vertebrae.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Dens (or odontoid process)<\/strong>: Projection from superior surface of centrum of C2.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Diaphysis<\/strong>: Shaft or central part of a long bone.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Distal<\/strong>: Further away from the center of the body or point of attachment.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Endochondral bone formation<\/strong>: Process of bone formation that occurs from a cartilage model.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Epiphysis<\/strong>: End of long bones.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Ethmoid bone<\/strong>: Unpaired bone of the skull that separates the nasal cavity from the brain.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>External occipital protuberance (EOP)<\/strong>: Projection from the occipital superior to nuchal lines.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Femur<\/strong>: Long bone of the thigh.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Fibula<\/strong>: Lateral bone of the leg.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Flat bone<\/strong>: Bones that are flat with thin layers of cortical bone surrounding cancellous bone.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Foramen magnum<\/strong>: Large opening in the occipital where the spinal cord passes.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Frontal bone<\/strong>: An unpaired bone that forms the anterior and superior part of the cranium.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Glabella<\/strong>: Part of the forehead between the eyebrows.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Glenoid cavity (or fossa)<\/strong>: Shallow depression for the articulation of the head of the humerus.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Gluteal tuberosity<\/strong>: Roughened attachment site for the gluteus maximus muscle.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Gonial (or mandibular) angle<\/strong>: Posterior border of the mandible at the junction of the ramus and body.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Greater sciatic notch<\/strong>: Large indentation of the ilium.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Greater trochanter<\/strong>: Large projection from the lateral surface of the proximal femur.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Greater tubercle<\/strong>: Large projection on the superior and lateral surface of the humerus.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Head of rib<\/strong>: Posterior part of the rib that articulates with the centrum.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Humerus<\/strong>: Long bone of the arm.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Hyoid bone<\/strong>: U-shaped bone in the neck that does not articulate with another bone.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Ilium<\/strong>: Large flat bone of the superior part of the coxa.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Incisal surface<\/strong>: Toward the cutting edge.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Incisors<\/strong>: Flat and shovel shaped teeth that are used to bite into a food item.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Inferior (caudal)<\/strong>: Away from the head or downward.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Inferior articular process<\/strong>: Inferior projections from the vertebral arch that connect to superior articular processes of the inferior vertebra.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Inferior nasal concha<\/strong>: Scroll-like paired bones that attach to the lateral part of the nasal cavity.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Intervertebral disc joints<\/strong>: Fibrocartilaginous joints that connect adjacent centra of vertebrae.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Intramembranous bone formation<\/strong>: Process of bone formation that occurs in mesenchyme and gives rise to flat bones of the skull.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Irregular bone<\/strong>: Bones that have a complex appearance.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Ischial spine<\/strong>: Thin, square projection from the ischium.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Ischial tuberosity<\/strong>: Large, round protrusion of the posterior and inferior ischium.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Ischiopubic ramus<\/strong>: Thin bar of bone that unites the pubis and ischium.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Ischium<\/strong>: The posterior and inferior portion of the os coxae.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Kyphosis<\/strong>: Anterior curvature of the spine.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Lacrimal bone<\/strong>: Paired bones that form the anterior and medial part of the orbit.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Lambdoidal suture<\/strong>: Joint that connects the parietal and occipital bones.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Lamina<\/strong>: Flattened portion of the vertebral arch.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Lateral<\/strong>: Further away from the midline.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Lateral malleolus<\/strong>: Prominence of the distal fibula that forms the outer part of the ankle.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Lesser trochanter<\/strong>: Projection from the medial surface of the proximal femur.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Lesser tubercle<\/strong>: Projection on the anterior and superior surface of the humerus.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Linea aspera<\/strong>: Elongated projection of the posterior surface of the femur.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Lingual<\/strong>: Toward the tongue.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Long bone<\/strong>: Bones that are longer than they are wide.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Lordosis<\/strong>: Posterior curvature of the spine.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Lumbar region<\/strong>: Lower back region that consists of 5 vertebrae.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Mandible<\/strong>: Lower jaw bone.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Mandibular condyle<\/strong>: Rounded projection of the mandibular ramus.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Mandibular fossa<\/strong>: Depression at the base of the temporal bone where the mandibular condyle articulates to form the temporomandibular (or jaw) joint.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Manubrium<\/strong>: Upper part of the sternum.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Mastoid process<\/strong>: Bony projection from the back of the temporal bone.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Maxilla bone<\/strong>: Upper jaw bone.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Medial<\/strong>: Toward the midline.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Medial malleolus<\/strong>: Prominence of the distal tibia that forms the inner part of the ankle.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Medullary cavity<\/strong>: Central cavity in the diaphysis of long bones that contains bone marrow.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Mental protuberance (eminence)<\/strong>: Triangular projection at the front of the mandible.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Mesial<\/strong>: Toward the middle.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Metacarpal<\/strong>: The 5 bones of the palm of the hand.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>M<\/strong><strong>etaphysis<\/strong>: Junction between diaphysis and epiphysis where bone growth occurs.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Metatarsal<\/strong>: The 5 bones at the distal part of the foot.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Metopic suture<\/strong>: Joint that connects paired frontal bones and usually fuses early in childhood.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Midsagittal plane<\/strong>: Plane that divides the body vertically into equal left and right halves. It is also called the medial plane, because it occurs on the midline of the body.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Molars:<\/strong> Teeth with flatter cusps that are used to grind food prior to swallowing.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Nasal aperture<\/strong>: Anterior opening of the nasal cavity.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Nasal bone<\/strong>: Paired bones that form the bridge of the nose and the roof of the nasal cavity.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Nasal spine<\/strong>: Bony projection from the inferior part of the nasal aperture.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Neurocranium<\/strong>: Bones of the cranium that protects the brain.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Nuchal lines<\/strong>: Ridges on occipital from attachment of neck and back muscles.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Obturator foramen<\/strong>: Irregularly shaped opening within the pubis and ischium.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Occipital bone<\/strong>: Unpaired bone at the posterior and base of the skull.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Occlusal<\/strong>: Toward the chewing surface.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Olecranon process<\/strong>: Posterior projection of the proximal ulna.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Orbit<\/strong>: Bony cavity that houses the eye and associated structures.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Os coxa<\/strong>: Hip bone, forms from the fusion of the ilium, ischium, and pubis.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Osteoblast<\/strong>: Cell that secretes the matrix for bone formation.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Osteoclast<\/strong>: A multinucleated bone cell that resorbs bone tissue during growth and repair.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Osteocyte<\/strong>: Mature bone cell that lies within the bone matrix.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Osteogenic cells<\/strong>: Stem cells that differentiate into osteoblasts.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Osteology<\/strong>: The study of bones.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Palatine bone<\/strong>: Paired bones that form the posterior part of the hard palate.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Parasagittal plane<\/strong>: A vertical imaginary line adjacent to the sagittal plane that divides the body into unequal halves.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Parietal bone<\/strong>: Paired bones forming the lateral walls of the cranium.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Patella<\/strong>: Knee cap; a bone that forms in the tendon of the quadriceps femoris muscle.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Pedicle<\/strong>: Projection that connects the lamina to the centrum.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Phalanges<\/strong>: The 14 bones of the digits.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Posterior (or dorsal)<\/strong>: Toward the back.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Premolars<\/strong>: Teeth with two rounded cusps that are used to grind and mash a food item.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Proximal<\/strong>: Closer to the center of the body or point of attachment.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Pterygoid plates<\/strong>: Flat projections of the sphenoid that serve as attachment sites for chewing muscles and muscles of the throat.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Pubic symphysis<\/strong>: Joint surface that unites the two pubic bones anteriorly.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Pubis<\/strong>: Anterior and inferior portion of the coxa.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Radial tuberosity<\/strong>: Rough projection for attachment of biceps brachii muscle.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Radius<\/strong>: Lateral bone of the forearm.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Ramus of the mandible<\/strong>: Bar-like portion of the posterior mandible.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Rib tubercle<\/strong>: Posterior part of the rib that articulates with the transverse process.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Sacrum<\/strong>: Triangular bone at the base of the spine that consists of 5 fused vertebrae.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Sagittal plane<\/strong>: An imaginary line that divides the body into left and right halves.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Sagittal suture<\/strong>: Joint that connects the parietal bones.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Scapula<\/strong>: Flat, triangular bone that connects the upper limb to the pectoral girdle.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Sesamoid bone<\/strong>: Bones that form within a tendon.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Short bone<\/strong>: Bones that are as wide as they are long.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Sphenoid bone<\/strong>: Unpaired bone that forms the anterior part of the base of the skull.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Spine<\/strong>: Elongated ridge on posterior surface.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Spinous process<\/strong>: Posterior projection of vertebral arch at the junction of the lamina.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Squamosal suture<\/strong>: Joint that connects the parietal and temporal bones.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Sternal end of the rib<\/strong>: Anterior part of rib that connects to the sternal body through costal cartilage.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Sternum<\/strong>: Breastbone; flat bone of the anterior chest wall.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Styloid process<\/strong>: Thin projection from the base of the temporal bone.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Styloid process of radius<\/strong>: Projection from the distal radius.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Styloid process of ulna<\/strong>: Projection from the distal ulna.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Subpubic concavity<\/strong>: Depression below the pubic symphysis to the ischiopubic rami.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Superior (or cranial)<\/strong>: Toward the head.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Superior articular process<\/strong>: Superior projections from the vertebral arch that connect to inferior articular processes of the superior vertebra.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Supraorbital margin<\/strong>: External ridge at the superior part of the orbit.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Talus<\/strong>: Ankle bone that articulates with the tibia.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Tarsal bones<\/strong>: The 7 bones at the proximal end of foot; talus, calcaneus, navicular, cuneiforms (medial, intermediate, lateral), and cuboid.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Temporal bone<\/strong>: Paired bones at the lateral and base of the skull that contain the middle and inner ear.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Temporal lines<\/strong>: Ridges on the parietal bone from attachments of temporalis muscle and fascia.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Temporal process of zygomatic bone<\/strong>: Long process that forms the anterior half of the zygomatic arch.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Thoracic region<\/strong>: Trunk region that consists of 12 vertebrae that attach to ribs.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Tibia<\/strong>: Medial bone of the leg.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Tibial tuberosity<\/strong>: Roughened attachment site on the anterior surface of the proximal tibia.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Transverse plane<\/strong>: An imaginary line that divides the body into superior and inferior halves.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Transverse process<\/strong>: Lateral projection at the junction of the pedicle and lamina.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Ulna<\/strong>: Medial bone of the forearm.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Vertebral arch<\/strong>: Circular ring of bone at the posterior vertebra.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Vertebral canal<\/strong>: Cavity that contains the spinal cord.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Vertebral foramen<\/strong>: Opening formed by the vertebral arch.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Viscerocranium<\/strong>: Bones of the cranium that make up the face skeleton.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Vomer<\/strong>: Unpaired bone that forms the inferior part of the bony nasal septum.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Xiphoid process<\/strong>: Lower part of the sternum.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Zygapophyseal (facet) joints<\/strong>: Synovial joints between the superior and inferior articular processes.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Zygomatic arch<\/strong>: Bridge of bone at the cheek.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Zygomatic bone<\/strong>: Paired bones that form the anterior and lateral parts of the mid-face.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Zygomatic process of temporal bone<\/strong>: Long process that forms the posterior half of the zygomatic arch.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Zygomatic process of the maxilla<\/strong>: Portion of the bone that articulates with the zygomatic bone to form the anterior portion of the zygomatic arch.<\/p>\n<h2 class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\">About the Authors<strong><br \/>\n<\/strong><\/h2>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\" data-wp-editing=\"1\"><img class=\"alignleft\" src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image3-7.jpg\" alt=\"A man with sandy grey hair and classes smiles at the camera. \" width=\"221\" height=\"260\" \/><\/p>\n<h3 class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Jason M. Organ, Ph.D.<\/strong><\/h3>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\">Indiana University School of Medicine, <a class=\"rId251\" href=\"mailto:jorgan@iupui.edu\">jorgan@iu.edu<\/a><\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\">Jason M. Organ is an associate professor of anatomy, cell biology, and physiology at the Indiana University School of Medicine (IUSM) and Editor-in-Chief of <em>Anatomical Sciences Education<\/em>, the premier peer-reviewed journal for anatomy education research. Jason earned an M.A. in anthropology from the University of Missouri and a PhD in functional anatomy and evolution from Johns Hopkins University School of Medicine, and he completed a postdoctoral research fellowship in physical medicine and rehabilitation at the Johns Hopkins Kennedy Krieger Institute. He is the director of the IUSM clinical anatomy and physiology M.S. program and was the 2018 recipient of the prestigious Basmajian Award from the American Association for Anatomy for excellence in teaching gross anatomy and outstanding accomplishments in biomedical research and scholarship in education. Follow him on Twitter: @OrganJM.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><img class=\"alignleft\" src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image31-2.jpg\" alt=\"A woman with long brown hair smiles at the camera.\" width=\"209\" height=\"314\" \/><\/p>\n<h3 class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\"><strong>Jessica N. Byram, Ph.D.<\/strong><\/h3>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\">Indiana University School of Medicine, <a class=\"rId253\" href=\"mailto:jbyram@iupui.edu\">jbyram@iu.edu<\/a><\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\">Jessica N. Byram is an assistant professor of anatomy, cell biology, and physiology at the Indiana University School of Medicine (IUSM). Jessica earned her M.S. in human biology with a focus in forensic anthropology from the University of Indianapolis and her Ph.D. in anatomy education at IUSM. Jessica is the director of the anatomy education track Ph.D. program at IUSM. Her research interests include medical professionalism, investigating professional identity formation in medical students and residents, and exploring how to improve the learning environments at medical institutions.<\/p>\n<h2 class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\">References<\/h2>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\">Bass, William M. 2005. <em>Human Osteology: A Laboratory and Field Manual, 5th edition.<\/em> Columbia, MO: Missouri Archaeological Society.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\">Boldsen, Jesper L., George R. Milner, Lyle W. Konigsberg, and James W. Wood. 2002. \u201cTransition Analysis: A New Method for Estimating Age from Skeletons.\u201d In <em>Paleodemography: Age Distributions from Skeletal Samples<\/em>, edited by Robert D. Hoppa and James W. Vaupel, 73\u2013106. Cambridge UK: Cambridge University Press.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\">Buikstra, Jane E., and Douglas H. Ubelaker. 1994. <em>Standards for Data Collection From Human Skeletal Remains<\/em>. Arkansas Archaeological Survey Research Series, 44. Fayetteville, AR: Arkansas Archeological Survey.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\">Burr, David B., and Jason M. Organ. 2017. \u201cPostcranial Skeletal Development and Its Evolutionary Implications.\u201d In <em>Building Bones: Bone Formation and Development in Anthropology<\/em>, edited by Christopher J. Percival and Joan T. Richtsmeier, 148\u2013174. Cambridge, UK: Cambridge University Press.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\">Christensen, Angi M., Nicholas V. Passalacqua, and Eric J. Bartelink. 2019. <em>Forensic Anthropology: Current Methods and Practice<\/em>. London: Academic Press.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\">Cunningham, Craig, Louise Scheuer, and Sue Black. 2017. <em>Developmental Juvenile Osteology, 2nd Edition<\/em>. London: Elsevier.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\">Hartnett, Kristen M. 2010 \u201cAnalysis of Age-at-Death Estimation Using Data from a New, Modern Autopsy Sample\u2014Part II: Sternal End of the Fourth Rib. <em>Journal of Forensic Sciences <\/em>55 (5): 1152\u20131156.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\">Meindl, Richard S., and C. Owen Lovejoy. 1985. \u201cEctocranial Suture Closure: A Revised Method for the Determination of Skeletal Age at Death Based on the Lateral-Anterior Sutures.\u201d <em>American Journal of Physical Anthropology<\/em> 68 (1): 57\u201366.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\">Nawrocki, Stephen P., Krista E. Latham, Thomas Gore, Rachel M. Hoffman, Jessica N. Byram, and Justin Maiers. 2018. \u201cUsing Elliptical Fourier Analysis to Interpret Complex Morphological Features in Global Populations.\u201d In <em>New Perspectives in Forensic Human Skeletal Identification<\/em>, edited by Krista E. Latham, Eric J. Bartelink, and Michael Finnegan, 301\u2013312. London: Elsevier\/Academic Press.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;text-indent: 0pt\">Walker, Phillip L. 2008. \u201cSexing Skulls Using Discriminant Function Analysis of Visually Assessed Traits.\u201d <em>American Journal of Physical Anthropology <\/em>136 (1): 39\u201350.<\/p>\n<\/div>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_281_1172\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_281_1172\"><div tabindex=\"-1\"><p>A space between the teeth, usually for large canines to fit when the mouth is closed.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_281_1693\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_281_1693\"><div tabindex=\"-1\"><div class=\"__UNKNOWN__\">\n<p class=\"import-Normal\">Michael B. C. Rivera, Ph.D., University of Cambridge<\/p>\n<p class=\"import-Normal\"><em>This chapter is a revision from <\/em><em>\"<\/em><a class=\"rId7\" href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/chapter\/__unknown__-12\/\"><em>Chapter 13: Race and Human Variation<\/em><\/a><em>\u201d by Michael B. C. Rivera. In <\/em><a class=\"rId8\" href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/\"><em>Explorations: An Open Invitation to Biological Anthropology, first edition<\/em><\/a><em>, edited by Beth Shook, Katie Nelson, Kelsie Aguilera, and Lara Braff, which is licensed under <\/em><a class=\"rId9\" href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\"><em>CC BY-NC 4.0<\/em><\/a><em>. <\/em><\/p>\n<div class=\"textbox textbox--learning-objectives\">\n<header class=\"textbox__header\">\n<h2 class=\"textbox__title\"><span style=\"color: #ffffff;\">Learning Objectives<\/span><\/h2>\n<\/header>\n<div class=\"textbox__content\">\n<ul>\n<li>Illustrate the troubling history of \u201crace\u201d concepts.<\/li>\n<li>Explain human variation and evolution as the thematic roots of biological anthropology as a discipline.<\/li>\n<li>Critique earlier \u201crace\u201d concepts based on a contemporary understanding of the apportionment of human genetic variation.<\/li>\n<li>Explain how biological variation in humans is distributed clinally and in accordance with both isolation-by-distance and Out-of-Africa models.<\/li>\n<li>Identify phenotypic traits that reflect selective and neutral evolution.<\/li>\n<li>Extend this more-nuanced view of human variation to today\u2019s research, the implications for biomedical studies, applications in forensic anthropology, and other social\/cultural\/political concerns.<\/li>\n<\/ul>\n<\/div>\n<\/div>\n<p>Humans exhibit biological variation.<span style=\"background-color: #ffff00;\"> Humans also have a universal desire to categorize other humans in order to make sense of the world around them<\/span>. Since the birth of the discipline of <strong>biological anthropology<\/strong> <span style=\"background-color: #ff99cc;\">(or <strong>physical anthropology<\/strong>, as referred to back then),<\/span> we have been interested in studying how humans vary biologically and what the sources of this variation are. Before we tackle these big problems, first consider this question: Why <em>should<\/em> we study human variation?<\/p>\n<figure style=\"width: 429px\" class=\"wp-caption alignright\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/06\/image26-3.png\" alt=\"Culturally and biologically diverse humans.\" width=\"429\" height=\"429\" \/><figcaption class=\"wp-caption-text\">Figure 13.1: Humans are culturally diverse (in that cultural differences contribute to a great degree of variation between individuals), but those shown are genetically undiverse. (Top left: Hadzabe members in Tanzania; top right: Inuit family; bottom left: Andean man in Peru; bottom right: English woman.) Credit: <a class=\"rId11\" href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/chapter\/__unknown__-12\/\">Humans are diverse (Figure 13.1)<\/a> original to <a class=\"rId12\" href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/\">Explorations: An Open Invitation to Biological Anthropology<\/a> by Michael Rivera is a collective work under a <a class=\"rId13\" href=\"https:\/\/creativecommons.org\/licenses\/by-nc-sa\/4.0\/\">CC BY-NC-SA 4.0<\/a> license. [Includes <a class=\"rId14\" href=\"https:\/\/commons.wikimedia.org\/wiki\/File:Tanzania_-_Hadzabe_hunter_(14533536392).jpg\">Tanzania - Hadzabe hunter (14533536392)<\/a> by <a class=\"rId15\" href=\"https:\/\/www.flickr.com\/people\/67947877@N06\">A_Peach<\/a>, <a class=\"rId16\" href=\"https:\/\/creativecommons.org\/licenses\/by\/2.0\/legalcode\">CC BY 2.0<\/a>; <a class=\"rId17\" href=\"https:\/\/commons.wikimedia.org\/wiki\/File:Inuit-Kleidung_1.jpg\">Inuit-Kleidung 1<\/a> by Ansgar Walk, <a class=\"rId18\" href=\"https:\/\/creativecommons.org\/licenses\/by-sa\/3.0\/legalcode\">CC BY-SA 3.0<\/a>; <a class=\"rId19\" href=\"https:\/\/commons.wikimedia.org\/wiki\/File:Andean_Man.jpg\">Andean Man<\/a> by <a class=\"rId20\" href=\"https:\/\/commons.wikimedia.org\/wiki\/User:Cacophony\">Cacophony<\/a>, <a class=\"rId21\" href=\"https:\/\/creativecommons.org\/licenses\/by-sa\/4.0\/legalcode\">CC BY-SA 4.0<\/a>; <a class=\"rId22\" href=\"https:\/\/commons.wikimedia.org\/wiki\/File:Jane_Goodall_GM.JPG\">Jane Goodall GM<\/a> by <a class=\"rId23\" href=\"https:\/\/commons.wikimedia.org\/wiki\/User:Floatjon\">Floatjon<\/a>, <a class=\"rId24\" href=\"https:\/\/creativecommons.org\/licenses\/by-sa\/3.0\/legalcode\">CC BY-SA 3.0<\/a>.<\/figcaption><\/figure>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">There are certainly academic reasons for studying human variation. First, it is highly interesting and important to consider the evolution of our species (see Chapters 9\u201312) and how our biological variation may be similar to (or different from) that of other species (e.g., other primates and apes; see Chapters 5 and 6). Second, anthropologists study modern human variation to understand how different biological traits developed over evolutionary time (see Figure 13.1). Suppose we are able to grasp the evolutionary processes that produce the differences in biology, physiology, body chemistry, behavior, and culture (<strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_804\">human variation<\/a><\/strong>). In that case, we can make more accurate inferences about evolution and adaptation among our hominin ancestors, complementing our study of fossil evidence and the archaeological record. Third, as will be discussed in more detail later on, it is important to consider that biological variation among humans has biomedical, forensic, and sociopolitical implications. For these reasons, the study of human variation and evolution has formed the basis of anthropological inquiry for centuries and continues to be a major source of intrigue and inspiration for scientific research conducted today.<\/p>\n<p class=\"import-Normal\">An even-more-important role of the biological anthropologist is to improve public understanding of human evolution and variation\u2014outside of academic circles. Terms such as <strong>race<\/strong> and <strong>ethnicity<\/strong> are used in everyday conversations and in formal settings within and outside academia. The division of humankind into smaller, discrete categories is a regular occurrence in day-to-day life. This can be seen regularly when governments acquire census data with a heading like \u201cgeographic origin\u201d or \u201cethnicity.\u201d Furthermore, such checkboxes and drop-down lists are commonly seen as part of the identifying information required for surveys and job applications.<\/p>\n<p class=\"import-Normal\">According to professors of anthropology, ethnic studies, and sociology, race is often understood as rooted in biological differences, ranging from such familiar traits as skin color or eye shape to variations at the genetic level. However, race can also be studied as an \u201cideological construct\u201d that goes beyond biological and genetic bases (Fuentes et al. 2019), at different times relating to our ethnicities, languages, religious beliefs, and cultural practices. Sometimes people associate racial identity with the concept of socioeconomic status or position, or they link ideas about race to what passport someone has, how long they have been in a country, or how well they have \u201cintegrated\u201d into a population.<\/p>\n<p class=\"import-Normal\">Some of these ideas about ethnicity have huge social and political impacts, and notions of race have been part of the motivation behind various forms of racism and prejudice today, as well as many wars and genocides throughout history. <strong>Racism<\/strong> manifests in many ways\u2014from instances of bullying between kids on school playgrounds to underpaid minorities in the workforce, and from verbal abuse hurled at people of color to violent physical behaviors against those of a certain race. <strong>Prejudice<\/strong> can be characterized as negative views toward another group based on some perceived characteristic that makes all members of that group worthy of disdain, disrespect, or exclusion (not solely along racial lines but also according to [dis]ability, gender, sexual orientation, or socioeconomic background, for example). According to Shay-Akil McLean (2014), \u201cRacism is not something particular to the United States and race is not the same everywhere in the world. Racial categories serve particular contextual purposes depending on the society they are used in, but generally follow the base logic of the supremacy of one type of human body over all others (ordering these human bodies in a hierarchical fashion).\u201d Choosing which biological or nonbiological features to use when discussing race is always a social process (Omi and Winant 2014). Race concepts have no validity to them unless people continue to use them in their daily lives\u2014and, in the worst cases, to use them to justify racist behaviors and problematic ideas about racial difference or superiority\/inferiority. Recent work in anthropological genetics has revealed the similarities amongst humans on a molecular level and the relatively few differences that exist between populations (Omi and Winant 2014).<\/p>\n<p class=\"import-Normal\">The role of the biological anthropologist becomes crucial in the public sphere, because we may be able to debunk myths surrounding human variation and shed light, for the nonanthropologists around us, on how human variation is actually distributed worldwide (see Figure 13.1). Rooted in scientific observations, our work can help nonanthropologists recognize how common ideas about \u201crace\u201d often have no biological or genetic basis. Many anthropologists work hard to educate students on the history of where race concepts come from, why and how they last in public consciousness, and how we become more conscious of racial issues and the need to fight against racism in our societies. Throughout this chapter, I will highlight how humans cannot actually be divided into discrete \u201craces,\u201d because most traits vary on a continuous basis and human biology is, in fact, very <strong>homogenous<\/strong> compared to the greater genetic variation we observe in closely related species. Molecular anthropology, or anthropological genetics, continues to add new layers to our understanding of human biological variation and the evolutionary processes that gave rise to the contemporary patterns of human variation. The study of human variation has not always been unbiased, and thinkers and scientists have always worked in their particular sociohistorical context. For this reason, this chapter opens with a brief overview of race concepts throughout history, many of which relied on unethical and unscientific notions about different human groups.<\/p>\n<\/div>\n<div class=\"textbox\">\n<h2 class=\"import-Normal\">Special Topic: My Experiences as an Asian Academic<\/h2>\n<figure style=\"width: 578px\" class=\"wp-caption aligncenter\"><img class=\"\" src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image10-4.jpg\" alt=\"Outdoor photo of this chapter\u2019s author.\" width=\"578\" height=\"433\" \/><figcaption class=\"wp-caption-text\">Figure 13.2: Michael B. C. Rivera in Hong Kong. Credit: Michael B. C. Rivera in Hong Kong original to Explorations: An Open Invitation to Biological Anthropology (2nd ed.) is under a <a class=\"rId26\" href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/\">CC BY-NC 4.0 License<\/a>.<\/figcaption><\/figure>\n<p>My name is Michael, and I am a biological anthropologist and archaeologist (Figure 13.2). What strikes me as most interesting to investigate is human biological variation today and the study of past human evolution. For instance, some of my research on ancient coastal populations has revealed positive effects of coastal living on dietary health and many unique adaptations in bones and teeth when living near rivers and beaches. I love talking to students and nonscientists about bioanthropologists\u2019 work, through teaching, science communication events, and writing book chapters like this one. I grew up in Hong Kong, a city in southern China. My father is from the Philippines and my mother is from Hong Kong, which makes me a mixed Filipino-Chinese academic. Growing up, I noticed that people came in all shapes, sizes, and colors. My life is very different now in that I have gained the expertise to explain those differences, and I feel a great responsibility to guide those new to anthropology toward their own understandings of diversity.<\/p>\n<p class=\"import-Normal\">Biological anthropology is not taught extensively in Hong Kong, so I moved to the United Kingdom to earn my bachelor\u2019s, master\u2019s, and doctorate degrees. It was fascinating to me that we could answer important questions about human variation and history using scientific methods. However, I did not have many minority academic role models to look up to while I was at university. My department was made up almost exclusively of white westerner faculty, and it was hard to imagine I could one day get a job at these western institutions. While pursuing my degrees, I also remember several instances of my research contributions being overlooked or dismissed. Sometimes professors and fellow students would make racist comments toward Asian scholars (including me) and other Black, Indigenous and researchers of color, making us greatly uncomfortable in those spaces. When one of us would work up the courage to tell university leaders our experiences of being stereotyped, dismissed, or insulted, we received little support and were further excluded from research and teaching activities. This is a common experience for Black, Indigenous, and other people of color who pursue biological anthropology, and we face the difficult choice between leaving the field or bearing with such unsafe spaces.<\/p>\n<p class=\"import-Normal\">It became important to me at that time to find other academics of color with whom to share experiences and form community. I feel inspired by all my colleagues who advocate for greater representation and diversity in universities (whether they are minority academics or not). I admire many of my fellow researchers who are underrepresented and do a great job of representing minority groups through their cutting-edge research and quality teaching at the undergraduate and graduate levels. Although I no longer work in the West, it has remained my great hope that those in the West and the \u201cGlobal North\u201d will continue to improve university culture, and I support any efforts there to welcome all scholars.<\/p>\n<p class=\"import-Normal\">My current work is based in Hong Kong, where I am deeply dedicated to helping develop biological anthropology in East and Southeast Asia and promoting research from our home regions on the international scene. The study of anthropology really highlights how we share a common humanity and history. Being somebody who is \u201cmixed race\u201d and Asian likely played a key role in steering me toward the study of human variation. As this chapter hopefully shows, there is a lot to discuss about race and ethnicity regarding the discipline\u2019s history and current understandings of <strong>human diversity<\/strong>. Some scientific and technological advancements today are misused for reasons to do with money, politics, or the continuation of antiquated ideas. It is my belief, alongside many of my friends and fellow anthropologists, that science should be more about empathy toward all members of our species and contributing to the intellectual and technological nourishment of society. After speaking to many members of the public, as well as my own undergraduate students, I have received lovely messages from other individuals of color expressing thanks and appreciation for my presence and understanding as a minority scientist and mentor figure. Anthropology needs much more diversity as well as to make room for those who have traveled different routes into the discipline. All paths taken into anthropology are valid and valuable. I would encourage everyone to study anthropology\u2014it is a field for understanding and celebrating the intricacies of human diversity.<\/p>\n<\/div>\n<div class=\"__UNKNOWN__\">\n<h2 class=\"import-Normal\">The History of \"Race\" Concepts<\/h2>\n<h3 class=\"import-Normal\"><strong>\u201cRace\u201d in the Classical Era<\/strong><\/h3>\n<figure style=\"width: 435px\" class=\"wp-caption alignleft\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image11-8.png\" alt=\"Painting of four individuals with varied skin colors, head hair, facial hair, and clothing styles.\" width=\"435\" height=\"331\" \/><figcaption class=\"wp-caption-text\">Figure 13.3: (From left to right) Depicting a Berber (Libyan), a Nubian, an Asiatic (Levantine), and an Egyptian, copied from a mural on the tomb of Seti I. Credit: Egyptian races drawing by Heinrich von Minutoli (1820) of a mural by an unknown artist from the tomb of Seti I is in the public domain.<\/figcaption><\/figure>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">The earliest classification systems used to understand human variation are evidenced by ancient manuscripts, scrolls, and stone tablets recovered through archaeological, historical, and literary research. The Ancient Egyptians had the <em>Book of Gates<\/em>, dated to the New Kingdom between 1550 B.C.E. and 1077 B.C.E (Figure 13.3). In one part of this tome dedicated to depictions of the underworld, scribes used pictures and hieroglyphics to illustrate a division of Egyptian people into the four categories known to them at the time: the Aamu (Asiatics), the Nehesu (Nubians), the Reth (Egyptians), and the Themehu (Libyans). Though not rooted in any scientific basis like our current understandings of human variation today, the Ancient Egyptians believed that each of these groups were made of a distinctive category of people, distinguishable by their skin color, place of origin, and even behavioral traits.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Another well-known early document is the Bible, where it is written that all humankind descends from one of three sons of Noah: Shem (the ancestor to all olive-skinned Asians), Japheth (the ancestor to pale-skinned Europeans), and Ham (the ancestor to darker-skinned Africans). Similar to the Ancient Egyptians, these distinctions were based on behavioral traits and skin color. More recent work in historiography and linguistics suggest that the branches of \u201cHamites,\u201d \u201cJaphethites,\u201d and \u201cShemites\u201d may also relate to the formation of three independent language groups some time between 1000 and 3000 B.C.E. With the continued proliferation of Christianity, this concept of approximately three racial groupings lasted until the Middle Ages and spread as far across Eurasia as crusaders and missionaries ventured at the time.<\/p>\n<figure style=\"width: 309px\" class=\"wp-caption alignright\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image9-9.png\" alt=\"Rows of organisms, with plants and animals at the bottom and humans, angels, and God at top.\" width=\"309\" height=\"449\" \/><figcaption class=\"wp-caption-text\">Figure 13.4: The Great Chain of Being from the Rhetorica Christiana by Fray Diego de Valades (1579). Credit: Great Chain of Being 2 by Didacus Valades (Diego Valades 1579) and photographed by Rhetorica Christiana (via Getty Research) is in the public domain.<\/figcaption><\/figure>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">There is also the \u201cGreat Chain of Being,\u201d conceived by ancient Greek philosophers like Plato (427\u2012348 B.C.E.) and Aristotle (384\u2012322 B.C.E.). They played a key role in laying the foundations of empirical science, whereby observations of everything from animals to humans were noted with the aim of creating taxonomic categories. Aristotle describes the Great Chain of Being as a ladder along which all objects, plants, animals, humans, and celestial bodies can be mapped in an overall hierarchy (in the order of existential importance, with humans placed near the top, just beneath divine beings; see Figure 13.4). When he writes about humans, Aristotle expressed the belief that certain people are inherently (or genetically) more instinctive rulers, while others are more natural fits for the life of a worker or enslaved person. Based on research by biological anthropologists, we currently recognize that these early systems of classification and hierarchization are unhelpful in studying human biological variation. Both behavioral traits and physical traits are coded for by multiple genes each, and how we exhibit those traits based on our genetics can vary significantly even between individuals of the same population.<\/p>\n<h3 class=\"import-Normal\"><strong>\u201cRace\u201d during the Scientific Revolution<\/strong><\/h3>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">The 1400s to 1600s saw the beginnings of the <strong>Scientific Revolution<\/strong> in Western societies, with thinkers like Nicholas Copernicus, Galileo Galilei, and Leonardo Da Vinci publishing some of their most important findings. While by no means the first or only scholars globally to use observation and experimentation to understand the world around them, early scientists living at the end of the medieval period in Europe increasingly employed more experimentation, quantification, and rational thought in their work. This is the main difference between the work of the ancient Egyptians, Romans, and Greeks and that of later scientists such as Isaac Newton and Carl Linnaeus in the 1600s and 1700s.<\/p>\n<figure style=\"width: 215px\" class=\"wp-caption alignleft\"><img class=\"\" src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image24-2.png\" alt=\"Historic painting of a man in 18th-century wig and garments.\" width=\"215\" height=\"259\" \/><figcaption class=\"wp-caption-text\">Figure 13.5: Carl Linnaeus. Credit: <a class=\"rId35\" href=\"https:\/\/commons.wikimedia.org\/wiki\/File:Carl_von_Linn%C3%A9.png\">Carl von Linn\u00e9<\/a> by <a class=\"rId36\" href=\"https:\/\/en.wikipedia.org\/wiki\/en:Alexander_Roslin\">Alexander Roslin<\/a> (1718-1793) is in the <a class=\"rId37\" href=\"https:\/\/en.wikipedia.org\/wiki\/Public_domain\">public domain<\/a>.<\/figcaption><\/figure>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Linnaeus is the author of <em>Systema Naturae<\/em> (1758), in which he classified all plants and animals under the formalized naming system known as <strong>binomial nomenclature<\/strong> (Figure 13.5). This system is <strong>typological<\/strong>, in that organisms are placed into groups according to how they are similar or different to others under study. What was most anthropologically notable about Linnaeus\u2019s typological system was that he was one of the first to group humans with apes and monkeys, based on the anatomical similarities between humans and nonhuman primates. However, Linnaeus viewed the world in line with <strong>essentialism<\/strong>, a problematic concept that dictates that there are a unique set of characteristics that organisms of a specific kind <em>must<\/em> have and that would remove organisms from taxonomic categorizations if they lacked any of the required criteria.<\/p>\n<p>Linnaeus subdivided the human species into four varieties, with overtly racist categories based on skin color and \u201cinherent\u201d behaviors. Some European scientists during this period were not aware of their own biases skewing their interpretations of biological variation, while others deliberately worked to shape public perceptions of human variation in ways that established \u201c<strong>otherness<\/strong>\u201d and enforced European domination and the subordination of non-European people. The conclusions and claims at which they arrived, consciously or subconsciously, often fit the times they were living through\u2014the so-called <strong>Age of Discovery<\/strong>, when the superiority of European cultures over others was a pervasive idea throughout people\u2019s social and political lives. Although much of Eurasia was linked by spice- and silk-trading routes, the European colonial period between the 1400s and 1700s was marked by many new and unfortunately violent encounters overseas (Figure 13.6). When Europeans arrived by ship on the shores of continents that were already inhabited, it was their first meeting with the Indigenous peoples of the Americas and Australasia, who looked, spoke, and behaved differently from peoples with whom they were familiar. Building on the idea of species and \u201csubspecies,\u201d natural historians of this time invented the term <em>race<\/em>, from the French <em>rasse<\/em> meaning \u201clocal strain.\u201d<\/p>\n<figure style=\"width: 421px\" class=\"wp-caption alignright\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image25-4.png\" alt=\"Spanish explorers with their military and religious gear surrounding indigenous people.\" width=\"421\" height=\"273\" \/><figcaption class=\"wp-caption-text\">Figure 13.6: A painting depicting the colonization of the Mississippi River environs by Spaniard Hernando DeSoto in 1541 (painted in 1853 by William H. Powell). Credit: <a class=\"rId39\" href=\"https:\/\/commons.wikimedia.org\/wiki\/File:Discovery_of_the_Mississippi.jpg\">Discovery of the Mississippi<\/a> by <a class=\"rId40\" href=\"https:\/\/en.wikipedia.org\/wiki\/en:William_Henry_Powell\">William Henry Powell<\/a> (photograph courtesy of <a class=\"rId41\" href=\"https:\/\/en.wikipedia.org\/wiki\/Architect_of_the_Capitol\">Architect of the Capitol<\/a>) is in the <a class=\"rId42\" href=\"https:\/\/en.wikipedia.org\/wiki\/Public_domain\">public domain<\/a>.<\/figcaption><\/figure>\n<p class=\"import-Normal\">Another scientist of the times, Johann Friedrich Blumenbach (1752\u20121840), classified humans into five races based on his observations of cranial form variation as well as skin color. He thus dubbed the \u201coriginal\u201d form of the human cranium the \u201cCaucasian\u201d form, with the idea that the ideal climate conditions for early humans would have been in the Caucasus region near the Caspian Sea. The key insight Blumenbach presented was that human variation in any particular trait should be more accurately viewed as falling along a gradation (Figure 13.7). While some of his theories were correct according to what we observe today with more knowledge in genetics, they erroneously believed that human \u201csubspecies\u201d were \u201cdegenerated\u201d or \u201ctransformed\u201d varieties of an ancestral Caucasian or European race. According to them, the Caucasian cranial dimensions were the least changed over human evolutionary time, while the other skull forms represented geographic variants of this \u201coriginal.\u201d As will be discussed in greater detail later in this chapter, we have genetic and craniometric evidence for sub-Saharan Africa being the origin of the human species instead (see Chapter 12 on the fossil record that places the origins of modern <em>Homo sapiens<\/em> in north and east Africa). Based on work that shows how most biological characteristics are coded for by nonassociated genes, it is not reasonable to draw links between individuals\u2019 personalities and their skull shapes.<\/p>\n<figure style=\"width: 686px\" class=\"wp-caption aligncenter\"><img class=\"\" src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image7-10.png\" alt=\"Historic drawing of five skulls.\" width=\"686\" height=\"259\" \/><figcaption class=\"wp-caption-text\">Figure 13.7: Five skull drawings representing specimens for Blumenbach\u2019s \u201cMongolian,\u201d \u201cAmerican,\u201d \u201cCaucasian,\u201d \u201cMalayan,\u201d and \u201cAethiopian\u201d races. Credit: <a class=\"rId44\" href=\"https:\/\/commons.wikimedia.org\/wiki\/File:Blumenbach's_five_races.JPG\">Blumenbach's five races<\/a> by Johann Friedrich Blumenbach is in the <a class=\"rId45\" href=\"https:\/\/en.wikipedia.org\/wiki\/Public_domain\">public domain<\/a>. Original in the 1795 Treatise on \"De generis humani varietate nativa,\" unnumbered page at the end of the book titled \"Tab II\".<\/figcaption><\/figure>\n<h3 class=\"import-Normal\"><strong>\u201cRace\u201d and the Dawn of Scientific Racism<\/strong><\/h3>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Between the 1800s and mid-1900s, and contrary to what you might expect, an increased use of scientific methods to justify racial schemes developed in scholarship. Differing from earlier views, which saw all humans as environmentally deviated from one \u201coriginal\u201d humankind, classification systems after 1800 became more <strong>polygenetic<\/strong> (viewing all people as having separate origins) rather than <strong>monogenetic<\/strong> (viewing all people as having a single origin). Instead of moving closer to our modern-day understandings of human variation, there was increased support for the notion that each race was created separately and with different attributes (intelligence, temperament, and appearance).<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">The 1800s were an important precursor to modern biological anthropology as we know it, given that this was when the scientific measurement of human physical features (anthropometry) truly became popularized. However, empirical studies in the 1800s pushed even further the idea that Europeans were culturally and biologically superior to others. While considered one of the pioneers of American \u201cphysical\u201d anthropology, Samuel George Morton (1799\u20121851) was a scholar who had a large role in perpetuating 1800s scientific racism. By measuring cranial size and shape, he calculated that \u201cCaucasians,\u201d on average, have greater cranial volumes than other groups, such as the Indigenous peoples of the Americas and peoples Morton referred to collectively as \u201cNegros.\u201d Today, we know that cranial size variation depends on such factors as Allen\u2019s and Bergmann\u2019s rules, which give a more likely explanation: in colder environments, it is advantageous for those living there to have larger and rounder heads because they conserve heat more effectively than more slender heads (Beals et al. 1984). The leading figures in craniometry during the 1800s instead were linked heavily with powerful individuals and wealthy sociopolitical institutions and financial bodies. Theories in support of hierarchical racial schemes using \u201cscientific\u201d bases certainly helped continue the exploitative and unethical trafficking and enslavement of Africans between the 1500s and 1800s.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Morton went on to write in his publication <em>Crania Americana<\/em> (1839) a number of views that fit with a concept called <strong>biological determinism<\/strong>. The idea behind biological determinism is that an association exists between people\u2019s physical characteristics and their behavior, intelligence, ability, values, and morals. If the idea is that some groups of people are essentially superior to others in cognitive ability and temperament, then it is easier to justify the unequal treatment of certain groups based on outward appearances. Another such problematic thinker was Paul Broca (1824\u20121880), after whom a region of the frontal lobe related to language use is named (Broca\u2019s area). Influenced by Morton, Broca likewise claimed that internal skull capacities could be linked with skin color and cognitive ability. He went on to justify the European colonization of other global territories by purporting it was noble for a biologically more \u201ccivilized\u201d population to improve the \u201chumanity\u201d of more \u201cbarbaric\u201d populations. Today, these theories of Morton, Broca, and others like them are known to have no scientific basis. If we could speak with them today, they would likely try to emphasize that their conclusions were based on empirical evidence and not <em>a priori<\/em> reasoning. However, we now can clearly see that their reasoning was biased and affected by prevailing societal views at the time.<\/p>\n<h3 class=\"import-Normal\"><strong>\u201cRace\u201d and the Beginnings of Physical Anthropology<\/strong><\/h3>\n<p class=\"import-Normal\">In the early 20th century, we saw a number of new figures coming into the science of human variation and shifting the theoretical focus within. Most notably, these included Ale\u0161 Hrdli\u010dka and Franz Boas.<\/p>\n<figure style=\"width: 430px\" class=\"wp-caption alignleft\"><img class=\"\" src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image19-4.jpg\" alt=\"Historic photo of a middle-aged person in suit and bowtie.\" width=\"430\" height=\"558\" \/><figcaption class=\"wp-caption-text\">Figure 13.8: Ale\u0161 Hrdli\u010dka (1869\u00ad\u20121943), a Czech anthropologist who founded the American Journal of Physical Anthropology. Credit: <a class=\"rId47\" href=\"https:\/\/siarchives.si.edu\/collections\/siris_sic_10822?back=%2Fcollections%2Fsearch%3Fquery%3Dczech%26online%3Dtrue%26page%3D1%26perpage%3D10%26sort%3Drelevancy%26view%3Dlist#\">(Ales Hrdlicka) SIA2009-4246<\/a> (1903) by an unknown photographer <a class=\"rId48\" href=\"https:\/\/www.si.edu\/termsofuse\">is used for educational and non-commercial purposes as outlined by the Smithsonian.<\/a>. [<a class=\"rId49\" href=\"https:\/\/www.si.edu\/\">Smithsonian Institution<\/a> Archives, Record Unit 9521, Box 1, T. Dale Stewart Oral History Interview; and Record Unit 9528, Box 1, Henry B. Collins Oral History Interview.]<\/figcaption><\/figure>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Ale\u0161 Hrdli\u010dka (1869\u00ad\u20121943) was a Czech anthropologist who moved to the United States. In 1903, he established the physical anthropology section of the National Museum of Natural History (Figure 13.8). In 1918, he founded the <em>American Journal of Physical Anthropology<\/em>, which remains one of the foremost scientific journals disseminating bioanthropological research. As part of his work and the scope of the journal, he differentiated \u201c<strong>physical anthropology<\/strong>\u201d from other kinds of anthropology: he wrote that physical anthropology is \u201cthe study of racial anatomy, physiology, and pathology\u201d and \u201cthe study of man\u2019s variation\u201d (Hrdli\u010dka 1918). In some ways, although the scope and technological capabilities of biological anthropologists have changed significantly, Hrdli\u010dka established an area of inquiry that has continued and prospered for over a hundred years.<\/p>\n<p class=\"import-Normal\">Franz Boas (1858\u20121942) was a German American anthropologist who established the four-field anthropology system in the United States and founded the American Anthropological Association in 1902. He argued that the scientific method should be used in the study of human cultures and the comparative method for looking at human biology worldwide. One of Boas\u2019s significant contributions to biological anthropology was the study of skull dimensions with respect to race. After a long-term research project, he demonstrated how cranial form was highly dependent on cultural and environmental factors and that human behaviors were influenced primarily not by genes but by social learning. He wrote in one essay for the journal <em>Science<\/em>: \u201cWhile individuals differ, biological differences between races are small. There is no reason to believe that one race is by nature so much more intelligent, endowed with great willpower, or emotionally more stable than another, that the difference would materially influence its culture\u201d (Boas 1931:6). This conclusion directly contrasted with the theories of the past that relied on biological determinism. Biological anthropologists today have found evidence that corroborates Boas\u2019s explanations: societies do not exist on a hierarchy or gradation of \u201ccivilizedness\u201d but instead are shaped by the world around them, their demographic histories, and the interactions they have with other groups.<\/p>\n<figure style=\"width: 358px\" class=\"wp-caption alignleft\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image2-7.png\" alt=\"Black-and-white sketch of tree labeled \u201cEugenics.\u201d \" width=\"358\" height=\"275\" \/><figcaption class=\"wp-caption-text\">Figure 13.9: Logo of the Second International Exhibition of Eugenics, held in 1921. The text of the logo states: \"Eugenics is the self-direction of human evolution. Like a tree, eugenics draws its materials from many sources and organizes them into an harmonious entity.\" Credit: <a class=\"rId51\" href=\"https:\/\/commons.wikimedia.org\/wiki\/File:Eugenics_congress_logo.png\">Eugenics congress logo<\/a> scanned from <a class=\"rId52\" href=\"https:\/\/en.wikipedia.org\/wiki\/Harry_H._Laughlin\">Harry H. Laughlin<\/a>, The Second International Exhibition of Eugenics held September 22 to October 22, 1921, is in the <a class=\"rId53\" href=\"https:\/\/en.wikipedia.org\/wiki\/Public_domain\">public domain<\/a>.<\/figcaption><\/figure>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">The first half of the 1900s still involved some research that was essentialist and focused on proving racial determinism. Anthropologists like Francis Galton (1822\u20121911) and Earnest A. Hooton (1887\u20121954) created the field of <strong>eugenics<\/strong> as an attempt to formalize the social scientific study of \u201cfitness\u201d and \u201csuperiority\u201d among members of 19th-century Europe. As a way of \u201cdealing with\u201d criminals, diseased individuals, and \u201cuncivilized\u201d people, eugenicists recommended prohibiting parts of the population from being married or sterilizing these members of society so they could no longer procreate (Figure 13.9). They instead encouraged \u201creproduction in individual families with sound physiques, good mental endowments, and demonstrable social and economic capability\u201d (Hooton 1936). In the 1930s, Nazi Germany used this false idea of there being \u201cpure races\u201d to highly destructive effect. The need to be protected against admixture from \u201cunfit\u201d groups was their justification for their blatant racism and purging of citizens that fell under their subjective criteria.<\/p>\n<p class=\"import-Normal\">It should be noted that eugenicist ideas were popularly discussed and debated in many non-European contexts, as in the U.S., China, and South Africa, too. The Immigration Restriction Act of 1924 was passed in the United States, with the explicit aim of reducing the country\u2019s \u201cburden\u201d of people considered inferior by restricting immigration of eastern European Jews, Italians, Africans, Arabs, and Asians. In the early 1900s, Chinese scientists and politicians showed great interest in eugenic ideologies, which came to dictate decisions in law-making, family life, and the medical field. Noted American anthropologist Ruth Benedict wrote extensively on Japanese culture and society during and after World War II. Her essentialist portrayals of Japanese people were heavily cited in popular discourse at the time. In 1950s South Africa, interracial marriages and sexual relations were banned by law; antimiscegenation became one of the huge focuses of apartheid resistance activists in later years. We still see the continuation of eugenics-based logic today around the world\u2014in exclusionary immigration laws, cases of incarcerated prison inmates being forcibly sterilized, and the persistence of intelligence testing as a form of measuring people\u2019s \u201cfitness\u201d in a society.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Shortly after World War II and the Nazi Holocaust, the full extent of essentialist, eugenicist thinking became clear. Social constructions of race, and the notion that one can predict psychological or behavioral traits based on external appearance, had become unpopular both within and outside the discipline. It was up to those in the field of physical anthropology at the time to separate physical anthropology from race concepts that supported unscientific and socially damaging agendas. This does not mean that there are no physiological or behavioral differences between different members of the human species. However, going forward, a number of physical anthropologists saw human biological variation as more complicated than simple typologies could describe.<\/p>\n<h3 class=\"import-Normal\"><strong>\u201cThe New Physical Anthropology\u201d<\/strong><\/h3>\n<figure style=\"width: 219px\" class=\"wp-caption alignright\"><img class=\"\" src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image14-6.png\" alt=\"Black-and-white photo of a person with short hair in a white shirt and tie.\" width=\"219\" height=\"291\" \/><figcaption class=\"wp-caption-text\">Figure 13.10: Theodosius Dobzhansky, an important scientist who formulated the 20th-century \u201cmodern synthesis\u201d reconciling Charles Darwin\u2019s theory of evolution and Gregor Mendel\u2019s ideas on heredity. Credit: <a class=\"rId55\" href=\"https:\/\/commons.wikimedia.org\/wiki\/File:Dobzhansky_no_Brasil_em_1943.jpg\">Dobzhansky no Brasil em 1943<\/a> by unknown photographer via <a class=\"rId56\" href=\"https:\/\/www.flickr.com\/photos\/celycarmo\/\">Flickr user Cely Carmo<\/a> is in the <a class=\"rId57\" href=\"https:\/\/en.wikipedia.org\/wiki\/Public_domain\">public domain<\/a>.<\/figcaption><\/figure>\n<p class=\"import-Normal\">After 1950, focus steered away from the concept of \u201crace\u201d as a unit of variation and toward understanding why variation exists in <strong>population<\/strong><strong>s<\/strong> from an evolutionary perspective. This was outlined by those pioneering the \u201cnew physical anthropology,\u201d such as Sherwood Washburn, Theodosius Dobzhansky (Figure 13.10), and Julian Huxley, who borrowed this approach from contemporary population geneticists. Whether using genetic or phenotypic markers as the units of study, \u201cgroups\u201d or \u201cclusters\u201d of humans differentiated by these became defined as populations that differ in the frequency of some gene or genes. Anthropologists consider what \u201cmakes\u201d a population\u2014a group of individuals potentially capable of or actually interbreeding due to shared geographic proximity, language, ethnicity, culture, and\/or values. Put another way, a population is a local interbreeding group with reduced gene flow between themselves and other groups of humans. Members of the same population may be expected to share many genetic traits (and, as a result, many phenotypic traits that may or may not be visible outwardly).<\/p>\n<figure style=\"width: 240px\" class=\"wp-caption alignleft\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image15-6.png\" alt=\"Black-and-white photo of smiling person in a suit and tie in front of a building.\" width=\"240\" height=\"300\" \/><figcaption class=\"wp-caption-text\">Figure 13.11: Julian Huxley (1942). Credit: <a class=\"rId59\" href=\"https:\/\/commons.wikimedia.org\/wiki\/File:Julian_Huxley_1-2.jpg\">Julian Huxley 1-2<\/a> by unknown photographer is in the <a class=\"rId60\" href=\"https:\/\/en.wikipedia.org\/wiki\/Public_domain\">public domain<\/a>.<\/figcaption><\/figure>\n<p class=\"import-Normal\">Thinking of humans in terms of populations was part of Julian Huxley\u2019s (1942) \u201cModern Synthesis\u201d\u2014so named because it helped to reconcile two fundamental principles about evolution that had not been made sense of together before (Figure 13.11). As discussed in Chapter 3, Gregor Mendel (1822\u20121884) was able to show that inheritance was mediated by discrete particles (or genes) and not blended in the offspring. However, it was difficult for some 19th-century scientists to accept this model of genetic inheritance at the time because much of biological variation appeared to be continuous and not particulate (take skin color or height as examples). In the 1930s, it was demonstrated that traits could be polygenic and that multiple alleles could be responsible for any one phenotypic trait, thus producing the continuous variation in traits such as eye color that we see today. Thus, Huxley\u2019s \u201cModern Synthesis\u201d outlines not only how human populations are capable of exchanging genes at the microevolutionary level but also how multiple alleles for one trait (polygenic exchanges) can cause gradual macroevolutionary changes.<\/p>\n<h2 class=\"import-Normal\">Human Variation in Biological Anthropology Today<\/h2>\n<h3 class=\"import-Normal\"><strong>Many Human Traits Are Nonconcordant<\/strong><\/h3>\n<p class=\"import-Normal\">In our studies of human (genetic) variation today, we understand most human traits to be nonconcordant (Figure 13.12). \u201c<strong>Nonconcordance<\/strong>\u201d is a term used to describe how biological traits vary independent of each other\u2014that is, they do not get inherited in a correlative manner with other genetically controlled traits. For example, if you knew an individual had genes that coded for tall height, you would not be able to predict if they are lighter-skinned or have red hair. This is different from earlier essentialist views of human variation: the idea that skin color could predict one\u2019s brain function or even \u201ctemperament\u201d and tendencies toward criminal behavior.<\/p>\n<figure style=\"width: 594px\" class=\"wp-caption aligncenter\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image17-2-1.jpg\" alt=\"World map with human silhouettes scattered across the continents.\" width=\"594\" height=\"304\" \/><figcaption class=\"wp-caption-text\">Figure 13.12: Most human biological traits are non-concordant, meaning traits vary independently and each trait has its own pattern of distribution around the world. In this image, different colors and patterns represent trait varieties. For example, the color and pattern of the head may represent hair color (dark to light), but sharing dark hair with another person does not mean you will share other traits (e.g. ability to digest lactose or ABO blood type). Credit: Nonconcordance original to Explorations: An Open Invitation to Biological Anthropology (2nd ed.) by Katie Nelson is under a <a class=\"rId62\" href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/\">CC BY-NC 4.0 License<\/a>.<\/figcaption><\/figure>\n<h3 class=\"import-Normal\"><strong>Human Variation Is Clinal\/Continuous (Not Discrete)<\/strong><\/h3>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Frank B. Livingstone (1928\u20122005) wrote: \u201cThere are no races, only clines\u201d (1962: 279). A <strong>cline<\/strong> is a gradation in the frequency of an allele\/trait between populations living in different geographic regions. Human variation cannot be broken into discrete \u201craces,\u201d because most physical traits vary on a continuous or \u201cclinal\u201d basis. One obvious example of this is how human height does not only come in three values (\u201cshort,\u201d \u201cmedium,\u201d and \u201ctall\u201d) but instead varies across a spectrum of vertical heights achievable by humans all over the world. On the one hand, we can describe human height as exhibiting <strong>continuous <\/strong><strong>variation<\/strong>, forming a continuous pattern, but height does not vary according to where people live across the globe and does not exhibit a clinal pattern. On the other hand, skin color variation between populations does show patterning that fits quite well on to how near or far they are from each other on a world map. This makes a trait like skin color clinally distributed worldwide. When large numbers of genetic loci for large numbers of samples were sampled from human populations distributed worldwide during the 1960s and 1970s, the view that certain facets of human diversity were clinally distributed was further supported by genetic data.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">To study human traits that are clinally distributed, genetic tests must be performed to uncover the true frequencies of an allele or trait across a certain geographic space. One easily visible example of a clinal distribution seen worldwide is the patterning of human variation in skin color. Whether in southern Asia, sub-Saharan Africa, or Australia, dark brown skin is found. Paler skin tones are found in higher-latitude populations such as those who have lived in areas like Europe, Siberia, and Alaska for millennia. Skin color is easily observable as a phenotypic trait exhibiting continuous variation.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">A clinal distribution still derives from genetic inheritance; however, clines often correspond to some gradually changing environmental factor. Clinal patterns arise when selective pressures in one geographic area differ from those in another as well as when people procreate and pass on genes together with their most immediate neighbors. There are several mechanisms, selective and neutral, that can lead to the clinal distribution of an allele or a biological trait. <strong>Natural selection<\/strong> <span style=\"background-color: #ff9900;\">is the mechanism that produced a global cline of skin color, whereby darker skin color protects equatorial populations from high amounts of UV radiation; there is a transition of lessening pigmentation in individuals that reside further and further away from the tropics (Jablonski 2004; Jablonski and Chaplin 2000; see Figure 13.13). The ability and inability to digest lactose (milk sugar) among different world communities varies according to differential practices and histories of milk and dairy-product consumption (Gerbault et al. 2011; Ingram et al. 2009). Where malaria seems to be most prevalent as a disease stressor on human populations, a clinal gradient of increasing sickle cell anemia experience toward these regions has been studied extensively by genetic anthropologists (Luzzatto 2012)<\/span>. Sometimes culturally defined mate selection based on some observable trait can lead to clinal variation between populations as well.<\/p>\n<figure style=\"width: 676px\" class=\"wp-caption aligncenter\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image22-6.png\" alt=\"A global map shaded representing skin colors. \" width=\"676\" height=\"370\" \/><figcaption class=\"wp-caption-text\">Figure 13.13: A global map of skin colors shows that dark skin pigmentation is more common in areas that receive more UV radiation (near the equator and in high altitude areas). Light skin is more common at northern and southern latitudes. It is worth bearing in mind, though, that these do not tell the full story of how human skin pigmentation varies worldwide. Each region will contain populations that exhibit a range of skin tones. In this way, this map is not perfect as an illustration of skin-color distribution. Credit: Mercator style projection map showing human skin color according to Biasutti 1940.png by Dark Tichondrias at English Wikipedia, modified (cropped) by Tuvalkin, is under a CC BY-SA 4.0 License.<\/figcaption><\/figure>\n<p class=\"import-Normal\">Two neutral microevolutionary processes that may produce a cline in a human allele or trait are <strong>gene flow<\/strong> and <strong>genetic drift <\/strong>(see Chapter 4). The ways in which neutral processes can produce clinal distributions is seen clearly when looking at clinal maps for different blood groups in the human ABO blood group system (Figure 13.14). For instance, scientists have identified an East-to-West cline in the distribution of the blood type <em>B<\/em> allele across Eurasia. The frequency of <em>B<\/em> allele carriers decreases gradually westward when we compare the blood groups of East and Southeast Asian populations with those in Europe. This shows how populations residing nearer to one another are more likely to interbreed and share genetic material (i.e., undergo gene flow). We also see 90%\u2012100% of native South American individuals, as well as between 70%\u201290% of Aboriginal Australian groups, carrying the <em>O<\/em> allele (Mourant, \u200b\u200bKope\u0107, and Domaniewska-Sobczak 1976). These high frequencies are likely due to random genetic drift and founder effects, in which population sizes were severely reduced by the earliest <em>O<\/em> allele-carrying individuals migrating into those areas. Over time, the <em>O<\/em> blood type has remained predominant.<\/p>\n<p class=\"import-Normal\"><img class=\"aligncenter\" src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image8.gif\" alt=\"World map showing varying frequencies of blood type A.\" width=\"516\" height=\"284\" \/><\/p>\n<p class=\"import-Normal\"><img class=\"aligncenter\" src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image5.gif\" alt=\"World map shows the highest frequencies of blood type B in parts of Asia.\" width=\"518\" height=\"283\" \/><\/p>\n<figure style=\"width: 516px\" class=\"wp-caption aligncenter\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image13.gif\" alt=\"World map shows the highest frequencies of blood type O.\" width=\"516\" height=\"284\" \/><figcaption class=\"wp-caption-text\">Figure 13.14a\u2013c: a. Global distribution of blood type A. b. Global distribution of blood type B. c. Global distribution of blood type O. <a href=\"https:\/\/docs.google.com\/document\/d\/1VUDKMBJYS_jNONjLxT04jQN0_z9Ua50BRN6auGSHUuU\/edit\" target=\"_blank\" rel=\"noopener\">A text description of this image is available<\/a>. Credit: a. <a class=\"rId69\" href=\"https:\/\/commons.wikimedia.org\/wiki\/File:Map_of_blood_group_a.gif\">Map of blood group a<\/a> by <a class=\"rId70\" href=\"https:\/\/en.wikipedia.org\/wiki\/User:Muntuwandi\">Muntuwandi<\/a> at <a class=\"rId71\" href=\"https:\/\/en.wikipedia.org\/\">en.wikipedia<\/a> is under a <a class=\"rId72\" href=\"https:\/\/creativecommons.org\/licenses\/by-sa\/3.0\/legalcode\">CC BY-SA 3.0 License<\/a>. b. <a class=\"rId73\" href=\"https:\/\/commons.wikimedia.org\/wiki\/File:Map_of_blood_group_b.gif\">Map of blood group b<\/a> by <a class=\"rId74\" href=\"https:\/\/en.wikipedia.org\/wiki\/User:Muntuwandi\">Muntuwandi<\/a> at <a class=\"rId75\" href=\"https:\/\/en.wikipedia.org\/\">en.wikipedia<\/a> is under a <a class=\"rId76\" href=\"https:\/\/creativecommons.org\/licenses\/by-sa\/3.0\/legalcode\">CC BY-SA 3.0 License<\/a>. c. <a class=\"rId77\" href=\"https:\/\/commons.wikimedia.org\/wiki\/File:Map_of_blood_group_o.gif\">Map of blood group o<\/a> is based on diagrams from <a class=\"rId78\" href=\"https:\/\/anthro.palomar.edu\/vary\/vary_3.htm\">https:\/\/anthro.palomar.edu\/vary\/vary_3.htm<\/a>, reproduced from A. E. Mourant et al. (1976), and is under a <a class=\"rId79\" href=\"https:\/\/creativecommons.org\/licenses\/by-sa\/3.0\/legalcode\">CC BY-SA 3.0 License<\/a>.<\/figcaption><\/figure>\n<h3 class=\"import-Normal\"><strong>Genetic Variation Is Greater Within Group than Between Groups<\/strong><\/h3>\n<figure style=\"width: 295px\" class=\"wp-caption alignleft\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image27-2.jpg\" alt=\"Two medium-sized circles labeled Asian and European largely overlap. A larger circle labeled African surrounds both. \" width=\"295\" height=\"274\" \/><figcaption class=\"wp-caption-text\">Figure 13.15: Circles represent human genetic variation. Most variants are shared among individuals on all continents. There are more variants in Africa, some of which are not found in Europe or Asia. Credit: Human Genetic Variation original to Explorations: An Open Invitation to Biological Anthropology (2nd ed.) by Katie Nelson is under a <a class=\"rId81\" href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/\">CC BY-NC 4.0 License<\/a>.<\/figcaption><\/figure>\n<p>One problem with race-based classifications is they relied on an erroneous idea that individuals with particular characteristics would share more similar genes with each other within a particular \u201crace\u201d and share less with individuals of other \u201craces\u201d possessing different traits and genetic makeups. However, since around 50 years ago, scientific studies have shown that the majority of human genetic differences worldwide exist <em>within<\/em> groups (or \u201craces\u201d) individually rather than <em>between<\/em> groups. Indeed, most genetic variation we see occurs in Africa, and many variants are shared among individuals on all continents (Figure 13.15).<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">In 2002, a landmark article by Noah Rosenberg and colleagues explored worldwide human genetic variation using an even-greater genetic data set. They used 377 highly variable markers in the human genome and sampled from 1,056 individuals representative of 52 populations. The markers chosen for study were not ones that code for any expressed genes. Because these regions of the human genome were made of unexpressed genes, we may understand these markers as neutrally derived (as opposed to selectively derived) because they do not code for functional advantages or disadvantages. These neutral genetic markers likely reflect an intricate combination of regional founder effects and population histories. Analyses of these neutral markers allowed scientists to identify that 93%\u201295% of global genetic differences, referred to as <strong>variance<\/strong>, can be accounted for by within-population differences, while only a small proportion of genetic variance (3%\u20125%) can be attributed to differences among major groups (Rosenberg et al. 2002). This research supports the theory that distinct biological races do not exist, even though misguided concepts of race may still have real social and political consequences.<\/p>\n<h3 class=\"import-Normal\"><strong>Biological Data Fit Isolation-By-Distance and Out-of-Africa Models<\/strong><\/h3>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">One further note is that the world\u2019s population may be genetically divided into \u201cgroups,\u201d \u201csubsets,\u201d \u201cclumps,\u201d or \u201cclusters\u201d that reflect some degree of genetic similarity. These identifiable clusters reflect genetic or geographic distances\u2014either with gene flow facilitated by proximity between populations or impeded by obstacles like oceans or environmentally challenging habitats (Rosenberg et al. 2005). Sometimes, inferred clusters using multiple genetic loci are interpreted by nongeneticists literally as \u201cancestral populations.\u201d However, it would be wrong to assume from these genetic results that highly differentiated and \u201cpure\u201d ancestral groups ever existed. These groupings reflect differences that have arisen over time due to clinal patterning, genetic drift, and\/or restricted or unrestricted gene flow (Weiss and Long 2009). The clusters identified by scientists are arbitrary and the parameters used to split up the global population into groups is subjective and dependent on the particular questions or distinctions being brought into focus (Relethford 2009).<\/p>\n<figure style=\"width: 341px\" class=\"wp-caption alignright\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image6-7.png\" alt=\"Map of the continent of Africa with the lower two-thirds shaded.\" width=\"341\" height=\"341\" \/><figcaption class=\"wp-caption-text\">Figure 13.16: Sub-Saharan Africa (shaded dark\/green). Credit: <a class=\"rId83\" href=\"https:\/\/commons.wikimedia.org\/wiki\/File:Sub-Saharan-Africa.png\">Sub-Saharan Africa<\/a> by <a class=\"rId84\" href=\"https:\/\/commons.wikimedia.org\/wiki\/User:Ezeu\">Ezeu<\/a> has been designated to the <a class=\"rId85\" href=\"https:\/\/creativecommons.org\/share-your-work\/public-domain\/cc0\/\">public domain (CC0)<\/a>.<\/figcaption><\/figure>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Additionally, research on worldwide genetic variation has shown that human variation decreases with increasing distance from sub-Saharan Africa, where there is evidence for this vast region being the geographical origin of anatomically modern humans (Liu et al. 2006; Prugnolle, Manica, and Balloux 2005; see Figures 13.16 and 13.17). Genetic differentiation decreases in human groups the further you sample data from relative to sub-Saharan Africa because of serial founder effects (Relethford 2004). Over the course of human colonization of the rest of the world outside Africa, populations broke away in expanding waves across continents into western Asia, then Europe and eastern Asia, followed by Oceania and the Americas. As a result, founder events occurred whereby genetic variation was lost, as the colonization of each new geographical region involved a smaller number of individuals moving from the original larger population to establish a new one (Relethford 2004). The most genetic variation is found across populations residing in different parts of sub-Saharan Africa, while other current populations in places like northern Europe and the southern tip of South America exhibit some of the least genetic differentiation relative to all global populations (Campbell and Tishkoff 2008).<\/p>\n<figure style=\"width: 469px\" class=\"wp-caption aligncenter\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image3-6.png\" alt=\"Two scatterplots.\" width=\"469\" height=\"516\" \/><figcaption class=\"wp-caption-text\">Figure 13.17: Comparison of the genetic distance and geographical distance between populations. In the top graph, the pattern reveals that genetic variation conforms to an Out-of-Africa model, as those populations further away from Addis Ababa in Ethiopia share a smaller number of alleles; in the bottom graph, we see the populations follow an isolation-by-distance model, as pairs of populations further apart geographically seem to have greater genetic distance (Kanitz et al. 2018). Credit: <a class=\"rId87\" href=\"https:\/\/journals.plos.org\/plosone\/article?id=10.1371\/journal.pone.0192460\">Complex genetic patterns (figure 1)<\/a> by Kanitz et al. (2018) is under a <a class=\"rId88\" href=\"https:\/\/creativecommons.org\/licenses\/by\/4.0\/\">CC BY 4.0 License<\/a>.<\/figcaption><\/figure>\n<\/div>\n<div class=\"__UNKNOWN__\">\n<figure style=\"width: 377px\" class=\"wp-caption alignleft\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image1-9.png\" alt=\"Two large circles connected by a small area.\" width=\"377\" height=\"309\" \/><figcaption class=\"wp-caption-text\">Figure 13.18: The founder effect is a change in a small population\u2019s gene pool due to a limited number of individuals breaking away from a parent population. Credit: <a class=\"rId90\" href=\"https:\/\/commons.wikimedia.org\/wiki\/File:Bottleneck_effect.jpg\">Bottleneck effect<\/a> by <a class=\"rId91\" href=\"https:\/\/wikieducator.org\/User:Tsaneda\">Tsaneda<\/a> is under a <a class=\"rId92\" href=\"https:\/\/creativecommons.org\/licenses\/by\/3.0\/legalcode\">CC BY 3.0 License<\/a>.<\/figcaption><\/figure>\n<p>Besides fitting nicely into the <strong>Out-of-Africa model<\/strong>, worldwide human genetic variation conforms to an <strong>isolation-by-distance model<\/strong>, which predicts that genetic similarity between groups will decrease exponentially as the geographic distance between them increases (Kanitz et al. 2018). This is because of the greater and greater restrictions to gene flow presented by geographic distance, as well as cultural and linguistic differences that occur as a result of certain degrees of isolation. Since genetic data conform to isolation-by-distance and Out-of-Africa models, these findings support the abolishment of \u201crace\u201d groupings. This research demonstrates that human variation is continuous and cannot be differentiated into geographically discrete categories. There are no \u201cinherent\u201d or \u201cinnate\u201d differences between human groups; instead, variation derives from some degree of natural selection, as well as neutral processes like <strong>population bottle-necking<\/strong>\u00a0(Figure 13.18), random <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_1474\"><strong>mutations<\/strong><\/a> in the DNA, genetic drift, and gene flow through between-mate interbreeding.<\/p>\n<h3 class=\"import-Normal\"><strong>Humans Have Higher Homogeneity Compared to Many Other Species<\/strong><\/h3>\n<p class=\"import-Normal\">An important fact to bear in mind is that humans are 99.9% identical to one another. This means that the apportionments of human variation discussed above only concern that tiny 0.1% of difference that exists between all humans globally. Compared to other mammalian species, including the other great apes, human variation is remarkably lower. This may be surprising given that the worldwide human population has already exceeded seven billion, and, at least on the surface level, we appear to be quite phenotypically diverse. Molecular approaches to human and primate genetics tells us that external differences are merely superficial. For a proper appreciation of human variation, we have to look at our closest relatives in the primate order and mammalian class. Compared to chimpanzees, bonobos, gorillas and other primates, humans have remarkably low average genome-wide <strong>heterogeneity<\/strong> (Osada 2005).<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">When we look at chimpanzee genetic variation, it is fascinating that western, central, eastern, and Cameroonian chimpanzee groups have substantially more genetic variation between them than large global samples of human DNA (Bowden et al. 2012; Figure 13.19). This is surprising given that all of these chimpanzee groups live relatively near one another in Africa, while measurements of human genetic variation have been conducted using samples from entirely different continents. First, geneticists suppose that this could reflect differential experiences of the founder effect between humans and chimpanzees. <span style=\"background-color: #ffff00;\">Because all non-African human populations descended from a small number of anatomically modern humans who left Africa,<\/span> it would be expected that all groups descended from that smaller ancestral group would be similar genetically. Second, our species is really young, given that we have only existed on the planet for around 150,000 to 300,000 years. This gave humans little time for random genetic mutations to occur as genes get passed down through genetic interbreeding and meiosis. Chimpanzees, however, have inhabited different <strong>ecological niches<\/strong>, and less interbreeding has occurred between the four chimpanzee groups over the past six to eight million years compared to the amount of gene flow that occurred between worldwide human populations (Bowden et al. 2012).<\/p>\n<figure style=\"width: 648px\" class=\"wp-caption aligncenter\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image16-7.png\" alt=\"Map of Africa showing the ranges of chimpanzees from west to east.\" width=\"648\" height=\"339\" \/><figcaption class=\"wp-caption-text\">Figure 13.19: Distribution of the genus Pan, including bonobos and the four subspecies of chimpanzee, across western and central Africa (Clee et al. 2015). <a href=\"https:\/\/docs.google.com\/document\/d\/1VUDKMBJYS_jNONjLxT04jQN0_z9Ua50BRN6auGSHUuU\/edit\" target=\"_blank\" rel=\"noopener\">A text description of this image is available<\/a>. Credit: <a class=\"rId94\" href=\"https:\/\/bmcecolevol.biomedcentral.com\/articles\/10.1186\/s12862-014-0275-z\">Chimpanzee subspecies ranges (Figure 1)<\/a> by Clee et al. 2015 is under a <a class=\"rId95\" href=\"https:\/\/creativecommons.org\/licenses\/by\/4.0\/\">CC BY 4.0 License<\/a>.<\/figcaption><\/figure>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\"><span style=\"background-color: #ccffcc;\">Recent advances have now enabled the attainment of genetic samples from the larger family of great apes and the evaluation of genetic variation among bonobos, orangutans, and gorillas alongside that of chimpanzees and humans (Prado-Martinez et al. 2013). Collecting such data and analyzing primate genetic variation has been important not only to elucidate how different ecological, demographic, and climatic factors have shaped our evolution but also to inform upon conservation efforts and medical research. Genes that may code for genetic susceptibilities to tropical diseases that affect multiple primates can be studied through genome-wide methods. Species differences in the genomes associated with speech, behavior, and cognition could tell us more about how human individuals may be affected by genetically derived neurological or speech-related disorders and conditions (Prado-Martinez et al. 2013; Staes et al. 2017). In 2018, a great ape genomic study also reported genetic differences between chimpanzees and humans related to brain cell divisions (Kronenberg et al. 2018). From these results, it may be inferred that cognitive or behavioral variation between humans and the great apes might relate to an increased number of cortical neurons being formed during human brain development (Kronenberg et al. 2018).<\/span> Comparative studies of human and nonhuman great ape genetic variation highlight the complex interactions of population histories, environmental changes, and natural selection between and within species. When viewed in the context of overall great ape variation, we may reconsider how variable the human species is relatively and how unjustified previous \u201crace\u201d concepts really were.<\/p>\n<h3 class=\"import-Normal\"><strong>Phenotypic Traits That Reflect Neutral Evolution<\/strong><\/h3>\n<p class=\"import-Normal\">Depending on the trait being observed, different patterns of phenotypic variation may be found within and among groups worldwide. In this subsection, some phenotypic traits that reflect the aforementioned patterns of genetic variation will be discussed.<\/p>\n<figure style=\"width: 301px\" class=\"wp-caption alignleft\"><img class=\"\" src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image18-4.jpg\" alt=\"Illustration of one anthropologist studying teeth, and another looking into a microscope.\" width=\"301\" height=\"301\" \/><figcaption class=\"wp-caption-text\">Figure 13.20: Contemporary anthropologists who use many types of skeletal markers have demonstrated that a majority of cranial variation occurs within populations rather than between populations and that there is a decrease in variation with distance from Africa. Credit: <a class=\"rId97\" href=\"https:\/\/img1.wsimg.com\/isteam\/ip\/0f6c1c17-41ea-4caf-b839-73c676d69f01\/DentalHeartNecklace.jpg\/:\/rs=w:1280,h:1280\">Dental Anthropologist Heart Necklace<\/a> by <a class=\"rId98\" href=\"https:\/\/anthroillustrated.com\/\">Anthro Illustrated<\/a> is under a <a class=\"rId99\" href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/\">CC BY-NC 4.0 License<\/a>.<\/figcaption><\/figure>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Looking beyond genetic variation briefly, recent studies have revisited biological anthropology\u2019s earlier themes of externally observable traits, such as skull shape. In the last 20 or so years, anthropologists have evaluated the level to which human cranial shape variation reflects the results from genetic markers, such as those used previously to fit against Out-of-Africa models (Relethford 2004) or those used in the apportionment of human variation between and within groups (Lewontin 1972; Rosenberg et al. 2002). Using larger sample sizes of cranial data collected from thousands of skulls worldwide and a long list of cranial measurements, studies demonstrate a similar decrease in variation with distance from Africa and show that a majority of cranial variation occurs within populations rather than between populations (Betti et al. 2009; Betti et al. 2010; Manica et al. 2007; Relethford 2001; von Cramon-Taubadel and Lycett 2008; see Figure 13.20). The greatest cranial variation is found among skulls of sub-Saharan African origin, while the least variation is found among populations inhabiting places like Tierra del Fuego at the southern tip of Argentina and Chile. While ancient and historical thinkers previously thought \u201crace\u201d categories could reasonably be determined based on skull dimensions, modern-day analyses using more informative sets of cranial traits simply show that migrations out of Africa and the relative distances between populations can explain a majority of worldwide cranial variation (Betti et al. 2009).<\/p>\n<figure style=\"width: 250px\" class=\"wp-caption alignright\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image21-6.png\" alt=\"Sketch of bone with bony loops at the top and coil at the bottom.\" width=\"250\" height=\"208\" \/><figcaption class=\"wp-caption-text\">Figure 13.21: Diagram of the bony labyrinth in the inner ear. Credit: <a class=\"rId101\" href=\"https:\/\/commons.wikimedia.org\/wiki\/File:Bony_labyrinth.png\">Bony labyrinth<\/a> by <a class=\"rId102\" href=\"https:\/\/commons.wikimedia.org\/wiki\/User:Selket\">Selket<\/a> has been designated to the <a class=\"rId103\" href=\"https:\/\/creativecommons.org\/share-your-work\/public-domain\/cc0\/\">public domain (CC0)<\/a>.<\/figcaption><\/figure>\n<p class=\"import-Normal\">This same patterning in phenotypic variation has even been found in studies examining shape variation of the pelvis (Betti et al. 2013; Betti et al. 2014), the teeth (Rathmann et al. 2017), and the human <strong>bony labyrinth<\/strong> of the ear (Ponce de Le\u00f3n et al. 2018;Figure 13.21). The skeletal morphology of these bones still varies worldwide, but a greater proportion of that variation can still be attributed to the ways in which human populations migrated across the world and exchanged genes with those closer to them rather than those further away. Human skeletal variation in these parts of the body is continuous and nondiscrete. Given the important functions of the cranium and these other skeletal parts, we may infer that the genes that underpin their development have been relatively conserved by neutral evolutionary processes such as genetic drift and gene flow. It is also important to note that while some traits such as height, weight, cranial dimensions, and body composition are determined, in part, by genes, the underlying developmental processes behind these traits are underpinned by complex polygenic mechanisms that have led to the continuous spectrum of variation in such variables among modern-day human populations.<\/p>\n<h3 class=\"import-Normal\"><strong>Phenotypic Traits That Reflect Natural Selection<\/strong><\/h3>\n<p class=\"import-Normal\">Even though 99.9% of our DNA is the same across all humans worldwide, and many traits reflect neutral processes, there are parts of that remaining 0.1% of the human genome that code for individual and regional differences. Similarly to craniometric analyses that have been conducted in recent decades, human variation in skin color has also been reassessed using new methods and in light of greater knowledge of biological evolution.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">New technologies allow scientists to use color photometry to sample and quantify the visible wavelength of skin color, in a way 19th- and 20th-century readers could not. In one report, it was found that 87.9% of global skin color variation can be attributed to genetic differences <em>between<\/em> groups, 3.2% to those among local populations within regions, and 8.9% <em>within<\/em> local populations (Relethford 2002). This apportionment differs significantly and is the reverse situation found in the distribution of genetic differences we see when we examine genetic markers such as blood type\u2013related alleles. However, this pattern of human skin color worldwide is not surprising, given that we now understand that past selection has occurred for darker skin near the equator and lighter skin at higher latitudes (Jablonski 2004; Jablonski and Chaplin 2000). While most genetic variation reflects neutral variation due to population migrations, geographic isolation, and restricted gene flow dynamics, some human genetic\/phenotypic variation is best explained as local adaptation to environmental conditions (i.e., selection). Given that skin color variation is atypical compared to other genetic markers and biological traits, this, in fact, goes against earlier \u201crace\u201d typologies. This is because recent studies ironically show how so much of genetic variation relates to neutral processes, while skin color does not. It follows that skin color <em>cannot<\/em> be viewed as useful in making inferences about other human traits.<\/p>\n<figure style=\"width: 580px\" class=\"wp-caption aligncenter\"><img class=\"\" src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image23-3.jpg\" alt=\"Person standing at podium in front of a screen with arms partly raised.\" width=\"580\" height=\"384\" \/><figcaption class=\"wp-caption-text\">Figure 13.22: Genomicists and biological anthropologists have dedicated efforts to improving quantitative methods of measuring hair and skin variation over the last twenty years. Dr. Nina Jablonski is one such biological anthropologist specializing in the evolution and variation of human skin pigmentation. Credit: <a class=\"rId105\" href=\"https:\/\/commons.wikimedia.org\/wiki\/File:Nina_Jablonski_2016_The_Skin_of_Homo_sapiens_01_%28cropped%29.jpg\">Nina Jablonski 2016 The Skin of Homo sapiens 01 (cropped)<\/a> by <a class=\"rId106\" href=\"https:\/\/commons.wikimedia.org\/wiki\/User:Ptolusque\">Ptolusque<\/a> is under a <a class=\"rId107\" href=\"https:\/\/creativecommons.org\/licenses\/by-sa\/4.0\">CC BY-SA 4.0 license<\/a>.<\/figcaption><\/figure>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">It is also true that some populations have not been studied extensively in skin pigmentation genetics (e.g., African, Austronesian, Melanesian, Southeast Asian, Indigenous American, and Pacific Islander populations, according to Lasisi and Shriver 2018). Earlier dispersals of these populations, and their local genetic varition, will have contributed to worldwide genetic variation, inclusive of skin pigmentation variation. Gene loci we did not previously appreciate as being linked to pigmentation are now being recognized thanks to better tools, more diverse genetic samples, and more accessible datasets (Quillen et al. 2018). Biological anthropologists look forward to further discoveries elucidating the different selective pressures and population dynamics that influence skin pigmentation evolution.<\/p>\n<h2 class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Social Implications<\/h2>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">To finish this chapter, we will consider the social, economic, political, and biological implications of poor understandings of race and the deliberate perpetuation of social and medical racism.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">The Black Lives Matter movement (BLM) of 2013 began with the work of racial justice activists and community organizers Alicia Garza, Opal Tometi, and Patrissa Cullors. First incited by the murder of Trayvon Martin, a 17-year-old African American, and the acquittal of the man who shot him, BLM went on to protest against the deaths of numerous Black individuals, most of whom were killed by police officers (for example, Ahmaud Arbery was killed in February of 2020 by two white non-police officers). Some key characteristics of BLM from the start were its decentralized grassroots structure, the role of university students and social media in spreading awareness of the movement, and its embrace of other movements (e.g., climate justice, ending police brutality, feminist campaigns, queer activism, immigration reform, etc.). When George Floyd was murdered by a white police officer on May 25, 2020, the BLM gained new momentum, across 2,000-plus cities in the United States, and among many protesting against historic racism and police brutality in other contexts around the globe. Many in the biological anthropology community have responded to these events with a great dedication to working against systemic racism in society and institutions (American Association of Biological Anthropologists 2020).<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">BLM continues to be an important movement, as is evidenced in the degree of community organizing, mutual aid efforts, calls for political reform, progress toward curriculum reform and equality, inclusion and diversity (EDI) work in businesses and universities, the removal of monuments honoring historical figures associated with slavery and racism, and many other important actions. Garza (2016) writes: \u201cThe reality is that race in the United States operates on a spectrum from black to white \u2026 the closer you are to white on that spectrum, the better off you are.\u201d Tometi (2016) has stated: \u201cWe need [a human rights movement that challenges systemic racism] because the global reality is that Black people are subject to all sorts of disparities in most of our challenging issues of our day. I think about climate change, and how six of the ten worst impacted nations by climate change are actually on the continent of Africa.\u201d In the words of Cullors (2016), \u201cBlack Lives Matter is our call to action. It is a tool to reimagine a world where Black people are free to exist, free to live. It is a tool for our allies to show up differently for us.\u201d We gather from their words the importance of learning from the egregious role that anthropologists have played in the past, recognizing the legacies of \u201cscientific\u201d justifications for eugenics and racism in our society today, and proactively working toward environmental and social equity.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Another major industry that engages in the quantification and interpretation of human variation is medical and clinical work (National Research Council [U.S.] Committee on Human Genome Diversity 1997). Large-scale genomic studies sampling from human populations distributed worldwide have produced detailed knowledge on variation in disease resistance or susceptibility between and within populations. Let\u2019s think about drug companies who develop medicines for Black patients particularly. The predispositions to particular diseases are higher among people of African descent than some pharmaceutical businesses have taken into account. Through targeted sampling of various world groups, clinical geneticists may also identify genetic risk factors of certain common disorders such as chronic heart disease, asthma, diabetes, autoimmune diseases, and behavioral disorders. Having an understanding of population-specific biology is crucial in the development of therapies, medicines, and vaccinations, as not all treatments may be suitable for every human, depending on their genotype. During diagnosis and treatment, it is important to have an evolutionary perspective on gene-environment relationships in patients. Typological concepts of \u201crace\u201d are not useful, given that most racial groups (whether self-identified or not) popularly recognized lack homogeneity and are, in fact, variable. <strong>Cystic fibrosis<\/strong>, for instance, occurs in all world populations but can often be underdiagnosed in populations with African ancestry because it is thought of as a \u201cwhite\u201d disease (Yudell et al. 2016).<\/p>\n<p class=\"import-Normal\">Sociologists, law scholars, and professors of race studies have written extensively on how genetic\/technological\/medical revolutions impact people of color. In her book, <em>Fatal Invention: How Science, Politics, and Big Business Re-create Race in the Twenty-First Century <\/em>(2013), Professor Dorothy E. Roberts writes about how technological advances have been used in resuscitating race as a biological category for dividing humans in essentialist ways (Figure 13.23). She notes how members of law enforcement have engaged in racial profiling, sometimes with the use of machine-learning and facial-recognition technologies. Ancestry-testing services also purport to tell us \u201cwhat\u201d we are and to insist that this information is \u201cwritten\u201d in our genes. Such advertising campaigns obscure the nuances of genetic variation with the primary motive of tapping into people\u2019s desire to \u201cknow themselves\u201d and driving up profits for their businesses. Commercial genetic testing reinforces the idea that genes map neatly onto race, all while generating massive stores of data in DNA databases. In Roberts\u2019s view, the myth of the biological concept of race being perpetuated in these ways undermines a just society and reproduces racial inequalities.<\/p>\n<figure style=\"width: 593px\" class=\"wp-caption aligncenter\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image12-6.png\" alt=\"Book cover with two DNA strands and next to the smiling portrait of the author.\" width=\"593\" height=\"305\" \/><figcaption class=\"wp-caption-text\">Figure 13.23: Professor Dorothy E. Roberts is a sociologist, legal scholar, and expert on the relationships among technology, medicine, bioethics, policymaking, race, and racism. Credit: <a class=\"rId109\" href=\"https:\/\/kpfa.org\/episode\/talkies-august-23-2016\/\">Dorothy Roberts author of Fatal Invention<\/a> by <a class=\"rId110\" href=\"https:\/\/kpfa.org\/\">https:\/\/kpfa.org\/<\/a> is copyrighted and used with permission.<\/figcaption><\/figure>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">The COVID-19 pandemic has had a significant impact on the world\u2019s population, particularly people living in the economic Global South and many Black, Indigenous and communities of color residing in the Global North. We have witnessed disproportionately high numbers of COVID-related deaths and infection cases among marginalized groups. Many immigrants and ethnic minorities in various societies have also experienced scapegoating and blame directed at them for being the source of COVID-19 spread.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">To inform us on how to interpret this current worldwide pandemic, historians and anthropologists are looking back at the lessons learned from past instances of racist medicine (discriminatory practices based on broader social discrimination) and medical racism (application of discriminatory practices justified on medical grounds). Historically, who could become doctors and medical professionals was often racialized, gendered, and class specific. This made it difficult for many to overcome prejudices against women, Black people, Indigenous individuals, or other people of color from becoming doctors and clinical researchers in places such as South Africa and the United States. This, in turn, affects the sorts of information we know about health levels and health outcomes among these very groups. In the past decade, long-overdue attention is finally being paid to how race affects biological outcomes. For instance, researchers have focused on the negative legacies of racial discrimination and racism-induced stress on hormone (im)balances, mental health disorders, cardiovascular disease prevalence, and other health outcomes (Kuzawa and Sweet 2009; Shonkoff, Slopen, and WIlliams 2021; Williams 2018). The technology and standards of protocol in medical testing have been scrutinized (for more on how pulse oximeters were not designed with nonwhite patients in mind, for example, see Sjoding et al. 2020). Scholars of race and medicine have also written on how illness and disease spread have often been used to perpetuate societal prejudices. This manifests as xenophobic tendencies at a societal level, such as the blaming of \u201coutgroups\u201d and increased \u201cin-group\u201d protectiveness. Overreliance on the idea that people are \u201cinherently\u201d disease carriers due to genetic or biological reasons leads to improper accounting for socioeconomic or infrastructural issues that lead to differential disease prevalence amongst minority communities. (For more on race and COVID, see Tsai 2021 as well as this textbook\u2019s Chapter 16: Contemporary Topics: Human Biology and Health.)<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\"><span style=\"background-color: #ff99cc;\">Lastly, consider the changing field of forensic anthropology. In the past, forensic anthropologists ascribed <strong>ancestry<\/strong> or racial categories to sets of skeletons, reliant on the belief that different human groups will exhibit biologically \u201cdiscrete\u201d assortments so as to divide along culturally constructed categories (Sauer 1992). Now, a number of forensic anthropologists have argued that we should abandon these methods, both because it is unscientific and because it further validates and perpetuates this idea that race is biologically meaningful. As scientists, whether we affirm biological race as real has huge influence on the beliefs of members of the public, the judicolegal system, and law enforcement. Not all forensic experts agree with abandoning ancestry estimation. Some prefer to refocus on the neutral or selective <em>causes<\/em> of human biological variation, and assess how <em>probabilistic<\/em> it may be to assign bones of certain dimensions to one of several identified racial categories. These debates continue today as this textbook chapter is being written. More details on population affinity may be found in Chapter 15: Bioarchaeology and Forensic Anthropology.<\/span><\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">It is important to remember that while it is possible to look for clues about one\u2019s ancestry or geographic origin based on skull morphology, again, the amount of distinctiveness in any given sample makes it impossible to distinguish whether a cranium belongs to one group (Relethford 2009). Individuals can vary in their skeletal dimensions by continental origin, country origin, regional origin, sex, age, environmental factors, and the time period in which they lived, making it difficult to assign individuals to particular categories in a completely meaningful way (Ousley, Jantz, and Freid 2009). When forensic reports and scientific journal articles give an estimation of ancestry, it is crucial to keep in mind that responsible assignments of ancestry will be done through robust statistical testing and stated as a probability estimate. Today, we also live in a more globalized world where a skeletal individual may have been born originally to parents of two separate traditional racial categories. In contexts of great heterogeneity within populations, this definitely adds difficulty to the work of forensic scientists and anthropologists preparing results for the courtroom (genetic testing may be comparatively more helpful in such situations).<\/p>\n<\/div>\n<div class=\"textbox\">\n<h2 class=\"import-Normal\">Did Deeper: Measuring F<sub>ST<\/sub><\/h2>\n<p class=\"import-Normal\">Richard Lewontin (1929\u2012) is a biologist and evolutionary geneticist who authored an article evaluating where the total genetic variation in humans lies. Titled \u201cThe Apportionment of Human Diversity\u201d (Lewontin 1972), the article addressed the following question: On average, how genetically similar are two randomly chosen people from the same group when compared to two randomly chosen people from different groups?<\/p>\n<p class=\"import-Normal\">Lewontin studied this problem by using genetic data. He obtained data for a large number of different human populations worldwide using 17 genetic markers (including alleles that code for various important enzymes and proteins, such as blood-group proteins). The statistical analysis he ran used a measure of human genetic differences in and among populations known as the fixation index (F<sub>ST<\/sub>).<\/p>\n<p class=\"import-Normal\">Technically, F<sub>ST<\/sub> can be defined as the proportion of total genetic variance within a <em>subpopulation<\/em> relative to the total genetic variance from an <em>entire population<\/em>. Therefore, F<sub>ST<\/sub> values range from 0 to 1 (or, sometimes you will see this stated as a percentage between 0% and 100%). The closer the F<sub>ST<\/sub> value of a population (e.g., the world\u2019s population) approaches 1, the higher the degree of genetic differentiation among subpopulations relative to the overall population (see Figure 13.24 for a detailed illustration).<\/p>\n<figure style=\"width: 561px\" class=\"wp-caption aligncenter\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image4-5.jpg\" alt=\"Three cases each illustrate two populations with a mix of two types of alleles.\" width=\"561\" height=\"473\" \/><figcaption class=\"wp-caption-text\">Figure 13.24: This diagram shows a range of different case studies with which we may understand how FST is calculated in different populations. In Case 1, the gene pools of Populations 1 and 2 are 100% different from each other but possess 0% variation within themselves, so FST has a value of 1. When there is no genetic variation at all between two populations and 100% variation within them, as in Case 2, we see that FST is calculated as 0. When we look at Case 3, where variation between and within are some values between 0% and 100%, we will get a decimal figure for FST dependent upon how much variation there is between and within populations. It is through such comparisons of population genetic data that we may quantify the relative similarities or differences between and within populations, and we may thus speak to the nonexistence of \u201cracial groups\u201d that divide up our species into broad continental or racial categories. Credit: F<sub>ST<\/sub> original to Explorations: An Open Invitation to Biological Anthropology (2nd ed.) by Katie Nelson is under a <a class=\"rId112\" href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/\">CC BY-NC 4.0 License<\/a>.<\/figcaption><\/figure>\n<p>&nbsp;<\/p>\n<p>In his article, Lewontin (1972) identified that most of human genetic differences (85.4%) were found within local subpopulations (e.g., the Germans or Easter Islanders), whereas 8.3% were found between populations within continental human groups, and 6.3% were attributable to traditional \u201crace\u201d groups (e.g., \u201cCaucasian\u201d or \u201cAmerind\u201d). These findings have been important for scientifically rejecting the existence of biological races (Long and Kittles 2003).<\/p>\n<\/div>\n<div class=\"__UNKNOWN__\">\n<h2 class=\"import-Normal\">Talking About Human Biological Variation Going Forward<\/h2>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">To conclude, utilizing the term <em>races<\/em> to describe human biological variation is not accurate or productive. Using a select few hundred genetic loci, or perhaps a number of phenotypic traits, it may be possible to assign individuals to a geographic ancestry, but what constitutes a bounded genetic or geographical grouping is both arbitrary and potentially harmful owing to ethical and historical reasons. The discipline of biological anthropology has moved past typological frameworks that shoehorn continuously variable human populations into discrete and socially constructed subsets. Improvements in the number of markers, the genetic technologies used to study variation, and the number of worldwide populations sampled have led to more nuanced understandings of human variation. It is of utmost importance that scientists make the following points clear to the public:<\/p>\n<ul>\n<li class=\"import-Normal\" style=\"text-indent: 0pt;\">Today, we refer to different local human groups as \u201cpopulations.\u201d What constitutes a population should be carefully defined in scientific reports based on some geographical, linguistic, or cultural criteria and some degree of relativity to other closely or distantly related human groups.<\/li>\n<li class=\"import-Normal\" style=\"text-indent: 0pt;\">Humans have significantly less genetic variation than other primates and mammals, and all human beings on Earth share 99.9% of their overall DNA. Some of the remaining 0.1% of human variation varies on a clinal or continuous basis, such as can be seen when looking at ABO blood-type <strong>polymorphisms<\/strong> worldwide.<\/li>\n<li class=\"import-Normal\" style=\"text-indent: 0pt;\">Many biological characteristics in humans are actually determined nonconcordantly and\/or polygenically. Therefore, superiority or inferiority in human behavior or body form cannot justifiably be linked to fixed and innate differences between groups.<\/li>\n<li class=\"import-Normal\" style=\"text-indent: 0pt;\">Genetic distances are correlated with geographic distances among the global human population. This is especially apparent when we consider that genetic variation is highest in sub-Saharan Africa, and average genetic heterogeneity decreases in populations further away from the African continent in accordance with the migratory history of anatomically modern <em>Homo sapiens<\/em>.<\/li>\n<li class=\"import-Normal\" style=\"text-indent: 0pt;\">The effects of gene flow, genetic drift, and population bottlenecking are reflected in some phenotypic traits, such as cranial shape.<\/li>\n<li class=\"import-Normal\" style=\"text-indent: 0pt;\">We recognize other traits, like skin color and lactase persistence, to be the products of many millennia of natural selective pressures influencing human biology from the external environment.<\/li>\n<\/ul>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Taken together, genetic analyses of human variation do not support 20th-century (or even-earlier) concepts of race. In discussions about human variation, these genomic results help clarify how biological variation is distributed across the human population today. Taking care to think about and debate the nature of human variation is important, because although the effects and events that produced genetic differences among groups occurred in the ancient past, sociocultural concepts about race and ethnicity continue to have real social, economic, and political consequences.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Beyond talking about variation in the university setting, it is important that teachers, researchers, and students of anthropology recognize and assume the responsibility of influencing public perspectives of human variation. Race-based classification systems were developed during the colonial era, the transatlantic trafficking of kidnapped Africans and the so-called \u201cScientific Revolution\u201d by the first \u201canthropologists\u201d and scholars of humankind\u2019s variation. Unfortunately, some of their early ideas have persisted and evolved into present-day lived realities. Some of today\u2019s politicians and socioeconomic bodies have racially charged agendas that promote racism or certain kinds of economic or racial inequalities. As anthropologists, we must acknowledge that while human \u201craces\u201d are not a biological reality, their status as a (misguided) social construction does have real consequences for many people (Antrosio 2011).<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">In other words, while \u201crace\u201d is a sociocultural invention, the treatment different individuals receive due to their perceived \u201crace\u201d can have significant financial, emotional, sociopolitical, and physiological costs. However\u2014and importantly assuming a \u201ccolor-blind\u201d position when it comes to the topics of \u201crace\u201d and ethnicity (especially in political discussions) is actually counterproductive, because the negative social consequences of modern \u201crace\u201d ideas could be ignored, making it harder to examine and address instances of discrimination properly (Wise 2010). Rather than shy away from these topics, we can use our scientific findings to establish socially relevant and biologically accurate ideas concerning human diversity. Today, research into genetic and phenotypic differentiation among and within various human populations continues to expand in its scope, its technological capabilities, its sample sizes, and its ethical concerns. It is thanks to such scientific work done in the past few decades that we now have a deeper understanding not only of how humans vary but also of how we are biologically a rather homogenous, intermixing world population.<\/p>\n<div class=\"textbox shaded\">\n<h2 class=\"import-Normal\">Review Questions<\/h2>\n<ul>\n<li class=\"import-Normal\">How is the genetic variation of the human species distributed worldwide?<\/li>\n<li class=\"import-Normal\">What evolutionary processes are responsible for producing genotypic\/phenotypic variation within and between human populations?<\/li>\n<li class=\"import-Normal\">Should we continue to attribute any value to \u201crace\u201d concepts older than 1950, based on our current understandings of human biological variation?<\/li>\n<li class=\"import-Normal\">How should we communicate scientific findings about human biological variation more accurately and responsibly to those outside the anthropological discipline?<\/li>\n<\/ul>\n<\/div>\n<h2 class=\"import-Normal\">Key Terms<strong><br \/>\n<\/strong><\/h2>\n<p class=\"import-Normal\"><strong>Age of Discovery<\/strong>: A period between the late 1400s and late 1700s when European explorers and ships sailed extensively across the globe in pursuit of new trading routes and territorial conquest.<\/p>\n<p class=\"import-Normal\"><strong>Ancestry<\/strong>: Biogeographical information about an individual, traced either through the study of an individual\u2019s genome, skeletal characteristics, or some other form of forensic\/archaeological evidence. Anthropologists carry out probabilistic estimates of ancestry. They attribute sets of human remains to distinctive \u201cancestral\u201d groups using careful statistical testing and should report ancestry estimations with statistical probability values.<\/p>\n<p class=\"import-Normal\"><strong>Binomial nomenclature<\/strong>: A system of naming living things developed by Linnaeus in the 1700s. It employs a scientific name made up of two italicized Latin or Greek words, with the first word capitalized and representative of an organism\u2019s genus and the second word indicating an organism\u2019s species (e.g., <em>Homo sapiens<\/em>, <em>Australopithecus afarensis<\/em>, <em>Pongo tapanuliensis<\/em>, etc.).<\/p>\n<p class=\"import-Normal\"><strong>Biological anthropology<\/strong>: A branch of study under anthropology (the study of humankind) that focuses on when and where humans and our human ancestors first originated, how we have evolved and adapted globally over time, and the reasons why we see biological variation among humans worldwide today.<\/p>\n<p class=\"import-Normal\"><strong>Biological determinism<\/strong>: The erroneous concept that an individual\u2019s behavioral characteristics are innate and determined by genes, brain size, or other physiological attributes\u2014and, notably, without the influence of social learning or the environment around the individual during development.<\/p>\n<p class=\"import-Normal\"><strong>Bony labyrinth<\/strong>: A system of interconnected canals within the auditory (ear- or hearing-related) apparatus, located in the inner ear and responsible for balance and the reception of sound waves.<\/p>\n<p class=\"import-Normal\"><strong>Cline<\/strong>: A gradient of physiological or morphological change in a single character or allele frequency among a group of species across environmental or geographical lines (e.g., skin color varies clinally, as, over many generations, human groups living nearer the equator have adapted to have more skin pigmentation).<\/p>\n<p class=\"import-Normal\"><strong>Continuous variation<\/strong>: This term refers to variation that exists between individuals and cannot be measured using distinct categories. Instead, differences between individuals within a population in relation to one particular trait are measurable along a smooth, continuous gradient.<\/p>\n<p class=\"import-Normal\"><strong>Cystic fibrosis<\/strong>: A genetic disorder in which one defective gene causes overproduction and buildup of mucus in the lungs and other bodily organs. It is most common in northern Europeans (but also occurs in other world populations).<\/p>\n<p class=\"import-Normal\"><strong>Ecological niche<\/strong>: The position or status of an organism within its community and\/or ecosystem, resulting from the organism\u2019s structural and functional adaptations (e.g., bipedalism, omnivorous diets, lactose digestion, etc.).<\/p>\n<p class=\"import-Normal\"><strong>Essentialism<\/strong>: A belief or view that an entity, organism, or human grouping has a specific set of characteristics that are fundamentally necessary to its being and classification into definitive categories.<\/p>\n<p class=\"import-Normal\"><strong>Ethnicity<\/strong>: A term used commonly in an interchangeable way with the term <em>race<\/em>, complicated because how different people define this term depends on the qualities and characteristics they use to assign a label or identity to themselves and\/or others (which may include aspects of family background, skin color, language(s) spoken, religion, physical proportions, behavior and temperament, etc.).<\/p>\n<p class=\"import-Normal\"><strong>Eugenics<\/strong>: A set of beliefs and practices that involves the controlled selective breeding of human populations with the hope of improving their heritable qualities, especially through surgical procedures like sterilization and legal rulings that affect marriage rights for interracial couples.<\/p>\n<p class=\"import-Normal\"><strong>Gene flow<\/strong>: A neutral (or nonselective) evolutionary process that occurs when genes get shared between populations.<\/p>\n<p class=\"import-Normal\"><strong>Genetic drift<\/strong>: A neutral evolutionary process in which allele frequencies change from generation to generation due to random chance.<\/p>\n<p class=\"import-Normal\"><strong>Heterogeneity<\/strong>: The quality of being diverse genetically.<\/p>\n<p class=\"import-Normal\"><strong>Homog<\/strong><strong>enous<\/strong>: The quality of being uniform genetically.<\/p>\n<p class=\"import-Normal\"><strong>Human diversity<\/strong>: Human diversity is a measure of variation that may describe how many different forms of human there are, separated or clustered into groups according to some genetic, phenotypic, or cultural trait(s). The term can be applied to culture (in which case humans can be described as significantly diverse) or genetics (in which case humans are not diverse because all humans on Earth share a majority of their genes).<\/p>\n<p class=\"import-Normal\"><strong>Human variation<\/strong>: Differences in biology, physiology, body chemistry, behavior, and culture. By measuring these differences, we understand the degrees of variation between individuals, groups, populations, or species.<\/p>\n<p class=\"import-Normal\"><strong>Isolation-by-distance model<\/strong>: A model that predicts a positive relationship between genetic distances and geographical distances between pairs of populations.<\/p>\n<p class=\"import-Normal\"><strong>Monogenetic<\/strong>: Pertaining to the idea that the origin of a species is situated in one geographic region or time (as opposed to <em>polygenetic<\/em>).<\/p>\n<p class=\"import-Normal\"><strong>Mutation<\/strong>: A gene alteration in the DNA sequence of an organism. As a random, neutral evolutionary process that occurs over the course of meiosis and early cell development, gene mutations are possible sources of variation in any given human gene pool. Genetic mutations that occur in more than 1% of a population are termed <em>polymorphisms<\/em>.<\/p>\n<p class=\"import-Normal\"><strong>Natural selection<\/strong>: An evolutionary process whereby certain traits are perpetuated through successive generations, likely owing to the advantages they give organisms in terms of chances of survival and\/or reproduction.<\/p>\n<p class=\"import-Normal\"><strong>Nonconcordance<\/strong>: The fact of genes or traits not varying with one another and instead being inherited independently.<\/p>\n<p class=\"import-Normal\"><strong>Otherness<\/strong>: In postcolonial anthropology, we now understand \u201cothering\u201d to mean any action by someone or some group that establishes a division between \u201cus\u201d and \u201cthem\u201d in relation to other individuals or populations. This could be based on linguistic or cultural differences, and it has largely been based on external characteristics throughout history.<\/p>\n<p class=\"import-Normal\"><strong>Out-of-Africa model<\/strong>: A model that suggests that all humans originate from one single group of <em>Homo sapiens<\/em> in (sub-Saharan) Africa who lived between 100,000 and 315,000 years ago and who subsequently diverged and migrated to other regions across the globe.<\/p>\n<p class=\"import-Normal\"><strong>Physical anthropology<\/strong>: This used to be the more common name given to the subdiscipline of anthropology centered upon the study of human origins, evolution and variation (also see <em>biological anthropology<\/em> above). This name for the field has gradually become less popular due to two reasons: first, it may not reflect our interests in other aspects of humankind that are not physical (such as those behavioral, cultural and spiritual), and second, using this term popular in the early decades of our field may be viewed by some as harkening back to a time when biological anthropologists conducted their work in unethical ways.<\/p>\n<p class=\"import-Normal\"><strong>Polygenetic<\/strong>: Having many different ancestries, as in older theories about human origins that involved multiple traditional groupings of humans evolving concurrently in different parts of the world before they merged into one species through interbreeding and\/or intergroup warfare. These earlier suggestions have now been overwhelmed by insurmountable evidence for a single origin of the human species in Africa (see the \u201cOut-of-Africa model\u201d).<\/p>\n<p class=\"import-Normal\"><strong>Polymorphism<\/strong>: A genetic variant within a population (caused either by a single gene or multiple genes) that occurs at a rate of over 1% among the population. Polymorphisms are responsible for variation in phenotypic traits such as blood type and skin color.<\/p>\n<p class=\"import-Normal\"><strong>Population<\/strong>: A group of humans living in a particular geographical area, with more local interbreeding within-group than interbreeding with other groups. A limited or restricted amount of gene flow between populations can occur due to geographical, cultural, linguistic, or environmental factors.<\/p>\n<p class=\"import-Normal\"><strong>Population bottlenecking<\/strong>: An event in which genetic variation is significantly reduced owing to a sharp reduction in population size. This can occur when environmental disaster strikes or as a result of human activities (e.g., genocides or group migrations). An important example of this loss in genetic variation occurred over the first human migrations out of Africa and into other continental regions.<\/p>\n<p class=\"import-Normal\"><strong>Prejudice<\/strong>: An unjustified attitude toward an individual or group that is not based on reason, whether positive (and showing preference for one group of people over another) or negative (and resulting in harm or injury to others).<\/p>\n<p class=\"import-Normal\"><strong>Race<\/strong>: The identification of a group based on a perceived distinctiveness that makes that group more similar to each other than they are to others outside the group. This may be based on cultural differences, genetic parentage, physical characteristics, behavioral attributes, or something arbitrarily and socially constructed. As a social or demographic category, perceptions of \u201crace\u201d can have real and serious consequences for different groups of people. This is despite the fact that biological anthropologists and geneticists have demonstrated that all humans are genetically homogenous and that more differences can be found within populations than between them in the overall apportionment of human biological variation. This term is sometimes used interchangeably with <em>ethnicity<\/em>.<\/p>\n<p class=\"import-Normal\"><strong>Racism<\/strong>: Any action or belief that discriminates against someone based on perceived differences in race or ethnicity.<\/p>\n<p class=\"import-Normal\"><strong>Scientific Revolution<\/strong>: A period between the 1400s and 1600s when substantial shifts occurred in the social, technological, and philosophical sense, when a scientific method based on the collection of empirical evidence through experimentation was emphasized and inductive reasoning was used to test hypotheses and interpret their results.<\/p>\n<p class=\"import-Normal\"><strong>Typolog<\/strong><strong>ical<\/strong>: Of or describing an assortment system that relies on the interpretation of qualitative similarities or differences in the study of variation among objects or people. The categorization of cultures or human groups according to \u201crace\u201d was performed with a typological approach in the earliest practice of anthropology, but this practice has since been discredited and abandoned.<\/p>\n<p class=\"import-Normal\"><strong>Variance<\/strong>: In statistics, variance measures the dispersal of a set of data around the mean or average value.<\/p>\n<h2 class=\"import-Normal\">About the Author<strong><br \/>\n<\/strong><\/h2>\n<p class=\"import-Normal\"><img class=\"alignleft\" src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image20-4.png\" alt=\"A man with short black hair and brown eyes, looks at the camera. \" width=\"247\" height=\"257\" \/><\/p>\n<h3 class=\"import-Normal\"><strong>Michael B. C. Rivera, Ph.D.<\/strong><\/h3>\n<p class=\"import-Normal\">University of Hong Kong, <a class=\"rId114\" href=\"mailto:mrivera@hku.hk\">mrivera@hku.hk<\/a><\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Michael B. C. Rivera is a biological anthropologist and human bioarchaeologist who studies human evolution and history and works to develop these disciplines in Hong Kong, East\/Southeast Asia, and the \u201cGlobal South.\u201d His doctoral thesis focused on the transition into agriculture in coastal environments and adaptations of ancient people along the beach. He is the only biological anthropologist working at the University of Hong Kong and the lead archaeologist managing the excavation of a WWII military aircraft that crashed in Hong Kong in 1945. Michael is also an advocate for greater inclusion, diversity, equality, and access to learning in academia. Much of his work also includes science communication and public engagement activities online, in schools, and in collaboration with museums.<\/p>\n<h2 class=\"import-Normal\">For Further Exploration<strong><br \/>\n<\/strong><\/h2>\n<h3 class=\"import-Normal\"><strong>Videos<\/strong><\/h3>\n<p>American Medical Association (AMA). 2020. \u201c<a href=\"https:\/\/www.youtube.com\/watch?v=tqA3KvvscYc\" target=\"_blank\" rel=\"noopener\">Examining Race-Based Medicine<\/a>.\u201d YouTube, October 29. Accessed June 4, 2023.<\/p>\n<p>Crenshaw, Kimberl\u00e9. 2016. \u201c<a href=\"https:\/\/www.youtube.com\/watch?v=akOe5-UsQ2o\" target=\"_blank\" rel=\"noopener\">The Urgency of Intersectionality<\/a>.\u201d YouTube, December 7. Accessed June 4, 2023.<\/p>\n<p>Golash-Boza, Tanya. 2018. \u201c<a href=\"https:\/\/www.youtube.com\/watch?v=NQOimokvJXo\" target=\"_blank\" rel=\"noopener\">What Is Race? What Is Ethnicity? Is There a Difference?<\/a>.\u201d YouTube, October 28. Accessed June 4, 2023.<\/p>\n<p>Lasisi, Tina. 2020. \u201c<a href=\"https:\/\/naturalhistory.si.edu\/education\/teaching-resources\/social-studies\/webinar-how-hair-reveals-futility-race-categories\" target=\"_blank\" rel=\"noopener\">How Hair Reveals the Futility of Race Categories<\/a>.\u201d National Museum of Natural History webinar, October 21.<\/p>\n<p>Lasisi, Tina. 2022. \u201c<a href=\"https:\/\/www.youtube.com\/watch?v=_BEJvVFxKV4\" target=\"_blank\" rel=\"noopener\">Where Does My Skin Color Come From?<\/a>.\u201d PBS Terra, August 18. Accessed June 4, 2023.<\/p>\n<p>PBS Origins. 2018. \u201c<a href=\"https:\/\/www.youtube.com\/watch?v=CVxAlmAPHec\" target=\"_blank\" rel=\"noopener\">The Origin of Race in the USA<\/a>.\u201d YouTube, April 3. Accessed June 4, 2023.<\/p>\n<p>Roberts, Dorothy. 2016. \u201c<a href=\"https:\/\/www.youtube.com\/watch?v=KxLMjn4WPBY\" target=\"_blank\" rel=\"noopener\">The Problem with Race-Based Medicine<\/a>.\u201d YouTube, March 4. Accessed June 4, 2023.<\/p>\n<p>Vox. 2015. \u201c<a href=\"https:\/\/www.youtube.com\/watch?v=VnfKgffCZ7U\" target=\"_blank\" rel=\"noopener\">The Myth of Race, Debunked in 3 Minutes<\/a>.\u201d YouTube, January 13. Accessed June 4, 2023.<\/p>\n<h3 class=\"import-Normal\"><strong>Podcast Episodes<\/strong><\/h3>\n<p>Kwong, Emily, and Rebecca Ramirez. 2021. \u201c<a href=\"https:\/\/www.npr.org\/2021\/10\/05\/1043391809\/heres-a-better-way-to-talk-about-hair\" target=\"_blank\" rel=\"noopener\">Here\u2019s a Better Way to Talk about Hair: A 16 Minute Listen with Tina, Lasisi<\/a>\u201d NPR Short Wave, October 6. Accessed June 4, 2023.<\/p>\n<p>Speaking of Race. 2020. \u201c<a href=\"https:\/\/soundcloud.com\/user-88955638\/sets\/race-and-health?fbclid=IwAR2U1jdQL3XYFS5llGvYZ6uSrvPikuakmbxUZb--8voxgAMKrLbu7Ym7LGU\" target=\"_blank\" rel=\"noopener\">Race and Health series<\/a>.\u201d Speaking of Race, April 10. Accessed June 4, 2023.<\/p>\n<h3 class=\"import-Normal\"><strong>Websites<\/strong><\/h3>\n<p>Choices Program. 2023. \u201c<a href=\"https:\/\/www.choices.edu\/teaching-news-lesson\/an-interactive-timeline-black-activism-and-the-long-fight-for-racial-justice\/\" target=\"_blank\" rel=\"noopener\">An Interactive Timeline: Black Activism and the Long Fight for Racial Justice<\/a>.\u201d <em>Choices Program, Brown University<\/em> [Interactive Timeline], Updated February, 2023.<\/p>\n<h2 class=\"import-Normal\">References<\/h2>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">American Association of Biological Anthropologists. 2020. \u201c<a href=\"https:\/\/bioanth.org\/about\/position-statements\/open-letter-our-community-response-police-brutality-against-african-americans-and-call-antiracist-action\/\" target=\"_blank\" rel=\"noopener\">An Open Letter to Our Community in Response to Police Brutality against African-Americans and a Call to Antiracist Action<\/a>\u201d. <em>American Association of Biological Anthropologists<\/em>, June 10, 2020. Accessed June 4, 2023.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Antrosio, Jason. 2011. \u201c\u2018<a href=\"https:\/\/www.livinganthropologically.com\/biological-anthropology\/race-reconciled-debunks-race\/\" target=\"_blank\" rel=\"noopener\">Race Reconciled\u2019: Race Isn\u2019t Skin Color, Biology, or Genetics<\/a>.\u201d <em>Living Anthropologically <\/em>(website), June 5, 2011; updated May 20, 2020. Accessed June 4, 2023.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Beals, Kenneth L., Courtland L. Smith, Stephen M. Dodd, J. Lawrence Angel, Este Armstrong, Bennett Blumenberg, Fakhry G. Girgis, et al. 1984. \u201cBrain Size, Cranial Morphology, Climate, and Time Machines [and Comments and Reply].\u201d <em>Current Anthropology<\/em> 25 (3): 301\u2012330.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Betti, Lia, Fran\u00e7ois Balloux, Tsunehiko Hanihara, and Andrea Manica. 2010. \u201cThe Relative Role of Drift and Selection in Shaping the Human Skull.\u201d <em>American Journal of Physical Anthropology<\/em> 141 (1): 76\u201282. https:\/\/doi.org\/10.1002\/ajpa.21115.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Betti, Lia, Fran\u00e7ois Balloux, William Amos, Tsunehiko Hanihara, and Andrea Manica. 2009. \u201cDistance from Africa, Not Climate, Explains Within-Population Phenotypic Diversity in Humans.\u201d <em>Proceedings: Biological Sciences<\/em> 276 (1658): 809\u2012814. https:\/\/doi.org\/10.1098\/rspb.2008.1563.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Betti, Lia, Noreen von Cramon-Taubadel, Andrea Manica, and Stephen J. Lycett. 2013. \u201cGlobal Geometric Morphometric Analyses of the Human Pelvis Reveal Substantial Neutral Population History Effects, Even across Sexes.\u201d <em>PloS ONE<\/em> 8 (2): e55909. https:\/\/doi.org\/10.1371\/journal.pone.0055909.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Betti, Lia, Noreen von Cramon-Taubadel, Andrea Manica, and Stephen J. Lycett. 2014. \u201cThe Interaction of Neutral Evolutionary Processes with Climatically Driven Adaptive Changes in the 3D Shape of the Human Os Coxae.\u201d <em>Journal of Human Evolution<\/em> 73 (August): 64\u201274. https:\/\/doi.org\/10.1016\/j.jhevol.2014.02.021.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Boas, Franz. 1931. \u201cRace and Progress.\u201d <em>Science<\/em> 74 1905): 1\u20128.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Bowden, Rory, Tammie S. MacFie, Simon Myers, Garrett Hellenthal, Eric Nerrienet, Ronald E. Bontrop, Colin Freeman, Peter Donnelly, and Nicholas I. Mundy. 2012. \u201cGenomic Tools for Evolution and Conservation in the Chimpanzee: <em>Pan troglodytes ellioti<\/em> Is a Genetically Distinct Population.\u201d <em>PLoS Genetics<\/em> 8 (3): e1002504. https:\/\/doi.org\/10.1371\/journal.pgen.1002504.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Campbell, Michael C., and Sarah A. Tishkoff. 2008. \u201cAfrican Genetic Diversity: Implications for Human Demographic History, Modern Human Origins, and Complex Disease Mapping.\u201d <em>Annual Review of Genomics and Human Genetics<\/em> 9: 403\u2012433.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Clee, Paul R. Sesink, Ekwoge E. Abwe, Ruffin D. Ambahe, Nicola M. Anthony, Roger Forso, Sabrina Locatelli, Fiona Maisels, et al. 2015. \u201cChimpanzee Population Structure in Cameroon and Nigeria Is Associated with Habitat Variation That May Be Lost Under Climate Change.\u201d <em>BMC Evolutionary Biology<\/em> 15: 2. https:\/\/doi.org\/10.1186\/s12862-014-0275-z.<\/p>\n<p class=\"import-Normal\">Cullors, Patrisse. 2016. \u201cAn Interview with the Founders of Black Lives Matter.\u201d TED Talks 2016, October 26\u201228. Accessed June 15, 2023. https:\/\/www.ted.com\/talks\/alicia_garza_patrisse_cullors_and_opal_tometi_an_interview_with_the_founders_of_black_lives_matter\/up-next.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Fuentes, Agust\u00edn, Rebecca Rogers Ackermann, Sheela Athreya, Deborah Bolnick, Tina Lasisi, Sang-Hee Lee, Shay-Akil McLean, and Robin Nelson. 2019. \u201cAAPA Statement on Race and Racism.\u201d <em>American Journal of Physical Anthropology<\/em> 169 (3): 400\u2012402.<\/p>\n<p class=\"import-Normal\">Garza, Alicia. 2016. \u201cAn Interview with the Founders of Black Lives Matter.\u201d TED Talks 2016, October 26\u201228. Accessed June 15, 2023. https:\/\/www.ted.com\/talks\/alicia_garza_patrisse_cullors_and_opal_tometi_an_interview_with_the_founders_of_black_lives_matter\/up-next.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Gerbault, Pascale, Anke Liebert, Yuval Itan, Adam Powell, Mathias Currat, Joachim Burger, Dallas M. Swallow, and Mark G. Thomas. 2011. \u201cEvolution of Lactase Persistence: An Example of Human Niche Construction.\u201d <em>Philosophical Transactions of the Royal Society B<\/em> 366 (1566): 863\u2012877. https:\/\/doi.org\/10.1098\/rstb.2010.0268.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Hooton, Earnest A. 1936. \u201cPlain Statements about Race.\u201d <em>Science<\/em> 83 (2161): 511\u2012513.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Hrdli\u010dka, Ale\u0161. 1918. \u201cPhysical Anthropology: Its Scope and Aims; Its History and Present Status in America. A: Physical Anthropology; Its Scopes and Aims.\u201d <em>American Journal of Physical Anthropology<\/em> 1 (1): 3\u201223.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Huxley, Julian. 1942. <em>Evolution: The Modern Synthesis<\/em>. London: Allen and Unwin.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Ingram, Catherine J. E., Charlotte A. Mulcare, Yuval Itan, Mark G. Thomas, and Dallas M. Swallow. 2009. \u201cLactose Digestion and the Evolutionary Genetics of Lactase Persistence.\u201d <em>Human Genetics<\/em> 124 (6): 579\u2012591. https:\/\/doi.org\/10.1007\/s00439-008-0593-6.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Jablonski, Nina G. 2004. \u201cThe Evolution of Human Skin and Skin Color.\u201d <em>Annual Review of Anthropology<\/em> 33: 585\u2012623. https:\/\/doi.org\/10.1146\/annurev.anthro.33.070203.143955.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Jablonski, Nina G., and George Chaplin. 2000. \u201cThe Evolution of Human Skin Coloration.\u201d <em>Journal of Human Evolution<\/em> 39 (1): 57\u2012106. https:\/\/doi.org\/10.1006\/jhev.2000.0403.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Kanitz, Ricardo, Elsa G. Guillot, Sylvain Antoniazza, Samuel Neuenschwander, and J\u00e9r\u00f4me Gedout. 2018. \u201cComplex Genetic Patterns in Human Arise from a Simple Range-Expansion Model over Continental Landmasses.\u201d <em>PLoS ONE<\/em> 13 (2): e0192460.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Kronenberg, Zev N., Ian T. Fiddes, David Gordon, Shwetha Murali, Stuart Cantsilieris, Olivia S. Meyerson, Jason G. Underwood, et al. 2018. \u201cHigh-Resolution Comparative Analysis of Great Ape Genomes.\u201d <em>Science<\/em> 360 (6393): eaar6343. https:\/\/doi.org\/10.1126\/science.aar6343.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Kuzawa, Christopher W., and Elizabeth Sweet. 2009. \u201cEpigenetics and the Embodiment of Race: Development Origins of US Racial Disparities in Cardiovascular Health.\u201d <em>American Journal of Human Biology<\/em> 21 (1) : 2\u201215.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Lasisi, Tina, and Mark D. Shriver. 2018. \u201cFocus on African Diversity Confirms Complexity of Skin Pigmentation Genetics.\u201d <em>Genomic Biology<\/em> 19: 13.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Lewontin, Richard. 1972. \u201cThe Apportionment of Human Diversity.\u201d In <em>Evolutionary Biology<\/em>, vol. 6, edited by Theodosius Dobzhansky, Max K. Hecht, and William C. Steere, 381\u2012398. New York: Springer.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Linnaeus, Carl. 1758. <em>Systema Naturae<\/em>. Stockholm: Laurentius Salvius. <a class=\"rId128\" href=\"https:\/\/www.cabdirect.org\/abstracts\/20057000018.html\">https:\/\/www.cabdirect.org\/abstracts\/20057000018.html<\/a>.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Liu, Hua, Franck Prugnolle, Andrea Manica, and Fran\u00e7ois Balloux. 2006. \u201cA Geographically Explicit Genetic Model of Worldwide Human-Settlement History.\u201d <em>American Journal of Human Genetics<\/em> 79 (2): 230\u2012237.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Livingstone, Frank B. 1962. \u201cOn the Nonexistence of Human Races.\u201d <em>Current Anthropology<\/em> 3 (3): 279\u2012281.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Long, Jeffery C., and Rick A. Kittles. 2003. \u201cHuman Genetic Diversity and the Nonexistence of Biological Races.\u201d <em>Human Biology<\/em> 75 (4): 449\u2012471.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Luzzatto, Lucio. 2012. \u201cSickle Cell Anaemia and Malaria.\u201d <em>Mediterranean Journal of Hematology and Infectious Diseases<\/em> 4 (1). https:\/\/doi.org\/10.4084\/MJHID.2012.065.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Manica, Andrea, William Amos, Fran\u00e7ois Balloux, and Tsunehiko Hanihara. 2007. \u201cThe Effect of Ancient Population Bottlenecks on Human Phenotypic Variation.\u201d <em>Nature<\/em> 448 (7151): 346\u2012348. https:\/\/doi.org\/10.1038\/nature05951.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">McLean, Shay-Akil. 2014. \u201c\u2018Race, Ethnicity, &amp; Racism.\u201d Decolonize ALL The Things Website, Accessed January 10, 2023. https:\/\/decolonizeallthethings.com\/learning-tools\/race-ethnicity-racism\/.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Morton, Samuel George. 1839. <em>Crania Americana, or, A Comparative View of the Skulls of Various Aboriginal Nations of North and South America.<\/em> Philadelphia: J. Dobson.<\/p>\n<p class=\"import-Normal\">Mourant, A. E., Ada C. Kope\u0107, and Kazimiera Domaniewska-Sobczak. 1976. <em>The Distribution of the Human Blood Groups and Other Polymorphisms<\/em>, 2nd edition. Oxford: Oxford University Press.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">National Research Council (U.S.) Committee on Human Genome Diversity. 1997. <em>Evaluating Human Genetic Diversity.<\/em> Washington, D.C.: National Academies Press.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Omi, Michael, and Howard Winant. 2014. \u201cThe Theory of Racial Formation.\u201d In <em>Racial Formation in the United States<\/em>,3rd edition, edited by Michael Omi and Howard Winant, 105\u2012126. Routledge: New York.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Osada, Naoki. 2015. \u201cGenetic Diversity in Humans and Non-Human Primates and Its Evolutionary Consequences.\u201d <em>Genes and Genetic Systems<\/em> 90 (3): 133\u2012145.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Ousley, Stephen D., Richard L. Jantz, and Donna Freid. 2009. \u201cUnderstanding Race and Human Variation: Why Forensic Anthropologists Are Good at Identifying Race.\u201d <em>American Journal of Physical Anthropology<\/em> 139 (1): 68\u201276. https:\/\/doi.org\/10.1002\/ajpa.21006.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Ponce de Le\u00f3n, Marcia S., Toetik Koesbardiati, John David Weissmann, Marco Millela, Carlos S. Reyna-Blanco, Gen Suwa, Osamu Kondo, Anna-Sapfo Malaspinas, Tim D. White, and Christoph P. E. Zollikofer. 2018. \u201cHuman Bony Labyrinth Is an Indicator of Population History and Dispersal from Africa.\u201d <em>Proceedings of the National Academy of Sciences<\/em> 115 (16): 4128\u20124133. https:\/\/doi.org\/10.1073\/pnas.1808125115.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Prado-Martinez, Javier, Peter H. Sudmant, Jeffrey M. Kidd, Heng Li, Joanna L. Kelley, Belen Lorente-Galdos, Krishna R. Veeramah, et al. 2013. \u201cGreat Ape Genetic Diversity and Population History.\u201d <em>Nature<\/em> 499 (7459): 471\u2013475. https:\/\/doi.org\/10.1038\/nature12228.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Prugnolle, Franck, Andrea Manica, and Fran\u00e7ois Balloux. 2005. \u201cGeography Predicts Neutral Genetic Diversity of Human Populations.\u201d <em>Current Biology<\/em> 15 (5): 159\u2012160.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Quillen, Ellen E., Heather L. Norton, Esteban J. Parra, Frida Lona-Durazo, Khai C. Ang, Florin Mircea Illiescu, Laurel N. Pearson, et al. 2018. \u201cShades of Complexity: New Perspectives on the Evolution and Genetic Architecture of Human Skin.\u201d <em>American Journal of Physical Anthropology<\/em> 168 (S67): 4\u201326.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Rathmann, Hannes, Hugo Reyes-Centeno, Silvia Ghirotto, Nicole Creanza, Tsunehiko Hanihara, and Katerina Harvati. 2017. \u201cReconstructing Human Population History from Dental Phenotypes.\u201d <em>Scientific Reports<\/em> 7: 12495. https:\/\/doi.org\/10.1038\/s41598-017-12621-y.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Relethford, John H. 2001. \u201cGlobal Analysis of Regional Differences in Craniometric Diversity and Population Substructure.\u201d <em>Human Biology<\/em> 73 (5): 629\u2012636. https:\/\/doi.org\/10.1353\/hub.2001.0073.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Relethford, John H. 2002. \u201cApportionment of Global Human Genetic Diversity Based on Craniometrics and Skin Color.\u201d <em>American Journal of Physical Anthropology<\/em> 118 (4): 393\u2012398. https:\/\/doi.org\/10.1002\/ajpa.10079.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Relethford, John H. 2004. \u201cGlobal Patterns of Isolation by Distance Based on Genetic and Morphological Data.\u201d <em>Human Biology<\/em> 76 (4): 499\u2012513. https:\/\/doi.org\/10.1353\/hub.2004.0060.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Relethford, John H. 2009. \u201cRace and Global Patterns of Phenotypic Variation.\u201d <em>American Journal of Physical Anthropology<\/em> 139 (1): 16\u201222. https:\/\/doi.org\/10.1002\/ajpa.20900.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Roberts, Dorothy. 2013. <em>Fatal Invention: How Science, Politics, and Big Business Re-Create Race in the Twenty-First Century<\/em>. New York: The New Press.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Rosenberg, Noah A., Saurabh Mahajan, Sohini Ramachandran, Chengfeng Zhao, Jonathan K. Pritchard, and Marcus W. Feldman. 2005. \u201cClines, Clusters, and the Effect of Study Design on the Inference of Human Population Structure.\u201d <em>PLoS Genetics<\/em> 1 (6): e70. https:\/\/doi.org\/10.1371 \/journal.pgen.0010070.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Rosenberg, Noah A., Jonathan K. Pritchard, James L. Weber, Howard M. Cann, Kenneth K. Kidd, Lev A. Zhivotovsky, and Marcus W. Feldman. 2002. \u201cGenetic Structure of Human Populations.\u201d <em>Science<\/em> 298 (5602): 2381\u20122385.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Sauer, Norman J. 1992. \u201cForensic Anthropology and the Concept of Race: If Races Don\u2019t Exist, Why Are Forensic Anthropologists So Good at Identifying Them?\u201d <em>Social Science and Medicine<\/em> 34 (2): 107\u2012111. https:\/\/doi.org\/10.1016\/0277-9536(92)90086-6.<\/p>\n<p class=\"import-Normal\">Shonkoff, Jack P., Natalie Slopen, and David R. Williams. 2021. \u201cEarly Childhood Adversity, Toxic Stress, and the Impacts of Racism on the Foundations of Health.\u201d <em>Annual Review of Public Health<\/em> 42: 115\u2012134.<\/p>\n<p class=\"import-Normal\">Sjoding, Michael W., Robert P. Dickson, Theodore J. Iwashyna, Steven E. Gay, and Thomas S. Valley. 2020. \u201cRacial Bias in Pulse Oximetry Measurement.\u201d <em>The New England Journal of Medicine<\/em> 383: 2477-2478.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Staes, Nicky, Chet C. Sherwood, Katharine Wright, Marc de Manuel, Elaine E. Guevara, Tomas Marques-Bonet, Michael Kr\u00fctzen, et al. 2017. \u201cFOXP2 Variation in Great Ape Populations Offers Insight into the Evolution of Communication Skills.\u201d <em>Scientific Reports<\/em> 7 (1): 1\u201210. https:\/\/doi.org\/10.1038\/s41598-017-16844-x.<\/p>\n<p class=\"import-Normal\">Tomati, Opal. 2016. \u201cAn Interview with the Founders of Black Lives Matter.\u201d TED Talks 2016, October 26\u201228. Accessed June 15, 2023. https:\/\/www.ted.com\/talks\/alicia_garza_patrisse_cullors_and_opal_tometi_an_interview_with_the_founders_of_black_lives_matter\/up-next.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Tsai, Jennifer. 2021. \u201cCOVID-19 Is Not a Story of Race, but a Record of Racism\u2014Our Scholarship Should Reflect That Reality.\u201d <em>The American Journal of Bioethics<\/em> 21 (2): 43\u201247. https:\/\/doi.org\/10.1080\/15265161.2020.1861377.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">von Cramon-Taubadel, Noreen, and Stephen J. Lycett. 2008. \u201cBrief Communication: Human Cranial Variation Fits Iterative Founder Effect Model with African Origin.\u201d <em>American Journal of Physical Anthropology<\/em> 136 (1): 108\u2012113. https:\/\/doi.org\/10.1002\/ajpa.20775.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Weiss, Kenneth M., and Jeffrey C. Long. 2009. \u201cNon-Darwinian Estimation: My Ancestors, My Genes\u2019 Ancestors.\u201d <em>Genome Research<\/em> 19: 703\u2012710. https:\/\/doi.org\/10.1101\/gr.076539.108.19.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Williams, David W. 2018. \u201cStress and the Mental Health of Populations of Color: Advancing Our Understanding of Race-related Stressors.\u201d <em>Journal of Health and Social Behavior<\/em> 59 (4): 466\u2012485.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Wise, Tim. 2010. <em>Colorblind: The Rise of Post-Racial Politics and the Retreat from Racial Equity<\/em>. San Francisco: City Lights.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Yudell, Michael, Dorothy Roberts, Rob DeSalle, and Sarah Tishkoff. 2016. \u201cTaking Race out of Human Genetics.\u201d <em>Science<\/em> 351 (6273): 564\u2012565. https:\/\/doi.org\/10.1126\/science.aac4951.<\/p>\n<\/div>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_281_1696\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_281_1696\"><div tabindex=\"-1\"><div class=\"__UNKNOWN__\">\n<p class=\"import-Normal\">Jonathan Marks, Ph.D., University of North Carolina at Charlotte<\/p>\n<p class=\"import-Normal\">Adam P. Johnson, M.A., University of North Carolina at Charlotte\/University of Texas at San Antonio<\/p>\n<p class=\"import-Normal\"><em>This chapter is an adaptation of \"<\/em><a class=\"rId9\" href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/chapter\/__unknown__\/\"><em>Chapter 2: Evolution<\/em><\/a><em>\u201d by Jonathan Marks. In <\/em><a class=\"rId10\" href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/\"><em>Explorations: An Open Invitation to Biological Anthropology, first edition<\/em><\/a><em>, edited by Beth Shook, Katie Nelson, Kelsie Aguilera, and Lara Braff, which is licensed under <\/em><a class=\"rId11\" href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\"><em>CC BY-NC 4.0<\/em><\/a><em>. <\/em><\/p>\n<div class=\"textbox textbox--learning-objectives\">\n<header class=\"textbox__header\">\n<h2 class=\"textbox__title\"><span style=\"color: #ffffff;\">Learning Objectives<\/span><\/h2>\n<\/header>\n<div class=\"textbox__content\">\n<ul>\n<li>Explain the relationship among genes, bodies, and organismal change.<\/li>\n<li>Discuss the shortcomings of simplistic understandings of genetics.<\/li>\n<li>Describe what is meant by the \"biopolitics of heredity.\"<\/li>\n<li>Discuss issues caused by misuse of ideas about adaptations and natural selection.<\/li>\n<li>Examine and correct myths about evolution.<\/li>\n<\/ul>\n<\/div>\n<\/div>\n<p class=\"import-Normal\">The Human Genome Project, an international initiative launched in 1990, sought to identify the entire genetic makeup of our species. For many scientists, it meant trying to understand the genetic underpinnings of what made humans uniquely human. James Watson, a codiscoverer of the helical shape of DNA, wrote that \u201cwhen finally interpreted, the genetic messages encoded within our DNA molecules will provide the ultimate answers to the chemical underpinnings of human existence\u201d (Watson 1990, 248). The underlying message is that what makes humans unique can be found in our <strong>genes<\/strong>. The Human Genome Project hoped to find the core of who we are and where we come from.<\/p>\n<p class=\"import-Normal\">Despite its lofty goal, the Human Genome Project\u2014even after publishing the entire human genome in January 2022\u2014could not fully account for the many factors that contribute to what it is to be human. Richard Lewontin, Steven Rose, and Leon Kamin (2017) argue that genetic determinism of the sort assumed by the Human Genome Project neglects other essential dimensions that contribute to the development and evolution of human bodies, not to mention the role that culture plays. They use an apt metaphor of a cake to illustrate the incompleteness of reductive models. Consider the flavor of a cake and think of the ingredients listed in the recipe. The recipe includes ingredients such as flour, sugar, shortening, vanilla extract, eggs, and milk. Does raw flour taste like cake? Does sugar, vanilla extract, or any of the other ingredients taste like cake? They do not, and knowing the individual flavors of each ingredient does not tell us much about what cake tastes like. Even mixing all of the ingredients in the correct proportions does not get us cake. Instead, external factors such as baking at the right temperature, for the right amount of time, and even the particularities of our evolved sense of taste and smell are all necessary components of experiencing the cake.<\/p>\n<p class=\"import-Normal\">Lewontin, Rose, and Kamin (2017) argue that the same is true for humans and other organisms.<\/p>\n<p class=\"import-Normal\">Knowing everything about cake ingredients does not allow us to fully know cake. Equally so, knowing everything about the genes found in our DNA does not allow us to fully know humans. Different, interacting levels are implicated in the development and evolution of all organisms, including humans. Genes, the structure of chromosomes, developmental processes, epigenetic tags, environmental factors, and still-other components all play key roles such that genetically reductive models of human development and evolution are woefully inadequate.<\/p>\n<p class=\"import-Normal\">The complex interactions across many levels\u2014genetic, developmental, and environmental\u2014explain why we still do not know how our one-dimensional DNA nucleotide sequence results in a four-dimensional organism. This was the unfulfilled promise of the inception of the Human Genome Project in the 1980s and 1990s: the project produced the complete DNA sequence of a human cell in the hopes that it would reveal how human bodies are built and how to cure them when they are built poorly. Yet, that information has remained elusive. Presumably, the knowledge of how organisms are produced from DNA sequences will one day permit us to reconcile the discrepancies between patterns in anatomical evolution and molecular evolution.<\/p>\n<p class=\"import-Normal\">In this chapter, we will consider multilevel evolution and explore evolution as a complex interaction between genetic and epigenetic factors as well as the environments in which organisms live. Next, we will examine the biopolitical nature of human evolution. We will then investigate problems that arise from attributing all traits to an adaptive function. Finally, we will address common misconceptions about evolution. The goal of this chapter is to provide you with the necessary toolkit for understanding the molecular, anatomical, and political dimensions of evolution.<\/p>\n<h2 class=\"import-Normal\">Evolution Happens at Multiple Levels<\/h2>\n<p class=\"import-Normal\">Following Richard Dawkins\u2019s publication of <em>The Selfish Gene <\/em>in 1976, the scientific imagination was captured by the potential of genomics to reveal how genes are copied by Darwinian selection. Dawkins argues that the genes in individuals that contribute to greater reproductive success are the units of selection. His conception of evolution at the molecular level undercuts the complex interactions between organisms and their environments, which are not expressed genomically but are nevertheless key drivers in evolution.<\/p>\n<p class=\"import-Normal\">By the 1980s, the acknowledgment among most biologists that even though genes construct bodies, genes and bodies evolve at different rates and with distinct patterns. This realization led to a renewed focus on how bodies change. The Evolutionary Synthesis of the 1930s\u20131970s had reduced organisms to their <strong>genotypes<\/strong> and species to their <strong>gene pools<\/strong>, which provided valuable insights about the processes of biological change, but it was only a first approximation. Animals are in fact reactive and adaptable beings, not passive and inert genotypes. Species are clusters of socially interacting and reproductively compatible organisms.<\/p>\n<figure style=\"width: 291px\" class=\"wp-caption alignleft\"><img class=\"\" src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/06\/image8-5.png\" alt=\"An asteroid hits the ocean. Pterodactyls fly among clouds in the foreground.\" width=\"291\" height=\"233\" \/><figcaption class=\"wp-caption-text\">Figure 17.1: A painting by Donald E. Davis representing the Chicxulub asteroid impact off the Yucatan Peninsula that contributed to the mass extinction that included the dinosaurs about 65 million years ago. Credit: <a href=\"https:\/\/commons.wikimedia.org\/wiki\/File:Chicxulub_impact_-_artist_impression.jpg\">Chicxulub impact - artist impression<\/a> by Donald E. Davis, <a href=\"https:\/\/www.nasa.gov\/\">NASA<\/a>, is in the <a href=\"https:\/\/en.wikipedia.org\/wiki\/Public_domain\">public domain<\/a>.<\/figcaption><\/figure>\n<p class=\"import-Normal\">Once we accept that evolutionary change is fundamentally genetic change, we can ask: How do bodies function and evolve? How do groups of animals come to see one another as potential mates or competitors for mates, as opposed to just other creatures in the environment? Are there evolutionary processes that are not explicable by population genetics? These questions\u2014which lead us beyond reductive assumptions\u2014were raised in the 1980s by Stephen Jay Gould, the leading evolutionary biologist of the late 20th century (see: Gould 2003; 1996).<\/p>\n<p class=\"import-Normal\">Gould spearheaded a movement to identify and examine higher-order processes and features of evolution that were not adequately explained by population genetics. For example, <strong>extinction<\/strong>, which was such a problem for biologists of the 1600s, could now be seen as playing a more complex role in the history of life than population genetics had been able to model. Gould recognized that there are two kinds of extinctions, each with different consequences: background extinctions and mass extinctions. Background extinctions are those that reflect the balance of nature, because in a competitive Darwinian world, some things go extinct and other things take their place. Ecologically, your species may be adapted to its niche, but if another species comes along that\u2019s better adapted to the same niche, eventually your species will go extinct. It sucks, but it is the way of all life: you come into existence, you endure, and you pass out of existence. But mass extinctions are quite different. They reflect not so much the balance of nature as the wholesale disruption of nature: many species from many different lineages dying off at roughly the same time\u2014presumably as the result of some kind of rare ecological disaster. The situation may not be survival of the fittest as much as survival of the luckiest. The result, then, would be an ecological scramble among the survivors. Having made it through the worst, the survivors could now simply divide up the new ecosystem amongst themselves, since their competitors were gone. Something like this may well have happened about 65 million years ago, when a huge asteroid hit the Yucatan Peninsula, which mammals survived but dinosaurs did not (Figure 17.1). Something like this may be happening now, due to human expansion and environmental degradation. Note, though, that there is only a limited descriptive role here for population genetics: the phenomena we are describing are about organisms and species in ecosystems.<\/p>\n<p class=\"import-Normal\">Another question involved the disconnect between properties of <em>species<\/em> and the properties of <em>gene pools<\/em>. For example, there are upwards of 15 species of gibbons but only two species of chimpanzees. Why? There are upwards of 20 species of guenons but fewer than ten of baboons. Why? Are there genes for that? It seems unlikely. Gould suggested that species, as units of nature, might have properties that are not reducible to the genes in their cells. For example, rates of speciation and extinction might be properties of their ecologies and histories rather than their genes. Thus, relationships between environmental contexts and variability within a species result in degrees of resistance to extinction and affect the frequency and rates at which clades diversify (Lloyd and Gould 1993). Consistent biases of speciation rates might well produce patterns of macroevolutionary diversity that are difficult to explain genetically and better understood ecologically. Gould called such biases in speciation rates <strong>species selection<\/strong>\u2014a higher-order process that invokes competition between species, in addition to the classic Darwinian competition between individuals.<\/p>\n<p class=\"import-Normal\">One of Gould\u2019s most important studies involved the very nature of species. In the classical view, a species is continually adapting to its environment until it changes so much that it is a different species than it was at the beginning of this sentence (Eldredge and Gould 1972). That implies that the species is a fundamentally unstable entity through time, continuously changing to fit in. But suppose, argued Gould along with paleontologist Niles Eldredge, a species is more stable through time and only really adapts during periods of ecological instability and change. Then we might expect to find in the fossil record long equilibrium periods\u2014a few million years or so\u2014in which species don\u2019t seem to change much, punctuated by relatively brief periods in which they change a bit and then stabilize again as new species. They called this idea <strong>punctuated equilibria<\/strong>. The idea helps to explain certain features of the fossil record, notably the existence of small anatomical \u201cgaps\u201d between closely related fossil forms (Figure 17.2). Its significance lies in the fact that although it incorporates genetics, punctuated equilibria is not really a theory of genetics but one of types bodies in deep time.<\/p>\n<p class=\"import-Normal\">Punctuated equilibria is seen across taxa, with long periods in the fossil record representing little phenotypic change. These periods of stability are disrupted by shorter periods of rapid <strong>adaptation<\/strong>, the process through which populations of organisms become suited to living in their environments. Phenotypic changes are often coupled with drastic climatic or ecological changes that affect the milieu in which organisms live. For example, throughout much of hominin evolutionary history, brain size was closely associated with body size and thus remained mostly stable. However, changes occurred in average hominin brain size at around 100 thousand years ago, 1 million years ago, and 1.8 million years ago. Several hypotheses have been put forth to explain these changes, including unpredictability in climate and environment (Potts 1998), social development (Barton 1996), and the evolution of language (Deacon 1998). Evidence from the fossil record, paleoclimate models, and comparative anatomy suggests that the changes observed in hominin lineage result from biocultural processes\u2014that is, the coalescence of environmental and cultural factors that selected for larger brains (Marks 2015; Shultz, Nelson, and Dunbar 2012).<\/p>\n<figure style=\"width: 461px\" class=\"wp-caption alignleft\"><img class=\"\" src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image5-8.png\" alt=\"Two graphs contrast phyletic gradualism and punctuated equilibria.\" width=\"461\" height=\"222\" \/><figcaption class=\"wp-caption-text\">Figure 17.2: Different ways of conceptualizing the evolutionary relationship between an earlier and a later species. With phyletic gradualism, species are envisioned transforming continually in a direct line over time. With punctuated equilibria species branch off at particular points over time.\u00a0 Credit: <a href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/chapter\/__unknown__\/\">Phyletic gradualism vs. punctuated equilibria (Figure 2.12)<\/a> original to <a href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/\">Explorations: An Open Invitation to Biological Anthropology<\/a> is under a <a href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/\">CC BY-NC 4.0 License<\/a>.<\/figcaption><\/figure>\n<p class=\"import-Normal\">In response to the call for a theory of the evolution of form, the field of <strong>evo-devo<\/strong>\u2014the intersection of evolutionary and developmental biology\u2014arose. The central focus here is on how changes in form and shape arise. An embryo matures by the stimulation of certain cells to divide, forming growth fields. The interactions and relationships among these growth fields generate the structures of the body. The <strong>hox genes<\/strong> that regulate these growth fields turn out to be highly conserved across the animal kingdom. This is because they repeatedly turn on and off the most basic genes guiding the animal\u2019s development, and thus any changes to them would be catastrophic. Indeed, these genes were first identified by manipulating them in fruit flies, such that one could produce a bizarre mutant fruit fly that grew a pair of legs where its antennae were supposed to be (Kaufman, Seeger, and Olsen 1990).<\/p>\n<p class=\"import-Normal\">Certain genetic changes can alter the fates of cells and the body parts, while other genetic changes can simply affect the rates at which neighboring groups of cells grow and divide, thus producing physical bumps or dents in the developing body. The result of altering the relationships among these fields of cellular proliferation in the growing embryo is <strong>allometry<\/strong>, or the differential growth of body parts. As an animal gets larger\u2014either over the course of its life or over the course of macroevolution\u2014it often has to change shape in order to live at a different size. Many important physiological functions depend on properties of geometric area: the strength of a bone, for example, is proportional to its cross-sectional area. But area is a two-dimensional quality, while growing takes place in three dimensions\u2014as an increase in mass or volume. As an animal expands, its bones necessarily weaken, because volume expands faster than area does. Consequently a bigger animal has more stress on its bones than a smaller animal does and must evolve bones even thicker than they would be by simply scaling the animal up proportionally. In other words, if you expand a mouse to the size of an elephant, it will nevertheless still have much thinner bones than the elephant does. But those giant mouse bones will unfortunately not be adequate to the task. Thus, a giant mouse would have to change aspects of its form to maintain function at a larger size (see Figure 17.3).<\/p>\n<p class=\"import-Normal\"><img class=\"aligncenter\" src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image6-6.png\" alt=\"Side-view of a mouse skeleton.\" width=\"515\" height=\"252\" \/><\/p>\n<figure style=\"width: 453px\" class=\"wp-caption aligncenter\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image7-9.png\" alt=\"Side-view of an elephant skeleton.\" width=\"453\" height=\"326\" \/><figcaption class=\"wp-caption-text\">Figure 17.3: Mouse (top) and elephant (bottom) skeletons. Notice the elephant\u2019s bones are more robust when the two animals are the same size. Credit: <a href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/chapter\/__unknown__\/\">Mouse and elephant skeletons (Figure 2.13)<\/a> original to <a href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/\">Explorations: An Open Invitation to Biological Anthropology<\/a> is under a <a href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/\">CC BY-NC 4.0 License<\/a>.<\/figcaption><\/figure>\n<p class=\"import-Normal\">Physiologically, we would like to know how the body \u201cknows\u201d when to turn on and off the genes that regulate growth to produce a normal animal. Evolutionarily, we would like to know how the body \u201clearns\u201d to alter the genetic on\/off switch (or the genetic \u201cslow down\/speed up\u201d switch) to produce an animal that looks different. Moreover, since organisms differ from one another, we would like to know how the developing body distinguishes a range of normal variation from abnormal variation. And, finally, how does abnormal variation eventually become normal in a descendant species?<\/p>\n<p class=\"import-Normal\">Taking up these questions, Gould invoked the work of a British geneticist named Conrad H. Waddington, who thought about genetics in less reductive ways than his colleagues. Rather than isolate specific DNA sites to analyze their function, Waddington instead studied the inheritance of an organism\u2019s reactivity\u2014its ability to adapt to the circumstances of its life. In a famous experiment, he grew fruit fly eggs in an atmosphere containing ether. Most died, but a few survived somehow by developing a weird physical feature: a second thorax with a second pair of wings. Waddington bred these flies and soon developed a stable line of flies who would reliably develop a second thorax when grown in ether. Then he began to lower the concentration of ether, while continuing to selectively breed the flies that developed the strange appearance. Eventually he had a line of flies that would stably develop the \u201cbithorax\u201d <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_1238\"><strong>phenotype<\/strong><\/a>\u2013the suite of traits of an organism\u2013even when there was no ether; it had become the \u201cnew normal.\u201d The flies had genetically assimilated the bithorax condition.<\/p>\n<p class=\"import-Normal\">Waddington was thus able to mimic the <strong>inheritance of acquired characteristics<\/strong>: what had been a trait stimulated by ether a few generations ago was now a normal part of the development of the descendants. Waddington recognized that while he had performed a selection experiment on genetic variants, he had not selected for particular traits. Rather, he helped produce the physiological tendency to develop particular traits when appropriately stimulated. He called that tendency <strong>plasticity<\/strong> and its converse, the tendency to stay the same even under weird environmental circumstances, <strong>canalization.<\/strong> Waddington had initially selected for plasticity, the tendency to develop the bithorax phenotype under weird conditions, and then, later, for canalization, the developmental normalization of that weird physical trait. Although Waddington had high stature in the community of geneticists, evolutionary biologists of the 1950s and 1960s regarded him with suspicion because he was not working within the standard mindset of reductionism, which saw evolution as the spread of genetic variants that coded for favorable traits. Both Waddington and Gould resisted contemporary intellectual paradigms that favored reductive accounts of evolutionary processes. They conceived of evolution as an emergent process in which many external factors (e.g. climate, environment, predation) and internal factors (e.g., genotypes, plasticity, canalization) coalesce to produce the evolutionary trends that we observe in the fossil record and our genome.<\/p>\n<p class=\"import-Normal\">While Gould and Waddington both looked beyond the genome to understand evolution, the Human Genome Project\u2014an international project with the goal of identifying each base pair in the human genome in the 1990s\u2014generated a great deal of public interest in analyzing the human DNA sequence from the standpoint of medical genetics. Some of the rhetoric aimed to sell the public on investing a lot of money and resources in sequencing the human genome in order to show the genetic basis of heritable traits, cure genetic diseases, and learn what it means ultimately to be biologically human. However, the Human Genome Project was not actually able to answer those questions through the use of genetics alone, and thus a broader, more holistic account was required.<\/p>\n<p class=\"import-Normal\">This holistic account came from decades of research in human biology and anthropology, which understood the human body as highly adaptable, dynamic, and emergent. For example, in the early 20th century, anthropologist Franz Boas measured the skulls of immigrants to the U.S., revealing that environmental, not merely genetic, factors affected skull shape. The growing human body adjusts itself to the conditions of life, such as diet, sunshine, high altitude, hard labor, population density, how babies are carried\u2014any and all of which can have subtle but consistent effects upon its development. There can thus be no normal human form, only a context-specific range of human forms.<\/p>\n<p class=\"import-Normal\">However, what the human biologists called human adaptability, evolutionary biologists called developmental plasticity, and evidence quickly began to mount for its cause being <strong>epigenetic <\/strong>modifications to DNA. Epigenetic modifications are changes to how genes are used by the body (as opposed to changes in the DNA sequences; see Chapter 3). Scientific interest shifted from the focus of the Human Genome Project to the ways that bodies are made by evolutionary-developmental processes, including epigenetics. What is meant by \u201cepigenetic modification\u201d? Evolution is about how descendants diverge from their ancestors. Inheritance from parent to offspring is still critical to this process, which occurs through genetic recombination: the pairing of homologous chromosomes and sharing of genetic material during meiosis (see Chapter 3). However, in the 21st century, the link between evolution and inheritance has broadened with a clearer understanding of how environmental and developmental factors shape bodies and the expression of genes, including epigenetic inheritance patterns. While offspring inherit their genes through random assortment during meiosis, environmental factors also shape how genes are used. When these epigenetic modifications occur in germ cells, they can be passed onto offspring. In these cases, there is no change in the DNA sequence but rather in how genes are used by the body due to DNA methylation and the structure of chromosomes due to histone acetylation (see Chapter 3).<\/p>\n<p class=\"import-Normal\">In addition, we now recognize that evolution is affected by two other forms of intergenerational transmission and inheritance (in addition to genetics and epigenetics). These forms include behavioral variation and culture. That is, behavioral information can be transmitted horizontally (intragenerationally), permitting more rapid ways for organisms to adjust to the environment. And, then there is the fourth mode of transmission: the cultural or symbolic mode. <span style=\"background-color: #ffff00;\">Humans are the only species<\/span> that horizontally transmits an arbitrary set of rules to govern communication, social interaction, and thought. This shared information is symbolic and has resulted in what we recognize as \u201cculture\u201d: locally emergent worlds of names, words, pictures, classifications, revered pasts, possible futures, spirits, dead ancestors, unborn descendants, in-laws, politeness, taboo, justice, beauty, and story, all accompanied by practices and a material world of tools.<\/p>\n<p class=\"import-Normal\">Consequently our contemporary ideas about evolution see the evolutionary processes as hierarchically organized and not restricted to the differential transmission of DNA sequences into the next generation. While that is indeed a significant part of evolution, the organism and species are nevertheless crucial to understanding how those DNA sequences get transmitted. Further, the transmission of epigenetic, behavioral, and symbolic information play a complex role in perpetuating our genes, bodies, and species. In the case of human evolution, one can readily see that symbolic information and cultural adaptation are far more central to our lives and our survival today than DNA and genetic adaptation. It is thus misleading to think of humans passively occupying an environmental niche. Rather, humans are actively engaged in constructing our own niches, as well as adapting to them and using them to adapt. The complex interplay between a species and its active engagement in creating its own ecology is known as <strong>niche construction<\/strong>. If we understand <strong>natural selection<\/strong>\u2013the process by which populations adapt to their specific environments\u2013as the effects that environmental context has on the reproductive success of organisms, then niche construction is the process through which organisms shape their own selective pressures.<\/p>\n<h2 class=\"import-Normal\">The Biopolitics of Heredity<\/h2>\n<p class=\"import-Normal\">\u201cScience isn\u2019t political\u201d is a sentiment that you have likely heard before. Science is supposed to be about facts and objectivity. It exists, or at least ought to, outside of petty human concerns. However, the sorts of questions we ask as scientists, the problems we choose to study, the categories and concepts we use, who gets to do science, and whose work gets cited are all shaped by culture. Doing science is a political act. This fact is markedly true for human evolution. While it is easier to create intellectual distance between us and fruit flies and viruses, there is no distance when we are studying ourselves. The hardest lesson to learn about human evolution is that it is intensely political. Indeed, to see it from the opposite side, as it were, the history of creationism\u2014the belief that the universe was divinely created around 6,000 years ago\u2014is essentially a history of legal decisions. For instance, in <em>Tennessee v. John T. Scopes<\/em> (1925), a schoolteacher was prosecuted for violating a law in Tennessee that prohibited the teaching of human evolution in public schools, where teachers were required by law to teach creationism.<\/p>\n<p class=\"import-Normal\">More recently, legal decisions aimed at legislating science education have shaped how students are exposed to evolutionary theory. For instance, <em>McLean v. Arkansas<\/em> (1982) dispatched \u201cscientific creationism\u201d by arguing that the imposition of balanced teaching of evolution and creationism in science classes violates the Establishment Clause, separating church and state. Additionally, <em>Kitzmiller v. Dover (Pennsylvania) Area School District<\/em> (2005) dispatched the teaching of \u201cintelligent design\u201d in public school classrooms as it was deemed to not be science. In some cases, people see unbiblical things in evolution, although most Christian theologians are easily able to reconcile science to the Bible. In other cases, people see immoral things in evolution, although there is morality and immorality everywhere. And some people see evolution as an aspect of alt-religion, usurping the authority of science in schools to teach the rejection of the Christian faith, which would be unconstitutional due to the protected separation of church and state.<\/p>\n<p class=\"import-Normal\">Clearly, the position that politics has nothing to do with science is untenable. But is the politics in evolution an aberration or is it somehow embedded in science? In the early 20th century, scientists commonly promoted the view that science and politics were separate: science was seen as a pure activity, only rarely corrupted by politics. And yet as early as World War I, the politics of nationalism made a hero of the German chemist Fritz Haber for inventing poison gas. And during World War II, both German doctors and American physicists, recruited to the war effort, helped to end many civilian lives. Therefore, we can think of the apolitical scientist as a self-serving myth that functions to absolve scientists of responsibility for their politics. The history of science shows how every generation of scientists has used evolutionary theory to rationalize political and moral positions. In the very first generation of evolutionary science, Darwin\u2019s <em>Origin of Species<\/em> (1859) is today far more readable than his <em>Descent of Man<\/em> (1871). The reason is that Darwin consciously purged <em>The Origin of Species<\/em> of any discussion of people. And when he finally got around to talking about people, in <em>The Descent of Man<\/em>, he simply imbued them with the quaint Victorian prejudices of his age, and the result makes you cringe every few pages. There is plenty of politics in there\u2014sexism, racism, and colonialism\u2014because <em>you cannot talk about people apolitically<\/em>.<\/p>\n<p class=\"import-Normal\">One immediate faddish deduction from Darwinism, popularized by Herbert Spencer (1864) as \u201csurvival of the fittest,\u201d held that unfettered competition led to advancement in nature and to human history. Since the poor were purported losers in that struggle, anything that made their lives easier would go against the natural order. This position later came to be known ironically as \u201cSocial Darwinism.\u201d Spencer was challenged by fellow Darwinian Thomas Huxley (1863), who agreed that struggle was the law of the jungle but observed that we don\u2019t live in jungles anymore. The obligation to make lives better for others is a moral, not a natural, fact. We simultaneously inhabit a natural universe of descent from apes and a moral universe of injustice and inequality, and science is not well served by ignoring the latter.<\/p>\n<p class=\"import-Normal\">Concurrently, the German biologist Ernst Haeckel\u2019s 1868 popularization of Darwinism was translated into English a few years later as <em>The History of Creation<\/em>. As we saw earlier, Haeckel was determined to convince his readers that they were descended from apes, even in the absence of fossil evidence attesting to it. When he made non-Europeans into the missing links that connected his readers to the apes, and depicted them as ugly caricatures, he knew precisely what he was doing. Indeed, even when the degrading racial drawings were deleted from the English translation of his book, the text nevertheless made his arguments quite clear. And a generation later, when the Americans had not yet entered the Great War in 1916, a biologist named Vernon Kellogg visited the German High Command as a neutral observer and found that the officers knew a lot about evolutionary biology, which they had gotten from Haeckel and which rationalized their military aggressions. Kellogg went home and wrote a bestseller about it, called <em>Headquarters Nights<\/em> (1917). World War I would have been fought with or without evolutionary theory, but as a source of scientific authority, evolution\u2014even if a perversion of the Darwinian theory\u2014had very quickly attained global geopolitical relevance.<\/p>\n<p class=\"import-Normal\">Oftentimes, politics in evolutionary science is subtle, due to the pervasive belief in the advancement of science. We recognize the biases of our academic ancestors and modify our scientific stories accordingly. But we can never be free of our own cultural biases, which are invisible to us, as much as our predecessors\u2019 biases were invisible to them. In some cases, the most important cultural issues resurface in different guises each generation, like scientific racism. <strong>Scientific racism<\/strong> is the recruitment of science for the evil political ends of racism, and it has proved remarkably impervious to evolution. Before Darwin, there was creationist scientific racism, and after Darwin, there was evolutionist scientific racism. And there is still scientific racism today, self-justified by recourse to evolution, which means that scientists have to be politically astute and sensitive to the uses of their work to counter these social tendencies.<\/p>\n<p class=\"import-Normal\">Consider this: Are you just your ancestry, or can you transcend it? If that sounds like a weird question, it was actually quite important to a turn-of-the-20th-century European society in which an old hereditary aristocracy was under increasing threat from a rising middle class. And that is why the very first English textbook of Mendelian genetics concluded with the thought that \u201cpermanent progress is a question of breeding rather than of pedagogics; a matter of gametes, not of training \u2026 the creature is not made but born\u201d (Punnett 1905, 60). <em>Translation: Not only do we now know a bit about how heredity works, but it\u2019s also the most important thing about you. Trust me, I\u2019m a scientist.<\/em><\/p>\n<p class=\"import-Normal\">Yet evolution is about how descendants come to differ from ancestors. Do we really know that your heredity, your DNA, your ancestry, is the most important thing about you? That you were born, not made? After all, we do know that you could be born into slavery or as a peasant, and come from a long line of enslaved people or peasants, and yet not have slavery or peasantry be the most important thing about you. Whatever your ancestors were may unfortunately constrain what you can become, but as a moral precept, it should not. But just as science is not purely \u201cfacts and objectivity,\u201d ancestry is not a strictly biological concept. Human ancestry is biopolitics, not biology.<\/p>\n<p class=\"import-Normal\">Evolution is fundamentally a theory about ancestry, and yet ancestors are, in the broad anthropological sense, sacred: ancestors are often more meaningful symbolically than biologically. Just a few years after <em>The Origin of Species <\/em>(Darwin 1859), the British politician and writer Benjamin Disraeli declared himself to be on the side of the angels, not the apes, and to \u201crepudiate with indignation and abhorrence those new-fangled theories\u201d (Monypenny, Flavelle, and Buckle 1920, 105). He turned his back on an ape ancestry and looked to the angel; yet, he did so as a prominent Jew-turned-Anglican, who had personally transcended his humble roots and risen to the pinnacle of the Empire. Ancestry was certainly important, and Disraeli was famously proud of his, but it was also certainly not the most important thing, not the primary determinant of his place in the world. Indeed, quite the opposite: Disraeli\u2019s life was built on the transcendence of many centuries of Jewish poverty and oppression in Europe. Humble ancestry was there to be superseded and nobility was there to be earned; Disraeli would later become the Earl of Beaconsfield. Clearly, \u201care you just your ancestry\u201d is not a value-neutral question, and \u201cthe creature is not made, but born\u201d is not a value-neutral answer.<\/p>\n<p class=\"import-Normal\">Ancestry being the most important thing about a person became a popular idea twice in 20th century science. First, at the beginning of the century, when the <strong>eugenics<\/strong> movement in America called attention to \u201cfeeble-minded stocks,\u201d which usually referred to the poor or to immigrants (see Figure 17.4; and see Chapter 2). This movement culminated in Congress restricting the immigration of \u201cfeeble-minded races\u201d (said to include Jews and Italians) in 1924, and the Supreme Court declaring it acceptable for states to sterilize their \u201cfeeble-minded\u201d citizens involuntarily in 1927. After the Nazis picked up and embellished these ideas during World War II, Americans moved swiftly away from them in some contexts (e.g., for most people of European descent) while still strictly adhering in other contexts (e.g., Japanese internment camps and immigration restrictions).<\/p>\n<figure style=\"width: 374px\" class=\"wp-caption alignright\"><img class=\"\" src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image4-6.png\" alt=\"Historic photo. People sit in front of a structure with a \u201cEugenic and Health Exhibit&quot; banner.\" width=\"374\" height=\"262\" \/><figcaption class=\"wp-caption-text\">Figure 17.4: Eugenic and Health Exhibit, Fitter Families exhibit, and examination building, Kansas State Free Fair. Credit: <a href=\"https:\/\/www.dnalc.org\/view\/16328-Gallery-14-Eugenics-Exhibit-at-the-Kansas-State-Free-Fair-1920.html\">Gallery 14: Eugenics Exhibit at the Kansas State Free Fair, 1920 ID (ID 16328)<\/a> by <a href=\"https:\/\/www.dnalc.org\/\">Cold Spring Harbor<\/a> (Courtesy American Philosophical Society) is under a <a href=\"https:\/\/creativecommons.org\/licenses\/by-nc-nd\/3.0\/us\/\">CC BY-NC-ND 3.0 License.<\/a><\/figcaption><\/figure>\n<p class=\"import-Normal\">Ancestry again became paramount in the drumming up of public support for the Human Genome Project in the 1990s. Public support for sequencing the human genome was encouraged by a popular science campaign that featured books titled <em>The Book of Man <\/em>(Bodmer and McKie 1997), <em>The Human Blueprint <\/em>(Shapiro 1991), and <em>The Code of Codes<\/em> (Kevles and Hood 1993). These books generally promised cures for genetic diseases and a deeper understanding of the human condition. We can certainly identify progress in molecular genetics over the last couple of decades since the human genome was sequenced, but that progress has notably not been accompanied by cures for genetic diseases, nor by deeper understandings of the human condition.<\/p>\n<p class=\"import-Normal\">Even at the most detailed and refined levels of genetic analysis, we still don\u2019t have much of an understanding of the actual basis by which things seem to \u201crun in families.\u201d While the genetic basis of simple, if tragic, genetic diseases have become well-known\u2014such as sickle-cell anemia, cystic fibrosis, and Tay-Sachs\u2019 Disease\u2014we still haven\u2019t found the ostensible genetic basis for traits that are thought to have a strong genetic component. For example, a recent genetic summary found over 12,000 genetic sites that contributed to height yet still explained only about 40-50 percent of the variation in height among European ancestry but no more than 10-20 percent of variation of other ancestries, which we know strongly runs in families (Yengo et al. 2022).<\/p>\n<p class=\"import-Normal\">Partly in reaction to the reductionistic hype of the Human Genome Project, the study of epigenetics has become the subject of great interest. One famous natural experiment involves a Nazi-imposed famine in Holland over the winter of 1944\u20131945. Children born during and shortly after the famine experienced a higher incidence of certain health problems as adults, many decades later. Apparently, certain genes had been down-regulated early in development and remained that way throughout the course of life. Indeed, this modified regulation of the genes in response to the severe environmental conditions may have been passed on to their children.<\/p>\n<p class=\"import-Normal\">Obviously one\u2019s particular genetic constitution may play an important role in one\u2019s life trajectory. But overvaluing that role may have important social and political consequences. In the first place, genotypes are rendered meaningful in a cultural universe. Thus, if you live in a strongly patriarchal society and are born without a Y chromosome (since human males are chromosomally XY and females XX), your genotype will indeed have a strong effect upon your life course. So even though the variation is natural, the consequences are political. The mediating factors are the cultural ideas about how people of different sexes ought to be treated, and the role of the state in permitting certain people to develop and thrive. More broadly, there are implications for public education if variation in intelligence is genetic. There are implications for the legal system if criminality is genetic. There are implications for the justice system if sexual preference, or sexual identity, is genetic. There are implications for the development of sports talent if that is genetic. And yet, even for the human traits that are more straightforward to measure and known to be strongly heritable, the DNA base sequence variation seems to explain little.<\/p>\n<p class=\"import-Normal\">Genetic determinism or <strong>hereditarianism<\/strong> is the idea that \u201cthe creature is made, not born\u201d\u2014or, in a more recent formulation by James Watson, that \u201cour fate is in our genes.\u201d One of the major implications drawn from genetic determinism is that the feature in question must inevitably express itself; therefore, we can\u2019t do anything about it. Therefore, we might as well not fund the social programs designed to ameliorate economic inequality and improve people\u2019s lives, because their courses are fated genetically. And therefore, they don\u2019t deserve better lives.<\/p>\n<p class=\"import-Normal\">All of the \u201ctherefores\u201d in the preceding paragraph are open to debate. What is important is that the argument relies on a very narrow understanding of the role of genetics in human life, and it misdirects the causes of inequality from cultural to natural processes. By contrast, instead of focusing on genes and imagining them to place an invisible limit upon social progress, we can study the ways in which your DNA sequence does <em>not<\/em> limit your capability for self-improvement or fix your place in a social hierarchy. In general, two such avenues exist. First, we can examine the ways in which the human body responds and reacts to environmental variation: human adaptability and plasticity. This line of research began with the anthropometric studies of immigrants by Franz Boas in the early 20th century and has now expanded to incorporate the epigenetic inheritance of modified human DNA. And second, we can consider how human lives are shaped by social histories\u2014especially the structural inequalities within the societies in which they grow up.<\/p>\n<p class=\"import-Normal\">Although it arises and is refuted every generation, the radical hereditarian position (genetic determinism) perennially claims to speak for both science and evolution. It does not. It is the voice of a radical fringe\u2014perhaps naive, perhaps evil. It is not the authentic voice of science or of evolution. Indeed, keeping Charles Darwin\u2019s name unsullied by protecting it from association with bad science often seems like a full-time job. Culture and epigenetics are very much a part of the human condition, and their roles are significant parts of the complete story of human evolution.<\/p>\n<p><span style=\"background-color: #00ffff;\"><span style=\"text-decoration: underline;\">(Sterilization of Indigenous women in Canada)<\/span> (https:\/\/www.thecanadianencyclopedia.ca\/en\/article\/sterilization-of-indigenous-women-in-canada)\u00a0<\/span><\/p>\n<h2 class=\"import-Normal\">Adaptationism and the Panglossian Paradigm<\/h2>\n<p class=\"import-Normal\">The story of human evolution, and the evolution of all life for that matter, is never settled because evolution is ongoing. Additionally, because the conditions that shape evolutionary trajectories are not predetermined, evolution itself is emergent. Even during periods of ecological stability, when fewer macroevolutionary changes occur, populations of organisms continue to experience change. When ecological stability is disrupted, populations must adapt to the changes. Darwin explained in naturalistic terms how animals adapt to their environments: traits that contribute to an organism's ability to survive and reproduce in specific environments will become more common. The most \u201cfit\u201d\u2014those organisms best suited to the <em>current<\/em> environmental conditions in which they live\u2014have survived over eons of the history of life on earth to cocreate ecosystems full of animals and plants. Our own bodies are full of evident adaptations: eyes for seeing, ears for hearing, feet for walking on, and so forth.<\/p>\n<p class=\"import-Normal\">But what about hands? Feet are adapted to be primarily weight-bearing structures (rather than grasping structures, as in the apes) and that is what we primarily use them for. But we use our hands in many ways: for fine-scale manipulation, greeting, pointing, stimulating a sexual partner, writing, throwing, and cooking, among other uses. So which of these uses express what hands are \u201cfor,\u201d when all of them express what hands do?<\/p>\n<p class=\"import-Normal\">Gould and Lewontin (1979) illustrate the problem with assuming that the function of a trait defines its evolutionary cause. Consider the case of Dr. Pangloss\u2014the protagonistic of Voltaire\u2019s <em>Candide<\/em>\u2014who believed that we lived in the best of all possible worlds. Gould and Lewontin use his pronouncement that \u201cnoses were made for spectacles and so we have spectacles\u201d to demonstrate the problem with assuming any trait has evolved for a specific purpose. Identifying a function of a trait does not necessitate that the function is the ultimate cause of the trait. Individual traits are not under selection pressures in isolation; in fact, an entire organism must be able to survive and reproduce in their environment. When natural selection results in adaptations, changes that occur in some traits can have cascading effects throughout the phenotype and features that are not under selection pressure can also change.<\/p>\n<figure style=\"width: 279px\" class=\"wp-caption alignleft\"><img class=\"\" src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image3-5.png\" alt=\"Human hand is smaller with smaller fingers and smoother skin compared to a chimpanzee hand.\" width=\"279\" height=\"264\" \/><figcaption class=\"wp-caption-text\">Figure 17.5: Drawings of a human hand (left) and a chimpanzee hand (right). Credit: <a href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/chapter\/__unknown__\/\">Human and chimpanzee hand (Figure 2.16)<\/a> by Mary Nelson original to <a href=\"https:\/\/explorations.americananthro.org\/\">Explorations: An Open Invitation to Biological Anthropology<\/a> is under a <a href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/\">CC BY-NC 4.0 License<\/a>.<\/figcaption><\/figure>\n<p class=\"import-Normal\">There is an important lesson in recognizing that what things do in the present is not a good guide to understanding why they came to exist. Gunpowder was invented for entertainment\u2014only later was it adopted for killing people. The Internet was invented to decentralize computers in case of a nuclear attack\u2014and only later adopted for social media. Apes have short thumbs and use their hands in locomotion; our ancestors stopped using their hands in locomotion by about six million years ago and had fairly modern-looking hands by about two million years ago. We can speculate that a combination of selection for abstract thought and dexterity led to evolution of the human hand, with its capability for toolmaking that exceeds what apes can do (see Figure 17.5). But let\u2019s face it\u2014how many tools have you made today?<\/p>\n<p class=\"import-Normal\">Consequently, we are obliged to see the human foot as having a purpose to which it is adapted and the human hand as having multiple purposes, most of which are different from what it originally evolved for. Paleontologists Gould and Elisabeth Vrba suggested that an original use be regarded as an adaptation and any additional uses be called \u201c<strong>exaptations.<\/strong>\u201d Thus, we would consider the human hand to be an adaptation for toolmaking and an exaptation for writing. So how do we know whether any particular feature is an adaptation, like the walking foot, rather than an exaptation, like the writing hand? Or more broadly, how can we reason rigorously from what a feature does to what it evolved for?<\/p>\n<p class=\"import-Normal\">The answer to the question \u201cwhat did this feature evolve for?\u201d creates an origin myth. This origin myth contains three assumptions: (1) features can be isolated as evolutionary units; (2) there is a specific reason for the existence of any particular feature; and (3) there is a clear and simplistic explanation for why the feature evolved.<\/p>\n<figure style=\"width: 378px\" class=\"wp-caption alignright\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image9-8.png\" alt=\"Head with images and human qualities drawn on it. Journal title printed at the bottom.\" width=\"378\" height=\"437\" \/><figcaption class=\"wp-caption-text\">Figure 17.6: According to the early 19th century science of phrenology, units of personality could be mapped onto units in the head, as shown on this cover of The Phrenology Journal. Credit: <a href=\"https:\/\/wellcomecollection.org\/works\/b6skynug\">Phrenology; Chart<\/a> [slide number 5278, photo number: L0000992, original print from Dr. E. Clark, The Phrenological Journal (Know Thyself)] by <a href=\"https:\/\/wellcomecollection.org\/\">Wellcome Collection<\/a>, is under a <a href=\"https:\/\/creativecommons.org\/licenses\/by\/4.0\/legalcode\">CC BY 4.0 License<\/a>.<\/figcaption><\/figure>\n<p class=\"import-Normal\">The first assumption was appreciated a century ago as the \u201cunit-character problem.\u201d Are the units by which the body grows and evolves the same as units we name? This is clearly not the case: we have genes and we have noses, and we have genes that affect noses, but we don\u2019t have \u201cnose genes.\u201d What is the relationship between the evolving elements that we see, identify, and name, and the elements that biologically exist and evolve? It is hard to know, but we can use the history of science as a guide to see how that fallacy has been used by earlier generations. Back in the 19th century, the early anatomists argued that since the brain contained the mind, they could map different mental states (acquisitiveness, punctuality, sensitivity) onto parts of the brain. Someone who was very introspective, say, would have an enlarged introspection part of the brain, a cranial bulge to represent the hyperactivity of this mental state. The anatomical science was known as <strong>phrenology<\/strong>, and it was predicated on the false assumption that units of thought or personality or behavior could be mapped to distinct parts of the brain and physically observed (see Figure17.6). This is the fallacy of reification, imagining that something named is something real.<\/p>\n<p class=\"import-Normal\"><span style=\"background-color: #ff99cc;\">Long alt text: Side view of human head. At the top are the words \u201cKnow Thyself.\u201d On the upper head are small illustrations and word qualities such as \u201cfriendship,\u201d \u201cself-esteem,\u201d and \u201csecretiveness.\u201d On the lower part of the man\u2019s man\u2019s face are the words <em>The Phrenological Journal and Science of Health, A First Class Monthly<\/em>. The caption at the bottom reads: \u201cSpecially devoted to the \u2018.\u2019 Contains PHRENOLOGY and PHYSIOGNOMY, with all the SIGNS OF CHARACTER, and how to read them; ETHNOLOGY, or the Natural History of Man in all his relations.\u201d (All emphases in original.)<\/span><\/p>\n<figure style=\"width: 295px\" class=\"wp-caption alignleft\"><img class=\"\" src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image1-8-1.png\" alt=\"A black-and-white drawing of a chimpanzee head and face.\" width=\"295\" height=\"236\" \/><figcaption class=\"wp-caption-text\">Figure 17.7: Chimpanzees have big ears. Credit: <a href=\"https:\/\/commons.wikimedia.org\/wiki\/File:Chimpanzee_head_sketch.png\">Chimpanzee head sketch<\/a> by <a href=\"https:\/\/de.wikipedia.org\/wiki\/Benutzer:Roger_Zenner\">Roger Zenner<\/a>, original by Brehms Tierleben (1887), is in the <a href=\"https:\/\/en.wikipedia.org\/wiki\/Public_domain\">public domain<\/a>.<\/figcaption><\/figure>\n<p class=\"import-Normal\">The second assumption, that everything has a reason, has long been recognized as a core belief of religion. Our desire to impose order and simplicity on the workings of the universe, however, does not constrain it to obey simple and orderly causes. Magic, witchcraft, spirits, and divine agency are all powerful explanations for why things happen. Consequently, it is probably not a good idea to lump natural selection in with those. Sometimes things do happen for a reason, of course, but other times things happen as byproducts of other things, or for very complicated and entangled reasons, or for no reason at all. What phenomena have reasons and thereby merit explanation? Chimpanzees have very large testicles, and we think we know why: their promiscuous sexual behavior triggers intense competition for high sperm count. But chimpanzees also have very large ears, but much less scientific attention has been paid to this trait (see Figure 17.7). Why not? Why should there be a reason for chimp testicles but not for chimp ears? What determines the kinds of features that we try to explain, as opposed to the ones that we do not? Again, the assumption that any specific feature has a reason is metaphysical; that is to say, it may be true in any particular case, but to assume it in all cases is gratuitous.<\/p>\n<p class=\"import-Normal\">And third, the possibility of knowing what the reason for any particular feature is, assuming that it has one, is a challenge for evolutionary epistemology (the theory of how we know things). Consider the big adaptations of our lineage: bipedalism and language. Nobody doubts that they are good, and they evolved by natural selection, and we know how they work. But why did they evolve? If talking and walking are simply better than not talking and not walking, then why did they evolve in just a single branch of the ape lineage in the primate family tree? We don\u2019t know what bipedalism evolved for, although there are plenty of speculations: walking long distances, running long distances, cooling the head, seeing over tall grass, carrying babies, carrying food, wading, threatening, counting calories, sexual display, and so on. Neither do we know what language evolved for, although there are speculations: coordinating hunting, gossiping, manipulating others. But it is also possible that bipedality is simply the way that a small arboreal ape travels on the ground, if it isn\u2019t in the treetops. Or that language is simply the way that a primate with small canine teeth and certain mental propensities comes to communicate. If that were true, then there might be no reason for bipedality or language: having the unique suite of preconditions and a fortuitous set of circumstances simply set them in motion, and natural selection elaborated and explored their potentials. It is possible that walking and talking simply solved problems that no other lineage had ever solved; but even if so, the fact remains that the rest of the species in the history of life have done pretty well without having solved them.<\/p>\n<p class=\"import-Normal\">It is certainly very optimistic to think that all three assumptions (that organisms can be meaningfully atomized, that everything has a reason, and that we can know the reason) would be simultaneously in effect. Indeed, just as there are many ways of adapting (genetically, epigenetically, behaviorally, culturally), there are also many ways of being nonadaptive, which would imply that there is no reason at all for the feature in question.<\/p>\n<p class=\"import-Normal\">First, there is the element of randomness of population histories. There are more cases of sickle-cell anemia among sub-Saharan Africans than other peoples, and there is a reason for it: carriers of sickle-cell anemia have a resistance to malaria, which is more frequent in parts of Africa (as discussed in Chapters 4 and 14). But there are more cases of a blood disease called variegated porphyria, a rare genetic metabolic disorder, in the Afrikaners of South Africa (descendants of mostly Dutch settlers in the 17th century) than in other peoples, and there is no reason for it. Yet we know the cause: One of the founding Dutch colonial settlers had the <strong>allele<\/strong>\u2013a variant of a gene\u2013and everyone in South Africa with it today is her descendant. But that is not a reason\u2014that is simply an accident of history.<\/p>\n<p class=\"import-Normal\">Second, there is the potential mismatch between the past and the present. The value of a particular feature in the past may be changed as the environmental circumstances change. Our species is diurnal, and our ancestors were diurnal. But beginning around a few hundred thousand years ago, our ancestors could build fires, which extended the light period, which was subsequently further amplified by lamps and candles. And over the course of the 20th century, electrical power has made it possible for people to stay up very late when it is dark\u2014working, partying, worrying\u2014to a greater extent than any other closely related species. In other words, we evolved to be diurnal, yet we are now far more nocturnal than any of our recent ancestors or close relatives. Are we adapting to nocturnality? If so, why? Does it even make any sense to speak of the human occupation of a nocturnal ape niche, despite the fact that we empirically seem to be doing just that? And if so, does it make sense to ask what the reason for it is?<\/p>\n<p class=\"import-Normal\">Third, there is a genetic phenomenon known as a selective sweep, or the hitchhiker effect. Imagine three genes\u2014A, B, and C\u2014located very closely together on a chromosome. They each have several variants, or alleles, in the population. Now, for whatever reason, it becomes beneficial to have one of the B alleles, say B4; this B4 allele is now under strong positive selection. Obviously, we will expect future generations to be characterized by mostly B4. But what was B4 attached to? Because whatever A and C alleles were adjacent to it will also be quickly spread, simply by virtue of the selection for B4. Even if the A and C alleles are not very good, they will spread because of the good B4 allele between them. Eventually the linkage groups will break up because of genetic crossing-over in future generations. But in the meantime, some random version of genes A and C are proliferating in the species simply because they are joined to superior allele B4. And clearly, the A and C alleles are there because of selection\u2014but not because of selection <em>for<\/em> them!<\/p>\n<p class=\"import-Normal\">Fourth, some features are simply consequences of other properties rather than adaptations to external conditions. We already noted the phenomenon of allometric growth, in which some physical features have to outgrow others to maintain function at an increased size. Can we ask the reason for the massive brow ridges of <em>Homo erectus<\/em>, or are brow ridges simply what you get when you have a conjunction of thick skull bones, a large face, and a sloping forehead\u2014and, thus, again would have a cause but no reason?<\/p>\n<p class=\"import-Normal\">Fifth, some features may be underutilized and on the way out. What is the reason for our two outer toes? They aren\u2019t propulsive, they don\u2019t do anything, and sometimes they\u2019re just in the way. Obviously they are there because we are descended from ancestors with five digits on their hands and feet. Is it possible that a million years from now, we will just have our three largest toes, just as the ancestors of the horse lost their digits in favor of a single hoof per limb? Or will our outer toes find another use, such as stabilizing the landings in our personal jet-packs? For the time being, we can just recognize vestigiality as another nonadaptive explanation for the presence of a given feature.<\/p>\n<p class=\"import-Normal\">Finally, Darwin himself recognized that many obvious features do not help an animal survive. Some things may instead help an animal breed. The peacock\u2019s tail feathers do not help it eat, but they do help it mate. There is competition, but only against half of the species. Darwin called this <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_1084\">sexual selection<\/a><\/strong>. Its result is not a fit to the environment but, rather, a fit to the opposite sex. In some species, that is literally the case, as the male and female genitalia have specific ways of anatomically fitting together. The specific form is less important than the specific match, so inquiring about the reason for a particular form of the reproductive anatomy may be misleading. The specific form may be effectively random, as long as it fits the opposite sex and is different from the anatomies of other species. Nor is sexual selection the only form of selection that can affect the body differently from natural selection. Competition might also take place between biological units other than organisms\u2014perhaps genes, perhaps cells, or populations, or species. The spread of cultural things, such as head-binding or cheap refined fructose or forced labor, can have significant effects upon bodies, which are also not adaptations produced by natural selection. They are often adaptive physiological responses to stresses but not the products of natural selection.<\/p>\n<p class=\"import-Normal\">With so many paths available by which a physical feature might have organically arisen without having been the object of natural selection, it is unwise to assume that any individual trait is an adaptation. And that generalization applies to the best-known, best-studied, and most materially based evolutionary adaptations of our lineage. But our cultural behaviors are also highly adaptive, so what about our most familiar social behaviors? Patriarchy, hierarchy, warfare\u2014are these adaptations? Do they have reasons? Are they good for something?<\/p>\n<p class=\"import-Normal\">This is where some sloppy thinking has been troublesome. What would it mean to say that patriarchy evolved by natural selection in the human species? If, on the one hand, it means that the human mind evolved by natural selection to be able to create and survive in many different kinds of social and political regimes, of which patriarchy is one, then biological anthropologists will readily agree. If, on the other hand, it means that patriarchy evolved by natural selection, that implies that patriarchy is genetically determined (since natural selection is a genetic process) and out-reproduced the alleles for other, more egalitarian, social forms. This in turn would imply that patriarchy is an adaptation and therefore of some beneficial value in the past and has become an ingrained part of human nature today. This would be bad news, say, if you harbored ambitions of dismantling it. Dismantling patriarchy in that case would be to go against nature, a futile gesture. In other words, this latter interpretation would be a naturalistic manifesto for a conservative political platform: don\u2019t try to dismantle the patriarchy, because it is within us, the product of evolution\u2014suck it up and live with it.<\/p>\n<p class=\"import-Normal\">Here, evolution is being used as a political instrument for transforming the human genome into an imaginary glass ceiling against equality. There is thus a convergence between the pseudo-biology of crude <strong>adaptationism <\/strong>(the idea that everything is the product of natural selection) and the pseudo-biology of hereditarianism. Naturalizing inequality is not the business of evolutionary theory, and it represents a difficult moral position for a scientist to adopt, as well as a poor scientific position.<\/p>\n<h2 class=\"import-Normal\"><span style=\"background-color: #ff99cc;\">Concluding Thoughts<\/span><\/h2>\n<p class=\"import-Normal\"><span style=\"background-color: #ff99cc;\">Now that you have finished reading this chapter, you are equipped to understand the historical and political dimensions of evolution. Evolution is an ongoing process of change and diversification. Evolutionary theory is a tool that we use to understand this process. The development of evolutionary theory is shaped both by scientific innovation and political engagement. Since Darwin first articulated natural selection as an observable mechanism by which species adapt to their environments, our understanding of evolution has grown. Initially, scientists focused on the adaptive aspects of evolution. However, with the emergence of genetics, our understanding of heredity and the level at which evolution acts has changed. Genetics led to a focus on the molecular dimensions of evolution. For some, this focus resulted in reductive accounts of evolution. Further developments in our understanding of evolution shifted our view to epigenetic processes and how organisms shape their own evolutionary pressures (e.g., niche construction).<\/span><\/p>\n<p class=\"import-Normal\"><span style=\"background-color: #ff99cc;\">Evolutionary theory will continue to develop in the future as we invent new technologies, describe new dimensions of biology, and experience cultural changes. Current innovations in evolutionary theory are asking us to consider evolutionary forces beyond natural selection and genetics to include the ways organisms shape their environments (niche construction), inheritances beyond genetics (inclusive inheritance), constraints on evolutionary change (developmental bias), and the ability of bodies to change in response to external factors (plasticity). The future of evolutionary theory looks bright as we continue to explore these and other dimensions. Biological anthropology is well-positioned to be a lively part of this conversation, as it extends standard evolutionary theory by considering the role of culture, social learning, and human intentionality in shaping the evolutionary trajectories of humans (Zeder 2018). Remember, at root, human evolutionary theory consists of two propositions: (1) the human species is descended from other similar species and (2) natural selection has been the primary agent of biological adaptation. Pretty much everything else is subject to some degree of contestation.<\/span><\/p>\n<div class=\"textbox shaded\">\n<h2 class=\"import-Normal\">Review Questions<\/h2>\n<ul>\n<li class=\"import-Normal\">How is the study of your ancestors biopolitical, not just biological? Does that make it less scientific or differently scientific?<\/li>\n<li class=\"import-Normal\">What was gained by reducing organisms to genotypes and species to gene pools? What is gained by reintroducing bodies and species into evolutionary studies?<\/li>\n<li class=\"import-Normal\">How do genetic or molecular studies complement anatomical studies of evolution?<\/li>\n<li class=\"import-Normal\">How are you reducible to your ancestry? If you could meet your ancestors from the year 1700 (and you would have well over a thousand of them!), would their lives be meaningfully similar to yours? Would you even be able to communicate with them?<\/li>\n<li class=\"import-Normal\">The molecular biologist Fran\u00e7ois Jacob argued that evolution is more like a tinkerer than an engineer. In what ways do we seem like precisely engineered machinery, and in what ways do we seem like jerry-rigged or improvised contraptions?<\/li>\n<li class=\"import-Normal\">How might biological anthropology contribute to future developments in evolutionary theory?<\/li>\n<\/ul>\n<\/div>\n<h2 class=\"import-Normal\">Key Terms<strong><br \/>\n<\/strong><\/h2>\n<p class=\"import-Normal\"><strong>Adaptation<\/strong>: A fit between the organism and environment.<\/p>\n<p class=\"import-Normal\"><strong>Adaptationism<\/strong>: The idea that everything is the product of natural selection.<\/p>\n<p class=\"import-Normal\"><strong>Allele<\/strong>: A genetic variant.<\/p>\n<p class=\"import-Normal\"><strong>Allometry<\/strong>: The differential growth of body parts.<\/p>\n<p class=\"import-Normal\"><strong>Canalization<\/strong>: The tendency of a growing organism to be buffered toward normal development.<\/p>\n<p class=\"import-Normal\"><strong>Epigenetics<\/strong>: The study of how genetically identical cells and organisms (with the same DNA base sequence) can nevertheless differ in stably inherited ways.<\/p>\n<p class=\"import-Normal\"><strong>Eugenics<\/strong>: An idea that was popular in the 1920s that society should be improved by breeding \u201cbetter\u201d kinds of people.<\/p>\n<p class=\"import-Normal\"><strong>Evo-devo<\/strong>: The study of the origin of form; a contraction of \u201cevolutionary developmental biology.\u201d<\/p>\n<p class=\"import-Normal\"><strong>Exaptation<\/strong>: An additional beneficial use for a biological feature.<\/p>\n<p class=\"import-Normal\"><strong>Extinction<\/strong>: The loss of a species from the face of the earth.<\/p>\n<p class=\"import-Normal\"><strong>Gene<\/strong>: A stretch of DNA with an identifiable function (sometimes broadened to include any DNA with recognizable structural features as well).<\/p>\n<p class=\"import-Normal\"><strong>Gene pool<\/strong>: Hypothetical summation of the entire genetic composition of population or species.<\/p>\n<p class=\"import-Normal\"><strong>Genotype<\/strong>: Genetic constitution of an individual organism.<\/p>\n<p class=\"import-Normal\"><strong>Hereditarianism<\/strong>: The idea that genes or ancestry is the most crucial or salient element in a human life. Generally associated with an argument for natural inequality on pseudo-genetic grounds.<\/p>\n<p class=\"import-Normal\"><strong>Hox genes<\/strong>: A group of related genes that control for the body plan of an embryo along the head-tail axis.<\/p>\n<p class=\"import-Normal\"><strong>Inheritance of acquired characteristics<\/strong>: The idea that you pass on the features that developed during your lifetime, not just your genes; also known as Lamarckian inheritance.<\/p>\n<p class=\"import-Normal\"><strong>Natural selection<\/strong>: A consistent bias in survival and fertility, leading to the overrepresentation of certain features in future generations and an improved fit between an average member of the population and the environment.<\/p>\n<p class=\"import-Normal\"><strong>Niche construction<\/strong>: The active engagement by which species transform their surroundings in favorable ways, rather than just passively inhabiting them.<\/p>\n<p class=\"import-Normal\"><strong>Phenotype<\/strong>: Observable manifestation of a genetic constitution, expressed in a particular set of circumstances. The suite of traits of an organism.<\/p>\n<p class=\"import-Normal\"><strong>Phrenology<\/strong>: The 19th-century anatomical study of bumps on the head as an indication of personality and mental abilities.<\/p>\n<p class=\"import-Normal\"><strong>Plasticity<\/strong>: The tendency of a growing organism to react developmentally to its particular conditions of life.<\/p>\n<p class=\"import-Normal\"><strong>Punctuated equilibria<\/strong>: The idea that species are stable through time and are formed very rapidly relative to their duration. (The opposite theory, that species are unstable and constantly changing through time, is called phyletic gradualism.)<\/p>\n<p class=\"import-Normal\"><strong>Scientific racism<\/strong>: The use of pseudoscientific evidence to support or legitimize racial hierarchy and inequality.<\/p>\n<p class=\"import-Normal\"><strong>Sexual selection<\/strong>: Natural selection arising through preference by one sex for certain characteristics in individuals of the other sex.<\/p>\n<p class=\"import-Normal\"><strong>Species selection<\/strong>: A postulated evolutionary process in which selection acts on an entire species population, rather than individuals.<\/p>\n<h2 class=\"import-Normal\">About the Authors<strong><br \/>\n<\/strong><\/h2>\n<p class=\"import-Normal\"><img class=\"alignleft\" src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image2-4-1.jpg\" alt=\"A bearded man wearing glasses smiles at the camera. \" width=\"202\" height=\"218\" \/><\/p>\n<h3 class=\"import-Normal\"><strong>Jonathan Marks, Ph.D.<\/strong><\/h3>\n<p class=\"import-Normal\">University of North Carolina at Charlotte, <a class=\"rId41\" href=\"mailto:jmarks@uncc.edu\">jmarks@uncc.edu<\/a><\/p>\n<p class=\"import-Normal\">Jonathan Marks is Professor of Anthropology at the University of North Carolina at Charlotte. He has published many books and articles on broad aspects of biological anthropology. In 2006 he was elected a Fellow of the American Association for the Advancement of Science. In 2012 he was awarded the First Citizen\u2019s Bank Scholar\u2019s Medal from UNC Charlotte. In recent years he has been a Visiting Research Fellow at the ESRC Genomics Forum in Edinburgh, a Visiting Research Fellow at the Max Planck Institute for the History of Science in Berlin, and a Templeton Fellow at the Institute for Advanced Study at Notre Dame. His work has received the W. W. Howells Book Prize and the General Anthropology Division Prize for Exemplary Cross-Field Scholarship from the American Anthropological Association as well as the J. I. Staley Prize from the School for Advanced Research. Two of his books are titled <em>What It Means to Be 98% Chimpanzee<\/em> and <em>Why I Am Not a Scientist<\/em>, but actually he is about 98 percent scientist and not a chimpanzee.<\/p>\n<p class=\"import-Normal\"><img class=\"alignleft\" src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image10-3.jpg\" alt=\"A bearded man wearing a fedora hat looks off in the distance. \" width=\"232\" height=\"232\" \/><\/p>\n<h3 class=\"import-Normal\"><strong>Adam P. Johnson, M.A.<\/strong><\/h3>\n<p class=\"import-Normal\">University of North Carolina at Charlotte\/University of Texas at San Antonio, <a class=\"rId43\" href=\"mailto:ajohn344@uncc.edu\">ajohn344@uncc.edu<\/a><\/p>\n<p class=\"import-Normal\">Adam Johnson is a doctoral candidate at the University of Texas at San Antonio and part-time lecturer at the University of North Carolina at Charlotte. He earned his M.A. in anthropology at UNC-Charlotte in 2017 and will complete his Ph.D. in anthropology at UTSA by 2024. His interests include human-animal relations, science studies, primate behavior, ecology, and the history of anthropology. His recent research project analyzes the social, historical, political, and evolutionary dimensions that shape human-javelina encounters. His goal is to understand how humans and animals find ways to get along in a precarious world.<\/p>\n<h2 class=\"import-Normal\">For Further Exploration <strong><br \/>\n<\/strong><\/h2>\n<p class=\"import-Normal\">Ackermann, Rebecca Rogers, Alex Mackay, and Michael L. Arnold. 2016. \u201cThe Hybrid Origin of \u2018Modern\u2019 Humans.\u201d <em>Evolutionary Biology<\/em> 43 (1): 1\u201311.<\/p>\n<p class=\"import-Normal\">Bateson, Patrick, and Peter Gluckman. 2011. <em>Plasticity, Robustness, Development and Evolution<\/em>. New York: Cambridge University Press.<\/p>\n<p class=\"import-Normal\">Cosans, Christopher E. 2009. <em>Owen's Ape and Darwin's Bulldog: Beyond Darwinism and Creationism<\/em>. Bloomington, IN: Indiana University Press.<\/p>\n<p class=\"import-Normal\">Desmond, Adrian, and James Moore. 2009. <em>Darwin's Sacred Cause: How a Hatred of Slavery Shaped Darwin's Views on Human Evolution<\/em>. New York: Houghton Mifflin Harcourt.<\/p>\n<p class=\"import-Normal\">Dobzhansky, Theodosius, Francisco J. Ayala, G. Ledyard Stebbins, and James W. Valentine. 1977. <em>Evolution<\/em>. San Francisco: W.H. Freeman and Company.<\/p>\n<p class=\"import-Normal\">Fuentes, Agust\u00edn. 2017. <em>The Creative Spark: How Imagination Made Humans Exceptional<\/em>. New York: Dutton.<\/p>\n<p class=\"import-Normal\">Gould, Stephen J. 2003.<em> The Structure of Evolutionary Theory<\/em>. Cambridge, MA: Harvard University Press.<\/p>\n<p class=\"import-Normal\">Haraway, Donna J. 1989. <em>Primate Visions: Gender, Race, and Nature in the World of Modern Science<\/em>. New York: Routledge.<\/p>\n<p class=\"import-Normal\">Huxley, Thomas. 1863. <em>Evidence as to Man's Place in Nature<\/em>. London: Williams &amp; Norgate.<\/p>\n<p class=\"import-Normal\">Jablonka, Eva, and Marion J. Lamb. 2005. <em>Evolution in Four Dimensions: Genetic, Epigenetic, Behavioral, and Symbolic Variation in the History of Life<\/em>. Cambridge, MA: The MIT Press.<\/p>\n<p class=\"import-Normal\">Kuklick, Henrika, ed. 2008. <em>A New History of Anthropology<\/em>. New York: Blackwell.<\/p>\n<p class=\"import-Normal\">Laland, Kevin N., Tobias Uller, Marcus W. Feldman, Kim Sterelny, Gerd B. Muller, Armin Moczek, Eva Jablonka, and John Odling-Smee. 2015. \u201cThe Extended Evolutionary Synthesis: Its Structure, Assumptions and Predictions.\u201d <em>Proceedings of the Royal Society, Series B<\/em> 282 (1813): 20151019.<\/p>\n<p class=\"import-Normal\">Lamarck, Jean Baptiste. 1809. <em>Philosophie Zoologique<\/em>. Paris: Dentu.<\/p>\n<p class=\"import-Normal\">Landau, Misia. 1991. <em>Narratives of Human Evolution<\/em>. New Haven: Yale University Press.<\/p>\n<p class=\"import-Normal\">Lee, Sang-Hee. 2017. <em>Close Encounters with Humankind: A Paleoanthropologist Investigates Our Evolving Species<\/em>. New York: W. W. Norton.<\/p>\n<p class=\"import-Normal\">Livingstone, David N. 2008. <em>Adam's Ancestors: Race, Religion, and the Politics of Human Origins<\/em>. Baltimore: Johns Hopkins University Press.<\/p>\n<p class=\"import-Normal\">Marks, Jonathan. 2015. <em>Tales of the Ex-Apes: How We Think about Human Evolution<\/em>. Berkeley, CA: University of California Press.<\/p>\n<p class=\"import-Normal\">Pigliucci, Massimo. 2009. \u201cThe Year in Evolutionary Biology 2009: An Extended Synthesis for Evolutionary Biology.\u201d <em>Annals of the New York Academy of Sciences<\/em> 1168: 218\u2013228.<\/p>\n<p class=\"import-Normal\">Simpson, George Gaylord. 1949. <em>The Meaning of Evolution: A Study of the History of Life and of Its Significance for Man<\/em>. New Haven: Yale University Press.<\/p>\n<p class=\"import-Normal\">Sommer, Marianne. 2016.<em> History Within: The Science, Culture, and Politics of Bones, Organisms, and Molecules<\/em>. Chicago: University of Chicago Press.<\/p>\n<p class=\"import-Normal\">Stoczkowski, Wiktor. 2002. <em>Explaining Human Origins: Myth, Imagination and Conjecture<\/em>. New York: Cambridge University Press.<\/p>\n<p class=\"import-Normal\">Tattersall, Ian, and Rob DeSalle. 2019. <em>The Accidental Homo sapiens: Genetics, Behavior, and Free Will<\/em>. New York: Pegasus.<\/p>\n<h2 class=\"import-Normal\">References<\/h2>\n<p class=\"import-Normal\">Barton, Robert A. 1996. \"Neocortex Size and Behavioural Ecology in Primates.\" <em>Proceedings of the Royal Society of London. Series B: Biological Sciences<\/em> 263 (1367): 173\u2013177.<\/p>\n<p class=\"import-Normal\">Bodmer, Walter, and Robin McKie. 1997. <em>The Book of Man: The Hman Genome Project and the Quest to Discover our Genetic Heritage.<\/em> Oxford University Press.<\/p>\n<p class=\"import-Normal\">Darwin, Charles. 1859.<em> On the Origin of Species by Means of Natural Selection, or, the Preservation of Favoured Races in the Struggle for Life<\/em>. London: J. Murray.<\/p>\n<p class=\"import-Normal\">Darwin, Charles. 1871. <em>The Descent of Man, and Selection in Relation to Sex.<\/em> London: J. Murray.<\/p>\n<p class=\"import-Normal\">Dawkins, Richard. 1976. <em>The Selfish Gene. <\/em>Oxford University Press.<\/p>\n<p class=\"import-Normal\">Deacon, T. W. 1998. <em>The Symbolic Species: The Co-evolution of Language and the Brain<\/em>. W. W. Norton &amp; Company.<\/p>\n<p class=\"import-Normal\">Eldredge, N., and S. J. Gould. 1972. \"Punctuated Equilibria: An Alternative to Phyletic Gradualism.\" In <em>Models in Paleobiology<\/em>, edited by T. J. Schopf, 82\u2013115. San Francisco: W. H. Freeman.<\/p>\n<p class=\"import-Normal\">Gould, Stephen J. 2003.<em> The Structure of Evolutionary Theory<\/em>. Cambridge, MA: Harvard University Press.<\/p>\n<p class=\"import-Normal\">Gould, Stephen J. 1996. <em>Mismeasure of Man<\/em>. New York: WW Norton &amp; Company.<\/p>\n<p class=\"import-Normal\">Gould, Stephen Jay, and Richard C. Lewontin. 1979. \"The Spandrels of San Marco and the Panglossian Paradigm: A Critique of the Adaptationist Programme.\" <em>Proceedings of the Royal Society of London. Series B: Biological Sciences<\/em> 205 (1151): 581\u2013598.<\/p>\n<p class=\"import-Normal\">Haeckel, Ernst. 1868. <em>Nat\u00fcrliche Sch\u00f6pfungsgeschichte<\/em>. Berlin: Reimer.<\/p>\n<p class=\"import-Normal\">Huxley, Thomas Henry. 1863. <em>Evidence as to Man\u2019s Place in Nature. <\/em>London: Williams and Norgate.<\/p>\n<p class=\"import-Normal\">Kaufman, Thomas C., Mark A. Seeger, and Gary Olsen. 1990. \"Molecular and Genetic Organization of the Antennapedia Gene Complex of <em>Drosophila melanogaster<\/em>.\" <em>Advances in Genetics<\/em> 27: 309\u2013362.<\/p>\n<p class=\"import-Normal\">Kellogg, Vernon. 1917. <em>Headquarters Nights<\/em>. Boston: The Atlantic Monthly Press.<\/p>\n<p class=\"import-Normal\">Kevles, Daniel J., and Leroy Hood. 1993. <em>The Code of Codes: Scientific and Social Issues in the Human Genome Project<\/em>. Cambridge, MA: Harvard University Press.<\/p>\n<p class=\"import-Normal\">Lewontin, Richard, Steven Rose, and Leon Kamin. 2017. <em>Not in Our Genes\u202f: Biology, Ideology, and Human Nature<\/em>, 2nd ed. Chicago: Haymarket Books.<\/p>\n<p class=\"import-Normal\">Lloyd, Elisabeth A., and Stephen J. Gould. 1993. \"Species Selection on Variability.\" <em>Proceedings of the National Academy of Sciences<\/em> 90 (2): 595\u2013599.<\/p>\n<p class=\"import-Normal\">Marks, Jonathan. 2015. \u201cThe Biological Myth of Human Evolution.\u201d In <em>Biologising the Social Sciences: Challenging Darwinian and Neuroscience Explanations<\/em>, edited by David Canter and David A. Turner, 59\u201378. London: Routledge.<\/p>\n<p class=\"import-Normal\">Monypenny, William Flavelle, and George Earle Buckle. 1929. <em>The Life of Benjamin Disraeli, Earl of Beaconsfield, Volume II: 1860\u20131881<\/em>. London: John Murray.<\/p>\n<p class=\"import-Normal\">Potts, Rick. 1998. \u201cVariability Selection in Hominid Evolution.\u201d <em>Evolutionary Anthropology <\/em><em>7<\/em><em>:<\/em> 81\u201396.<\/p>\n<p class=\"import-Normal\">Punnett, R. C. 1905. <em>Mendelism<\/em>. Cambridge: Macmillan and Bowes.<\/p>\n<p class=\"import-Normal\">Shapiro, Robert. 1991. <em>The Human Blueprint: The Race to Unlock the Secrets of Our Genetic Script.<\/em> New York: St. Martin\u2019s Press.<\/p>\n<p class=\"import-Normal\">Shultz, Susanne, Emma Nelson, and Robin Dunbar. 2012. \"Hominin Cognitive Evolution: Identifying Patterns and Processes in the Fossil and Archaeological Record.\" <em>Philosophical Transactions of the Royal Society B: Biological Sciences<\/em> 367 (1599): 2130\u20132140.<\/p>\n<p class=\"import-Normal\">Spencer, Herbert. 1864. <em>Principles of Biology.<\/em> London: Williams and Norgate.<\/p>\n<p class=\"import-Normal\">Watson, James D. 1990. \"The Human Genome Project: Past, Present, and Future.\" <em>Science<\/em> 248 (4951): 44\u201349.<\/p>\n<p class=\"import-Normal\">Yengo, L., Vedantam, S., Marouli, E., Sidorenko, J., Bartell, E., Sakaue, S., Graff, M., Eliasen, A.U., Jiang, Y., Raghavan, S. and Miao, J., 2022. A saturated map of common genetic variants associated with human height. <em>Nature<\/em>, <em>610 <\/em>(7933): 704-712.<\/p>\n<p class=\"import-Normal\">Zeder, Melinda A. 2018. \"Why Evolutionary Biology Needs Anthropology: Evaluating Core Assumptions of the Extended Evolutionary Synthesis.\" <em>Evolutionary Anthropology: Issues, News, and Reviews<\/em> 27 (6): 267\u2013284.<\/p>\n<\/div>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_281_1723\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_281_1723\"><div tabindex=\"-1\"><div class=\"learning-objectives\">\n<p>Stephanie Etting, Ph.D., Sacramento City College<\/p>\n<p><em>This chapter is a revision from \"<a href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/chapter\/__unknown__-4\/\">Chapter 5: Meet the Living Primates<\/a>\u201d by Stephanie Etting. In <a href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/\">Explorations: An Open Invitation to Biological Anthropology, first edition,<\/a> edited by Beth Shook, Katie Nelson, Kelsie Aguilera, and Lara Braff, which is licensed under <a href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\">CC BY-NC 4.0<\/a>. <\/em><\/p>\n<div class=\"textbox textbox--learning-objectives\">\n<header class=\"textbox__header\">\n<h2 class=\"textbox__title\"><span style=\"color: #ffffff\">Learning Objectives<\/span><\/h2>\n<\/header>\n<div class=\"textbox__content\">\n<ul>\n<li class=\"import-Normal\">Describe how studying nonhuman primates is important in anthropology.<\/li>\n<li class=\"import-Normal\">Compare two ways of categorizing taxa: grades and clades.<\/li>\n<li class=\"import-Normal\">Define different types of traits used to evaluate primate taxa.<\/li>\n<li class=\"import-Normal\">Identify key ways that primates differ from other mammals.<\/li>\n<li class=\"import-Normal\">Distinguish between the major primate taxa using their key characteristics.<\/li>\n<li class=\"import-Normal\">Describe your place in nature by learning your taxonomic classification.<\/li>\n<\/ul>\n<\/div>\n<\/div>\n<p class=\"import-Normal\">You may be wondering why a field dedicated to the study of humans includes discussions of nonhuman animals. Our primary goal in biological anthropology is to understand how humans are similar to and different from the rest of the natural world, why we have the traits we have, and how we got to be the way we are. But to fully grasp our place in nature, we must look to our closest living relatives, the nonhuman primates. In this chapter, we focus on the organization and diversity within the Order Primates.<\/p>\n<h2 class=\"import-Normal\">Studying Primates in Biological Anthropology<\/h2>\n<p class=\"import-Normal\">Primates are one of at least twenty Orders belonging to the Class Mammalia, and probably one of the oldest. One genetic estimate puts the origin of primates at approximately 91 million years ago (mya), predating the extinction of the dinosaurs (Bininda-Emonds et al. 2007). Today, the Order Primates is a diverse group of animals that includes lemurs and lorises, tarsiers, monkeys, apes, and humans, all of which are united in sharing a suite of anatomical, behavioral, and life history characteristics. While nonhuman primates are fascinating animals in their own right, their close relationship to humans makes them ideal for studying humans via <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_944\">homology<\/a>, <\/strong>looking at traits that are shared between taxa because they inherited the trait from a common ancestor. For example, humans (genus <em>Homo<\/em>) and chimpanzees (genus <em>Pan<\/em>) both share the trait of male cooperation in hunting. This trait\u2014along with many others that chimpanzees and humans share\u2014is likely homologous<em>, <\/em>meaning it was probably passed down from the last common ancestor of <em>Homo<\/em> and <em>Pan, <\/em>which lived about 6\u20138 million years ago.<\/p>\n<p class=\"import-Normal\">Nonhuman primates also make excellent comparators for learning about humans via <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_948\">analogy<\/a><\/strong>. Many nonhuman primates live in environments similar to those in which our ancestors lived and therefore exhibit traits similar to what we see in humans. For example, baboons and humans both have long legs. In humans, this is because about 1.7 million years ago, our ancestors moved into savanna habitats where longer legs helped them move more efficiently over long distances. Baboons, who also live in savanna habitats, independently evolved longer arms and legs for the same reason\u2014to be able to cover more ground, more efficiently. This means that having long legs is an analogous trait in baboons and humans: \u2014that is, this adaptation evolved independently in the two species but for the same purpose. Using homology and analogy, our closest living relatives provide the critical context in which to understand human biology, morphology, and behavior. It is only by studying how humans compare with our primate relatives that we can fully comprehend our place in nature.<\/p>\n<h3 class=\"import-Normal\"><strong>Ways of Organizing Taxa<\/strong><\/h3>\n<p class=\"import-Normal\">You learned in Chapter 2 about Linnaeus and the hierarchical nature of taxonomic classification. Our goal in classifying taxa is to create categories that reflect clade relationships. A <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_1116\">clade<\/a> <\/strong>is a grouping of organisms based on relatedness that reflects a branch of the evolutionary tree. Clade relationships are determined using traits shared by groups of taxa as well as genetic similarities. An example of a clade would be a grouping that includes humans, chimpanzees, bonobos, and gorillas (Figure 5.1). These taxa are in what is referred to as the <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_1118\">African clade<\/a><\/strong> of hominoids (a taxonomic group you will learn about later in this chapter). The African clade grouping reflects how humans, chimpanzees, bonobos, and gorillas all share a more recent ancestor with each other than any of them do with other species\u2014that is, we are on the same branch of the evolutionary tree. We know members of the African clade are most closely related based on shared morphological traits as well as genetic similarities. Excluded from this grouping is the orangutan, which is considered a member of the <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_1120\">Asian clade<\/a><\/strong> of hominoids.<\/p>\n<figure style=\"width: 800px\" class=\"wp-caption aligncenter\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/06\/image1-3.jpg\" alt=\"Diagram shows large-bodied hominoids grouped by grade or clade.\" width=\"800\" height=\"358\" \/><figcaption class=\"wp-caption-text\">Figure 5.1: Grades vs. Clades. A grade grouping of apes places orangutans, gorillas, chimpanzees, and bonobos together based on their similar appearance and lifestyle, but excludes humans. Clade classification is based on shared derived traits and genetic evidence (both reflecting close evolutionary relationships). A clade grouping of apes places humans with gorillas, chimpanzees, and bonobos., whereas orangutans are separated. Credit: <a href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/chapter\/__unknown__-4\/\">Grades vs. clades comparison (Figure 5.12)<\/a> original to <a href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/\">Explorations: An Open Invitation to Biological Anthropology<\/a> by Stephanie Etting is a collective work under a <a href=\"https:\/\/creativecommons.org\/licenses\/by-nc-sa\/4.0\/\">CC BY-NC-SA 4.0 License<\/a>. [Includes <a href=\"https:\/\/commons.wikimedia.org\/wiki\/File:Orangutan_on_a_tree_(Unsplash).jpg\">Orangutan on a tree (Unsplash)<\/a> by Dawn Armfield, <a href=\"https:\/\/creativecommons.org\/publicdomain\/zero\/1.0\/legalcode\">public domain (CC0 1.0)<\/a>; <a href=\"https:\/\/commons.wikimedia.org\/wiki\/File:Gorilla_Profile_(17997840570).jpg\">Gorilla Profile (17997840570)<\/a> by <a href=\"https:\/\/www.flickr.com\/people\/100915417@N07\">Charlie Marshall<\/a> from Bristol UK, modified (cropped), <a href=\"https:\/\/creativecommons.org\/licenses\/by\/2.0\/legalcode\">CC BY 2.0 License<\/a>; <a href=\"https:\/\/commons.wikimedia.org\/wiki\/File:Chimpanzee_(14679767561).jpg\">Chimpanzee (14679767561)<\/a> by <a href=\"https:\/\/www.flickr.com\/people\/120374925@N06\">Magnus Johansson<\/a>, modified (cropped), <a href=\"https:\/\/creativecommons.org\/licenses\/by-sa\/2.0\/legalcode\">CC BY-SA 2.0<\/a>; <a href=\"https:\/\/pixabay.com\/photos\/pointing-finger-hand-pointing-1922074\/\">Pointing finger (1922074)<\/a> by <a href=\"https:\/\/pixabay.com\/users\/truthseeker08-2411480\/\">truthseeker08<\/a>, <a href=\"https:\/\/pixabay.com\/service\/terms\/#license\">Pixabay License<\/a>.]<\/figcaption><\/figure>\n<p class=\"import-Normal\">In contrast, <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_1122\">grades<\/a> <\/strong>are groupings that reflect levels of adaptation or overall similarity and not necessarily evolutionary relationships. An example of a grade would be placing orangutans, gorillas, bonobos, and chimpanzees into a group, and excluding humans. Grouping in this way is based on the superficial similarities of the apes in being large-bodied, having lots of body hair, living in tropical forests, climbing and sleeping in trees, and so on. According to these criteria, humans seem to be unusual in that we differ in our morphology, behavior, and ecology. Separating humans from the large-bodied apes is the system that was used historically. We now know that grouping orangutans, gorillas, bonobos, and chimpanzees and excluding humans does not accurately reflect our true evolutionary relationships. Since our goal in taxonomic classification is to organize animals to reflect their evolutionary relationships, we prefer to use clade classifications.<\/p>\n<h3 class=\"import-Normal\"><strong>Types of Traits<\/strong><\/h3>\n<p class=\"import-Normal\">When evaluating relationships between taxa, we use key traits that allow us to determine which species are most closely related to one another. Traits can be either ancestral or derived. <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_1124\">Ancestral traits<\/a><\/strong> are those that a taxon has because it has inherited the trait from a distant ancestor. For example, all primates have body hair because we are mammals and all mammals share an ancestor hundreds of millions of years ago that had body hair. This trait has been passed down to all mammals from a shared ancestor, so all mammals alive today have body hair. <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_1126\">Derived traits<\/a><\/strong> are those that have been more recently altered. This type of trait is most useful when we are trying to distinguish one group from another because derived traits tell us which taxa are more closely related to each other. For example, humans walk on two legs.The many adaptations that humans possess that allow us to move in this way evolved after humans split from the Genus <em>Pan<\/em>. This means that when we find fossil taxa that share derived traits for walking on two legs, we can conclude that they are likely more closely related to humans than to chimpanzees and bonobos<em>. <\/em><\/p>\n<p class=\"import-Normal\">There are a couple of other important points about ancestral and derived traits that will become apparent as we discuss primate diversity. First, the terms <em>ancestral<\/em> and <em>derived<\/em> are relative terms, meaning that a trait can be either one depending on the taxa being compared. For example, in the previous paragraph, body hair was used as an example for an ancestral trait among primates. All mammals have body hair because we share a distant ancestor who had this trait. The presence of body hair therefore doesn\u2019t allow you to distinguish whether monkeys are more closely related to apes or lemurs because they all share this trait. However, if we are comparing mammals to birds and fish, then body hair becomes a derived trait of mammals. It evolved after mammals diverged from birds and fish, and it tells us that all mammals are more closely related to each other than they are to birds or fish.The second important point is that very often when one lineage splits into two, one taxon will stay more similar to the last common ancestor in retaining more ancestral traits, whereas the other lineage will usually become more different from the last common ancestor by developing more derived traits. This will become very apparent when we discuss the two suborders of primates, Strepsirrhini and Haplorrhini. When these two lineages diverged, strepsirrhines retained more ancestral traits (those present in the earliest primates) and haplorrhines developed more derived traits (became more different from ancestral primates).<\/p>\n<p class=\"import-Normal\">There are two other types of traits that will be relevant to our discussions here: generalized and specialized traits. <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_1128\">Generalized traits<\/a> <\/strong>are those characteristics that are useful for a wide range of things. Having <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_1138\">opposable thumbs<\/a><\/strong> that go in a different direction than the rest of your fingers is a very useful, generalized trait. You can hold a pen, grab a branch, peel a banana, or text your friends all thanks to your opposable thumbs! <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_1130\">Specialized traits<\/a> <\/strong>are those that have been modified for a specific purpose. These traits may not have a wide range of uses, but they will be very efficient at their job. Hooves in horses are a good example of a specialized trait: they allow horses to run quickly on the ground on all fours. You can think of generalized traits as a Swiss Army knife, useful for a wide range of tasks but not particularly good at any one of them. That is, if you\u2019re in a bind, then a Swiss Army knife can be very useful to cut a rope or fix a loose screw, but if you were going to build furniture or fix a kitchen sink, then you\u2019d want specialized tools for the job. As we will see, most primate traits tend to be generalized.<\/p>\n<h2 class=\"import-Normal\">What Makes Something a Primate?<\/h2>\n<p class=\"import-Normal\">The Order Primates is distinguished from other groups of mammals in having a <em>suite of characteristics<\/em>. This means that there is no individual trait that you can use to instantly identify an animal as a primate; instead, you have to look for animals that possess a collection of traits. What this also means is that each individual trait we discuss may be found in nonprimates, but if you see an animal that has most or all of these traits, there is a good chance it is a primate.<\/p>\n<p class=\"import-Normal\">Primates are most distinguishable from other organisms in traits related to our vision. Our Order relies on vision as a primary sense, which is reflected in many areas of our anatomy and behavior. All primates have eyes that face forward with convergent (overlapping) visual fields. So if you cover one eye with your hand, you can still see most of the room with your other one. This also means that we cannot see on the sides or behind us as well as some other animals can. In order to protect the sides of the eyes from the muscles we use for chewing, all primates have at least a <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_1132\">postorbital bar<\/a>, <\/strong>a bony ring around the outside of the eye (Figure 5.2). Primate taxa with more convergent eyes need extra protection, so animals with greater orbital convergence will have a <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_1134\">postorbital plate<\/a> <\/strong>or<strong> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_1136\">postorbital closure<\/a> <\/strong>in addition to the bar (Figure 5.2).The postorbital bar is a derived trait of primates, appearing in our earliest ancestors.<\/p>\n<figure style=\"width: 661px\" class=\"wp-caption aligncenter\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image2-4.jpg\" alt=\"Skulls of a monkey and lemur viewed from the side and top.\" width=\"661\" height=\"430\" \/><figcaption class=\"wp-caption-text\">Figure 5.2: All primates have bony protection around their eyes. Some have a postorbital bar only (right), but many have full postorbital closure, also called a postorbital plate, that completely protects the back of the eye socket (left). Credit: <a href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/chapter\/__unknown__-4\/\">Postorbital bar\/Postorbital closure (Figure 5.1)<\/a> a derivative work original to <a href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/\">Explorations: An Open Invitation to Biological Anthropology<\/a> by Stephanie Etting is under a <a href=\"https:\/\/creativecommons.org\/licenses\/by-nc-sa\/4.0\/\">CC BY-NC-SA 4.0 License<\/a>. [Includes <a href=\"https:\/\/animaldiversity.org\/accounts\/Otolemur_crassicaudatus\/specimens\/collections\/contributors\/phil_myers\/ADW_mammals\/specimens\/Primates\/Otolemur_crassicaudatus\/lateral\/\">Otolemur crassicaudatus (greater galago)<\/a> by <a href=\"https:\/\/animaldiversity.org\/\">Animal Diversity Web<\/a>, <a href=\"https:\/\/creativecommons.org\/licenses\/by-nc-sa\/3.0\/\">CC BY-NC-SA 3.0<\/a>; <a href=\"https:\/\/animaldiversity.org\/accounts\/Otolemur_crassicaudatus\/specimens\/collections\/contributors\/phil_myers\/ADW_mammals\/specimens\/Primates\/Otolemur_crassicaudatus\/dorsal1809\/\">Macaca fascicularis (long-tailed macaque)<\/a> by <a href=\"https:\/\/animaldiversity.org\/\">Animal Diversity Web<\/a>, <a href=\"https:\/\/creativecommons.org\/licenses\/by-nc-sa\/3.0\/\">CC BY-NC-SA 3.0<\/a>.]<\/figcaption><\/figure>\n<p class=\"import-Normal\">Another distinctive trait of our Order is that many primates have <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_1140\">trichromatic color vision<\/a><\/strong>, the ability to distinguish reds and yellows in addition to blues and greens. Birds, fish, and reptiles are <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_1142\">tetrachromatic<\/a> <\/strong>(they can see reds, yellows, blues, greens, and even ultraviolet), but most mammals, including some primates, are only <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_1144\">dichromatic<\/a> <\/strong>(they see only in blues and greens). It is thought that the nocturnal ancestors of mammals benefited from seeing better at night rather than in color, and so dichromacy is the ancestral condition for mammals. Trichromatic primates are known to use their color vision for all sorts of purposes: finding young leaves and ripe fruits, identifying other species, and evaluating signals of health and fertility.<\/p>\n<p class=\"import-Normal\">The primate visual system uses a lot of energy, so primates have compensated by cutting back on other sensory systems, particularly our sense of smell. Compared to other mammals, primates have reduced snouts, another derived trait that appears even in the earliest primate ancestors. There is variation across primate taxa in how much snouts are reduced. Those with a better sense of smell usually have poorer vision than those with a relatively dull sense of smell. The reason for this is that all organisms have a limited amount of energy to spend on running our bodies, so we make <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_1146\">evolutionary trade-offs<\/a><\/strong>, as energy spent on one trait cuts back on energy spent on another. So primates with better vision are spending more energy on vision and thus have a poorer smell (and shorter snout), and those who spend less energy on vision will have a better sense of smell (and a longer snout).<\/p>\n<p class=\"import-Normal\">Primates also differ from other mammals in the size and complexity of our brains. On average, primates have brains that are twice as big for their body size when compared to other mammals. Not unexpectedly, the visual centers of the brain are larger in primates and the wiring is different from that in other animals, reflecting our reliance on this sense. The neocortex, which is used for higher functions like consciousness and language in humans, as well as sensory perception and spatial awareness, is also larger in primates relative to other animals. In nonprimates this part of the brain is often smooth, but in primates it is made up of many folds, which increase the surface area. It has been proposed that the more complex neocortex of primates is related to diet, with fruit-eating primates having larger relative brain sizes than leaf-eating primates, due to the more challenging cognitive demands required to find and process fruits (Clutton-Brock and Harvey 1980). An alternative hypothesis argues that larger brain size is necessary for navigating the complexities of primate social life, with larger brains occurring in species who live in bigger, more complex groups relative to those living in pairs or solitarily (Dunbar 1998). There seems to be support for both hypotheses, as large brains are a benefit under both sets of selective pressures.<\/p>\n<p class=\"import-Normal\">Animals with large brains usually have extended life history patterns, and primates are no exception. <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_1148\">Life history<\/a> <\/strong>refers to the pace at which an organism grows, reproduces, and ages. Some animals grow very quickly and reproduce many offspring in a short time frame but do not live very long. Other animals grow slowly, reproduce few offspring, reproduce infrequently, and live a long time. Primates are all in the \u201cslow lane\u201d of life history patterns. Compared to animals of similar body size, primates grow and develop more slowly, have fewer offspring per pregnancy, reproduce less often, and live longer. Primates also invest heavily in each offspring. With a few exceptions, most primates only have one offspring at a time. A group of small-bodied monkeys in South America regularly give birth to twins, and some lemurs can give birth to multiple offspring at a time, but these primates are the exception rather than the rule. Primates also reproduce relatively infrequently. The fastest-reproducing primates will produce offspring about every six months, while the slowest, the orangutan, reproduces only once every seven to nine years. This very slow reproductive rate makes the orangutan the slowest-reproducing animal on the planet! Primates are also characterized by having long lifespans. The group that includes humans and large-bodied apes has the most extended life history patterns among all primates, with some large-bodied apes estimated to live up to 58 years in the wild (Robson et al. 2006).<\/p>\n<figure style=\"width: 392px\" class=\"wp-caption alignleft\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image3-5.jpg\" alt=\"Various hands and feet of different primate species.\" width=\"392\" height=\"624\" \/><figcaption class=\"wp-caption-text\">Figure 5.3: These drawings of the hands and feet of different primates show the opposable thumbs and big toes, pentadactyly, flattened nails, and tactile pads characteristic of our Order. Credit: <a href=\"https:\/\/commons.wikimedia.org\/wiki\/File:PrimateFeet.jpg\">PrimateFeet<\/a> by <a href=\"https:\/\/en.wikipedia.org\/wiki\/Richard_Lydekker\">Richard Lydekker<\/a>, original from The Royal Natural History 1:15 (1893), is in the <a href=\"https:\/\/en.wikipedia.org\/wiki\/Public_domain\">public domain<\/a>.<\/figcaption><\/figure>\n<p>Primates also differ from other animals in our hands and feet. The Order Primates is a largely <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_1150\">arboreal<\/a><\/strong> taxonomic group, meaning that most primates spend a significant amount of their time in trees. As a result, the hands and feet of primates have evolved to move in a three-dimensional environment. Primates have the generalized trait of <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_1152\">pentadactyly<\/a><\/strong>\u2014 possessing five digits (fingers and toes) on each limb. Many nonprimates, like dogs and horses, have fewer digits because they are specialized for high-speed, <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_1154\">terrestrial<\/a><\/strong> (on the ground) running. Pentadactyly is also an ancestral trait, one that dates back to the earliest four-footed animals. Primates today have opposable thumbs and, with the exception of humans, opposable big toes (Figure 5.3). Opposable thumbs and toes are a derived trait that appeared in the earliest primate fossils about 55 million years ago. Having thumbs and big toes that go in a different direction from the rest of the fingers and toes allow primates to be excellent climbers in trees as well as to manipulate objects. Our ability to manipulate objects is further enhanced by the flattened nails on the backs of our fingers and toes that we possess in the place of the claws and hooves that many other mammals have. On the other side of our digits, we have sensitive <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_1156\">tactile pads<\/a> <\/strong>that allow us to have a fine sense of touch. Primates use this fine sense of touch for handling food and, in many species, grooming themselves and others. In primates, grooming is an important social currency, through which individuals forge and maintain social bonds.<\/p>\n<table class=\"alignright\" style=\"width: 219.75pt;height: 407px\">\n<caption>Figure 5.4: Primate Traits at a Glance: This table summarizes the suite of traits that differentiate primates from other mammals. Credit: <a href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/chapter\/__unknown__-4\/\">Primate at a glance table (Figure 5.3)<\/a> by Stephanie Etting original to <a href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/\">Explorations: An Open Invitation to Biological Anthropology<\/a> is under a <a href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/\">CC BY-NC 4.0 License<\/a>.<\/caption>\n<thead>\n<tr style=\"height: 30px\">\n<td class=\"a-C\" style=\"background-color: transparent;padding: 5pt;border: 1pt solid #000000;height: 30px;width: 361.667px\">\n<p class=\"import-Normal\" style=\"text-align: center\"><strong>Primate suite of traits<\/strong><\/p>\n<\/td>\n<\/tr>\n<\/thead>\n<tbody>\n<tr class=\"a-R\" style=\"height: 362px\">\n<td class=\"a-C\" style=\"background-color: transparent;padding: 5pt;border: 1pt solid #000000;height: 362px;width: 361.667px\">\n<p class=\"import-Normal\" style=\"text-align: center\">Convergent eyes<\/p>\n<p class=\"import-Normal\" style=\"text-align: center\">Postorbital bar<\/p>\n<p class=\"import-Normal\" style=\"text-align: center\">Many have trichromatic color vision<\/p>\n<p class=\"import-Normal\" style=\"text-align: center\">Short snouts<\/p>\n<p class=\"import-Normal\" style=\"text-align: center\">Opposable thumbs and big toes<\/p>\n<p class=\"import-Normal\" style=\"text-align: center\">Pentadactyly<\/p>\n<p class=\"import-Normal\" style=\"text-align: center\">Flattened nails<\/p>\n<p class=\"import-Normal\" style=\"text-align: center\">Tactile pads<\/p>\n<p class=\"import-Normal\" style=\"text-align: center\">Highly arboreal<\/p>\n<p class=\"import-Normal\" style=\"text-align: center\">Large brains<\/p>\n<p class=\"import-Normal\" style=\"text-align: center\">Extended life histories<\/p>\n<p class=\"import-Normal\" style=\"text-align: center\">Live in the tropics<\/p>\n<\/td>\n<\/tr>\n<tr style=\"height: 15px\">\n<td style=\"height: 15px;width: 362.033px\"><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>Lastly, primates are very social animals. All primates, even those that search for food alone, establish strong social networks within species. Unlike many animals, primates do not migrate: they stay in a relatively stable area for their whole life, often interacting with the same individuals for their long lives. The long-term relationships that primates form with others of their species lead to complex and fascinating social behaviors (see Chapter 6). Finally, nonhuman primates show a clear preference for tropical regions of the world. Most primates are found between the Tropic of Cancer and the Tropic of Capricorn, with only a few taxa living outside these regions. Figure 5.4 shows a summary of primate traits.<\/p>\n<h2 class=\"import-Normal\">Key Traits Used to Distinguish Between Primate Taxa<\/h2>\n<p class=\"import-Normal\">When placing primate species into specific taxonomic groups, we focus on dental characteristics, behavioral adaptations, and locomotor adaptations. Differences in these characteristics across groups reflect constraints of evolutionary history as well as variation in adaptations.<\/p>\n<h3 class=\"import-Normal\"><strong>Dental Characteristics<\/strong><\/h3>\n<p class=\"import-Normal\">Teeth may not seem like the most exciting topic with which to start, but we can learn a tremendous amount about an organism from its teeth. First, teeth are vital to survival. Wild animals do not have the benefit of knives and forks; they rely on their teeth to process their food. Because of this, teeth of any species have evolved to reflect what that organism eats and therefore have a lot to tell us about their diet. Second, variation in tooth size, shape, and number reveals an organism\u2019s evolutionary history. Some taxa have more teeth than others or different forms of teeth. Furthermore, differences in teeth between males and females can tell us about competition over mates (see Chapter 6). Lastly, teeth are overly represented in the fossil record. Enamel is hard, and there is little meat on jaws so carnivores and scavengers often leave them behind. Sometimes, the only remains we have from an extinct taxon is its teeth!<\/p>\n<figure style=\"width: 356px\" class=\"wp-caption alignleft\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image4-4-1.jpg\" alt=\"Yawning baboon with large teeth.\" width=\"356\" height=\"266\" \/><figcaption class=\"wp-caption-text\">Figure 5.5: This picture of an open-mouthed Hamadryas baboon demonstrates the diastema between his upper canine and front teeth. This space is taken up by his lower canine when he closes his mouth. Credit: <a href=\"https:\/\/commons.wikimedia.org\/wiki\/File:Ha,ha,ha_...._(14986571843).jpg\">Ha,ha,ha .... (14986571843)<\/a> by <a href=\"https:\/\/www.flickr.com\/people\/104249543@N07\">Rolf Dietrich Brecher<\/a> from Germany is under a <a href=\"https:\/\/creativecommons.org\/licenses\/by-sa\/2.0\/legalcode\">CC BY-SA 2.0 License<\/a>.<\/figcaption><\/figure>\n<p>Like other mammals, primates are <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_1158\">heterodont<\/a><\/strong>: they have multiple types of teeth that are used for different purposes. We have <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_1160\">incisors<\/a> <\/strong>for slicing; <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_1162\">premolars<\/a> <\/strong>and <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_1164\">molars<\/a> <\/strong>for grinding up our food; and <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_1166\">canines<\/a><\/strong>, which most primates (not humans) use as weapons against predators and each other. The sizes of canines vary across species and can often be <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_1168\">sexually dimorphic<\/a><\/strong>, with males tending to have larger canines than females. Some nonhuman primates <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_1170\">hone<\/a><\/strong>, or sharpen, their canines by gnashing the teeth together to sharpen the sides. The upper canine sharpens on the first lower premolar and the lower canine sharpens on the front of the upper canine. As canines get larger, they require a space to fit in order for the jaws to close. This space between the teeth is called a <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_1172\">diastema<\/a><\/strong> (Figure 5.5).<\/p>\n<p class=\"import-Normal\">We use a <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_1174\">dental formula<\/a><\/strong> to specify how many incisors, canines, premolars, and molars are in each quadrant of the mouth (half of the top or bottom). For example, Figure 5.6 shows half of the lower teeth of a human. You can see that in half of the mandible, there are two incisors, one canine, two premolars, and three molars. This dental formula is written as 2:1:2:3. (The first number represents the number of incisors, followed by the number of canines, premolars, and molars).<\/p>\n<figure style=\"width: 241px\" class=\"wp-caption alignright\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image5-5.png\" alt=\"Human mandible with four types of teeth.\" width=\"241\" height=\"424\" \/><figcaption class=\"wp-caption-text\">Figure 5.6:\u00a0 This drawing shows half of the human mandible. With the four types of teeth labeled, you can determine that the dental formula is 2:1:2:3. Credit: <a href=\"https:\/\/commons.wikimedia.org\/wiki\/File:Gray997.png\">Gray997<\/a> by <a href=\"https:\/\/en.wikipedia.org\/wiki\/Henry_Vandyke_Carter\">Henry Vandyke Carter<\/a>, original in Henry Gray (1918) Anatomy of the Human Body, Plate 997, is in the <a href=\"https:\/\/en.wikipedia.org\/wiki\/Public_domain\">public domain<\/a>.<\/figcaption><\/figure>\n<p class=\"import-Normal\">To determine the dental formula, you need to be able to identify the different types of teeth. You can recognize incisors because they often look like spatulas with a flat, blade-like surface. Premolars and molars can be differentiated by the number of <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_1176\">cusps<\/a><\/strong> that they have. Cusps are the bumps that you can feel with your tongue on the surface of your back teeth. Premolars are smaller than molars and, in primates, often have one or two cusps on them. Molars are bigger, providing a larger chewing surface, and have more cusps. Depending on the species and whether you\u2019re looking at upper or lower teeth, primate molars can have between three and five cusps. Molar cusps can also vary between taxa in how they are arranged; you will learn more about this later in this chapter. Canines are often easy to distinguish because, in most taxa, they are much longer and more conical than the other teeth.<\/p>\n<p class=\"import-Normal\">Teeth also directly reflect an organism\u2019s diet. Primates are known to eat a wide range of plant parts, insects, gums, and, rarely, meat. While all primates eat a variety of foods, what differs among primates are the proportions of each of these food items in the diet. That is, two primates living in the same forest may be eating the same foods but in vastly different proportions, and so we would categorize them as different dietary types. The most common dietary types among primates are those whose diets consist primarily of fruit (<strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_954\">frugivores<\/a><\/strong>), those who eat mostly insects (<strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_958\">insectivores<\/a><\/strong>), and those who eat primarily leaves (<strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_956\">folivores<\/a><\/strong>). A few primate taxa are <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_1178\">gummivores<\/a><\/strong>, specializing in eating gums and saps, but we will only focus on the adaptations found in the three primary dietary groups.<\/p>\n<h4 class=\"import-Normal\"><em>Frugivores<\/em><\/h4>\n<p class=\"import-Normal\">Plants want animals to eat their fruits because, in doing so, animals eat the seeds of the fruit and then disperse them far away from the parent plant. Therefore, plants often \u201cadvertise\u201d fruits by making them colorful and easy to spot, full of easy-to-digest sugars that make them taste good and, often, easy to chew and digest (not being too fibrous or tough). For these reasons, frugivores often do not need a lot of specialized traits to consume a diet rich in fruits (Figure 5.7). Their molars usually have a broad chewing surface with low, rounded cusps (referred to as <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_1180\">bunodont<\/a> <\/strong>molars). Frugivores have large incisors for slicing through the outer coatings on fruit, and they tend to have stomachs, colons, and small intestines that are intermediate in terms of size and complexity between insectivores and folivores (Chivers and Hladik 1980). They are also usually of intermediate body size between the other two dietary types. Because fruit does not contain protein, frugivores must supplement their diet with protein from insects, leaves, and\/or seeds. Frugivores who get protein by eating seeds evolved to have thicker enamel on their teeth to protect them from excessive wear.<\/p>\n<figure style=\"width: 503px\" class=\"wp-caption aligncenter\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image6-2.jpg\" alt=\"Upper teeth and maxilla of a frugivore monkey.\" width=\"503\" height=\"331\" \/><figcaption class=\"wp-caption-text\">Figure 5.7: Frugivores are characterized by large incisors, bunodont molars, and digestive tracts that are intermediate in complexity between the other two dietary types. Credit: <a href=\"https:\/\/animaldiversity.org\/collections\/contributors\/phil_myers\/ADW_mammals\/specimens\/Primates\/Papio_papio\/utr0087\/\">Papio papio (Guinea baboon).jpg<\/a> by Phil Myers on <a href=\"https:\/\/animaldiversity.org\">Animal Diversity Web<\/a> is under a <a href=\"https:\/\/creativecommons.org\/licenses\/by-nc-sa\/3.0\/\">CC BY-NC-SA 3.0 License. <\/a><\/figcaption><\/figure>\n<h4 class=\"import-Normal\"><em>Insectivores<\/em><\/h4>\n<p class=\"import-Normal\">While insects can be difficult to find and catch, they are easy to chew and digest. As a result, insectivorous primates usually have small molars with pointed cusps to puncture the exoskeleton of the insects (Figure 5.8), and they have simple stomachs and colons with a long small intestine to process the insects. Nutritionally, insects provide a lot of protein and fat but are not plentiful enough in the environment to support large-bodied animals, so insectivores are usually the smallest of the primates.<\/p>\n<figure style=\"width: 351px\" class=\"wp-caption aligncenter\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image7-3.jpg\" alt=\"Mandible, upper teeth, and maxilla of insectivore tarsier.\" width=\"351\" height=\"280\" \/><figcaption class=\"wp-caption-text\">Figure 5.8: Insectivores need sharp, pointed molar cusps to break through the exoskeletons of insects. Insects are easy to digest, so these primates have simple digestive tracts. Credit: Tarsier (an insectivor)\u2019s teeth original to Explorations: An Open Invitation to Biological Anthropology (2nd ed.) by Stephanie Etting is a collective work under a <a href=\"https:\/\/creativecommons.org\/licenses\/by-nc-sa\/3.0\/\">CC BY-NC-SA 3.0 License.<\/a> [Includes <a href=\"https:\/\/animaldiversity.org\/collections\/contributors\/phil_myers\/ADW_mammals\/specimens\/Primates\/Tarsius_syrichta\/lower_lateral1942\/\">Lower_lateral1942<\/a> by Phil Myers on <a href=\"https:\/\/animaldiversity.org\">Animal Diversity Web<\/a>, <a href=\"https:\/\/creativecommons.org\/licenses\/by-nc-sa\/3.0\/\">CC BY-NC-SA 3.0<\/a>; <a href=\"https:\/\/animaldiversity.org\/collections\/contributors\/phil_myers\/ADW_mammals\/specimens\/Primates\/Tarsius_syrichta\/ventral\/\">Ventral<\/a> by Phil Myers on <a href=\"https:\/\/animaldiversity.org\">Animal Diversity Web<\/a>, <a href=\"https:\/\/creativecommons.org\/licenses\/by-nc-sa\/3.0\/\">CC BY-NC-SA 3.0<\/a>.]<\/figcaption><\/figure>\n<h4 class=\"import-Normal\"><em>Folivores<\/em><\/h4>\n<p class=\"import-Normal\">Plants rely on leaves to get energy from the sun, so plants do not want animals to eat their leaves (unlike their fruit). As a result, plants evolved to try to discourage animals from eating their leaves. Leaves often carry toxins, taste bitter, are very fibrous and difficult to chew, and are made of large cellulose molecules that are difficult to break down into usable sugars. Thus, animals who eat leaves need a lot of specialized traits (Figure 5.9). Folivorous primates have broad molars with high, sharp cusps connected by <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_1182\">shearing crests<\/a><\/strong>. These molar traits allow folivores to physically break down fibrous leaves when chewing. Folivores then chemically break down cellulose molecules into usable energy. To do this, some folivores have complex stomachs with multiple compartments, while others have large, long intestines and special gut bacteria that can break up cellulose. Folivores are usually the largest bodied of all primates, and they tend to spend a large portion of their day digesting their food, so they are less active than frugivores or insectivores.<\/p>\n<figure style=\"width: 468px\" class=\"wp-caption aligncenter\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image8-2.jpg\" alt=\"Upper teeth and maxilla of a monkey shows folivore traits.\" width=\"468\" height=\"337\" \/><figcaption class=\"wp-caption-text\">Figure 5.9: To derive energy from leaves, folivores, like this Trachypithecus (dusky leaf monkey), have smaller incisors and high sharp molar cusps connected by shearing crests. Credit: <a href=\"https:\/\/animaldiversity.org\/collections\/contributors\/phil_myers\/ADW_mammals\/specimens\/Primates\/Trachypithecus_obscurus\/utr0075\/\">Trachypithecus obscurus (dusky leaf monkey) upper teeth<\/a> by Phil Myers on <a href=\"https:\/\/animaldiversity.org\">Animal Diversity Web<\/a> has been modified (background removed, labels added by Stephanie Etting) is under a <a href=\"https:\/\/creativecommons.org\/licenses\/by-nc-sa\/3.0\/\">CC BY-NC-SA 3.0 License<\/a>.<\/figcaption><\/figure>\n<h3 class=\"import-Normal\"><strong>Behavioral Adaptations<\/strong><\/h3>\n<p class=\"import-Normal\">Since Chapter 6 is dedicated to primate behavior, we will only briefly discuss variations in activity patterns, social grouping, and habitat use. Primate groups differ in <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_1184\">activity patterns<\/a><\/strong>: whether they are active during the day (<strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_1012\">diurnal<\/a><\/strong>), at night (<strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_1010\">nocturnal<\/a><\/strong>), or through the 24-hour period (<strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_1186\">cathemeral<\/a><\/strong>). Primate taxa vary in social groupings: some are primarily solitary, others live in pairs, and still others live in groups of varying sizes and compositions. Lastly, some taxa are primarily arboreal while others are more terrestrial.<\/p>\n<h3 class=\"import-Normal\"><strong>Locomotor Adaptations<\/strong><\/h3>\n<p class=\"import-Normal\">Finally, primate groups vary in their adaptations for different forms of <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_1188\">locomotion<\/a><\/strong>, or how they move around. Living primates are known to move by vertical clinging and leaping, quadrupedalism, brachiation, and bipedalism.<\/p>\n<p class=\"import-Normal\"><strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_1190\">Vertical clinging and leaping<\/a> <\/strong>is when an animal grasps a vertical branch with its body upright, pushes off with long hind legs, and then lands on another vertical support branch (Figure 5.10a). Animals who move in this way usually have longer legs than arms, long fingers and toes, and smaller bodies. Vertical clinger leapers also tend to have elongated ankle bones, which serve as a lever to help them push off with their legs and leap to another branch (Figure 5.10b).<\/p>\n<\/div>\n<figure id=\"attachment_182\" aria-describedby=\"caption-attachment-182\" style=\"width: 608px\" class=\"wp-caption aligncenter\"><img class=\"wp-image-148\" src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/5.10.jpg\" alt=\"Movement of vertical clinger and leaper, and tarsier skeleton.\" width=\"608\" height=\"462\" \/><figcaption id=\"caption-attachment-182\" class=\"wp-caption-text\">Figure 5.10: Vertical clingers and leapers have longer legs than arms, long lower backs, and long fingers and toes. They also have elongated ankle bones to help them push off when leaping. Credit: a. <a href=\"https:\/\/upload.wikimedia.org\/wikipedia\/commons\/6\/6e\/Propithecus_vertical_clinging_and_leaping.svg\">Propithecus vertical clinging and leaping<\/a> by Terpsichores is under a<a href=\"https:\/\/creativecommons.org\/licenses\/by-sa\/3.0\/\"> CC BY-SA 3.0 License<\/a>. b. <a href=\"https:\/\/commons.wikimedia.org\/wiki\/File:Em_-_Tarsius_tarsier_-_3.jpg\">Tarsier skeleton<\/a> by Em\u0151ke D\u00e9nes has been modified (background removed) by Stephanie Etting and is under a <a href=\"https:\/\/creativecommons.org\/licenses\/by-sa\/4.0\/\">CC BY-SA 4.0 License<\/a>. Original Spectral tarsier (Tarsius tarsier) skeleton at the Cambridge University Museum of Zoology, England.)<\/figcaption><\/figure>\n<p>&nbsp;<\/p>\n<div class=\"learning-objectives\">\n<p class=\"import-Normal\"><strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_1192\">Quadrupedalism<\/a><\/strong>, walking on all fours, is the most common form of locomotion among primates. Quadrupedal animals usually have legs and arms that are about the same length and a tail for balance. Arboreal quadrupeds (Figure 5.11a) usually have shorter arms and legs and longer tails, while terrestrial quadrupeds (Figure 5.11b) have longer arms and legs and, often, shorter tails. These differences relate to the lower center of gravity needed by arboreal quadrupeds for balance in trees and the longer tail required for better balance when moving along the tops of branches. Terrestrial quadrupeds have longer limbs to help them cover more distance more efficiently.<\/p>\n<\/div>\n<figure id=\"attachment_182\" aria-describedby=\"caption-attachment-182\" style=\"width: 704px\" class=\"wp-caption aligncenter\"><img class=\"wp-image-149\" src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/5.11.jpg\" alt=\"Arboreal quadrupedal monkey and terrestrial quadrupedal monkey.\" width=\"704\" height=\"251\" \/><figcaption id=\"caption-attachment-182\" class=\"wp-caption-text\">Figure 5.11: Two examples of quadrupedal primates. The capuchin monkey skeleton on the left (a) is a typical arboreal quadruped with shorter arms and legs, longer fingers and toes, and a long tail. The baboon skeleton on the right (b) is a terrestrial quadruped with relatively long arms and legs, shorter fingers and toes, and a short tail. Credit: a. <a href=\"https:\/\/commons.wikimedia.org\/wiki\/File:Description_iconographique_compar%C3%A9e_du_squelette_et_du_syst%C3%A8me_dentaire_des_mammif%C3%A8res_r%C3%A9cents_et_fossiles_(Sapajus_apella).jpg\">Capuchin monkey skeleton<\/a> by Henri-Marie Ducrotay de Blainville is in the <a href=\"https:\/\/en.wikipedia.org\/wiki\/Public_domain\">public domain<\/a>. b. <a href=\"https:\/\/commons.wikimedia.org\/wiki\/File:Description_iconographique_compar%C3%A9e_du_squelette_et_du_syst%C3%A8me_dentaire_des_mammif%C3%A8res_r%C3%A9cents_et_fossiles_(Papio_ursinus).jpg\">Baboon<\/a> by Henri-Marie Ducrotay de Blainville is in the <a href=\"https:\/\/en.wikipedia.org\/wiki\/Public_domain\">public domain<\/a>.<\/figcaption><\/figure>\n<div class=\"learning-objectives\">\n<p class=\"import-Normal\">The third form of locomotion seen in primates is<strong> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_1194\">brachiation<\/a><\/strong>, the way of moving you used if you played on \u201cmonkey bars\u201d as a child. Brachiation involves swinging below branches by the hands (Figure 5.12a). To be an efficient brachiator, a primate needs to have longer arms than legs, flexible shoulders and wrists, a short lower back, and no tail (Figure 5.12b). Some primates move via <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_1196\">semi-brachiation<\/a><\/strong>, in which they swing below branches but do not have all of the same specializations as brachiators. Semi-brachiators have flexible shoulders, but their arms and legs are about the same length, which is useful because they are quadrupedal when on the ground. They also use long <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_1198\">prehensile tails<\/a><\/strong> as a third limb when swinging (Figure 5.13). The underside of the tail has a tactile pad, resembling your fingerprints, for better grip.<\/p>\n<\/div>\n<figure id=\"attachment_182\" aria-describedby=\"caption-attachment-182\" style=\"width: 1600px\" class=\"wp-caption alignnone\"><img class=\"wp-image-150 size-full\" src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/5.12.jpg\" alt=\"Primate swinging through branches and gibbon skeleton.\" width=\"1600\" height=\"800\" \/><figcaption id=\"caption-attachment-182\" class=\"wp-caption-text\">Figure 5.12: a. Example of brachiation. b. Skeleton of a typical brachiator, showing longer arms than legs, short back, and lack of a tail. Credit: a. <a href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/chapter\/__unknown__-4\/\">Brachiator (Figure 5.9b)<\/a> original to <a href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/\">Explorations: An Open Invitation to Biological Anthropology<\/a> by Mary Nelson is under a <a href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/\">CC BY-NC 4.0 License<\/a>. b. <a href=\"https:\/\/upload.wikimedia.org\/wikipedia\/commons\/a\/a3\/Giboia.jpg\">Skeleton of Gibbon (Giboia) <\/a>by Joxerra Aihartza is under a <a href=\"https:\/\/artlibre.org\">Free Art License<\/a>.<\/figcaption><\/figure>\n<div class=\"learning-objectives\">\n<figure style=\"width: 565px\" class=\"wp-caption aligncenter\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image15-1.jpg\" alt=\"Spider monkey swinging below a rope.\" width=\"565\" height=\"377\" \/><figcaption class=\"wp-caption-text\">Figure 5.13. Spider monkeys are considered semi-brachiators, as they can swing below branches but use their tails as a third limb. On the ground they move via quadrupedal locomotion. Credit: <a href=\"https:\/\/commons.wikimedia.org\/wiki\/File:Ateles-fusciceps_54724770b.jpg\">Ateles-fusciceps 54724770b<\/a> by <a href=\"https:\/\/commons.wikimedia.org\/wiki\/User:LeaMaimone\">LeaMaimone<\/a> is under a <a href=\"https:\/\/creativecommons.org\/licenses\/by\/2.5\/legalcode\">CC BY 2.5 License<\/a>.<\/figcaption><\/figure>\n<p class=\"import-Normal\">Lastly, humans move around on two feet, called <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_1200\">bipedalism<\/a><\/strong>. Some nonhuman primates will occasionally travel on two feet but do so awkwardly and never for long distances. Among mammals, only humans have evolved to walk with a striding gait on two legs as a primary form of locomotion.<\/p>\n<h2 class=\"import-Normal\"><span style=\"background-color: #ccffcc\">Primate Diversity<\/span><\/h2>\n<p class=\"import-Normal\">As we begin exploring the different taxa of primates, it is important to keep in mind the hierarchical nature of taxonomic classification and how this relates to the key characteristics that will be covered. Figure 5.14 summarizes the major taxonomic groups of primates that you will learn about here. If you locate humans on the chart, you can trace our classification and see all of the categories getting more inclusive as you work your way up to the Order Primates. This means that humans will have the key traits of each of those groups. It is a good idea to refer to the figure to orient yourself as we discuss each taxon.<\/p>\n<figure style=\"width: 2048px\" class=\"wp-caption alignnone\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image16-1.jpg\" alt=\"Taxonomic chart shows primate order, suborder, infraorder, superfamily, and species.\" width=\"2048\" height=\"1154\" \/><figcaption class=\"wp-caption-text\">Figure 5.14: This taxonomy chart shows the major groups of primate taxa, starting with the largest category (Order) and moving to more specific categories and examples. <a href=\"https:\/\/docs.google.com\/document\/d\/1VUDKMBJYS_jNONjLxT04jQN0_z9Ua50BRN6auGSHUuU\/edit\">A full text description of this image is available<\/a>. Credit: <a href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/chapter\/__unknown__-4\/\">Primate taxonomy char (Figure 5.11)<\/a> original to <a href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/\">Explorations: An Open Invitation to Biological Anthropology<\/a> by Stephanie Etting is a collective work under a <a href=\"https:\/\/creativecommons.org\/licenses\/by-sa\/4.0\/\">CC BY-NC 4.0 License<\/a>. [Includes <a href=\"https:\/\/phylopic.org\/image\/d6cfb28f-136e-4a20-a5ac-8eb353c7fc4a\/\">Lemur catta Linnaeus, 1759<\/a> by Roberto D\u00edaz Sibaja, <a href=\"https:\/\/creativecommons.org\/licenses\/by\/3.0\/\">CC BY 3.0<\/a>; <a href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/chapter\/__unknown__-4\/\">Lorisoidea<\/a> original to<a href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/\"> Explorations: An Open Invitation to Biological Anthropology<\/a> by Katie Nelson, <a href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/\">CC BY-NC 4.0<\/a>; <a href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/chapter\/__unknown__-4\/\">Tarsiiformes<\/a> original to <a href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/\">Explorations: An Open Invitation to Biological Anthropology<\/a> by Mary Nelson, <a href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/\">CC BY-NC 4.0<\/a>; <a href=\"https:\/\/phylopic.org\/image\/156b515d-f25c-4497-b15b-5afb832cc70c\/\">Cebinae Bonaparte, 1831<\/a> by Sarah Werning, <a href=\"https:\/\/creativecommons.org\/licenses\/by\/3.0\/\">CC BY 3.0<\/a>; <a href=\"https:\/\/phylopic.org\/image\/899742c2-9a40-4fa0-b2cd-2eb133c8f6e8\/\">Colobus guereza Ruppell, 1835<\/a> by Yan Wong, designated to the <a href=\"https:\/\/creativecommons.org\/publicdomain\/zero\/1.0\/\">public domain (CC0)<\/a>; <a href=\"https:\/\/phylopic.org\/image\/72f2f854-f3cd-4666-887c-35d5c256ab0f\/\">Papio cynocephalus<\/a> by Owen Jones, designated to the <a href=\"https:\/\/creativecommons.org\/publicdomain\/zero\/1.0\/\">public domain (CC0)<\/a>; <a href=\"https:\/\/pixabay.com\/vectors\/animals-silhouette-wolf-elephant-2755766\/\">animals silhouette wolf elephant (2755766)<\/a> by <a href=\"https:\/\/pixabay.com\/users\/mohamed_hassan-5229782\/\">mohamed_hassan<\/a>, <a href=\"https:\/\/pixabay.com\/service\/terms\/#license\">Pixabay License<\/a>.]<\/figcaption><\/figure>\n<h3 class=\"import-Normal\"><strong>Suborder Strepsirrhini<\/strong><\/h3>\n<figure style=\"width: 387px\" class=\"wp-caption aligncenter\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image17-1.jpg\" alt=\"Eight strepsirrhine species.\" width=\"387\" height=\"605\" \/><figcaption class=\"wp-caption-text\">Figure 5.15: (Clockwise from top right) sifaka, black-and-white ruffed lemur, loris, galago, slender loris, mouse lemur, aye-aye, and ring-tailed lemur. Credit: <a href=\"https:\/\/commons.wikimedia.org\/wiki\/File:Extant_Strepsirrhini.jpg\">Extant Strepsirrhini<\/a> a collective work by <a href=\"https:\/\/www.flickr.com\/people\/23661161@N02\">Mark Dumont<\/a> is under a <a href=\"https:\/\/creativecommons.org\/licenses\/by-sa\/3.0\/legalcode\">CC BY-SA 3.0 License<\/a>. [Includes <a href=\"https:\/\/commons.wikimedia.org\/wiki\/File:Katta_csal%C3%A1d.jpg\">Katta csal\u00e1d<\/a> by Veszpr\u00e9mi \u00c1llatkert, <a href=\"https:\/\/creativecommons.org\/licenses\/by-sa\/3.0\/legalcode\">CC BY-SA 3.0<\/a>; <a href=\"https:\/\/commons.wikimedia.org\/wiki\/File:Aye-aye_at_night_in_the_wild_in_Madagascar.jpg\">Aye-aye at night in the wild in Madagascar<\/a> by Frank Vassen, <a href=\"https:\/\/creativecommons.org\/licenses\/by\/2.0\/deed.en\">CC BY 2.0<\/a>; <a href=\"https:\/\/commons.wikimedia.org\/wiki\/File:Diademed_ready_to_push_off.jpg\">Diademed ready to push off<\/a> by Michael Hogan, designated to the <a href=\"https:\/\/creativecommons.org\/share-your-work\/public-domain\/cc0\/\">public domain (CC0)<\/a>; <a href=\"https:\/\/commons.wikimedia.org\/wiki\/File:Juvenile_Black-and-White_Ruffed_Lemur,_Mantadia,_Madagascar.jpg\">Juvenile Black-and-White Ruffed Lemur, Mantadia, Madagascar<\/a> by <a href=\"https:\/\/www.flickr.com\/people\/42244964@N03\">Frank Vassen<\/a>, <a href=\"https:\/\/creativecommons.org\/licenses\/by\/2.0\/legalcode\">CC BY 2.0<\/a>; <a href=\"https:\/\/commons.wikimedia.org\/wiki\/File:Microcebus_murinus_-Artis_Zoo,_Amsterdam,_Netherlands-8a.jpg\">Microcebus murinus -Artis Zoo, Amsterdam, Netherlands-8a<\/a> by <a href=\"https:\/\/www.flickr.com\/photos\/46956042@N00\">Arjan Haverkamp<\/a>, <a href=\"https:\/\/creativecommons.org\/licenses\/by\/2.0\/legalcode\">CC BY 2.0<\/a>; <a href=\"https:\/\/commons.wikimedia.org\/wiki\/File:Slow_Loris.jpg\">Slow Loris<\/a> by Jmiksanek, <a href=\"https:\/\/creativecommons.org\/licenses\/by-sa\/3.0\/legalcode\">CC BY-SA 3.0<\/a>; <a href=\"https:\/\/commons.wikimedia.org\/wiki\/File:Slender_Loris.jpg\">Slender Loris<\/a> by Kalyan Varma (<a href=\"https:\/\/commons.wikimedia.org\/wiki\/User:Kalyanvarma\">Kalyanvarma<\/a>), <a href=\"https:\/\/creativecommons.org\/licenses\/by-sa\/4.0\/legalcode\">CC BY-SA 4.0<\/a>; <a href=\"https:\/\/commons.wikimedia.org\/wiki\/File:Garnett's_Galago_(Greater_Bushbaby).jpg\">Garnett's Galago (Greater Bushbaby)<\/a> by <a href=\"https:\/\/www.flickr.com\/people\/23661161@N02\">Mark Dumont<\/a>, <a href=\"https:\/\/creativecommons.org\/licenses\/by\/2.0\/legalcode\">CC BY 2.0<\/a>.]<\/figcaption><\/figure>\n<p>The Order Primates is subdivided into Suborder Strepsirrhini and Suborder Haplorrhini, which, according to molecular estimates, split about 70\u201380 million years ago (Pozzi et al. 2014). The strepsirrhines include the groups commonly called lemurs, lorises, and galagos (Figure 5.15). Strepsirrhines differ from haplorrhines in many ways, most of which involve retaining ancestral traits from the earliest primates. Strepsirrhines do have two key derived traits that evolved after they diverged from the haplorrhines: the <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_1202\">grooming claw<\/a> <\/strong>(Figure 5.16) on the second digit of each foot, and the <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_1204\">tooth comb<\/a><\/strong> (or <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_1206\">dental comb<\/a><\/strong>) located on the lower, front teeth (Figure 5.17). In most strepsirrhines, there are six teeth in the toothcomb\u2014four incisors and two canines. Other than the tooth comb, the teeth of strepsirrhines are fairly simple and are neither large or distinctive relative to haplorrhines.<\/p>\n<figure style=\"width: 237px\" class=\"wp-caption alignleft\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image18.jpg\" alt=\"A long, thin dark claw is visible in contrast to flat dark nails on the other digits.\" width=\"237\" height=\"202\" \/><figcaption class=\"wp-caption-text\">Figure 5.16: The foot of a ring-tailed lemur showing its grooming claw on the second digit. Credit: <a href=\"https:\/\/commons.wikimedia.org\/wiki\/File:Lemur_catta_toilet_claw.jpg\">Lemur catta toilet claw<\/a> by Alex Dunkel (Maky) is under a <a href=\"https:\/\/creativecommons.org\/licenses\/by\/3.0\/legalcode\">CC BY 3.0 License.<\/a><\/figcaption><\/figure>\n<p class=\"import-Normal\">Compared to haplorrhines, strepsirrhines rely more on nonvisual senses. Strepsirrhines get their name because they have wet noses (<strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_1208\">rhinariums<\/a><\/strong>) like cats and dogs, a trait that, along with a longer snout, reflect strepsirrhines\u2019 greater reliance on olfaction relative to haplorrhines. Many strepsirrhines use <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_1210\">scent marking<\/a><\/strong>, including rubbing scent glands or urine on objects in the environment to communicate with others. Additionally, many strepsirrhines have mobile ears that they use to locate insect prey and predators. While strepsirrhines have a better sense of smell than haplorrhines, their visual adaptations are more ancestral. Strepsirrhines have less convergent eyes than haplorrhines and therefore all have postorbital bars, whereas haplorrhines have full postorbital closure (see Figure 5.2). All strepsirrhines have a <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_1212\">tapetum lucidum<\/a><\/strong>, a reflective layer at the back of the eye that reflects light and thereby enhances the ability to see in low-light conditions. It is the same layer that causes your dog or cat to have \u201cyellow eye\u201d when you take photos of them with the flash on. This is a trait thought to be ancestral among mammals as a whole.<\/p>\n<figure style=\"width: 292px\" class=\"wp-caption alignright\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image19-1.jpg\" alt=\"The lower, front teeth are long, thin, tightly together in a line, and project towards the lips.\" width=\"292\" height=\"354\" \/><figcaption class=\"wp-caption-text\">Figure 5.17: The lower front teeth of a ring-tailed lemur showing the six teeth of the tooth comb: four incisors and two canines. The teeth that superficially look like canines are premolars. Credit: <a href=\"https:\/\/commons.wikimedia.org\/wiki\/File:Lemur_catta_toothcomb.jpg\">Lemur catta toothcomb<\/a> by Alex Dunkel (Maky) is under a <a href=\"https:\/\/creativecommons.org\/licenses\/by\/3.0\/legalcode\">CC BY 3.0 license.<\/a><\/figcaption><\/figure>\n<p class=\"import-Normal\">Strepsirrhines also differ from haplorrhines in some aspects of their ecology and behavior. The majority of strepsirrhines are solitary, traveling alone to search for food; a few taxa are more social. Most strepsirrhines are also nocturnal and arboreal. Strepsirrhines are, on average, smaller than haplorrhines, and so many of them have a diet consisting of insects and fruit, with few taxa eating primarily leaves. Lastly, most strepsirrhines are good at leaping, with several taxa specialized for vertical clinging and leaping. In fact, among primates, all but one of the vertical clinger leapers belong to the Suborder Strepsirrhini.<\/p>\n<p class=\"import-Normal\">Strepsirrhines can be found all across Asia, Africa, and on the island of Madagascar (Figure 5.18). The Suborder Strepsirrhini is divided into two groups: (1) the lemurs of Madagascar and (2) the lorises, pottos, and galagos of Africa and Asia. By molecular estimates, these two groups split about 65 million years ago (Pozzi et al. 2014).<\/p>\n<figure style=\"width: 443px\" class=\"wp-caption aligncenter\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image20-1.png\" alt=\"Map strepsirrhine primates locations.\" width=\"443\" height=\"342\" \/><figcaption class=\"wp-caption-text\">Figure 5.18: Geographic distribution of living strepsirrhines. Lemurs live only on Madagascar, while lorises and galagos live across Central Africa and South and Southeast Asia. Credit: <a href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/chapter\/__unknown__-4\/\">Geographic distribution of living strepsirrhines (Figure 5.16)<\/a> original to <a href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/\">Explorations: An Open Invitation to Biological Anthropology<\/a> by Elyssa Ebding at <a href=\"https:\/\/www.csuchico.edu\/geop\/geoplace\/index.shtml\">GeoPlace, California State University, Chico<\/a> is under a <a href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/\">CC BY-NC 4.0 License<\/a>.<\/figcaption><\/figure>\n<h4><em>Lemurs of Madagascar<\/em><\/h4>\n<p class=\"import-Normal\">Madagascar is an island off the east coast of Africa, and it is roughly the size of California, Oregon, and Washington combined. It has been separated from Africa for about 130 million years and from India for about 85 million years, which means it was already an island when strepsirrhines got there approximately 60\u201370 million years ago. Only a few mammal species ever reached Madagascar, and so when lemurs arrived they were able to flourish into a variety of forms.<\/p>\n<p class=\"import-Normal\">The lemurs of Madagascar are much more diverse compared to their mainland counterparts, the lorises and galagos. While many Malagasy strepsirrhines are nocturnal, plenty of others are diurnal or cathemeral. They range in body size from the smallest of all primates, the mouse lemur, some species of which weigh a little over an ounce (see Figure 5.15), up to the largest of all strepsirrhines, the indri, which weighs up to about 20 pounds (Figure 5.19). Lemurs include species that are insectivorous, frugivorous, and folivorous. A couple of members of this group have unusual diets for primates, including the gummivorous fork-marked and bamboo lemurs, who are able to metabolize the cyanide in bamboo. The most unique lemur is the aye-aye (depicted in Figure 5.15). This nocturnal lemur has rodent-like front teeth that grow continuously and a long-bony middle finger that it uses to fish grubs out of wood. It has a very large brain compared to other strepsirrhines, which it fuels with a diet that includes bird\u2019s eggs and other animal matter. Based on genetic estimates and morphological studies, it is believed that aye-ayes were the first lemurs to separate from all other strepsirrhines and to evolve on their own since strepsirrhines arrived in Madagascar (Matsui et al. 2009).<\/p>\n<figure style=\"width: 326px\" class=\"wp-caption alignright\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image21-1-1.jpg\" alt=\"Two Indis in a tree.\" width=\"326\" height=\"217\" \/><figcaption class=\"wp-caption-text\">Figure 5.19: Indris, the largest of the lemurs. These folivorous lemurs are vertical clingers and leapers and live in pairs. Credit: <a href=\"https:\/\/commons.wikimedia.org\/wiki\/File:Indri_indri_0003.jpg\">Indri indri 0003<\/a> by <a href=\"https:\/\/commons.wikimedia.org\/wiki\/User:Christophe_Germain\">Christophe Germain<\/a> is under a <a href=\"https:\/\/creativecommons.org\/licenses\/by-sa\/4.0\/legalcode\">CC BY-SA 4.0 License<\/a>.<\/figcaption><\/figure>\n<p class=\"import-Normal\">Lemurs are also diverse in terms of social behavior: Many lemurs are solitary foragers, some live in pairs, others in small groups, still others in larger groups, and some, like the red-ruffed lemur, live in unique and complex social groups (Vasey 2006). Lemurs include some of the best vertical clingers and leapers, and while many lemurs are quadrupedal, even the quadrupedal lemurs are quite adept at leaping. Malagasy strepsirrhines also exhibit a few unusual traits. They are highly seasonal breeders, often mating only during a short window once a year (Wright 1999). Female ring-tailed lemurs, for example, come into estrus one day a year for a mere six hours. Unlike most primates, where males are typically large and dominant, Malagasy strepsirrhines feature socially dominant females that are similar in size to males and have priority access to resources.<\/p>\n<h4 class=\"import-Normal\"><em>Lorises, Pottos, and Galagos of Asia and Africa<\/em><\/h4>\n<figure style=\"width: 207px\" class=\"wp-caption alignleft\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image22-1.jpg\" alt=\"Slow loris hanging from a branch.\" width=\"207\" height=\"309\" \/><figcaption class=\"wp-caption-text\">Figure 5.20: This slow loris, like all others in this taxonomic group, is solitary and nocturnal, with a diet heavy in insects and fruit. Credit: <a href=\"https:\/\/commons.wikimedia.org\/wiki\/File:Nycticebus_coucang_002.jpg\">Nycticebus coucang 002<\/a> by David Haring \/ Duke Lemur Center is under a <a href=\"https:\/\/creativecommons.org\/licenses\/by-sa\/3.0\/deed.en\">CC BY-SA 3.0 License<\/a>.<\/figcaption><\/figure>\n<p>Unlike the lemurs of Madagascar, lorises, pottos, and galagos live in areas where they share their environments with monkeys and apes, who often eat similar foods. Lorises live across South and Southeast Asia, while pottos and galagos live across Central Africa. Because of competition with larger-bodied monkeys and apes, mainland strepsirrhines are more restricted in the niches they can fill in their environments and so are less diverse than the lemurs.<\/p>\n<p>The strepsirrhines of Africa and Asia are all nocturnal and solitary, with little variation in body size and diet. For the most part, the diet of lorises, pottos, and galagos consists of fruits and insects. A couple of species eat more gum, but overall the diet of this group is narrow when compared to the Malagasy lemurs. Lorises (Figure 5.20) and pottos are known for being slow, quadrupedal climbers, moving quietly through the forests to avoid being detected by predators. These strepsirrhines have developed additional defenses against predators. Lorises, for example, eat a lot of caterpillars, which makes their saliva slightly toxic. Loris mothers bathe their young in this toxic saliva, making the babies unappealing to predators. In comparison to the slow-moving lorises and pottos, galagos are active quadrupedal runners and leapers that scurry about the forests at night. Galagos make distinctive calls that sound like a baby crying, which has led to their nickname \u201cbushbabies.\u201d Figure 5.21 summarizes the key differences between these two groups of strepsirrhines.<\/p>\n<table class=\"aligncenter\" style=\"width: 468pt\">\n<caption>Figure 5.21: Strepsirrhini at a glance: This table summarizes the key differences between the two groups of strepsirrhines. Credit: <a href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/chapter\/__unknown__-4\/\">Strepsirrhines at a glance table (Figure 5.19)<\/a> original to <a href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/\">Explorations: An Open Invitation to Biological Anthropology<\/a> by Stephanie Etting is a collective work under a <a href=\"https:\/\/creativecommons.org\/licenses\/by-nc-sa\/4.0\/\">CC BY-NC-SA 4.0 License<\/a>. [Includes <a href=\"https:\/\/commons.wikimedia.org\/wiki\/File:Ringtailed_Lemurs_in_Berenty.jpg\">Ringtailed Lemurs in Berenty<\/a> by <a href=\"https:\/\/www.flickr.com\/photos\/50852241@N00\">David Dennis<\/a>, <a href=\"https:\/\/creativecommons.org\/licenses\/by-sa\/2.0\/legalcode\">CC BY-SA 2.0<\/a>; <a href=\"https:\/\/commons.wikimedia.org\/wiki\/File:Komba_u%C5%A1at%C3%A1.jpg\">Komba u\u0161at\u00e1<\/a> by Petr Hamern\u00edk, <a href=\"https:\/\/creativecommons.org\/licenses\/by-sa\/4.0\/legalcode\">CC BY-SA 4.0<\/a>.]<\/caption>\n<thead>\n<tr>\n<td class=\"a0-C\" style=\"background-color: transparent;padding: 5pt 5pt 5pt 5pt;border: solid #000000 1pt\">\n<p class=\"import-Normal\" style=\"text-align: center\">\n<\/td>\n<td class=\"a0-C\" style=\"background-color: transparent;padding: 5pt 5pt 5pt 5pt;border: solid #000000 1pt\">\n<p class=\"import-Normal\" style=\"text-align: center\"><strong><img class=\"alignnone\" src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image23-1.jpg\" alt=\"Baby primate on the back of adult primate.\" width=\"231\" height=\"165\" \/><\/strong><\/p>\n<p class=\"import-Normal\" style=\"text-align: center\"><strong>Lemurs<\/strong><\/p>\n<\/td>\n<td class=\"a0-C\" style=\"background-color: transparent;padding: 5pt 5pt 5pt 5pt;border: solid #000000 1pt\">\n<p class=\"import-Normal\" style=\"text-align: center\"><strong><img class=\"alignnone\" src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image24-1.jpg\" alt=\"Small primate with big eyes and long tail.\" width=\"198\" height=\"132\" \/><\/strong><\/p>\n<p class=\"import-Normal\" style=\"text-align: center\"><strong>Lorises, Pottos, and Galagos<\/strong><\/p>\n<\/td>\n<\/tr>\n<\/thead>\n<tbody>\n<tr class=\"a0-R\">\n<td class=\"a0-C\" style=\"background-color: transparent;vertical-align: middle;padding: 5pt 5pt 5pt 5pt;border: solid #000000 1pt\">\n<p class=\"import-Normal\" style=\"text-align: center\"><strong>Geographic range<\/strong><\/p>\n<\/td>\n<td class=\"a0-C\" style=\"background-color: transparent;vertical-align: middle;padding: 5pt 5pt 5pt 5pt;border: solid #000000 1pt\">\n<p class=\"import-Normal\" style=\"text-align: center\">Madagascar<\/p>\n<\/td>\n<td class=\"a0-C\" style=\"background-color: transparent;vertical-align: middle;padding: 5pt 5pt 5pt 5pt;border: solid #000000 1pt\">\n<p class=\"import-Normal\" style=\"text-align: center\">South and Southeast Asia<\/p>\n<p class=\"import-Normal\" style=\"text-align: center\">Central Africa<\/p>\n<\/td>\n<\/tr>\n<tr class=\"a0-R\">\n<td class=\"a0-C\" style=\"background-color: transparent;vertical-align: middle;padding: 5pt 5pt 5pt 5pt;border: solid #000000 1pt\">\n<p class=\"import-Normal\" style=\"text-align: center\"><strong>Activity patterns<\/strong><\/p>\n<\/td>\n<td class=\"a0-C\" style=\"background-color: transparent;vertical-align: middle;padding: 5pt 5pt 5pt 5pt;border: solid #000000 1pt\">\n<p class=\"import-Normal\" style=\"text-align: center\">Diurnal, nocturnal, or cathemeral<\/p>\n<\/td>\n<td class=\"a0-C\" style=\"background-color: transparent;vertical-align: middle;padding: 5pt 5pt 5pt 5pt;border: solid #000000 1pt\">\n<p class=\"import-Normal\" style=\"text-align: center\">Nocturnal<\/p>\n<\/td>\n<\/tr>\n<tr class=\"a0-R\">\n<td class=\"a0-C\" style=\"background-color: transparent;vertical-align: middle;padding: 5pt 5pt 5pt 5pt;border: solid #000000 1pt\">\n<p class=\"import-Normal\" style=\"text-align: center\"><strong>Dietary types<\/strong><\/p>\n<\/td>\n<td class=\"a0-C\" style=\"background-color: transparent;vertical-align: middle;padding: 5pt 5pt 5pt 5pt;border: solid #000000 1pt\">\n<p class=\"import-Normal\" style=\"text-align: center\">Insectivore, frugivore, or folivore<\/p>\n<\/td>\n<td class=\"a0-C\" style=\"background-color: transparent;vertical-align: middle;padding: 5pt 5pt 5pt 5pt;border: solid #000000 1pt\">\n<p class=\"import-Normal\" style=\"text-align: center\">Insectivore, frugivore<\/p>\n<\/td>\n<\/tr>\n<tr class=\"a0-R\">\n<td class=\"a0-C\" style=\"background-color: transparent;vertical-align: middle;padding: 5pt 5pt 5pt 5pt;border: solid #000000 1pt\">\n<p class=\"import-Normal\" style=\"text-align: center\"><strong>Social groupings<\/strong><\/p>\n<\/td>\n<td class=\"a0-C\" style=\"background-color: transparent;vertical-align: middle;padding: 5pt 5pt 5pt 5pt;border: solid #000000 1pt\">\n<p class=\"import-Normal\" style=\"text-align: center\">Solitary, pairs, or small to large groups<\/p>\n<\/td>\n<td class=\"a0-C\" style=\"background-color: transparent;vertical-align: middle;padding: 5pt 5pt 5pt 5pt;border: solid #000000 1pt\">\n<p class=\"import-Normal\" style=\"text-align: center\">Solitary<\/p>\n<\/td>\n<\/tr>\n<tr class=\"a0-R\">\n<td class=\"a0-C\" style=\"background-color: transparent;vertical-align: middle;padding: 5pt 5pt 5pt 5pt;border: solid #000000 1pt\">\n<p class=\"import-Normal\" style=\"text-align: center\"><strong>Forms of locomotion<\/strong><\/p>\n<\/td>\n<td class=\"a0-C\" style=\"background-color: transparent;vertical-align: middle;padding: 5pt 5pt 5pt 5pt;border: solid #000000 1pt\">\n<p class=\"import-Normal\" style=\"text-align: center\">Vertical clinger leapers, quadrupedal<\/p>\n<\/td>\n<td class=\"a0-C\" style=\"background-color: transparent;vertical-align: middle;padding: 5pt 5pt 5pt 5pt;border: solid #000000 1pt\">\n<p class=\"import-Normal\" style=\"text-align: center\">Slow quadrupedal climbers and active quadrupedal runners<\/p>\n<\/td>\n<\/tr>\n<tr>\n<td><\/td>\n<td><\/td>\n<td><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<h3 class=\"import-Normal\"><strong>Suborder Haplorrhini<\/strong><\/h3>\n<p class=\"import-Normal\">When the two primate suborders split from one another, strepsirrhines retained more ancestral traits while haplorrhines developed more derived traits, which are discussed below.<\/p>\n<p class=\"import-Normal\">As mentioned earlier, haplorrhines have better vision than strepsirrhines. This is demonstrated by the full postorbital closure protecting the more convergent eyes that haplorrhines possess (with one exception seen in Figure 5.2). Most haplorrhines are trichromatic, and all have a <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_1410\">fovea<\/a><\/strong>, a depression in the retina at the back of the eye containing concentrations of cells that allows them to see things very close up in great detail. The heavier reliance on vision over olfaction is also reflected in the shorter snouts ending with the <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_1412\">dry nose<\/a> <\/strong>(no rhinarium) of haplorrhines. All but two genera of living haplorrhines are active during the day, so this group lacks the tapetum lucidum that is so useful to nocturnal species. On average, haplorrhines also have larger brains relative to their body size when compared with strepsirrhines.<\/p>\n<p class=\"import-Normal\">The Haplorrhini differ from the Strepsirrhini in their ecology and behavior as well. Haplorrhines are generally larger than strepsirrhines, and they tend to be folivorous and frugivorous. This dietary difference is reflected in the teeth of haplorrhines, which are broader with more surface area for chewing. The larger body size of this taxon also influences locomotion. Only one haplorrhine is a vertical clinger and leaper. Most members of this suborder are quadrupedal, with one subgroup specialized for brachiation. A few haplorrhine taxa are <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_1414\">monomorphic<\/a><\/strong>, meaning males and females are the same size, but many members of this group show moderate to high sexual dimorphism in body size and canine size. Haplorrhines also differ in social behavior. All but two haplorrhines live in groups, which is very different from the primarily solitary strepsirrhines. Differences between the two suborders are summarized in Figure 5.22.<\/p>\n<table class=\"aligncenter\" style=\"width: 468pt\">\n<caption>Figure 5.22: Suborders at a glance: This table summarizes the key differences between the two primate suborders. Credit: <a href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/chapter\/__unknown__-4\/\">Suborders at a glance table (Figure 5.20)<\/a> original to <a href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/\">Explorations: An Open Invitation to Biological Anthropology<\/a> by Stephanie Etting is a collective work under a <a href=\"https:\/\/creativecommons.org\/licenses\/by-nc-sa\/4.0\/\">CC BY-NC-SA 4.0 License<\/a>. [Includes <a href=\"https:\/\/commons.wikimedia.org\/wiki\/File:Black-and-White_Ruffed_Lemur,_Mantadia,_Madagascar.jpg\">Black-and-White Ruffed Lemur, Mantadia, Madagascar<\/a> by <a href=\"https:\/\/www.flickr.com\/people\/42244964@N03\">Frank Vassen<\/a>, <a href=\"https:\/\/creativecommons.org\/licenses\/by\/2.0\/legalcode\">CC BY 2.0<\/a>; <a href=\"https:\/\/commons.wikimedia.org\/wiki\/File:Crab_eating_macaque_face.jpg\">Crab eating macaque face<\/a> by <a href=\"https:\/\/commons.wikimedia.org\/wiki\/User:Bruce89\">Bruce89<\/a>, <a href=\"https:\/\/creativecommons.org\/licenses\/by-sa\/4.0\/legalcode\">CC BY-SA 4.0<\/a>.]<\/caption>\n<thead>\n<tr>\n<td class=\"a1-C\" style=\"background-color: transparent;padding: 5pt 5pt 5pt 5pt;border: solid #000000 1pt\">\n<p class=\"import-Normal\" style=\"text-align: center\">\n<\/td>\n<td class=\"a1-C\" style=\"background-color: transparent;padding: 5pt 5pt 5pt 5pt;border: solid #000000 1pt\">\n<p class=\"import-Normal\" style=\"text-align: center\"><strong><img class=\"alignnone\" src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image25.jpg\" alt=\"Black-and-white ruffed lemur.\" width=\"213\" height=\"159\" \/><\/strong><strong>Suborder Strepsirrhini<\/strong><\/p>\n<\/td>\n<td class=\"a1-C\" style=\"background-color: transparent;padding: 5pt 5pt 5pt 5pt;border: solid #000000 1pt\">\n<p class=\"import-Normal\" style=\"text-align: center\"><strong><img class=\"alignnone\" src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image26-1.jpg\" alt=\"Crab-eating macaque.\" width=\"137\" height=\"137\" \/><\/strong><\/p>\n<p class=\"import-Normal\" style=\"text-align: center\"><strong>Suborder Haplorrhini<\/strong><\/p>\n<\/td>\n<\/tr>\n<\/thead>\n<tbody>\n<tr class=\"a1-R\">\n<td class=\"a1-C\" style=\"background-color: transparent;vertical-align: middle;padding: 5pt 5pt 5pt 5pt;border: solid #000000 1pt\">\n<p class=\"import-Normal\" style=\"text-align: center\"><strong>Sensory adaptations<\/strong><\/p>\n<\/td>\n<td class=\"a1-C\" style=\"background-color: transparent;vertical-align: middle;padding: 5pt 5pt 5pt 5pt;border: solid #000000 1pt\">\n<p class=\"import-Normal\" style=\"text-align: center\">Rhinarium<\/p>\n<p class=\"import-Normal\" style=\"text-align: center\">Longer snout<\/p>\n<p class=\"import-Normal\" style=\"text-align: center\">Eyes less convergent<\/p>\n<p class=\"import-Normal\" style=\"text-align: center\">Postorbital bar<\/p>\n<p class=\"import-Normal\" style=\"text-align: center\">Tapetum lucidum<\/p>\n<p class=\"import-Normal\" style=\"text-align: center\">Mobile ears<\/p>\n<\/td>\n<td class=\"a1-C\" style=\"background-color: transparent;vertical-align: middle;padding: 5pt 5pt 5pt 5pt;border: solid #000000 1pt\">\n<p class=\"import-Normal\" style=\"text-align: center\">No rhinarium<\/p>\n<p class=\"import-Normal\" style=\"text-align: center\">Short snout<\/p>\n<p class=\"import-Normal\" style=\"text-align: center\">Eyes more convergent<\/p>\n<p class=\"import-Normal\" style=\"text-align: center\">Postorbital plate<\/p>\n<p class=\"import-Normal\" style=\"text-align: center\">No tapetum lucidum<\/p>\n<p class=\"import-Normal\" style=\"text-align: center\">Many are trichromatic<\/p>\n<p class=\"import-Normal\" style=\"text-align: center\">Fovea<\/p>\n<\/td>\n<\/tr>\n<tr class=\"a1-R\">\n<td class=\"a1-C\" style=\"background-color: transparent;vertical-align: middle;padding: 5pt 5pt 5pt 5pt;border: solid #000000 1pt\">\n<p class=\"import-Normal\" style=\"text-align: center\"><strong>Dietary differences<\/strong><\/p>\n<\/td>\n<td class=\"a1-C\" style=\"background-color: transparent;vertical-align: middle;padding: 5pt 5pt 5pt 5pt;border: solid #000000 1pt\">\n<p class=\"import-Normal\" style=\"text-align: center\">Mostly insectivores and frugivores, few folivores<\/p>\n<\/td>\n<td class=\"a1-C\" style=\"background-color: transparent;vertical-align: middle;padding: 5pt 5pt 5pt 5pt;border: solid #000000 1pt\">\n<p class=\"import-Normal\" style=\"text-align: center\">Few insectivores, mostly frugivores and folivores<\/p>\n<\/td>\n<\/tr>\n<tr class=\"a1-R\">\n<td class=\"a1-C\" style=\"background-color: transparent;vertical-align: middle;padding: 5pt 5pt 5pt 5pt;border: solid #000000 1pt\">\n<p class=\"import-Normal\" style=\"text-align: center\"><strong>Activity patterns and Ecology<\/strong><\/p>\n<\/td>\n<td class=\"a1-C\" style=\"background-color: transparent;vertical-align: middle;padding: 5pt 5pt 5pt 5pt;border: solid #000000 1pt\">\n<p class=\"import-Normal\" style=\"text-align: center\">Mostly nocturnal, few diurnal or cathemeral<\/p>\n<p class=\"import-Normal\" style=\"text-align: center\">Almost entirely arboreal<\/p>\n<\/td>\n<td class=\"a1-C\" style=\"background-color: transparent;vertical-align: middle;padding: 5pt 5pt 5pt 5pt;border: solid #000000 1pt\">\n<p class=\"import-Normal\" style=\"text-align: center\">Only two are nocturnal, rest are diurnal<\/p>\n<p class=\"import-Normal\" style=\"text-align: center\">Many arboreal taxa, also many terrestrial taxa<\/p>\n<\/td>\n<\/tr>\n<tr class=\"a1-R\">\n<td class=\"a1-C\" style=\"background-color: transparent;vertical-align: middle;padding: 5pt 5pt 5pt 5pt;border: solid #000000 1pt\">\n<p class=\"import-Normal\" style=\"text-align: center\"><strong>Social groupings<\/strong><\/p>\n<\/td>\n<td class=\"a1-C\" style=\"background-color: transparent;vertical-align: middle;padding: 5pt 5pt 5pt 5pt;border: solid #000000 1pt\">\n<p class=\"import-Normal\" style=\"text-align: center\">Mostly solitary, some pairs, small to large groups<\/p>\n<\/td>\n<td class=\"a1-C\" style=\"background-color: transparent;vertical-align: middle;padding: 5pt 5pt 5pt 5pt;border: solid #000000 1pt\">\n<p class=\"import-Normal\" style=\"text-align: center\">Only two are solitary, all others live in pairs, small to very large groups<\/p>\n<\/td>\n<\/tr>\n<tr class=\"a1-R\">\n<td class=\"a1-C\" style=\"background-color: transparent;vertical-align: middle;padding: 5pt 5pt 5pt 5pt;border: solid #000000 1pt\">\n<p class=\"import-Normal\" style=\"text-align: center\"><strong>Sexual dimorphism<\/strong><\/p>\n<\/td>\n<td class=\"a1-C\" style=\"background-color: transparent;vertical-align: middle;padding: 5pt 5pt 5pt 5pt;border: solid #000000 1pt\">\n<p class=\"import-Normal\" style=\"text-align: center\">Minimal to none<\/p>\n<\/td>\n<td class=\"a1-C\" style=\"background-color: transparent;vertical-align: middle;padding: 5pt 5pt 5pt 5pt;border: solid #000000 1pt\">\n<p class=\"import-Normal\" style=\"text-align: center\">Few taxa have little\/none, many taxa show moderate to high dimorphism<\/p>\n<\/td>\n<\/tr>\n<tr>\n<td><\/td>\n<td><\/td>\n<td><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p class=\"import-Normal\">Suborder Haplorrhini is divided into three infraorders: Tarsiiformes, which includes the tarsiers of Asia; Platyrrhini, which includes the monkeys of Central and South America; and Catarrhini, a group that includes the monkeys of Asia and Africa, apes, and humans. According to molecular estimates, tarsiers split from the other haplorrhines close to 70 million years ago, and platyrrhines split from catarrhines close to 46 million years ago (Pozzi et al. 2014).<\/p>\n<h4 class=\"import-Normal\"><em>Infraorder Tarsiiformes of Asia<\/em><\/h4>\n<figure style=\"width: 188px\" class=\"wp-caption alignleft\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image27-1.jpg\" alt=\"Tarsier gripping a branch.\" width=\"188\" height=\"160\" \/><figcaption class=\"wp-caption-text\">Figure 5.23: Tarsiers are the only living representatives of this Infraorder. Credit: <a href=\"https:\/\/commons.wikimedia.org\/wiki\/File:Tarsier_Sanctuary,_Corella,_Bohol_(2052878890).jpg\">Tarsier Sanctuary, Corella, Bohol (2052878890)<\/a> by <a href=\"https:\/\/www.flickr.com\/people\/46274125@N00\">yeowatzup<\/a> is under a <a href=\"https:\/\/creativecommons.org\/licenses\/by\/2.0\/legalcode\">CC BY 2.0 License<\/a>.<\/figcaption><\/figure>\n<figure style=\"width: 362px\" class=\"wp-caption alignright\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image28-1.png\" alt=\"Map of Southeast Asia shows distribution of tarsiers.\" width=\"362\" height=\"279\" \/><figcaption class=\"wp-caption-text\">Figure 5.24: Tarsiiformes are found in the tropical forests of multiple islands in Southeast Asia including Sumatra, Borneo, Celebes, and the Philippines. Credit: <a href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/chapter\/__unknown__-4\/\">Infraorder Tarsiiformes of Asia map (Figure 5.22)<\/a> original to <a href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/\">Explorations: An Open Invitation to Biological Anthropology<\/a> by Elyssa Ebding at <a href=\"https:\/\/www.csuchico.edu\/geop\/geoplace\/index.shtml\">GeoPlace, California State University, Chico<\/a> is under a <a href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/\">CC BY-NC 4.0 License<\/a>.<\/figcaption><\/figure>\n<p>Today, the Infraorder Tarsiiformes includes only one genus, <em>Tarsius <\/em>(Figure 5.23). Tarsiers are small-bodied primates that live in Southeast Asian forests (Figure 5.24) and possess an unusual collection of traits that have led to some debate about their position in the primate taxonomy. They are widely considered members of the haplorrhine group because they share several derived traits with monkeys, apes, and humans, including dry noses, a fovea, not having a tapetum lucidum, and eyes that are more convergent. Tarsiers also have some traits that are more like strepsirrhines and some that are unique. Tarsiers are the only haplorrhine that are specialized vertical clinger leapers, a form of locomotion only otherwise seen in some strepsirrhines. Tarsiers actually get their name because their ankle (tarsal) bones are elongated to provide a lever for vertical clinging and leaping. Tarsiiformes are also small, with most species weighing between 100 and 150 grams. Like strepsirrhines, tarsiers are nocturnal, but because they lack a tapetum lucidum, tarsiers compensate by having enormous eyes. In fact, each eye of a tarsier is larger than its brain. These large eyes allow enough light in for tarsiers to still be able to see well at night without the reflecting layer in their eyes. To protect their large eyes, tarsiers have a partially closed postorbital plate that appears somewhat intermediate between the postorbital bar of strepsirrhines and the full postorbital closure of other haplorrhines (Figure 5.25). Tarsiers have different dental formulas on their upper and lower teeth. On the top, the dental formula is 2:1:3:3, but on the bottom it is 1:1:3:3. Other unusual traits of tarsiers include having two grooming claws on each foot and the ability to rotate their heads around 180 degrees, a trait useful in locating insect prey. The tarsier diet is considered <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_1416\">faunivorous<\/a> <\/strong>because it consists entirely of animal matter, making them the only primate not to eat any vegetation. They are only one of two living haplorrhines to be solitary, the other being the orangutan. Most tarsiers are not sexually dimorphic, like strepsirrhines, although males of a few species are slightly larger than females.<\/p>\n<figure style=\"width: 486px\" class=\"wp-caption aligncenter\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image29-1.jpg\" alt=\"Front view of tarsier skull.\" width=\"486\" height=\"323\" \/><figcaption class=\"wp-caption-text\">Figure 5.25: Skull of a tarsier showing very large eye sockets and partially closed postorbital plates. Credit: <a href=\"https:\/\/commons.wikimedia.org\/wiki\/File:Tarsier_skull.jpg\">Tarsier skull<\/a> by <a href=\"https:\/\/www.flickr.com\/people\/65438265@N00\">Andrew Bardwell<\/a> is under a <a href=\"https:\/\/creativecommons.org\/licenses\/by-sa\/2.0\/legalcode\">CC BY-SA 2.0 License.<\/a><\/figcaption><\/figure>\n<p class=\"import-Normal\">Two alternative classifications have emerged due to the unusual mix of traits that tarsiers have. Historically, tarsiers were grouped with lemurs, lorises, and galagos into a suborder called Prosimii. This classification was based on tarsiers, lemurs, lorises, and galagos all having grooming claws and similar lifestyles. Monkeys, apes, and humans were then separated into a suborder called the Anthropoidea. These suborder groupings were based on <em>grade<\/em> rather than <em>clade<\/em>. Today, most people use Suborders Strepsirrhini and Haplorrhini, which are clade groupings based on the derived traits that tarsiers share with monkeys, apes, and humans. The Strepsirrhini\/Haplorrhini dichotomy is also supported by the genetic evidence that indicates tarsiers are more closely related to monkeys, apes, and humans (Jameson et al. 2011). Figure 5.26 summarizes the unusual mix of traits seen in tarsiers.<\/p>\n<table class=\"aligncenter\" style=\"width: 468pt\">\n<caption>Figure 5.26: Tarsiers at a glance: Tarsiers have a mix of traits that lead to debate about their classification. While they have some unique characteristics, they also have traits that superficially resemble strepsirrhines, and many derived traits shared with haplorrhines. Credit: <a href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/chapter\/__unknown__-4\/\">Tarsiers at a glance table (Figure 5.24)<\/a> original to <a href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/\">Explorations: An Open Invitation to Biological Anthropology<\/a> by Stephanie Etting is under a <a href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/\">CC BY-NC 4.0 License<\/a>.<\/caption>\n<thead>\n<tr>\n<td class=\"a2-C\" style=\"background-color: transparent;padding: 5pt 5pt 5pt 5pt;border: solid #000000 1pt\">\n<p class=\"import-Normal\" style=\"text-align: center\"><strong>Like Strepsirrhini<\/strong><\/p>\n<\/td>\n<td class=\"a2-C\" style=\"background-color: transparent;padding: 5pt 5pt 5pt 5pt;border: solid #000000 1pt\">\n<p class=\"import-Normal\" style=\"text-align: center\"><strong>Unique<\/strong><\/p>\n<\/td>\n<td class=\"a2-C\" style=\"background-color: transparent;padding: 5pt 5pt 5pt 5pt;border: solid #000000 1pt\">\n<p class=\"import-Normal\" style=\"text-align: center\"><strong>Like Haplorrhini<\/strong><\/p>\n<\/td>\n<\/tr>\n<\/thead>\n<tbody>\n<tr class=\"a2-R\">\n<td class=\"a2-C\" style=\"background-color: transparent;padding: 5pt 5pt 5pt 5pt;border: solid #000000 1pt\">\n<p class=\"import-Normal\" style=\"text-align: center\">Very small<\/p>\n<p class=\"import-Normal\" style=\"text-align: center\">Nocturnal<\/p>\n<p class=\"import-Normal\" style=\"text-align: center\">Highly insectivorous<\/p>\n<p class=\"import-Normal\" style=\"text-align: center\">Solitary<\/p>\n<p class=\"import-Normal\" style=\"text-align: center\">Vertical clinger-leapers<\/p>\n<p class=\"import-Normal\" style=\"text-align: center\">Little\/no sexual dimorphism<\/p>\n<\/td>\n<td class=\"a2-C\" style=\"background-color: transparent;padding: 5pt 5pt 5pt 5pt;border: solid #000000 1pt\">\n<p class=\"import-Normal\" style=\"text-align: center\">Two grooming claws<\/p>\n<p class=\"import-Normal\" style=\"text-align: center\">2:1:3:3\/1:1:3:3 dental formula<\/p>\n<p class=\"import-Normal\" style=\"text-align: center\">Do not eat vegetation<\/p>\n<p class=\"import-Normal\" style=\"text-align: center\">Can rotate their heads nearly 180 degrees<\/p>\n<\/td>\n<td class=\"a2-C\" style=\"background-color: transparent;padding: 5pt 5pt 5pt 5pt;border: solid #000000 1pt\">\n<p class=\"import-Normal\" style=\"text-align: center\">Almost full PO closure<\/p>\n<p class=\"import-Normal\" style=\"text-align: center\">More convergent eyes<\/p>\n<p class=\"import-Normal\" style=\"text-align: center\">No tapetum lucidum<\/p>\n<p class=\"import-Normal\" style=\"text-align: center\">No rhinarium<\/p>\n<p class=\"import-Normal\" style=\"text-align: center\">Genetic evidence<\/p>\n<p class=\"import-Normal\" style=\"text-align: center\">Fovea<\/p>\n<\/td>\n<\/tr>\n<tr>\n<td><\/td>\n<td><\/td>\n<td><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<h4 class=\"import-Normal\"><em>Infraorder Platyrrhini of Central and South America<\/em><\/h4>\n<figure id=\"attachment_180\" aria-describedby=\"caption-attachment-180\" style=\"width: 329px\" class=\"wp-caption alignleft\"><img class=\"wp-image-166\" src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image30-e1686352290168.png\" alt=\"Map of South America shows where platyrrhines live.\" width=\"329\" height=\"324\" \/><figcaption id=\"caption-attachment-180\" class=\"wp-caption-text\">Figure 5.27: Geographic distribution of the platyrrhines across the southern part of Central America and the tropical and termporate regions of South America. Credit: <a href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/chapter\/__unknown__-4\/\">Infraorder Platyrrhini map<\/a> original to <a href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/\">Explorations: An Open Invitation to Biological Anthropology<\/a> by Elyssa Ebding at <a href=\"https:\/\/www.csuchico.edu\/geop\/geoplace\/index.shtml\">GeoPlace, California State University, Chico<\/a> is under a <a href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/\">CC BY-NC 4.0 License<\/a>.<\/figcaption><\/figure>\n<p>The platyrrhines are the only nonhuman primates in Central and South America (Figure 5.27) and so, like the lemurs of Madagascar, have diversified into a variety of forms in the absence of competition. Infraorder Platyrrhini get their name from their distinctive nose shape. \u201cPlaty\u201d means flat and \u201crhini\u201d refers to noses, and, indeed, platyrrhines have noses that are flat and wide, with nostrils that are far apart, facing outward, and usually round in shape (Figure 5.28). This nose shape is very different from what we see in catarrhines.<\/p>\n<p>On average, platyrrhines are smaller and less sexually dimorphic than catarrhines, and they have retained the more ancestral primate dental formula of 2:1:3:3. Platyrrhines are all highly arboreal, whereas many catarrhines spend significant time on the ground. The monkeys in Central and South America also differ in having less well-developed vision. This is reflected in the wiring in the visual system of the brain as well as in their <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_1418\">polymorphic color vision<\/a><\/strong>. The genes that enable individuals to distinguish reds and yellows from blues and greens are on the X chromosome. Different genes code for being able to see different wavelengths of light so to distinguish between them you need to be heterozygous for seeing color. The X chromosomes of platyrrhines each carry the genes for seeing one wavelength, so male platyrrhines (with only one X chromosome) are always dichromatic. Female platyrrhines can be dichromatic (if they are homozygous for one version of the color vision gene) or trichromatic (if they are heterozygous) (Kawamura et al. 2012). We currently know of two exceptions to this pattern among platyrrhines. Nocturnal owl monkeys are <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_1420\">monochromatic<\/a><\/strong>, meaning that they cannot distinguish any colors. The other exception are howler monkeys, which have evolved to have two color vision genes on each X chromosome. This means that both male and female howler monkeys are able to see reds and yellows. By contrast, catarrhine males and females are all trichromatic.<\/p>\n<figure style=\"width: 279px\" class=\"wp-caption alignright\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image31-1.jpg\" alt=\"White-faced capuchin monkey.\" width=\"279\" height=\"190\" \/><figcaption class=\"wp-caption-text\">Figure 5.28: A capuchin monkey demonstrating a typical platyrrhine nose shape with round nostrils pointing outward on a flat nose. Credit: <a href=\"https:\/\/commons.wikimedia.org\/wiki\/File:CARABLANCA_-_panoramio.jpg\">CARABLANCA - panoramio<\/a> by Manuel Velazquez is under a <a href=\"https:\/\/creativecommons.org\/licenses\/by\/3.0\/legalcode\">CC BY 3.0 License<\/a>.<\/figcaption><\/figure>\n<p class=\"import-Normal\">Platyrrhines include the smallest of the monkeys, the marmosets and tamarins (Figure 5.29), all of which weigh less than one kilogram and live in cooperative family groups, wherein usually only one female reproduces and everyone else helps carry and raise the offspring. They are unusual primates in that they regularly produce twins. Marmosets and tamarins largely eat gums and saps, so these monkeys have evolved claw-like nails that enable them to cling to the sides of tree trunks like squirrels as well as special teeth that allow them to gnaw through bark. Except for the Goeldi\u2019s monkey, these small monkeys have one fewer molar than other platyrrhines, giving them a dental formula of 2:1:3:2.<\/p>\n<figure style=\"width: 428px\" class=\"wp-caption aligncenter\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image32-1.jpg\" alt=\"Six marmoset and tamarin species.\" width=\"428\" height=\"470\" \/><figcaption class=\"wp-caption-text\">Figure 5.29: Clockwise from top right: golden-headed lion tamarin, pygmy marmoset, Goeldi\u2019s monkey, bare-eared marmoset, emperor tamarin, and common marmoset. Credit: <a href=\"https:\/\/commons.wikimedia.org\/wiki\/File:Callitrichinae_genus.jpg\">Callitrichinae genus<\/a> by Miguelrangeljr is a collective work under a <a href=\"https:\/\/creativecommons.org\/licenses\/by-sa\/3.0\/deed.en\">CC BY-SA 3.0 License<\/a>. [Includes <a href=\"https:\/\/commons.wikimedia.org\/wiki\/File:Wei%C3%9Fb%C3%BCschelaffe_(Callithrix_jacchus).jpg\">Wei\u00dfb\u00fcschelaffe_(Callithrix_jacchus)<\/a> by <a href=\"https:\/\/commons.wikimedia.org\/wiki\/User:Raymond\">Raymond<\/a>, <a href=\"https:\/\/creativecommons.org\/licenses\/by-sa\/4.0\/\">CC BY-SA 4.0<\/a>;\u00a0 <a href=\"https:\/\/commons.wikimedia.org\/wiki\/File:Leontopithecus_chrysomelas_(portrait).jpg\">Leontopithecus chrysomelas (portrait)<\/a> by Hans Hillewaert, <a href=\"https:\/\/creativecommons.org\/licenses\/by-sa\/4.0\/\">CC BY-SA 4.0<\/a>; <a href=\"https:\/\/commons.wikimedia.org\/wiki\/File:Emperor_Tamarin_portrait_2_edit1.jpg\">Emperor_Tamarin_portrait_2_edit1<\/a> by <a href=\"https:\/\/sites.google.com\/site\/thebrockeninglory\/\">Brocken Inaglory<\/a>, <a href=\"https:\/\/creativecommons.org\/licenses\/by-sa\/4.0\/\">CC BY-SA 4.0<\/a>; <a href=\"https:\/\/commons.wikimedia.org\/wiki\/File:Dv%C3%A6rgsilkeabe_Callithrix_pygmaea.jpg\">Dv\u00e6rgsilkeabe_Callithrix_pygmaea<\/a> by Malene Thyssen (User <a href=\"https:\/\/da.wikipedia.org\/wiki\/User:Malene\">Malene<\/a>), <a href=\"https:\/\/en.wikipedia.org\/wiki\/GNU_Free_Documentation_License\">GNU Free Documentation License<\/a>; <a href=\"https:\/\/commons.wikimedia.org\/wiki\/File:Mico_argentatus_(portrait).jpg\">Mico_argentatus_(portrait)<\/a> by Hans Hillewaert, <a href=\"https:\/\/creativecommons.org\/licenses\/by-sa\/4.0\/\">CC BY-SA 4.0<\/a>; <a href=\"https:\/\/commons.wikimedia.org\/wiki\/File:Titi_Monkey.jpg\">Titi Monkey<\/a> by Jeff Kubina, <a href=\"https:\/\/creativecommons.org\/licenses\/by-sa\/2.0\/deed.en\">CC BY-SA 2.0<\/a>].]<\/figcaption><\/figure>\n<p class=\"import-Normal\">The largest platyrrhines are a family that include spider monkeys, woolly spider monkeys, woolly monkeys, and howler monkeys (Figure 5.30). These monkeys can weigh up to 9\u201315 kg and have evolved prehensile tails that can hold their entire body weight. It is among this group that we see semi-brachiators, like the spider monkey (see Figure 5.13). To make them more efficient in this form of locomotion, spider monkeys evolved to not have thumbs so that their hands work more like hooks that can easily let go of branches while swinging. Howler monkeys are another well-known member of this group, earning their name due to their loud calls, which can be heard miles away. To make these loud vocalizations, howler monkeys have a specialized vocal system that includes a large larynx and hyoid bone. Howler monkeys are the most folivorous of the platyrrhines and are known for spending a large portion of their day digesting their food.<\/p>\n<figure style=\"width: 458px\" class=\"wp-caption aligncenter\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image33-1.jpg\" alt=\"Four platyrrhine species.\" width=\"458\" height=\"457\" \/><figcaption class=\"wp-caption-text\">Figure 5.30: Clockwise from top right: howler monkey, woolly monkey, woolly spider monkey, and spider monkey. Credit: <a href=\"https:\/\/commons.wikimedia.org\/wiki\/File:Atelidae_Family.jpg\">Atelidae Family<\/a> by <a href=\"https:\/\/commons.wikimedia.org\/wiki\/User:Miguelrangeljr\">Miguelrangeljr<\/a> is a collective work under a <a href=\"https:\/\/creativecommons.org\/licenses\/by-sa\/3.0\/legalcode\">CC BY-SA 3.0 License<\/a>. [Includes <a href=\"https:\/\/commons.wikimedia.org\/wiki\/File:Ateles_marginatus_(Sao_Paulo_zoo).jpg\">Ateles marginatus (Sao Paulo zoo)<\/a> by <a href=\"https:\/\/commons.wikimedia.org\/wiki\/User:Miguelrangeljr\">Miguelrangeljr<\/a>, <a href=\"https:\/\/creativecommons.org\/licenses\/by-sa\/3.0\/legalcode\">CC BY-SA 3.0<\/a>; <a href=\"https:\/\/commons.wikimedia.org\/wiki\/File:Alouatta_caraya_male.JPG\">Alouatta caraya male<\/a> by <a href=\"https:\/\/commons.wikimedia.org\/wiki\/User:Miguelrangeljr\">Miguelrangeljr<\/a>, <a href=\"https:\/\/creativecommons.org\/licenses\/by-sa\/3.0\/legalcode\">CC BY-SA 3.0<\/a>; <a href=\"https:\/\/commons.wikimedia.org\/wiki\/File:Lagothrix_lagotricha_(walking).jpg\">Lagothrix lagotricha (walking)<\/a> by Hans Hillewaert, <a href=\"https:\/\/creativecommons.org\/licenses\/by-sa\/3.0\/legalcode\">CC BY-SA 3.0<\/a>; <a href=\"https:\/\/commons.wikimedia.org\/wiki\/File:Brachyteles_hypoxanthus2.jpg\">Brachyteles hypoxanthus2<\/a> by <a href=\"https:\/\/www.flickr.com\/photos\/42956474@N04\/with\/4133258867\/\">Paulo B. Chaves<\/a>, <a href=\"https:\/\/creativecommons.org\/licenses\/by\/2.0\/legalcode\">CC BY 2.0<\/a>.]<\/figcaption><\/figure>\n<p class=\"import-Normal\">There are many other monkeys in Central and South America, including the gregarious capuchins (see Figure 5.28) and squirrel monkeys, the pair-living titi monkeys, and the nocturnal owl monkeys. There are also the seed-eating saki monkeys and uakaris. In many areas across Central and South America, multiple species of platyrrhines share the forests, with some even traveling together in association. According to molecular evidence, the diversity of platyrrhines that we see today seems to have originated about 25 million years ago (Schneider and Sampaio 2015). Figure 5.31 summarizes the key traits of platyrrhines relative to the other infraorders of Haplorrhini.<\/p>\n<table class=\"aligncenter\" style=\"width: 468pt\">\n<caption>Figure 5.31: Platyrrhini at a glance: Summary of the key traits we use to distinguish platyrrhines. Traits indicated with an * are those with exceptions detailed in the text. Credit: <a href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/chapter\/__unknown__-4\/\">Platyrrhini at a glance table (Figure 5.29)<\/a> original to <a href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/\">Explorations: An Open Invitation to Biological Anthropology<\/a> by Stephanie Etting is under a <a href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/\">CC BY-NC 4.0 License<\/a>.<\/caption>\n<tbody>\n<tr class=\"a3-R\">\n<td class=\"a3-C\" style=\"background-color: transparent;padding: 5pt 5pt 5pt 5pt;border: solid #000000 1pt\">\n<p class=\"import-Normal\" style=\"text-align: center\"><strong>Platyrrhini traits<\/strong><\/p>\n<\/td>\n<\/tr>\n<tr class=\"a3-R\">\n<td class=\"a3-C\" style=\"background-color: transparent;padding: 5pt 5pt 5pt 5pt;border: solid #000000 1pt\">\n<p class=\"import-Normal\" style=\"text-align: center\">Flat nose with rounded nostrils pointing to the side<\/p>\n<p class=\"import-Normal\" style=\"text-align: center\">Highly arboreal<\/p>\n<p class=\"import-Normal\" style=\"text-align: center\">Less sexually dimorphic on average<\/p>\n<p class=\"import-Normal\" style=\"text-align: center\">2:1:3:3 dental formula*<\/p>\n<p class=\"import-Normal\" style=\"text-align: center\">Polymorphic color vision*<\/p>\n<\/td>\n<\/tr>\n<tr>\n<td><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<h4 class=\"import-Normal\"><em>Infraorder Catarrhini of Asia and Africa <\/em><\/h4>\n<figure style=\"width: 191px\" class=\"wp-caption alignleft\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image34.jpg\" alt=\"Wolf\u2019s guenon.\" width=\"191\" height=\"287\" \/><figcaption class=\"wp-caption-text\">Figure 5.32: A Wolf\u2019s guenon demonstrating a typical catarrhine nose with teardrop-shaped nostrils close together and pointed downward. Credit: <a href=\"https:\/\/commons.wikimedia.org\/wiki\/File:Wolf's_Guenon_Picking_Up_Food_(19095137693).jpg\">Wolf's Guenon Picking Up Food (19095137693)<\/a> by <a href=\"https:\/\/www.flickr.com\/people\/8749778@N06\">Eric Kilby<\/a> is under a <a href=\"https:\/\/creativecommons.org\/licenses\/by-sa\/2.0\/legalcode\">CC BY-SA 2.0 License<\/a>.<\/figcaption><\/figure>\n<p class=\"import-Normal\">Infraorder Catarrhini includes Superfamily Cercopithecoidea (the monkeys of Africa and Asia) and Superfamily Hominoidea (apes and humans). Nonhuman catarrhines are found all over Africa and South and Southeast Asia, with some being found as far north as Japan. The most northerly and southerly catarrhines are cercopithecoid monkeys. In contrast, apes are less tolerant of drier, more seasonal environments and so have a relatively restricted geographic range.<\/p>\n<p class=\"import-Normal\">Relative to other haplorrhine infraorders, catarrhines are distinguished by several characteristics. Catarrhines have a distinctive nose shape, with teardrop-shaped nostrils that are close together and point downward (Figure 5.32) and one fewer premolar than most other primates, giving us a dental formula of 2:1:2:3 (Figure 5.33). On average, catarrhines are the largest and most sexually dimorphic of all primates. Gorillas are the largest living primates, with males weighing up to 220 kg. The most sexually dimorphic of all primates are mandrills. Mandrill males not only have much more vibrant coloration than mandrill females but also have larger canines and can weigh up to three times more (Setchell et al. 2001). The larger body size of catarrhines is related to the more terrestrial lifestyle of many members of this infraorder. In fact, the most terrestrial of living primates can be found in this group. Among all primates, vision is the most developed in catarrhines. Catarrhines independently evolved the same adaptation as howler monkeys in having each X chromosome with genes to distinguish both reds and yellows, so all male and female catarrhines are trichromatic, which is useful for these diurnal primates.<\/p>\n<figure style=\"width: 632px\" class=\"wp-caption aligncenter\"><img class=\"\" src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image35-1.jpg\" alt=\"Platyrrhine, cercopithecoid, and hominoid mandibles.\" width=\"632\" height=\"331\" \/><figcaption class=\"wp-caption-text\">Figure 5.33: Catarrhines have two premolars whereas most other primate taxa (including platyrrhini) have three premolars. This image also shows one of the derived traits of cercopithecoids, their bilophodont molars, which differ from the more ancestral Y-5 molars of apes and humans. Credit: <a href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/chapter\/__unknown__-4\/\">Platyrrhini vs. Catarrhini dentition<\/a> original to <a href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/\">Explorations: An Open Invitation to Biological Anthropology<\/a> by Stephanie Etting is a collective work under a <a href=\"https:\/\/creativecommons.org\/licenses\/by-nc-sa\/4.0\/\">CC BY-NC-SA 4.0 License<\/a>. [Includes <a href=\"https:\/\/animaldiversity.org\/accounts\/Animalia\/specimens\/collections\/contributors\/phil_myers\/ADW_mammals\/specimens\/Primates\/Cebus_apella\/lower_dorsal2216\/?start=135;f=subject::specimen::lower%20jaw\">Cebus apella (brown capuchin)<\/a> at Animal Diversity Web by <a href=\"https:\/\/animaldiversity.org\/collections\/contributors\/phil_myers\/ADW_mammals\/specimens\/Primates\/Hylobates_syndactylus\/lower_dorsal0097\/\">Phil Myers<\/a>, <a href=\"https:\/\/creativecommons.org\/licenses\/by-nc-sa\/4.0\/\">CC BY-NC-SA 3.0<\/a>; <a href=\"https:\/\/animaldiversity.org\/accounts\/Animalia\/specimens\/collections\/contributors\/phil_myers\/ADW_mammals\/specimens\/Primates\/Lophocebus_albigena\/lower_dorsal2060\/?start=525;f=subject::specimen::lower%20jaw\">Lophocebus albigena (gray-cheeked mangaby)<\/a> at Animal Diversity Web by <a href=\"https:\/\/animaldiversity.org\/collections\/contributors\/phil_myers\/ADW_mammals\/specimens\/Primates\/Hylobates_syndactylus\/lower_dorsal0097\/\">Phil Myers<\/a>, <a href=\"https:\/\/creativecommons.org\/licenses\/by-nc-sa\/3.0\/\">CC BY-NC-SA 3.0<\/a>; <a href=\"https:\/\/animaldiversity.org\/accounts\/Primates\/specimens\/collections\/contributors\/phil_myers\/ADW_mammals\/specimens\/Primates\/Hylobates_syndactylus\/lower_dorsal0097\/?start=105;f=subject::specimen::lower%20jaw\">Symphalangus syndactylus (siamang)<\/a> at Animal Diversity Web by <a href=\"https:\/\/animaldiversity.org\/collections\/contributors\/phil_myers\/ADW_mammals\/specimens\/Primates\/Hylobates_syndactylus\/lower_dorsal0097\/\">Phil Myers<\/a>, <a href=\"https:\/\/creativecommons.org\/licenses\/by-nc-sa\/3.0\/\">CC BY-NC-SA 3.0<\/a>.]<\/figcaption><\/figure>\n<p class=\"import-Normal\">The two superfamilies of catarrhines\u2014Superfamily Cercopithecoidea, the monkeys of Africa and Asia, and Superfamily Hominoidea, which includes apes and humans\u2014are believed to have split about 32 million years ago based on molecular evidence (Pozzi et al. 2014). This fits with the fossil record, which shows evidence of these lineages by about 25 million years ago (see Chapter 8).<\/p>\n<h4 class=\"import-Normal\"><em>Superfamily Cercopithecoidea of Africa and Asia<\/em><\/h4>\n<figure style=\"width: 285px\" class=\"wp-caption alignleft\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image36-1.jpg\" alt=\"Pinkish ischial callosities on a crested black macaque.\" width=\"285\" height=\"214\" \/><figcaption class=\"wp-caption-text\">Figure 5.34: The second derived trait of cercopithecoids are their ischial callosities, shown here on a crested black macaque. Credit: <a href=\"https:\/\/commons.wikimedia.org\/wiki\/File:Sulawesi_trsr_DSCN0572_v1.JPG\">Sulawesi trsr DSCN0572 v1<\/a> by <a href=\"https:\/\/commons.wikimedia.org\/wiki\/User:Shankar_Raman\">T. R. Shankar Ramanis<\/a> is under a <a href=\"https:\/\/creativecommons.org\/licenses\/by-sa\/3.0\/legalcode\">CC BY-SA 3.0 License.<\/a><\/figcaption><\/figure>\n<p>Compared to hominoids, cercopithecoids have an ancestral quadrupedal body plan with two key derived traits. The first derived trait of cercopithecoids is their <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_1422\">bilophodont<\/a> <\/strong>molars (\u201cbi\u201d meaning two, \u201cloph\u201d referring to ridge, and \u201cdont\u201d meaning tooth). If you refer back to Figure 5.33, you will see how the molars of cercopithecoids have four cusps arranged in a square pattern and have two ridges connecting them. It is thought that this molar enabled these monkeys to eat a wide range of foods, thus allowing them to live in habitats that apes cannot. The other key derived trait that all cercopithecoids share is having <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_1424\">ischial callosities<\/a> <\/strong>(Figure 5.34). The ischium is the part of your pelvis that you are sitting on right now (see Appendix A: Osteology). In cercopithecoids, this part of the pelvis has a flattened surface that, in living animals, has callused skin over it. These function as seat pads for cercopithecoids, who often sit above branches when feeding and resting.<\/p>\n<figure style=\"width: 359px\" class=\"wp-caption alignright\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image37-1.png\" alt=\"Areas of Europe, Asia, Africa, and Australia where cercopithecoids live.\" width=\"359\" height=\"277\" \/><figcaption class=\"wp-caption-text\">Figure 5.35: Geographic distribution of the cercopithecoid monkeys. Catarrhines have the widest geographic distribution due to the success of cercopithecoids who are found all across subsaharan Africa and southern Asia. Credit: <a href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/chapter\/__unknown__-4\/\">Superfamily Cercopithecoidea map (Figure 5.33)<\/a> original to <a href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/\">Explorations: An Open Invitation to Biological Anthropology<\/a> by Elyssa Ebding at <a href=\"https:\/\/www.csuchico.edu\/geop\/geoplace\/index.shtml\">GeoPlace, California State University, Chico<\/a> is under a <a href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/\">CC BY-NC 4.0 License<\/a>.<\/figcaption><\/figure>\n<p>Cercopithecoid monkeys are the most geographically widespread group of nonhuman primates (Figure 5.35). Since their divergence from hominoids, this monkey group has increased in numbers and diversity due, in part, to their fast reproductive rates. On average, cercopithecoids will reproduce every one to two years, whereas hominoids will reproduce once every four to nine years, depending on the taxon.<\/p>\n<figure style=\"width: 180px\" class=\"wp-caption alignleft\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image38-1.jpg\" alt=\"Two silver leaf monkeys hold orange-haired infants.\" width=\"180\" height=\"240\" \/><figcaption class=\"wp-caption-text\">Figure 5.36: Silver leaf monkey infants are born with orange fur, dramatically contrasting the adult coat color of their mothers. After a few months, the infants gradually change color to that of their parents. Credit: <a href=\"https:\/\/commons.wikimedia.org\/wiki\/File:Silverleaf_Monkey_(Kuala_Lumpur).jpg\">Silverleaf Monkey (Kuala Lumpur)<\/a> by <a href=\"https:\/\/www.flickr.com\/people\/10815162@N07\">Andrea Lai<\/a> from Auckland, New Zealand, is under a <a href=\"https:\/\/creativecommons.org\/licenses\/by\/2.0\/legalcode\">CC BY 2.0 License.<\/a><\/figcaption><\/figure>\n<p>Cercopithecoidea is split into two groups, the leaf monkeys and the cheek-pouch monkeys. Both groups coexist in Asia and Africa; however, the majority of leaf monkey species live in Asia with only a few taxa in Africa. In contrast, only one genus of cheek-pouch monkey lives in Asia, and all the rest of them in Africa. As you can probably guess based on their names, the two groups differ in terms of diet. Leaf monkeys are primarily folivores, with some species eating a significant amount of seeds. Cheek-pouch monkeys tend to be more frugivorous or omnivorous, with one taxon, geladas, eating primarily grasses. The two groups also differ in some other interesting ways. Leaf monkeys tend to produce infants with <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_1426\">natal coats<\/a><\/strong>\u2014infants whose fur is a completely different color from their parents (Figure 5.36). Leaf monkeys are also known for having odd noses (Figure 5.37), and so they are sometimes called \u201codd-nosed monkeys.\u201d Cheek-pouch monkeys are able to pack food into their cheek pouches (Figure 5.38), thus allowing them to move to a location safe from predators or aggressive individuals of their own species where they can eat in peace.<\/p>\n<figure style=\"width: 408px\" class=\"wp-caption aligncenter\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image39.jpg\" alt=\"Male proboscis monkey.\" width=\"408\" height=\"272\" \/><figcaption class=\"wp-caption-text\">Figure 5.37: Proboscis monkeys are one of several \u201codd-nosed\u201d leaf monkeys. Male proboscis monkeys, like this one, have large, pendulous noses, while females have much smaller noses. Credit: <a href=\"https:\/\/commons.wikimedia.org\/wiki\/File:Proboscis_monkey_(Nasalis_larvatus)_male_head.jpg\">Proboscis monkey (Nasalis larvatus) male head<\/a> by <a href=\"https:\/\/www.sharpphotography.co.uk\/\">Charles J Sharp<\/a> creator QS:P170,Q54800218 is under a <a href=\"https:\/\/creativecommons.org\/licenses\/by-sa\/4.0\/legalcode\">CC BY-SA 4.0 License<\/a>.<\/figcaption><\/figure>\n<figure style=\"width: 414px\" class=\"wp-caption aligncenter\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image40-1.jpg\" alt=\"Bonnet macaque with full cheek pouches.\" width=\"414\" height=\"275\" \/><figcaption class=\"wp-caption-text\">Figure 5.38: This bonnet macaque has filled its cheek pouches with food, an adaptation that is useful in transporting food to a safer location to eat. Credit: <a href=\"https:\/\/commons.wikimedia.org\/wiki\/File:Bonnet_macaque_DSC_0893.jpg\">Bonnet macaque DSC 0893<\/a> by <a href=\"https:\/\/commons.wikimedia.org\/wiki\/User:Shankar_Raman\">T. R. Shankar Raman<\/a> is under a <a href=\"https:\/\/creativecommons.org\/licenses\/by-sa\/4.0\/legalcode\">CC BY-SA 4.0 License<\/a>.<\/figcaption><\/figure>\n<h4 class=\"import-Normal\"><em>Superfamily Hominoidea of Africa and Asia<\/em><\/h4>\n<figure style=\"width: 438px\" class=\"wp-caption aligncenter\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image41.png\" alt=\"Areas of Europe, Asia, Africa, and Australia where hominoidea live.\" width=\"438\" height=\"339\" \/><figcaption class=\"wp-caption-text\">Figure 5.39: Geographic distribution of apes across Central and West Africa and Southeast Asia. Hominoids overlap geographically with cercopithecoid monkeys but have a lower tolerance for seasonal environments and so are found only in tropical forests across these regions. Credit: <a href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/chapter\/__unknown__-4\/\">Superfamily Hominoidea map (Figure 5.38)<\/a> original to <a href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/\">Explorations: An Open Invitation to Biological Anthropology<\/a> by Elyssa Ebding at <a href=\"https:\/\/www.csuchico.edu\/geop\/geoplace\/index.shtml\">GeoPlace, California State University, Chico<\/a> is under a <a href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/\">CC BY-NC 4.0 License<\/a>.<\/figcaption><\/figure>\n<p class=\"import-Normal\">Superfamily Hominoidea of Africa and Asia (Figure 5.39) includes the largest of the living primates: apes and humans. Whereas cercopithecoid monkeys have bilophodont molars, hominoids have the more ancestral <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_1428\">Y-5 molars<\/a><\/strong>, which feature five cusps separated by a \u201cY\u201d-shaped groove pattern (see Figure 5.33). The Y-5 molar was present in the common ancestors of hominoids and cercopithecoids, thus it is the more ancestral molar pattern of the two. Hominoids differ the most from other primates in our body plans, due to the unique form of locomotion that hominoids are adapted for: brachiation (Figure 5.40).<\/p>\n<p>To successfully swing below branches, many changes to the body needed to occur. Hominoid arms are much longer than the legs to increase reach, and the lower back is shorter and less flexible to increase control when swinging. The torso, shoulders, and arms of hominoids have evolved to increase range of motion and flexibility (see again Figure 5.12). The clavicle, or collar bone, is longer to stabilize the shoulder joint out to the side, thus enabling us to rotate our arms 360 degrees. Hominoid rib cages are wider side to side and shallower front to back than those of cercopithecoids and we do not have tails, as tails are useful for balance when running on all fours but generally not useful while swinging. Hominoids also have modified ulnae, one of the two bones in the forearm (see Appendix A: Osteology). At the elbow end of the ulna, hominoids have a short <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_1430\">olecranon process<\/a><\/strong>, which allows for improved extension in our arms. At the wrist end of the ulna, hominoids have a short <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_1432\">styloid process<\/a><\/strong>, which enables us to have very flexible wrists, a trait critical for swinging. Both the olecranon process and styloid process are long in quadrupedal animals who carry much of their weight on their forelimbs when traveling and who therefore need greater stability rather than flexibility in those joints.<\/p>\n<table class=\"aligncenter\" style=\"width: 468pt\">\n<caption>Figure 5.40: Quadrupedalism vs. brachiation: Summary of the key anatomical differences between a quadrupedal primate and one adapted for brachiation. To view these traits using photos of bones, check out the interactive skeletal websites in \u201cFurther Explorations\u201d below. Credit: <a href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/chapter\/__unknown__-4\/\">Quadrupedalism vs. Brachiation table (Figure 5.39)<\/a> original to <a href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/\">Explorations: An Open Invitation to Biological Anthropology<\/a> by Stephanie Etting is under a <a href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/\">CC BY-NC 4.0 License<\/a>.<\/caption>\n<thead>\n<tr>\n<td class=\"a4-C\" style=\"background-color: transparent;padding: 5pt 5pt 5pt 5pt;border: solid #000000 1pt\">\n<p class=\"import-Normal\" style=\"text-align: center\">\n<\/td>\n<td class=\"a4-C\" style=\"background-color: transparent;padding: 5pt 5pt 5pt 5pt;border: solid #000000 1pt\">\n<p class=\"import-Normal\" style=\"text-align: center\"><strong>Quadrupedalism<\/strong><\/p>\n<\/td>\n<td class=\"a4-C\" style=\"background-color: transparent;padding: 5pt 5pt 5pt 5pt;border: solid #000000 1pt\">\n<p class=\"import-Normal\" style=\"text-align: center\"><strong>Brachiation<\/strong><\/p>\n<\/td>\n<\/tr>\n<\/thead>\n<tbody>\n<tr class=\"a4-R\">\n<td class=\"a4-C\" style=\"background-color: transparent;padding: 5pt 5pt 5pt 5pt;border: solid #000000 1pt\">\n<p class=\"import-Normal\" style=\"text-align: center\"><strong>Arm length vs. leg length<\/strong><\/p>\n<\/td>\n<td class=\"a4-C\" style=\"background-color: transparent;padding: 5pt 5pt 5pt 5pt;border: solid #000000 1pt\">\n<p class=\"import-Normal\" style=\"text-align: center\">About equal<\/p>\n<\/td>\n<td class=\"a4-C\" style=\"background-color: transparent;padding: 5pt 5pt 5pt 5pt;border: solid #000000 1pt\">\n<p class=\"import-Normal\" style=\"text-align: center\">Arms are longer<\/p>\n<\/td>\n<\/tr>\n<tr class=\"a4-R\">\n<td class=\"a4-C\" style=\"background-color: transparent;padding: 5pt 5pt 5pt 5pt;border: solid #000000 1pt\">\n<p class=\"import-Normal\" style=\"text-align: center\"><strong>Shoulder position<\/strong><\/p>\n<\/td>\n<td class=\"a4-C\" style=\"background-color: transparent;padding: 5pt 5pt 5pt 5pt;border: solid #000000 1pt\">\n<p class=\"import-Normal\" style=\"text-align: center\">More on the front<\/p>\n<\/td>\n<td class=\"a4-C\" style=\"background-color: transparent;padding: 5pt 5pt 5pt 5pt;border: solid #000000 1pt\">\n<p class=\"import-Normal\" style=\"text-align: center\">Out to the side<\/p>\n<\/td>\n<\/tr>\n<tr class=\"a4-R\">\n<td class=\"a4-C\" style=\"background-color: transparent;padding: 5pt 5pt 5pt 5pt;border: solid #000000 1pt\">\n<p class=\"import-Normal\" style=\"text-align: center\"><strong>Ribcage shape<\/strong><\/p>\n<\/td>\n<td class=\"a4-C\" style=\"background-color: transparent;padding: 5pt 5pt 5pt 5pt;border: solid #000000 1pt\">\n<p class=\"import-Normal\" style=\"text-align: center\">Deep front-to-back<\/p>\n<p class=\"import-Normal\" style=\"text-align: center\">Narrow side-to-side<\/p>\n<\/td>\n<td class=\"a4-C\" style=\"background-color: transparent;padding: 5pt 5pt 5pt 5pt;border: solid #000000 1pt\">\n<p class=\"import-Normal\" style=\"text-align: center\">Shallow front-to-back<\/p>\n<p class=\"import-Normal\" style=\"text-align: center\">Wide side-to-side<\/p>\n<\/td>\n<\/tr>\n<tr class=\"a4-R\">\n<td class=\"a4-C\" style=\"background-color: transparent;padding: 5pt 5pt 5pt 5pt;border: solid #000000 1pt\">\n<p class=\"import-Normal\" style=\"text-align: center\"><strong>Length of lower back<\/strong><\/p>\n<\/td>\n<td class=\"a4-C\" style=\"background-color: transparent;padding: 5pt 5pt 5pt 5pt;border: solid #000000 1pt\">\n<p class=\"import-Normal\" style=\"text-align: center\">Long<\/p>\n<\/td>\n<td class=\"a4-C\" style=\"background-color: transparent;padding: 5pt 5pt 5pt 5pt;border: solid #000000 1pt\">\n<p class=\"import-Normal\" style=\"text-align: center\">Short<\/p>\n<\/td>\n<\/tr>\n<tr class=\"a4-R\">\n<td class=\"a4-C\" style=\"background-color: transparent;padding: 5pt 5pt 5pt 5pt;border: solid #000000 1pt\">\n<p class=\"import-Normal\" style=\"text-align: center\"><strong>Collar bone length<\/strong><\/p>\n<\/td>\n<td class=\"a4-C\" style=\"background-color: transparent;padding: 5pt 5pt 5pt 5pt;border: solid #000000 1pt\">\n<p class=\"import-Normal\" style=\"text-align: center\">Short<\/p>\n<\/td>\n<td class=\"a4-C\" style=\"background-color: transparent;padding: 5pt 5pt 5pt 5pt;border: solid #000000 1pt\">\n<p class=\"import-Normal\" style=\"text-align: center\">Long<\/p>\n<\/td>\n<\/tr>\n<tr class=\"a4-R\">\n<td class=\"a4-C\" style=\"background-color: transparent;padding: 5pt 5pt 5pt 5pt;border: solid #000000 1pt\">\n<p class=\"import-Normal\" style=\"text-align: center\"><strong>Ulnar olecranon process<\/strong><\/p>\n<\/td>\n<td class=\"a4-C\" style=\"background-color: transparent;padding: 5pt 5pt 5pt 5pt;border: solid #000000 1pt\">\n<p class=\"import-Normal\" style=\"text-align: center\">Long<\/p>\n<\/td>\n<td class=\"a4-C\" style=\"background-color: transparent;padding: 5pt 5pt 5pt 5pt;border: solid #000000 1pt\">\n<p class=\"import-Normal\" style=\"text-align: center\">Short<\/p>\n<\/td>\n<\/tr>\n<tr class=\"a4-R\">\n<td class=\"a4-C\" style=\"background-color: transparent;padding: 5pt 5pt 5pt 5pt;border: solid #000000 1pt\">\n<p class=\"import-Normal\" style=\"text-align: center\"><strong>Ulnar styloid process<\/strong><\/p>\n<\/td>\n<td class=\"a4-C\" style=\"background-color: transparent;padding: 5pt 5pt 5pt 5pt;border: solid #000000 1pt\">\n<p class=\"import-Normal\" style=\"text-align: center\">Long<\/p>\n<\/td>\n<td class=\"a4-C\" style=\"background-color: transparent;padding: 5pt 5pt 5pt 5pt;border: solid #000000 1pt\">\n<p class=\"import-Normal\" style=\"text-align: center\">Short<\/p>\n<\/td>\n<\/tr>\n<tr class=\"a4-R\">\n<td class=\"a4-C\" style=\"background-color: transparent;padding: 5pt 5pt 5pt 5pt;border: solid #000000 1pt\">\n<p class=\"import-Normal\" style=\"text-align: center\"><strong>Tail<\/strong><\/p>\n<\/td>\n<td class=\"a4-C\" style=\"background-color: transparent;padding: 5pt 5pt 5pt 5pt;border: solid #000000 1pt\">\n<p class=\"import-Normal\" style=\"text-align: center\">Short to long<\/p>\n<\/td>\n<td class=\"a4-C\" style=\"background-color: transparent;padding: 5pt 5pt 5pt 5pt;border: solid #000000 1pt\">\n<p class=\"import-Normal\" style=\"text-align: center\">None<\/p>\n<\/td>\n<\/tr>\n<tr>\n<td><\/td>\n<td><\/td>\n<td><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p class=\"import-Normal\">Apes and humans also differ from other primates in behavior and life history characteristics. Hominoids all seem to show some degree of female dispersal at sexual maturity but, as you will learn in Chapter 6, it is more common that males leave. Some apes show males dispersing in addition to females, but the hominoid tendency for female dispersal is a bit unusual among primates. Our superfamily is also characterized by the most extended life histories of all primates. All members of this group take a long time to grow and reproduce much less frequently compared to cercopithecoids. The slow pace of this life history is likely related to why hominoids have decreased in diversity since they first evolved. Figure 5.41 summarizes the key traits of Infraorder Catarrhini and its two superfamilies. Today, there are only five types of hominoids left: gibbons and siamangs, orangutans, gorillas, chimpanzees and bonobos, and humans.<\/p>\n<table class=\"aligncenter\">\n<caption>Figure 5.41a: Catarrhini at a glance: Summary of key traits of the Infraorder Catarrhini. Credit: <a href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/chapter\/__unknown__-4\/\">Catarrhini at a glance (Figure 5.40)<\/a> original to <a href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/\">Explorations: An Open Invitation to Biological Anthropology<\/a> by Stephanie Etting is a collective work under a <a href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/\">CC BY-NC 4.0 License<\/a>. [Includes <a href=\"https:\/\/commons.wikimedia.org\/wiki\/File:Duskyleafmonkey1.jpg\">Duskyleafmonkey1<\/a> by <a href=\"https:\/\/www.the-ninth.com\/about\">Robertpollai<\/a>, <a href=\"https:\/\/creativecommons.org\/licenses\/by\/3.0\/at\/deed.en\">CC BY 3.0 AT<\/a>; <a href=\"https:\/\/commons.wikimedia.org\/wiki\/File:Male_Bornean_Orangutan_-_Big_Cheeks.jpg\">Male Bornean Orangutan - Big Cheeks<\/a> by <a href=\"https:\/\/www.flickr.com\/people\/8749778@N06\">Eric Kilby<\/a>, <a href=\"https:\/\/creativecommons.org\/licenses\/by-sa\/2.0\/legalcode\">CC BY-SA 2.0<\/a>.]<\/caption>\n<thead>\n<tr style=\"height: 22pt\">\n<td class=\"a5-C\" style=\"background-color: transparent;padding: 5pt 5pt 5pt 5pt;border: solid #000000 1pt\" colspan=\"2\">\n<p class=\"import-Normal\" style=\"text-align: center\"><strong>Infraorder Catarrhini<\/strong><\/p>\n<\/td>\n<\/tr>\n<\/thead>\n<tbody>\n<tr class=\"a5-R\" style=\"height: 22pt\">\n<td class=\"a5-C\" style=\"background-color: transparent;padding: 5pt 5pt 5pt 5pt;border: solid #000000 1pt\" colspan=\"2\">\n<p class=\"import-Normal\" style=\"text-align: center\">Downward facing, tear-drop shaped nostrils, close together<\/p>\n<p class=\"import-Normal\" style=\"text-align: center\">Arboreal and more terrestrial taxa<\/p>\n<p class=\"import-Normal\" style=\"text-align: center\">On average, largest primates<\/p>\n<p class=\"import-Normal\" style=\"text-align: center\">On average, most sexually dimorphic taxonomic group<\/p>\n<p class=\"import-Normal\" style=\"text-align: center\">2:1:2:3 dental formula<\/p>\n<p class=\"import-Normal\" style=\"text-align: center\">All trichromatic<\/p>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<table class=\"aligncenter\" style=\"width: 468pt\">\n<caption>Figure 5.41b: Characteristics used to distinguish between the two Catarrhini superfamilies. Credit: <a href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/chapter\/__unknown__-4\/\">Catarrhini at a glance (Figure 5.40)<\/a> original to <a href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/\">Explorations: An Open Invitation to Biological Anthropology<\/a> by Stephanie Etting is a collective work under a <a href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/\">CC BY-NC 4.0 License<\/a>. [Includes <a href=\"https:\/\/commons.wikimedia.org\/wiki\/File:Duskyleafmonkey1.jpg\">Duskyleafmonkey1<\/a> by <a href=\"https:\/\/www.the-ninth.com\/about\">Robertpollai<\/a>, <a href=\"https:\/\/creativecommons.org\/licenses\/by\/3.0\/at\/deed.en\">CC BY 3.0 AT<\/a>; <a href=\"https:\/\/commons.wikimedia.org\/wiki\/File:Male_Bornean_Orangutan_-_Big_Cheeks.jpg\">Male Bornean Orangutan - Big Cheeks<\/a> by <a href=\"https:\/\/www.flickr.com\/people\/8749778@N06\">Eric Kilby<\/a>, <a href=\"https:\/\/creativecommons.org\/licenses\/by-sa\/2.0\/legalcode\">CC BY-SA 2.0<\/a>.]<\/caption>\n<thead>\n<tr>\n<td class=\"a5-C\" style=\"background-color: transparent;padding: 5pt 5pt 5pt 5pt;border: solid #000000 1pt\">\n<p class=\"import-Normal\" style=\"text-align: center\"><strong><img class=\"alignnone\" src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image42-1.jpg\" alt=\"Dusky leaf monkey\" width=\"248\" height=\"186\" \/><\/strong><strong>Superfamily Cercopithecoidea<\/strong><\/p>\n<\/td>\n<td class=\"a5-C\" style=\"background-color: transparent;padding: 5pt 5pt 5pt 5pt;border: solid #000000 1pt\">\n<p class=\"import-Normal\" style=\"text-align: center\"><strong><img class=\"alignnone\" src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image43-1.jpg\" alt=\"Orangutan\" width=\"274\" height=\"183\" \/><\/strong><strong>Superfamily Hominoidea<\/strong><\/p>\n<\/td>\n<\/tr>\n<\/thead>\n<tbody>\n<tr class=\"a5-R\">\n<td class=\"a5-C\" style=\"background-color: transparent;padding: 5pt 5pt 5pt 5pt;border: solid #000000 1pt\">\n<p class=\"import-Normal\" style=\"text-align: center\">Wide geographic distribution<\/p>\n<p class=\"import-Normal\" style=\"text-align: center\">Bilophodont molars<\/p>\n<p class=\"import-Normal\" style=\"text-align: center\">Ischial callosities<\/p>\n<p class=\"import-Normal\" style=\"text-align: center\">Reproduce every 1\u20132 years<\/p>\n<\/td>\n<td class=\"a5-C\" style=\"background-color: transparent;padding: 5pt 5pt 5pt 5pt;border: solid #000000 1pt\">\n<p class=\"import-Normal\" style=\"text-align: center\">Tropical forests of Africa and Asia<\/p>\n<p class=\"import-Normal\" style=\"text-align: center\">Y-5 molars<\/p>\n<p class=\"import-Normal\" style=\"text-align: center\">Adaptations for brachiation<\/p>\n<p class=\"import-Normal\" style=\"text-align: center\">Reproduce every 4\u20139 years<\/p>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<h4 class=\"import-Normal\"><em>Family <\/em>Hylobatidae <em>of Southeast Asia<\/em><\/h4>\n<figure style=\"width: 441px\" class=\"wp-caption alignleft\"><img class=\"\" src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image44-1.jpg\" alt=\"Siamang with outstretched arms.\" width=\"441\" height=\"294\" \/><figcaption class=\"wp-caption-text\">Figure 5.42: Siamangs are the largest of the Hylobatidae family. They are all black with a throat sac that can become inflated to give out loud calls. Credit: <a href=\"https:\/\/www.flickr.com\/photos\/suneko\/373310729\/\">Shout (373310729)<\/a> by <a href=\"https:\/\/www.flickr.com\/photos\/suneko\/\">su neko<\/a> is under a <a href=\"https:\/\/creativecommons.org\/licenses\/by\/2.0\/\">CC BY-SA 2.0 License<\/a>.<\/figcaption><\/figure>\n<p class=\"import-Normal\">The number of genera in this group has been changing in recent years, but the taxa broadly encompasses gibbons and siamangs. Both are found across Southeast Asian tropical forests. Gibbons weigh, on average, about 13 pounds and tend to be more frugivorous, whereas siamangs are larger than gibbons and also more folivorous. Unlike the larger-bodied apes (orangutans, chimps, bonobos, and gorillas) who make nests to sleep in every night, gibbons and siamangs will develop callused patches on their ischium resembling ischial callosities. Gibbon species are quite variable in their coloration and markings, while siamangs are all black with big throat sacs that are used in their exuberant vocalizations (Figure 5.42). Both gibbons and siamangs live in pairs with very little sexual dimorphism, although males and females do differ in coloration in some gibbon species.<\/p>\n<h4 class=\"import-Normal\">Pongo<em> of Southeast Asia<\/em><\/h4>\n<p class=\"import-Normal\">The Genus <em>Pongo <\/em>refers to orangutans. These large red apes are found in Southeast Asia, with the two well-known species each living on the islands of Borneo and Sumatra. A third, very rare species, was recently discovered in Southern Sumatra (Nater et al. 2017). Orangutans are highly frugivorous but will supplement their diet with leaves and bark when fruit is less available. As mentioned earlier, orangutans are the only diurnal, solitary taxon among primates and are extremely slow to reproduce, producing only one offspring about every seven to nine years. They are highly sexually dimorphic (Figure 5.43 a and b), with fully developed, \u201cflanged\u201d males being approximately twice the size of females. These males have large throat sacs; long, shaggy coats; and cheek flanges. The skulls of male orangutans often feature a <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_1434\">sagittal crest<\/a><\/strong>, which is believed to function as additional attachment area for chewing muscles as well as a trait used in sexual competition (Balolia, Soligo, and Wood 2017). An unusual feature of orangutan biology is <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_1436\">male bimaturism<\/a><\/strong>. Male orangutans are known to delay maturation until one of the more dominant, flanged males disappears. The males that delay maturation are called \u201cunflanged\u201d males, and they can remain in this state for their entire life. Unflanged males resemble females in their size and appearance and will sneak copulations with females while avoiding the bigger, flanged males. Flanged and unflanged male orangutans represent alternative reproductive strategies, both of which successfully produce offspring (Utami et al. 2002).<\/p>\n<p>&nbsp;<\/p>\n<\/div>\n<figure id=\"attachment_182\" aria-describedby=\"caption-attachment-182\" style=\"width: 1900px\" class=\"wp-caption aligncenter\"><img class=\"wp-image-181 size-full\" src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/5.43.jpg\" alt=\"a. Female orangutan with infant. b. Male orangutan in a tree.\" width=\"1900\" height=\"800\" \/><figcaption id=\"caption-attachment-182\" class=\"wp-caption-text\">Figure 5.43: (a) A female orangutan eating fruit with her infant nearby and (b) a flanged adult male eating leaves. Male orangutans are about twice the size of females and have a longer coat length, cheek flanges, and throat sac. Credit: a. <a href=\"https:\/\/commons.wikimedia.org\/wiki\/File:Orang_Utan_(Pongo_pygmaeus)_female_with_baby_(8066259067).jpg\">Orang Utan (Pongo pygmaeus) female with baby (8066259067)<\/a> by <a href=\"https:\/\/www.flickr.com\/people\/65695019@N07\">Bernard DUPONT<\/a> is under a <a href=\"https:\/\/creativecommons.org\/licenses\/by-sa\/2.0\/\">CC BY-SA 2.0 Licence<\/a>. b. <a href=\"https:\/\/commons.wikimedia.org\/wiki\/File:Orangutan_-Zoologischer_Garten_Berlin-8a.jpg\">Orangutan -Zoologischer Garten Berlin-8a<\/a> by <a href=\"https:\/\/www.flickr.com\/photos\/37088680@N03\">David Forsman<\/a> is under a <a href=\"https:\/\/creativecommons.org\/licenses\/by\/2.0\/\">CC BY 2.0 License<\/a>.<\/figcaption><\/figure>\n<div class=\"learning-objectives\">\n<h4 class=\"import-Normal\">Gorilla <em>of Africa<\/em><\/h4>\n<p class=\"import-Normal\">There are several species of gorillas that can be found across Central Africa. Gorilla males, like orangutan males, are about twice the size of female gorillas (Figure 5.44a and b). When on the ground, gorillas use a form of quadrupedalism called <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_1438\">knuckle-walking<\/a><\/strong>, wherein the fingers are curled under and the weight is carried on the knuckles. Male gorillas have a large sagittal crest and large canines compared with females. Adult male gorillas are often called \u201csilverbacks\u201d because when they reach about twelve to thirteen years old, the hair on their backs turns silvery gray. Gorillas typically live in groups of one male and several females. Gorillas are considered folivorous, although some species can be more frugivorous depending on fruit seasonality (Remis 1997).<\/p>\n<\/div>\n<figure id=\"attachment_182\" aria-describedby=\"caption-attachment-182\" style=\"width: 1900px\" class=\"wp-caption aligncenter\"><img class=\"wp-image-182 size-full\" src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/5.44.jpg\" alt=\"a. Female gorilla with offspring. b. Male gorilla.\" width=\"1900\" height=\"800\" \/><figcaption id=\"caption-attachment-182\" class=\"wp-caption-text\">Figure 5.44: (a) A female gorilla with her two offspring and (b) a silverback adult male. Male gorillas are about twice the size of females. They also differ from females in having a large sagittal crest and a silver back, which appears as they mature. Credit: a. <a href=\"https:\/\/commons.wikimedia.org\/wiki\/File:Enzo_naomi_echo.jpg\">Enzo naomi echo<\/a> by Zoostar is under a <a href=\"https:\/\/creativecommons.org\/licenses\/by\/3.0\/legalcode\">CC BY 3.0 License<\/a>. b. <a href=\"https:\/\/commons.wikimedia.org\/wiki\/File:Male_gorilla_in_SF_zoo.jpg\">Male gorilla in SF zoo<\/a> by Brocken Inaglory is under a <a href=\"https:\/\/creativecommons.org\/licenses\/by-sa\/3.0\/legalcode\">CC BY-SA 3.0 License<\/a>.<\/figcaption><\/figure>\n<div class=\"learning-objectives\">\n<h4 class=\"import-Normal\">Pan<em> of Africa<\/em><\/h4>\n<figure style=\"width: 252px\" class=\"wp-caption alignleft\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image49-1.jpg\" alt=\"Bonobo looks away from the camera.\" width=\"252\" height=\"222\" \/><figcaption class=\"wp-caption-text\">Figure 5.45: Bonobo (Pan paniscus). You can see the distinctive hair-part on this bonobo. Credit: <a href=\"https:\/\/commons.wikimedia.org\/wiki\/File:Bonobo_male_Jasongo_15yo_Twycross_582a_(2014_11_14_01_04_18_UTC).jpg\">Bonobo male Jasongo 15yo Twycross 582a (2014 11 14 01 04 18 UTC)<\/a> by William H. Calvin is under a <a href=\"https:\/\/creativecommons.org\/licenses\/by-sa\/4.0\/legalcode\">CC BY-SA 4.0 License<\/a>.<\/figcaption><\/figure>\n<p>The Genus <em>Pan <\/em>includes two species: <em>Pan troglodytes <\/em>(the common chimpanzee) and <em>Pan paniscus <\/em>(the bonobo). These species are separated by the Congo River, with chimpanzees ranging across West and Central Africa and bonobos located in a restricted area south of the Congo River. Chimpanzees and bonobos both have broad, largely frugivorous diets.The two species differ morphologically in that bonobos are slightly smaller, have their hair parted down the middle of their foreheads, and are born with dark faces (Figure 5.45). In contrast, chimpanzees do not have the distinctive parted hair and are born with light faces that darken as they mature (Figure 5.46). Chimpanzees and bonobos live in a grouping called a fission-fusion community, which you will learn more about in Chapter 6. Both species are moderately sexually dimorphic, with males about 20% larger than females. When on the ground, chimpanzees and bonobos knuckle-walk like gorillas do.<\/p>\n<figure style=\"width: 418px\" class=\"wp-caption aligncenter\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image50-1.jpg\" alt=\"Female chimpanzee with offspring in a tree.\" width=\"418\" height=\"278\" \/><figcaption class=\"wp-caption-text\">Figure 5.46: A common chimpanzee (Pan troglodytes) female (center) and her offspring. Note the pink face of the youngest individual. Bonobos are born with dark-skinned faces, but chimpanzees are born with pink faces that darken with age. Credit: <a href=\"https:\/\/commons.wikimedia.org\/wiki\/File:Chimpanzees_in_Uganda_(5984913059).jpg\">Chimpanzees in Uganda (5984913059)<\/a> by <a href=\"https:\/\/www.flickr.com\/people\/57424551@N06\">USAID Africa Bureau<\/a> uploaded by <a href=\"https:\/\/commons.wikimedia.org\/wiki\/User:Elitre\">Elitre<\/a> is in the <a href=\"https:\/\/en.wikipedia.org\/wiki\/Public_domain\">public domain<\/a>.<\/figcaption><\/figure>\n<h4 class=\"import-Normal\">Homo<\/h4>\n<p class=\"import-Normal\">The last member of the Hominoidea to discuss is our own taxon, Genus <em>Homo<\/em>. Later chapters will discuss the many extinct species of <em>Homo<\/em>, but today there is only one living species of <em>Homo, <\/em>our own species, <em>sapiens<\/em>. While it is interesting to focus on how humans differ from apes in many aspects of our morphology, behavior, and life history, one objective of this chapter, and of biological anthropology in general, is to understand our place in nature. This means looking for aspects of human biology that link us to the taxonomic diversity we have discussed. To that end, here we will focus on similarities humans share with other hominoids.<\/p>\n<p class=\"import-Normal\">Like other hominoids, humans lack a tail and possess upper-body adaptations for brachiation. While our lower body has been modified for a bipedal gait, we are still able to swing from branches and throw a baseball, all thanks to our mobile shoulder joint. Humans, like other hominoids, also have a Y-5 cusp pattern on our molars. All hominoids, including humans, have an extended life history, taking time to grow and develop, and reproducing slowly over a long life span. Lastly, while humans show a great deal of variation across cultures, many human societies show tendencies for female dispersal (Burton et al. 1996).<\/p>\n<p class=\"import-Normal\">Among the hominoids, humans show particular affinities with other members of the African Clade, <em>Pan <\/em>and <em>Gorilla<\/em>. Humans share over 96% of our DNA with gorillas (Scally et al. 2012), and over 98% with <em>Pan <\/em>(Ebersberger et al. 2002). Even without this strong genetic evidence, the African Clade of hominoids share many morphological similarities, including having wide-set eye sockets and backward-sweeping cheekbones. Today, <em>Pan<\/em> and <em>Gorilla<\/em> knuckle-walk when on the ground, and it has been suggested the last common ancestor of chimpanzees, bonobos, gorillas, and humans did as well (Richmond, Begun, and Strait 2001). Further, humans, chimpanzees, and bonobos all live in fission-fusion social groups characterized by shared behaviors, like male cooperation in hunting and territoriality, as well as tool use.<\/p>\n<div class=\"textbox\">\n<h2 class=\"import-Normal\">Special Topic: Primates in Culture and Religion<\/h2>\n<p class=\"import-Normal\">One of the best parts of teaching anthropology for me is getting to spend time watching primates at zoos. What I also find interesting is watching people watch primates. I have very often heard a parent and child walk up to a chimpanzee enclosure and exclaim \u201cLook at the monkeys!\u201d The parent and child often don\u2019t know that a chimpanzee is not a monkey, nor are they likely to know that chimpanzees share more than 98% of their DNA with us. What strikes me as significant is that, although most people do not know the difference between a monkey, an ape, and a lemur, they nonetheless recognize something in the animals as being similar to themselves. In fact, recognition of similarities between humans and other primates is very ancient, dating back far earlier than Linnaeus. For many of us, we only ever get to see primates in zoos and animal parks, but in many areas of the world, humans have coexisted with these animals for thousands of years. In areas where humans and primates have a long, shared history, nonhuman primates often play key roles in creation myths and cultural symbolism.<\/p>\n<p class=\"import-Normal\">Hamadryas baboons feature significantly in Ancient Egyptian iconography. Ancient Egyptian deities and beliefs transformed over time, as did the role of hamadryas baboons. Early on, baboons were thought to represent dead ancestors, and one monkey deity, called Babi or Baba, was thought to feed off of dead souls. Later, baboons became the totem animal for Thoth, the deity of science, writing, wisdom, and measurement, who also wrote the Book of the Dead. Sunbathing hamadryas baboons led ancient Egyptians to associate them with Ra, the sun god, who was the son of Thoth. During mummification, human organs were removed and put into canopic jars, one of which was topped with the head of the baboon-headed god, Hapi. Hamadryas baboons were also often kept as pets, as depicted in hieroglyphics, and occasionally mummified as well.<\/p>\n<p class=\"import-Normal\">On Madagascar, indris and aye-ayes play roles in the creation myths and omens of local people.There are many myths regarding the origins of indris and their relationship to humans, including one where two brothers living in the forest separated, with one brother leaving the forest and becoming a human while the other stayed in the forest to become the indri. Like humans, indris have long legs, no tail, and upright posture. They are considered sacred and are therefore protected. Unfortunately, the aye-aye is not treated with the same reverence. Because of their unusual appearance (see Figure 5.15), aye-ayes are seen as omens of death.They are usually killed when encountered because it is believed that someone will die if an aye-aye points at them.<\/p>\n<p class=\"import-Normal\">In India, monkeys play a key role in the Hindu religion. Hanuman, who resembles a monkey, is a key figure in the Ramayana. Hanuman is thought to be a guardian deity, and so local monkeys like Hanuman langurs and macaques are protected in India (Figure 5.47). In Thailand, where Hinduism is also practiced, the Hindu reverence for monkeys extends to \u201cmonkey feasts,\u201d where large quantities of food are spread out in gratitude to the monkeys for bringing good fortune.<\/p>\n<figure style=\"width: 308px\" class=\"wp-caption alignleft\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image51-1.jpg\" alt=\"Three macaques outside a temple in India.\" width=\"308\" height=\"261\" \/><figcaption class=\"wp-caption-text\">Figure 5.47: Because of important monkey-like figures in the Hindu religion, macaques are protected in India and often live near temples where they are fed by local peoples. Credit: <a href=\"https:\/\/commons.wikimedia.org\/wiki\/File:Macaque_India_4.jpg\">Macaque India 4<\/a> by <a href=\"https:\/\/commons.wikimedia.org\/wiki\/User:Mosmas\">Thomas Schoch<\/a> (<a href=\"https:\/\/commons.wikimedia.org\/wiki\/User:Mosmas\">Mosmas<\/a>) is under a <a href=\"https:\/\/creativecommons.org\/licenses\/by-sa\/3.0\/\">CC BY-SA 3.0 License<\/a>.<\/figcaption><\/figure>\n<p class=\"import-Normal\">The people of Japan have coexisted with Japanese macaques for thousands of years, and so monkeys play key roles in both of the major Japanese religions. In the Shinto religion, macaques are thought of as messengers between the spirit world and humans, and monkey symbols are thought to be good luck. The other major religion in Japan is Buddhism, and monkeys play a role in symbolism of this religion as well. The \u201cThree Wise Monkeys\u201d who see no evil, speak no evil, and hear no evil derive from Buddhist iconography of monkeys.<\/p>\n<p class=\"import-Normal\">In Central and South America, monkeys feature often in Mayan and Aztec stories. In the Mayan creation story, the Popol Vuh, the \u201chero brothers,\u201d are actually a howler monkey and a spider monkey, who represent ancestors of humans in the story. In the Aztec religion, spider monkeys are associated with the god of arts, pleasure, and playfulness. A spider monkey is also represented in a Peruvian Nazca geoglyph, a large design made on the ground by moving rocks.<\/p>\n<p class=\"import-Normal\">In many of these regions today, the relationships between humans and nonhuman primates are complicated. The bushmeat and pet trades make these animals valuable at the expense of many animals\u2019 lives, and in some areas, nonhuman primates have become pests who raid crop fields and consume valuable foods. All of this has led to the development of a new subarea of anthropology called <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_1440\">Ethnoprimatology<\/a><\/strong>, which involves studying the political, economic, symbolic, and practical relationships between humans and nonhuman primates.This field highlights the particular challenges for humans of having to coexist with animals with whom we share so much in common. It also provides insight into some of the challenges facing primate conservation efforts (see Appendix B: Primate Conservation).<\/p>\n<\/div>\n<h2 class=\"import-Normal\"><span style=\"background-color: #ff99cc\">Conclusion<\/span><\/h2>\n<p class=\"import-Normal\"><span style=\"background-color: #ff99cc\">The Order Primates is a diverse and fascinating group of animals united in sharing a suite of characteristics\u2014visual specialization, grasping hands and feet, large brains, and extended life histories\u2014that differentiates us from other groups of mammals. In this chapter, we surveyed the major taxonomic groups of primates, discussing where humans fit among our close relatives as well as discovering that primates are interesting animals in their own right. We discussed a range of key traits used to distinguish between the many taxa of living primates, including dietary, locomotor, and behavioral characteristics. Because of our long, shared evolutionary history with these animals, nonhuman primates provide a crucial resource for understanding our current biology. In Chapter 6, you will discover the fascinating and complex social behaviors of nonhuman primates, which provide further insight into our evolutionary biology.<\/span><\/p>\n<div class=\"textbox shaded\">\n<h2 class=\"import-Normal\">Review Questions<\/h2>\n<ul>\n<li class=\"import-Normal\">Why does the field of anthropology, a field dedicated to the study of humans, include the study of nonhuman animals? What can we learn from nonhuman primates?<\/li>\n<li class=\"import-Normal\">Why is it important to try to place taxa into a clade classification rather than groupings based on grade? Can you think of an example?<\/li>\n<li class=\"import-Normal\">One of the important goals of an introductory biological anthropology course is to teach you about your place in nature. What is the full taxonomic classification of humans, and what are some of the traits we have of each of these categories?<\/li>\n<li class=\"import-Normal\">When you have seen primates in person, did you observe any facial expressions, behaviors, or physical traits that seemed familiar to you? If so, which ones and why?<\/li>\n<li class=\"import-Normal\">Draw out a tree showing the major taxonomic group of primates described here, making sure to leave room in between each level. Underneath each taxon, list some of the key features of this group so that you can compare traits between groups.<\/li>\n<\/ul>\n<\/div>\n<h2 class=\"import-Normal\">Key Terms<\/h2>\n<p class=\"import-Normal\"><strong>Activity pattern<\/strong>: Refers to the time of day an animal is typically active.<\/p>\n<p class=\"import-Normal\"><strong>African clade<\/strong>: A grouping that includes gorillas, chimpanzees, bonobos, humans, and their extinct relatives.<\/p>\n<p class=\"import-Normal\"><strong>Analogy<\/strong>: When two or more taxa exhibit similar traits that have evolved independently, the similar traits evolve due to similar selective pressures. (Also sometimes called convergent evolution, parallel evolution, or homoplasy.)<\/p>\n<p class=\"import-Normal\"><strong>Ancestral trait<\/strong>: A trait that has been inherited from a distant ancestor.<\/p>\n<p class=\"import-Normal\"><strong>Arboreal<\/strong>: A descriptor for an organism that spends most of its time in trees.<\/p>\n<p class=\"import-Normal\"><strong>Asian clade<\/strong>: A grouping that includes orangutans and their extinct relatives.<\/p>\n<p class=\"import-Normal\"><strong>Bilophodont<\/strong>: Molar pattern of cercopithecoid monkeys in which there are usually four cusps that are arranged in a square pattern and connected by two ridges.<\/p>\n<p class=\"import-Normal\"><strong>Bipedalism<\/strong>: Walking on two legs.<\/p>\n<p class=\"import-Normal\"><strong>Brachiation<\/strong>: A form of locomotion in which the organism swings below branches using the forelimbs.<\/p>\n<p class=\"import-Normal\"><strong>Bunodont<\/strong>: Low, rounded cusps on the cheek teeth.<\/p>\n<p class=\"import-Normal\"><strong>Canines<\/strong>: In most primates, these are the longest of the teeth, often conical in shape and used as a weapon against predators or others of their species.<\/p>\n<p class=\"import-Normal\"><strong>Cathemeral<\/strong>: Active throughout the 24-hour period.<\/p>\n<p class=\"import-Normal\"><strong>Clade<\/strong>: A grouping based on ancestral relationships; a branch of the evolutionary tree.<\/p>\n<p class=\"import-Normal\"><strong>Cusps<\/strong>: The bumps on the chewing surface of the premolars and molars, which can be quite sharp in some species.<\/p>\n<p class=\"import-Normal\"><strong>Dental formula<\/strong>: The number of each type of tooth in one quadrant of the mouth, written as number of incisors: canines: premolars: molars.<\/p>\n<p class=\"import-Normal\"><strong>Derived trait<\/strong>: A trait that has been recently modified, most helpful when assigning taxonomic classification.<\/p>\n<p class=\"import-Normal\"><strong>Diastema<\/strong>: A space between the teeth, usually for large canines to fit when the mouth is closed.<\/p>\n<p class=\"import-Normal\"><strong>Dichromatic<\/strong>: Being able to see only blues and greens.<\/p>\n<p class=\"import-Normal\"><strong>Diurnal<\/strong>: Active during the day.<\/p>\n<p class=\"import-Normal\"><strong>Dry nose<\/strong>: The nose and upper lip are separated and the upper lip can move independently; sometimes referred to as a \u201chairy\u201d or \u201cmobile\u201d upper lip.<\/p>\n<p class=\"import-Normal\"><strong>Ethnoprimatology<\/strong>: A subarea of anthropology that studies the complexities of human-primate relationships in the modern environment.<\/p>\n<p class=\"import-Normal\"><strong>Evolutionary trade-off<\/strong>: When an organism, which is limited in the time and energy it can put into aspects of its biology and behavior, is shaped by natural selection to invest in one adaptation at the expense of another.<\/p>\n<p class=\"import-Normal\"><strong>Faunivorous<\/strong>: Having a diet consisting entirely of animal matter: insects, eggs, lizards, etc.<\/p>\n<p class=\"import-Normal\"><strong>Folivore<\/strong>: Having a diet consisting primarily of leaves.<\/p>\n<p class=\"import-Normal\"><strong>Fovea<\/strong>: A depressed area in the retina at the back of the eye containing a concentration of cells that allow one to focus on objects very close to one\u2019s face.<\/p>\n<p class=\"import-Normal\"><strong>Frugivore<\/strong>: Having a diet consisting primarily of fruit.<\/p>\n<p class=\"import-Normal\"><strong>Generalized trait<\/strong>: A trait that is useful for a wide range of tasks.<\/p>\n<p class=\"import-Normal\"><strong>Grade<\/strong>: A grouping based on overall similarity in lifestyle, appearance, and behavior.<\/p>\n<p class=\"import-Normal\"><strong>Grooming claw<\/strong>: A claw present on the second pedal digit in strepsirrhines.<\/p>\n<p class=\"import-Normal\"><strong>Gummivore<\/strong>: Having a diet consisting primarily of gums and saps.<\/p>\n<p class=\"import-Normal\"><strong>Heterodont<\/strong>: Having different types of teeth.<\/p>\n<p class=\"import-Normal\"><strong>Homology<\/strong>: When two or more taxa share characteristics because they inherited them from a common ancestor.<\/p>\n<p class=\"import-Normal\"><strong>Hone<\/strong>: When primates sharpen their canines by wearing them on adjacent teeth.<\/p>\n<p class=\"import-Normal\"><strong>Incisors<\/strong>: The spatula-shaped teeth at the front of the mouth.<\/p>\n<p class=\"import-Normal\"><strong>Insectivore<\/strong>: Having a diet consisting primarily of insects.<\/p>\n<p class=\"import-Normal\"><strong>Ischial callosities<\/strong>: Modified seat bones of the pelvis that are flattened and over which calluses form; function as seat pads for sitting and resting atop branches.<\/p>\n<p class=\"import-Normal\"><strong>Knuckle-walking<\/strong>: A form of quadrupedal movement used by <em>Gorilla<\/em> and <em>Pan<\/em> when on the ground, wherein the front limbs are supported on the knuckles of the hands.<\/p>\n<p class=\"import-Normal\"><strong>Life history<\/strong>: Refers to an organism\u2019s pace of growth, reproduction, lifespan, etc.<\/p>\n<p class=\"import-Normal\"><strong>Locomotion<\/strong>: How an organism moves around.<\/p>\n<p class=\"import-Normal\"><strong>Male bimaturism<\/strong>: Refers to the alternative reproductive strategies in orangutans in which males can delay maturation, sometimes indefinitely, until a fully mature, \u201cflanged\u201d male disappears.<\/p>\n<p class=\"import-Normal\"><strong>Molars<\/strong>: The largest teeth at the back of the mouth; used for chewing. In primates, these teeth usually have between three and five cusps.<\/p>\n<p class=\"import-Normal\"><strong>Monochromatic<\/strong>: Being able to see only in shades of light to dark, no color.<\/p>\n<p class=\"import-Normal\"><strong>Monomorphic<\/strong>: When males and females of a species do not exhibit significant sexual dimorphism.<\/p>\n<p class=\"import-Normal\"><strong>Natal coat<\/strong>: Refers to the contrasting fur color of baby leaf monkeys compared to adults.<\/p>\n<p class=\"import-Normal\"><strong>Nocturnal<\/strong>: Active at night.<\/p>\n<p class=\"import-Normal\"><strong>Olecranon process<\/strong>: Bony projection at the elbow end of the ulna.<\/p>\n<p class=\"import-Normal\"><strong>Opposable thumb <\/strong>or <strong>opposable big toe<\/strong>: Having thumbs and toes that go in a different direction from the rest of the fingers, allows for grasping with hands and feet.<\/p>\n<p class=\"import-Normal\"><strong>Pentadactyly<\/strong>: Having five digits or fingers and toes.<\/p>\n<p class=\"import-Normal\"><strong>Polymorphic color vision<\/strong>: A system in which individuals of a species vary in their abilities to see color. In primates, it refers to males being dichromatic and females being either trichromatic or dichromatic.<\/p>\n<p class=\"import-Normal\"><strong>Postorbital bar<\/strong>: A bony ring that surrounds the eye socket, open at the back.<\/p>\n<p class=\"import-Normal\"><strong>Postorbital closure\/plate<\/strong>: A bony plate that provides protection to the side and back of the eye.<\/p>\n<p class=\"import-Normal\"><strong>Prehensile tail<\/strong>: A tail that is able to hold the full body weight of an organism, which often has a tactile pad on the underside of the tip for improved grip.<\/p>\n<p class=\"import-Normal\"><strong>Premolars<\/strong>: Smaller than the molars, used for chewing. In primates, these teeth usually have one or two cusps.<\/p>\n<p class=\"import-Normal\"><strong>Quadrupedalism<\/strong>: Moving around on all fours.<\/p>\n<p class=\"import-Normal\"><strong>Rhinariums<\/strong>: Wet noses; resulting from naked skin of the nose which connects to the upper lip and smell-sensitive structures along the roof of the mouth.<\/p>\n<p class=\"import-Normal\"><strong>Sagittal crest<\/strong>: A bony ridge along the top\/middle of the skull, used for attachment of chewing muscles.<\/p>\n<p class=\"import-Normal\"><strong>Scent marking<\/strong>: The behavior of rubbing scent glands or urine onto objects as a way of communicating with others.<\/p>\n<p class=\"import-Normal\"><strong>Semi-brachiation<\/strong>: A form of locomotion in which an organism swings below branches using a combination of forelimbs and prehensile tail.<\/p>\n<p class=\"import-Normal\"><strong>Sexually dimorphic<\/strong>: When a species exhibits sex differences in morphology, behavior, hormones, and\/or coloration.<\/p>\n<p class=\"import-Normal\"><strong>Shearing crests<\/strong>: Sharpened ridges that connect cusps on a bilophodont molar.<\/p>\n<p class=\"import-Normal\"><strong>Specialized trait<\/strong>: A trait that has been modified for a specific purpose.<\/p>\n<p class=\"import-Normal\"><strong>Styloid process of ulna<\/strong>: A bony projection of the ulna at the end near the wrist.<\/p>\n<p class=\"import-Normal\"><strong>Tactile pads<\/strong>: Sensitive skin at the fingertips for sense of touch. Animals with a prehensile tail have a tactile pad on the underside of the tail as well.<\/p>\n<p class=\"import-Normal\"><strong>Tapetum lucidum<\/strong>: Reflecting layer at the back of the eye that magnifies light.<\/p>\n<p class=\"import-Normal\"><strong>Terrestrial<\/strong>: A descriptor for an organism that spends most of its time on the ground.<\/p>\n<p class=\"import-Normal\"><strong>Tetrachromatic<\/strong>: Having the ability to see reds, yellows, blues, greens, and ultraviolet.<\/p>\n<p class=\"import-Normal\"><strong>Tooth comb<\/strong> or <strong>dental comb<\/strong>: A trait of the front, lower teeth of strepsirrhines in which, typically, the four incisors and canines are long and thin and protrude outward.<\/p>\n<p class=\"import-Normal\"><strong>Trichromatic color vision<\/strong>: Being able to distinguish yellows and reds in addition to blues and greens.<\/p>\n<p class=\"import-Normal\"><strong>Vertical clinging and leaping<\/strong>: A locomotor pattern in which animals are oriented upright while clinging to vertical branches, push off with hind legs, and land oriented upright on another vertical branch.<\/p>\n<p class=\"import-Normal\"><strong>Y-5 molar<\/strong>: Molar cusp pattern in which five molar cusps are separated by a \u201cY\u201d-shaped groove pattern.<\/p>\n<h2>About the Author<\/h2>\n<p class=\"import-Normal\"><img class=\"alignleft\" src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image52.jpg\" alt=\"Author with horse.\" width=\"181\" height=\"271\" \/><\/p>\n<p class=\"import-Normal\">Stephanie Etting, Ph.D.<\/p>\n<p class=\"import-Normal\">Sacramento City College and Sonoma State University, ettings@scc.losrios.edu<\/p>\n<p class=\"import-Normal\">Dr. Etting became hooked on biological anthropology as a freshman at UC Davis when she took the \u201cIntroduction to Biological Anthropology\u201d course. She obtained her Ph.D. in anthropology in 2011 from UC Davis, where she studied anti-predator behavior toward snakes in rhesus macaques, squirrel monkeys, and black-and-white ruffed lemurs. While in graduate school, Dr. Etting discovered her love of teaching and, since finishing her dissertation, has taught at UC Berkeley; Sonoma State University; UC Davis; California State University, Sacramento; and Sacramento City College.In addition to her interests in primate behavior, Dr. Etting is also very interested in primate evolution and functional anatomy.<\/p>\n<h2 class=\"import-Normal\">For Further Exploration<\/h2>\n<p class=\"import-Normal\"><a href=\"https:\/\/animaldiversity.org\/accounts\/Primates\/specimens\/\">Animal Diversity Web<\/a>.\u00a0This website is hosted by the Zoology Department at the University of Michigan. It has photographs of skulls, teeth, hands, arms, and feet of many primate species.<\/p>\n<p class=\"import-Normal\"><a href=\"https:\/\/www.eskeletons.org\">eSkeletons<\/a>.\u00a0This website is hosted by the Department of Anthropology at University of Texas, Austin. It is an interactive website where you can compare specific bones from different species of primates.<\/p>\n<p class=\"import-Normal\">Fleagle, John G. 2013. <em>Primate Adaptation and Evolution<\/em>. Third edition. San Diego: Academic Press.<\/p>\n<p class=\"import-Normal\">Fuentes, Agust\u00edn, and Kimberley J. Hockings. 2010. \u201cThe Ethnoprimatological Approach in Primatology.\u201d <em>American Journal of Primatology<\/em> 72 (10): 841\u2013847.<\/p>\n<p class=\"import-Normal\">Rowe, Noel. 1996. <em>Pictorial Guide to the Living Primates<\/em>. Charlestown, RI: Pogonias Press.<\/p>\n<p class=\"import-Normal\">Whitehead, Paul F., William K. Sacco, and Susan B. Hochgraf. 2005. <em>A Photographic Atlas for Physical Anthropology<\/em>. Englewood, CO: Morton Publishing.<\/p>\n<h2>References<\/h2>\n<p class=\"import-Normal\">Balolia, Katharine L., Christophe Soligo, and Bernard Wood. 2017. \u201cSagittal Crest Formation in Great Apes and Gibbons.\u201d <em>Journal of Anatomy<\/em> 230 (6): 820\u2013832.<\/p>\n<p class=\"import-Normal\">Bininda-Emonds, Olaf R., Marcel Cardillo, Kate E. Jones, Ross D. E. MacPhee, Robin M. D. Beck, Richard Grenyer, Samantha A. Price, Rutger A. Vos, John L. Gittleman, and Andy Purvis. 2007. \u201cThe Delayed Rise of Present-Day Mammals.\u201d <em>Nature<\/em> 446 (7135): 507\u2013512.<\/p>\n<p class=\"import-Normal\">Burton, Michael L., Carmella C. Moore, John W. M. Whiting, A. Kimball Romney, David F. Aberle, Juan A. Barcelo, Malcolm M. Dow, et al. 1996. \u201cRegions Based on Social Structure.\u201d <em>Current Anthropology<\/em> 37 (1): 87\u2013123.<\/p>\n<p class=\"import-Normal\">Chivers, David J., and C. M. Hladik. 1980. \u201cMorphology of the Gastrointestinal Tract in Primates: Comparisons with Other Mammals in Relation to Diet.\u201d <em>Journal of Morphology<\/em> 166 (3): 337\u2013386.<\/p>\n<p class=\"import-Normal\">Clutton-Brock, T. H., and Paul H. Harvey. 1980. \u201cPrimates, Brains, and Ecology.\u201d <em>Journal of Zoology<\/em> 190 (3): 309\u2013323.<\/p>\n<p class=\"import-Normal\">Dunbar, Robin I. M. 1998. \u201cThe Social Brain Hypothesis.\u201d <em>Evolutionary Anthropology<\/em> 6 (5): 178\u2013190.<\/p>\n<p class=\"import-Normal\">Ebersberger, Ingo, Dirk Metzler, Carsten Schwarz, and Svante P\u00e4\u00e4bo. 2002. \u201cGenomewide Comparison of DNA Sequences Between Humans and Chimpanzees.\u201d <em>American Journal of Human Genetics<\/em> 70 (6): 1490\u20131497.<\/p>\n<p class=\"import-Normal\">Jameson, Natalie M., Zhuo-Cheng Hou, Kirstin N. Sterner, Amy Weckle, Morris Goodman, Michael E. Steiper, and Derek E. Wildman. 2011. \u201cGenomic Data Reject the Hypothesis of a Prosimian Primate Clade.\u201d <em>Journal of Human Evolution<\/em> 61 (3): 295\u2013305.<\/p>\n<p class=\"import-Normal\">Kawamura, Shoji, Chihiro Hiramatsu, Amanda D. Melin, Colleen M. Schaffner, Filippo Aureli, and Linda M. Fedigan. 2012. \u201cPolymorphic Color Vision in Primates: Evolutionary Considerations.\u201d In <em>Post-Genome Biology of Primates<\/em>, edited by H. Irai, H. Imai, and Y. Go, 93\u2013120. Tokyo: Springer.<\/p>\n<p class=\"import-Normal\">Matsui, Atsushi, Felix Rakotondraparany, Isao Munechika, Masami Hasegawa, and Satoshi Horai. 2009. \u201cMolecular Phylogeny and Evolution of Prosimians Based on Complete Sequences of Mitochondrial DNAs.\u201d <em>Gene<\/em> 441 (1\u20132): 53\u201366.<\/p>\n<p class=\"import-Normal\">Nater, Alexander, Maja P. Mattle-Greminger, Anton Nurcahyo, Matthew G. Nowak, Marc de Manuel, Tariq Desai, Colin Groves, et al. 2017. \u201cMorphometric, Behavioral, and Genomic Evidence for a New Orangutan Species.\u201d <em>Current Biology<\/em> 27 (22): 3487\u20133498.<\/p>\n<p class=\"import-Normal\">Pozzi, Luca, Jason A. Hodgson, Andrew S. Burrell, Kirstin N. Sterner, Ryan L. Raaum, and Todd R. Disotell. 2014. \u201cPrimate Phylogenetic Relationships and Divergence Dates Inferred from Complete Mitochondrial Genomes.\u201d <em>Molecular Phylogenetics and Evolution<\/em> 75: 165\u2013183.<\/p>\n<p class=\"import-Normal\">Remis, Melissa J. 1997. \u201cWestern Lowland Gorillas (<em>Gorilla gorilla gorilla<\/em>) as Seasonal Frugivores: Use of Variable Resources.\u201d <em>American Journal of Primatology<\/em> 43 (2): 87\u2013109.<\/p>\n<p class=\"import-Normal\">Richmond, Brian G., David R. Begun, and David S. Strait. 2001. \u201cOrigin of Human Bipedalism: The Knuckle\u2010Walking Hypothesis Revisited.\u201d <em>American<\/em> <em>Journal of Physical Anthropology<\/em> 116 (S33): 70\u2013105.<\/p>\n<p class=\"import-Normal\">Robson, Shannen L., Carel P. van Schaik, and Kristen Hawkes. 2006. \u201cThe Derived Features of Human Life History.\u201d In <em>The Evolution of Human Life History, edited by Kristen Hawkes and Richard R. Paine, <\/em>17\u201344. Santa Fe: SAR Press.<\/p>\n<p class=\"import-Normal\">Scally, Aylwyn, Julien Y. Dutheil, LaDeana W. Hillier, Gregory E. Jordan, Ian Goodhead, Javier Herrero, Asger Hobolth, et al. 2012. \u201cInsights into Hominid Evolution from the Gorilla Genome Sequence.\u201d <em>Nature<\/em> 483 (7388): 169\u2013175.<\/p>\n<p class=\"import-Normal\">Schneider, Horacio, and Iracilda Sampaio. 2015. \u201cThe Systematics and Evolution of New World Primates: A Review.\u201d <em>Molecular Phylogenetics and Evolution<\/em> 82 (B): 348\u2013357.<\/p>\n<p class=\"import-Normal\">Setchell, Joanna M., Phyllis C. Lee, E. Jean Wickings, and Alan F. Dixson. 2001. \u201cGrowth and Ontogeny of Sexual Size Dimorphism in the Mandrill (<em>Mandrillus sphinx<\/em>).\u201d <em>American Journal of Physical Anthropology<\/em> 115 (4): 349\u2013360.<\/p>\n<p class=\"import-Normal\">Utami, Sri Suci, Beno\u00eet Goossens, Michael W. Bruford, Jan R. de Ruiter, and Jan A. R. A. M. van Hooff. 2002. \u201cMale Bimaturism and Reproductive Success in Sumatran Orang-utans.\u201d <em>Behavioral Ecology<\/em> 13 (5): 643\u2013652.<\/p>\n<p class=\"import-Normal\">Vasey, Natalie. 2006. \u201cImpact of Seasonality and Reproduction on Social Structure, Ranging Patterns, and Fission\u2013Fusion Social Organization in Red Ruffed Lemurs.\u201d In <em>Lemurs: Ecology and Adaptation<\/em>, edited by Lisa Gould and Michelle L. Sauther, 275\u2013304. New York: Springer.<\/p>\n<p class=\"import-Normal\">Wright, Patricia C. 1999. \u201cLemur Traits and Madagascar Ecology: Coping with an Island Environment.\u201d <em>American Journal of Physical Anthropology<\/em> 110 (S29): 31\u201372.<\/p>\n<h2>Acknowledgments<\/h2>\n<p class=\"import-Normal\">The author would very much like to thank the editors for the opportunity to contribute to this textbook, along with anonymous reviewers who provided useful feedback on earlier drafts of this chapter. She would particularly like to thank Karin Enstam Jaffe for her support and encouragement during the writing of this chapter and its revision. Most of all, the author would like to thank all of the Introduction to Biological Anthropology students that she has had over the years who have listened to her lecture endlessly on these animals that she finds so fascinating and who have helped her to hone her pedagogy in a field that she loves.<\/p>\n<\/div>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_281_1695\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_281_1695\"><div tabindex=\"-1\"><div class=\"__UNKNOWN__\">\n<p class=\"import-Normal\">Ashley Kendell, Ph.D., California State University, Chico<\/p>\n<p class=\"import-Normal\">Alex Perrone, M.A., M.S.N, R.N., P.H.N., Butte Community College<\/p>\n<p class=\"import-Normal\">Colleen Milligan, Ph.D., California State University, Chico<\/p>\n<p class=\"import-Normal\"><em>This chapter is a revision from \"<\/em><a class=\"rId7\" href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/chapter\/__unknown__-5\/\"><em>Chapter 15: Bioarchaeology and Forensic Anthropology<\/em><\/a><em>\u201d by Ashley Kendell, Alex Peronne, and Colleen Milligan. In <\/em><a class=\"rId8\" href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/\"><em>Explorations: An Open Invitation to Biological Anthropology, first edition<\/em><\/a><em>, edited by Beth Shook, Katie Nelson, Kelsie Aguilera, and Lara Braff, which is licensed under <\/em><a class=\"rId9\" href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\"><em>CC BY-NC 4.0<\/em><\/a><em>. <\/em><\/p>\n<p class=\"import-Normal\"><strong>Content Warning and Disclaimer:<\/strong> This chapter includes images of human remains as well as discussions centered on human skeletal analyses. All images are derived from casts, sketches, nonhuman skeletal material, as well as non-Indigenous skeletal materials curated within the CSU, Chico Human Identification Lab, and the Hartnett-Fulginiti donated skeletal collection.<\/p>\n<div class=\"textbox textbox--learning-objectives\">\n<header class=\"textbox__header\">\n<h2 class=\"textbox__title\"><span style=\"color: #ffffff;\">Learning Objectives<\/span><\/h2>\n<\/header>\n<div class=\"textbox__content\">\n<ul>\n<li class=\"import-Normal\" style=\"text-indent: 18pt;\">Define forensic anthropology as a subfield of biological anthropology.<\/li>\n<li class=\"import-Normal\" style=\"text-indent: 18pt;\">Describe the seven steps carried out during skeletal analysis.<\/li>\n<li class=\"import-Normal\" style=\"text-indent: 18pt;\">Outline the four major components of the biological profile.<\/li>\n<li class=\"import-Normal\" style=\"text-indent: 18pt;\">Contrast the four categories of trauma.<\/li>\n<li class=\"import-Normal\" style=\"text-indent: 18pt;\">Explain how to identify the different taphonomic agents that alter bone.<\/li>\n<li class=\"import-Normal\" style=\"text-indent: 18pt;\">Discuss ethical considerations for forensic anthropology.<\/li>\n<\/ul>\n<\/div>\n<\/div>\n<p class=\"import-Normal\"><strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_1214\">Forensic anthropology<\/a><\/strong> is a subfield of biological anthropology and an applied area of anthropology. Forensic anthropologists use skeletal analysis to gain information about humans in the present or recent past, then they apply this information within a medicolegal context. This means that forensic anthropologists specifically conduct their analysis on recently deceased individuals (typically within the last 50 years) as part of investigations by law enforcement. Forensic anthropologists can assist law enforcement agencies in several different ways, including aiding in the identification of human remains whether they are complete, fragmentary, burned, scattered, or decomposed. Additionally, forensic anthropologists can help determine what happened to the deceased at or around the time of death as well as what processes acted on the body after death (e.g., whether the remains were scattered by animals, whether they were buried in the ground, or whether they remained on the surface as the soft tissue decomposed).<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Many times, because of their expertise in identifying human skeletal remains, forensic anthropologists are called to help with outdoor search-and-recovery efforts, such as locating remains scattered across the surface or carefully excavating and documenting buried remains. In other cases, forensic anthropologists recover remains after natural disasters or accidents, such as fire scenes, and can help identify whether each bone belongs to a human or an animal. Forensic anthropology spans a wide scope of contexts involving the law, including incidences of mass disasters, genocide, and war crimes.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">A point that can be somewhat confusing for students is that although the term <em>forensic<\/em> is included in this subfield of biological anthropology, there are many forensic techniques that are not included in the subfield. Almost exclusively, forensic anthropology deals with skeletal analysis. While this can include the comparison of antemortem (before death) and postmortem (after death) radiographs to identify whether remains belong to a specific person, or using photographic superimposition of the cranium, it does not include analyses beyond the skeleton. For example, blood-spatter analysis, DNA analysis, fingerprints, and material evidence collection do not fall under the scope of forensic anthropology.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">So, what can forensic anthropologists glean from bones alone? Forensic anthropologists can address a number of questions about a human individual based on their skeletal remains. Some of those questions are as follows: How old was the person? Was the person biologically male or female? How tall was the person? What happened to the person at or around their time of death? Were they sick? The information from the skeletal analysis can then be matched with missing persons records, medical records, or dental records, aiding law enforcement agencies with identifications and investigations.<\/p>\n<h2 class=\"import-Normal\">Skeletal Analysis<\/h2>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Forensic anthropology relies on skeletal analysis to reveal information about the deceased. <span style=\"background-color: #00ffff;\">The methodology and approaches outlined below are specific to the United States.<\/span> Forensic anthropological methods differ depending on the country conducting an investigation. In the United States, there are typically seven steps or questions to the process:<\/p>\n<ul>\n<li class=\"import-Normal\" style=\"text-indent: 0pt;\">Is it bone?<\/li>\n<li class=\"import-Normal\" style=\"text-indent: 0pt;\">Is it human?<\/li>\n<li class=\"import-Normal\" style=\"text-indent: 0pt;\">Is it modern or archeological?<\/li>\n<li class=\"import-Normal\" style=\"text-indent: 0pt;\">How many individuals are present or what is the minimum number of individuals (MNI)?<\/li>\n<li class=\"import-Normal\" style=\"text-indent: 0pt;\">Who is it?<\/li>\n<li class=\"import-Normal\" style=\"text-indent: 0pt;\">Is there evidence of trauma before or around the time of death?<\/li>\n<li class=\"import-Normal\" style=\"text-indent: 0pt;\">What happened to the remains after death?<\/li>\n<\/ul>\n<h3 class=\"import-Normal\"><strong>Is It Bone?<\/strong><\/h3>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">One of the most important steps in any skeletal analysis starts with determining whether or not material suspected to be bone is in fact bone. Though it goes without saying that a forensic anthropologist would only carry out analysis on bone, this step is not always straightforward. Whole bones are relatively easy to identify, but determining whether or not something is bone becomes more challenging once it becomes fragmentary. As an example, in high heat such as that seen on fire scenes, bone can break into pieces. During a house fire with fatalities, firefighters watered down the burning home. After the fire was extinguished, the sheetrock (used to construct the walls of the home) was drenched and crumbled. The crumbled sheetrock was similar in color and form to burned, fragmented bone, therefore mistakable for human remains (Figure 15.1). Forensic anthropologists on scene were able to separate the bones from the construction material, helping to confirm the presence of bone and hence the presence of individual victims of the fire. In this case, forensic anthropologists were able to recognize the anatomical and layered structure of bone and were able to distinguish it from the uniform and unlayered structure of sheetrock.<\/p>\n<p class=\"import-Normal\"><strong><img class=\"aligncenter\" src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/06\/image3.png\" alt=\"Long rectangular sheetrock with exposed porous surface.\" width=\"182\" height=\"208\" \/><\/strong><\/p>\n<figure style=\"width: 372px\" class=\"wp-caption aligncenter\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image6-1.png\" alt=\"Two examples of sheetrock with dried or burnt surfaces.\" width=\"372\" height=\"210\" \/><figcaption class=\"wp-caption-text\">Figure 15.1: Burned sheetrock used as building material appears similar to human bone but can be differentiated by the fact that it is the same density throughout. Credit: <a href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/chapter\/__unknown__-5\/\">Example of burned sheetrock (Figure 15.1)<\/a> original to <a href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/\">Explorations: An Open Invitation to Biological Anthropology<\/a> by Alex Perrone is under a <a href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/\">CC BY-NC 4.0 License<\/a>.<\/figcaption><\/figure>\n<p class=\"import-Normal\">As demonstrated by the example above, both the macrostructure (visible with the naked eye) and microstructure (visible with a microscope) of bone are helpful in bone identification. Bones are organs in the body made up of connective tissue. The connective tissue is hardened by a mineral deposition, which is why bone is rigid in comparison to other connective tissues such as cartilage (Tersigni-Tarrant and Langley 2017, 82\u201383; White and Folkens 2005, 31). In a living body, the mineralized tissue does not make up the only component of bone\u2014there are also blood, bone marrow, cartilage, and other types of tissues. However, in dry bone, two distinct layers of the bone are the most helpful for identification. The outer layer is made up of densely arranged osseous (bone) tissue called <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_1216\">compact (cortical) bone<\/a><\/strong>. The inner layer is composed of much more loosely organized, porous bone tissue whose appearance resembles that of a sponge, hence the name <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_1218\"><strong>spongy (trabecular) bone<\/strong><\/a>. Knowing that most bone contains both layers helps with the macroscopic identification of bone (Figures 15.2, 15.3). For example, a piece of coconut shell might look a lot like a fragment of a human skull bone. However, closer inspection will demonstrate that coconut shell only has one very dense layer, while bone has both the compact and spongy layers.<\/p>\n<figure style=\"width: 380px\" class=\"wp-caption aligncenter\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image27-1.png\" alt=\"Drawing showing thick exterior compact bone and porous internal cortical bone.\" width=\"380\" height=\"371\" \/><figcaption class=\"wp-caption-text\">Figure 15.2: Cross section of human long bone with compact and cortical bone layers visible. Credit: <a href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/chapter\/__unknown__-5\/\">Cross section of human long bone (Figure 15.2)<\/a> original to<a href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/\"> Explorations: An Open Invitation to Biological Anthropology<\/a> by Mary Nelson is under a <a href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/\">CC BY-NC 4.0 License<\/a>.<\/figcaption><\/figure>\n<p>&nbsp;<\/p>\n<figure style=\"width: 364px\" class=\"wp-caption aligncenter\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image25-2.png\" alt=\"Cranial bone cross section called a periosteum with spongy bone (diploe) and compact bone labeled. Compact bone is a thin slice at the top and bottom and is smooth and hard. Spongy bone is in the middle and has irregular holes and indentations throughout. \" width=\"364\" height=\"184\" \/><figcaption class=\"wp-caption-text\">Figure 15.3: Cranial anatomy is slightly different as compared to that of a long bone in cross section. The compact (cortical) bone layers sandwich the spongy (trabecular) bone. One layer of compact bone forms the very outer surface of the skull and the other lines the internal surface of the skull. Credit: <a href=\"https:\/\/cnx.org\/contents\/FPtK1zmh@6.27:kwbeYj9S@3\/Bone-Structure\">Anatomy of a Flat Bone (Anatomy &amp; Physiology, Figure 6.3.3)<\/a> by<a href=\"https:\/\/openstax.org\/\"> OpenStax<\/a> is under a<a href=\"https:\/\/creativecommons.org\/licenses\/by\/4.0\/\"> CC BY 4.0 License<\/a>.<\/figcaption><\/figure>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">The microscopic identification of bone relies on knowledge of <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_1220\">osteons<\/a><\/strong>, or bone cells (Figure 15.4). Under magnification, bone cells are visible in the outer, compact layer of bone. The bone cells are arranged in a concentric pattern around blood vessels for blood supply. The specific shape of the cells can help differentiate, for example, a small piece of PVC (white plastic) pipe from a human bone fragment (Figure 15.5).<\/p>\n<p>&nbsp;<\/p>\n<figure style=\"width: 340px\" class=\"wp-caption aligncenter\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image14-3.png\" alt=\"Microscope image showing clustered osteons. Each has many rings and a dark center.\" width=\"340\" height=\"218\" \/><figcaption class=\"wp-caption-text\">Figure 15.4: Bone microstructure (osteons). Credit: <a href=\"https:\/\/commons.wikimedia.org\/wiki\/File:Bone_(248_12)_Bone_cross_section.jpg\">Bone (248 12) Bone cross section<\/a> by <a href=\"https:\/\/cs.wikipedia.org\/wiki\/Josef_Reischig\">Doc. RNDr. Josef Reischig, CSc.<\/a> is under a <a href=\"https:\/\/creativecommons.org\/licenses\/by-sa\/3.0\/legalcode\">CC BY-SA 3.0 License<\/a>.<\/figcaption><\/figure>\n<p>&nbsp;<\/p>\n<figure style=\"width: 332px\" class=\"wp-caption aligncenter\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image7-1.png\" alt=\"Flat, white section of PVC. Edges are broken and surface rough.\" width=\"332\" height=\"268\" \/><figcaption class=\"wp-caption-text\">Figure 15.5: Fragments of plastic PVC pipe, such as those seen in this photo, may be mistaken for human bone. Credit: <a href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/chapter\/__unknown__-5\/\">Example of PVC pipe<\/a> original to <a href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/\">Explorations: An Open Invitation to Biological Anthropology<\/a> by Alex Perrone is under a <a href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/\">CC BY-NC 4.0 License<\/a>.<\/figcaption><\/figure>\n<h3 class=\"import-Normal\"><strong>Is It Human?<\/strong><\/h3>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Once it has been determined that an object is bone, the next logical step is to identify whether the bone belongs to a human or an animal. Forensic anthropologists are faced with this question in everyday practice because human versus nonhuman bone identification is one of the most frequent requests they receive from law enforcement agencies.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">There are many different ways to distinguish human versus nonhuman bone. The morphology (the shape\/form) of human bone is a good place for students to start. Identifying the 206 bones in the adult human skeleton and each bone\u2019s distinguishing features (muscle attachment sites, openings and grooves for nerves and blood vessels, etc.) is fundamental to skeletal analysis.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Nevertheless, there are many animal bones and human bones that look similar. For example, the declawed skeleton of a bear paw looks a lot like a human hand, pig molars appear similar to human molars, and some smaller animal bones might be mistaken for those of an infant. To add to the confusion, fragmentary bone may be even more difficult to identify as human or nonhuman. However, several major differences between human and nonhuman vertebrate bone help distinguish the two.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Forensic anthropologists pay special attention to the density of the outer, compact layer of bone in both the cranium and in the long bones. Human cranial bone has three distinctive layers. The spongy bone is sandwiched between the outer (ectocranial) and inner (endocranial) compact layers. In most other mammals, the distinction between the spongy and compact layers is not always so definite. Secondly, the compact layer in nonhuman mammal long bones can be much thicker than observed in human bone. Due to the increased density of the compact layer, nonhuman bone tends to be heavier than human bone (Figure 15.6).<\/p>\n<figure style=\"width: 399px\" class=\"wp-caption aligncenter\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image11-2.png\" alt=\"Ring-like cross section of bone.\" width=\"399\" height=\"266\" \/><figcaption class=\"wp-caption-text\">Figure 15.6: The compact layer of this animal bone is very thick, with almost no spongy bone visible. Compare with Figure 15.2 to visualize the difference in structure between human and nonhuman bone. Credit: <a href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/chapter\/__unknown__-5\/\">Animal bone cross section (Figure 15.6)<\/a> original to <a href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/\">Explorations: An Open Invitation to Biological Anthropology<\/a> by Alex Perrone is under a <a href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/\">CC BY-NC 4.0 License<\/a>.<\/figcaption><\/figure>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">The size of a bone can also help determine whether it belongs to a human. Adult human bones are larger than subadult or infant bones. However, another major difference between human adult bones and those of a young individual or infant human can be attributed to development and growth of the <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_1222\">epiphyses<\/a><\/strong> (ends of the bone). The epiphyses of human subadult bones are not fused to the shaft (Figure 15.7). Therefore, if a bone is small and it is suspected to belong to a human subadult or infant, the epiphyses would not be fused. Many small animal bones appear very similar in form compared to adult human bones, but they are much too small to belong to an adult human. Yet they can be eliminated as subadult or infant bones if the epiphyses are fused to the shaft.<\/p>\n<figure style=\"width: 288px\" class=\"wp-caption aligncenter\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image13-3.png\" alt=\"X-ray image of child\u2019s ankle.\" width=\"288\" height=\"412\" \/><figcaption class=\"wp-caption-text\">Figure 15.7: An x-ray of a subadult\u2019s ankle with the epiphyses of the tibia and fibula visible. The gap between the shaft of the bone and the end of the bone (epiphysis) is the location of the growth plate. Therefore, the growth plate gap is what separates the shafts from the epiphyses in the image. Credit: <a href=\"https:\/\/commons.wikimedia.org\/wiki\/File:Tib_fib_growth_plates.jpg\">Tib fib growth plates<\/a> by <a href=\"https:\/\/en.wikipedia.org\/wiki\/User:Gilo1969\">Gilo1969<\/a> at <a href=\"https:\/\/en.wikipedia.org\/wiki\/\">English Wikipedia<\/a> is under a <a href=\"https:\/\/creativecommons.org\/licenses\/by\/3.0\/legalcode\">CC BY 3.0 License<\/a>.<\/figcaption><\/figure>\n<h3 class=\"import-Normal\"><strong>Is It Modern or Archaeological? <\/strong><\/h3>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Forensic anthropologists work with modern cases that fall within the scope of law enforcement investigations. Accordingly, it is important to determine whether discovered human remains are <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_1224\">archaeological<\/a> <\/strong>or forensic in nature. Human remains that are historic are considered archeaological. The scientific study of human remains from archaeological sites is called <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_1226\">bioarchaeology<\/a><\/strong>.<\/p>\n<div class=\"textbox shaded\">\n<h2 class=\"import-Normal\"><span style=\"background-color: #ff99cc;\">Dig Deeper: Bioarchaeology<\/span><\/h2>\n<p class=\"import-Normal\"><span style=\"background-color: #ff99cc;\">For readers who are interested in the sister subfield of bioarchaeology, which studies human remains and material culture from the past, please refer to chapter 8 of <em>Bioarchaeology: Interpreting Human Behavior from Skeletal Remains,<\/em> in <em>TRACES: An Open Invitation to Archaeology<\/em> (Blatt, Michael, and Bright forthcoming).<\/span><\/p>\n<\/div>\n<p>A forensic anthropologist should begin their analysis by reviewing the context in which the remains were discovered. This will help them understand a great deal about the remains, including determining whether they are archaeological or forensic in nature as well as considering legal and ethical issues associated with the collection, analysis, and storage of human remains (see \u201cEthics and Human Rights\u201d section of this chapter for more information).<\/p>\n<figure style=\"width: 403px\" class=\"wp-caption alignleft\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image10-3.png\" alt=\"Four teeth in a person\u2019s mouth. First molar with silver filling.\" width=\"403\" height=\"303\" \/><figcaption class=\"wp-caption-text\">Figure 15.8: A human tooth with a filling. Credit: <a href=\"https:\/\/commons.wikimedia.org\/wiki\/File:Filling.jpg#filehistory\">Filling<\/a> by Kauzio has been designated to the <a href=\"https:\/\/creativecommons.org\/share-your-work\/public-domain\/cc0\/\">public domain (CC0)<\/a>.<\/figcaption><\/figure>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">The \u201ccontext\u201d refers to the relationship the remains have to the immediate area in which they were found. This includes the specific place where the remains were found, the soil or other organic matter immediately surrounding the remains, and any other objects or artifacts in close proximity to the body. For example, imagine that a set of remains has been located during a house renovation. The remains are discovered below the foundation. Do the remains belong to a murder victim? Or was the house built on top of an ancient burial ground? Observing information from the surroundings can help determine whether the remains are archaeological or modern. How long ago was the foundation of the house erected? Are there artifacts in close proximity to the body, such as clothing or stone tools? These are questions about the surroundings that will help determine the relative age of the remains.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Clues directly from the skeleton may also indicate whether the remains are archaeological or modern. For example, tooth fillings can suggest that the individual was alive recently (Figure 15.8). In fact, filling material has changed over the decades, so the specific type of material used to fix a cavity can be matched with specific time periods. Gold was used in dental work in the past, but more recently composite (a mixture of plastic and fine glass) fillings have become more common.<\/p>\n<h3><strong>How <\/strong><strong>Many Individuals Are Present?<\/strong><\/h3>\n<h4 class=\"import-Normal\"><em>What Is MNI?<\/em><\/h4>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Another assessment that an anthropologist can perform is the calculation of the number of individuals in a mixed burial assemblage. Because not all burials consist of a single individual, it is important to <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_1268\">burial assemblage<\/a><\/strong> be able to estimate the number of individuals in a forensic context. Quantification of the number of individuals in a <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_1524\">burial assemblage<\/a><\/strong> can be done through the application of a number of methods, including the following: the Minimum Number of Individuals (MNI), the Most Likely Number of Individuals (MLNI), and the Lincoln Index (LI). The most commonly used method in biological anthropology, and the focus of this section, is determination of the MNI.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">The MNI presents \u201cthe minimum estimate for the number of individuals that contributed to the sample\u201d (Adams and Konigsberg 2008, 243). Many methods of calculating MNI were originally developed within the field of zooarchaeology for use on calculating the number of individuals in faunal or animal assemblages (Adams and Konigsberg 2008, 241). What MNI calculations provide is a lowest possible count for the total number of individuals contributing to a skeletal assemblage. Traditional methods of calculating MNI include separating a skeletal assemblage into categories according to the individual bone and the side the bone comes from and then taking the highest count per category and assigning that as the minimum number (Figure 15.9).<\/p>\n<p>&nbsp;<\/p>\n<figure style=\"width: 664px\" class=\"wp-caption aligncenter\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image28-3.png\" alt=\"Many bone portions laying on individual plastic bags on a table.\" width=\"664\" height=\"441\" \/><figcaption class=\"wp-caption-text\">Figure 15.9: Skeletal elements from a commingled faunal assemblage. Credit: Commingled animal remains from Eden-Farson Pre-Contact site in southwest Wyoming by Matt O\u2019Brien original to Explorations: An Open Invitation to Biological Anthropology (2nd ed.) is under a <a href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/\">CC BY-NC 4.0 License<\/a>.<\/figcaption><\/figure>\n<h4 class=\"import-Normal\"><em>Why Calculate MNI?<\/em><\/h4>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">In a forensic context, the determination of MNI is most applicable in cases of mass graves, <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_1232\">commingled burials<\/a><\/strong>, and mass fatality incidents. The term <em>commingled<\/em> is applied to any burial assemblage in which individual skeletons are not separated into separate burials. As an example, the authors of this chapter have observed commingling of remains resulting from mass fatality wildfire events. Commingled remains may also be encountered in events such as a plane or vehicle crash. It is important to remember that in any forensic context, MNI should be referenced and an MNI of one should be substantiated by the fact that there was no repetition of elements associated with the case.<\/p>\n<h3 class=\"import-Normal\"><strong>Constructing the Biological Profile<\/strong><\/h3>\n<h4 class=\"import-Normal\"><em>Who Is It?<\/em><\/h4>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">\u201cWho is it?\u201d is one of the first questions that law enforcement officers ask when they are faced with a set of skeletal remains. To answer this question, forensic anthropologists construct a biological profile (White and Folkens 2005, 405). A <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_1228\">biological profile<\/a> <\/strong>is an individual\u2019s identifying characteristics, or biological information, which include the following: biological sex, age at death, stature, population affinity, skeletal variation, and evidence of trauma and pathology.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\"><span style=\"background-color: #ff99cc;\">Forensic anthropologists typically construct a biological profile to help positively identify a deceased person. The following section will lay out each component of the biological profile and briefly review standard methodology used for each.<\/span><\/p>\n<h4 class=\"import-Normal\"><em>Assessing Biological Sex <\/em><\/h4>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Assessment of biological sex is often one of the first things considered when establishing a biological profile because several other parts, such as age and stature estimations, rely on an assessment of biological sex to make the calculations more accurate.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Assessment of biological sex focuses on differences in both morphological (form or structure) and metric (measured) traits in individuals. When assessing morphological traits, the skull and the pelvis are the most commonly referenced areas of the skeleton. These differences are related to sexual dimorphism usually varying in the amount of robusticity seen between males and females. <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_1230\">Robusticity<\/a> <\/strong>deals with strength and size; it is frequently used as a term to describe a large size or thickness. In general, males will show a greater degree of robusticity than females. For example, the length and width of the mastoid process, a bony projection located behind the opening for the ear, is typically larger in males. The mastoid process is an attachment point for muscles of the neck, and this bony projection tends to be wider and longer in males. In general, cranial features tend to be more robust in males (Figure 15.10).<\/p>\n<figure style=\"width: 601px\" class=\"wp-caption aligncenter\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image26-3.png\" alt=\"Front and side images of a male (left) and female (right) cranium.\" width=\"601\" height=\"632\" \/><figcaption class=\"wp-caption-text\">Figure 15.10: Anterior and lateral view of a male and female cranium. Credit: <a href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/chapter\/__unknown__-5\/\">Anterior and lateral view of a male and female cranium (Figure 15.10)<\/a> original to <a href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/\">Explorations: An Open Invitation to Biological Anthropo logy<\/a> by Ashley Kendell is a collective work under a <a href=\"https:\/\/creativecommons.org\/licenses\/by-nc-sa\/4.0\/\">CC BY-NC-SA 4.0 License<\/a>. [Includes <a href=\"https:\/\/boneclones.com\/product\/modern-human-asian-female-skull-BC-149\/category\/all-human-skulls\/human-anatomy\">Human Female Asian Skull<\/a> and <a href=\"https:\/\/boneclones.com\/product\/human-asian-male-skull-BC-016\/category\/all-human-skulls\/human-anatomy\">Human Male Asian Skull<\/a> by <a href=\"https:\/\/boneclones.com\/\">\u00a9BoneClones<\/a>, used by permission.]<\/figcaption><\/figure>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">When considering the pelvis, the features associated with the ability to give birth help distinguish females from males. During puberty, estrogen causes a widening of the female pelvis to allow for the passage of a baby. Several studies have identified specific features or bony landmarks associated with the widening of the hips, and this section will discuss one such method. The Phenice Method (Phenice 1969) is traditionally the most common reference used to assess morphological characteristics associated with sex. The Phenice Method specifically looks at the presence or absence of (1) a ventral arc, (2) the presence or absence of a subpubic concavity, and (3) the width of the medial aspect of the ischiopubic ramus (Figure 15.11). When present, the ventral arc, a ridge of bone located on the ventral surface of the pubic bone, is indicative of female remains. Likewise the presence of a subpubic concavity and a narrow medial aspect of the ischiopubic ramus is associated with a female sex estimation. Assessments of these features, as well as those of the skull (when both the pelvis and skull are present), are combined for an overall estimation of sex.<\/p>\n<p>&nbsp;<\/p>\n<figure style=\"width: 1603px\" class=\"wp-caption alignnone\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image29-3.png\" alt=\"Male and female os coxae (anterior portions).\" width=\"1603\" height=\"582\" \/><figcaption class=\"wp-caption-text\">Figure 15.11: Features associated with the Phenice Method. Images derived from CSU-HIL donated skeletal collection. Credit: <a href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/chapter\/__unknown__-5\/\">Features associated with the Phenice Method (Figure 15.11)<\/a> original to <a href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/\">Explorations: An Open Invitation to Biological Anthropology<\/a> by Colleen Milligan is under a <a href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/\">CC BY-NC 4.0 License<\/a>.<\/figcaption><\/figure>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Metric analyses are also used in the estimation of sex. Measurements taken from every region of the body can contribute to estimating sex through statistical approaches that assign a predictive value of sex. These approaches can include multiple measurements from several skeletal elements in what is called multivariate (multiple variables) statistics. Other approaches consider a single measurement, such as the diameter of the head of the femur, of a specific element in a univariate (single variable) analysis (Berg 2017, 152\u2013156).<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">It is important to note that, although forensic anthropologists usually begin assessment of biological profile with biological sex, there is one major instance in which this is not appropriate. The case of two individuals found in California, on July 8, 1979, is one example that demonstrates the effect age has on the estimation of sex. The identities of the two individuals were unknown; therefore, law enforcement sent them to a lab for identification. A skeletal analysis determined that the remains represented one adolescent male and one adolescent female, both younger than 18 years of age. This information did not match with any known missing children at the time.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">In 2015, the cold case was reanalyzed, and DNA samples were extracted. The results indicated that the remains were actually those of two girls who went missing in 1978. The girls were 15 years old and 14 years old at the time of death. It is clear that the 1979 results were incorrect, but this mistake also provides the opportunity to discuss the limitations of assessing sex from a subadult skeleton.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Assessing sex from the human skeleton is based on biological and genetic traits associated with females and males. These traits are linked to differences in sexual dimorphism and reproductive characteristics between females and males. The link to reproductive characteristics means that most indicators of biological sex do not fully manifest in prepubescent individuals, making estimations of sex unreliable in younger individuals (SWGANTH 2010b). This was the case in the example of the 14-year-old girl. When examined in 1979, her remains were misidentified as male because she had not yet fully developed female pelvic traits.<\/p>\n<h4 class=\"import-Normal\"><em>Sex vs. Gender<\/em><\/h4>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Biological sex is a different concept than <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_1234\">gender<\/a><\/strong>. While biological anthropologists can estimate sex from the skeleton, estimating an individual\u2019s gender would require a greater context because gender is defined culturally rather than biologically. Take, for example, an individual who identifies as transgender. This individual has a gender identity that is different from their biological sex. The gender identity of any individual depends on factors related to self-identification, situation or context, and cultural factors. <span style=\"background-color: #00ffff;\">While in the U.S<\/span>. we have historically thought of sex and gender as binary concepts (male or female), many cultures throughout the world recognize several possible gender identities. In this sense, gender is seen as a continuous or fluid variable rather than a fixed one.<\/p>\n<p class=\"import-Normal\">Historically, forensic anthropologists have used a binary construct to categorize human skeletal remains as either male or female (with the accompanying categories of probable male, probable female, and indeterminate). In the case of transgender and gender nonconforming individuals, the binary approach to sex assessment may delay or hinder identification efforts (Buchanan 2014; Schall, Rogers, and Deschamps-Braly 2020; Tallman, Kincer, and Plemons 2021). As such, many forensic anthropologists have begun to address the inherent problems associated with a binary approach to sex identification and to explore ways of assessing social identity and self-identified gender using skeletal remains and forensic context.<\/p>\n<p class=\"import-Normal\"><span style=\"background-color: #ff99cc;\">For the duration of this section, the term <em>transgender<\/em> refers to individuals whose gender identity differs from the sex assigned at birth (Schall, Rogers, and Deschamps-Braly 2020:2). <\/span>Transgender individuals transition from one gender binary to another, such as male-to-female (MTF) or female-to-male (FTM). While many of the gender-affirming procedures available to trans and gender-nonconforming individuals are focused on soft tissue modifications (e.g., breast augmentation, genital reconstruction, hormone therapies, etc.), there are a number of gender-affirmation surgeries that do leave a permanent record on the skeleton. Generally speaking, FTM transgender people are reported to undergo fewer surgical procedures than do MTF transgender people (Buchanan 2014). The discussion below focuses on Facial Feminization Surgery (FFS), which leaves a permanent record on the human skeleton that may be used to help make an identification.<\/p>\n<p class=\"import-Normal\">FFS refers to a combination of procedures focused on sexually dimorphic features of the face, with the intent of transforming typically male facial features into more feminine forms. Facial Feminization Surgery procedures were developed by Dr. Douglas Ousterhout, a San Francisco based cranio-maxillofacial surgeon, in the mid-1980s (Schall, Rogers, and Deschamps-Braly 2020:2). FFS can include one or a combination of the following: hairline lowering, forehead reduction and contouring, brow lift, reduction rhinoplasty, cheek enhancement, lift lift, lip filling, chin contouring, jaw contouring, and\/or tracheal shave (Buchanan 2014; Schall, Rogers, and Deschamps-Braly 2020:2). Of the procedures outlined previously, four are known to directly affect the facial skeleton: forehead contouring, rhinoplasty, chin contouring, and jaw contouring (Buchanan 2014; Schall, Rogers, and Deschamps-Braly 2020:2).<\/p>\n<p class=\"import-Normal\">Because FFS procedures have been widely documented in the medical (and more recently the forensic anthropological) literature, there are a number of indicators that a forensic anthropologist can use to make more informed evaluations of gender, including evidence of bone remodeling in sexually dimorphic regions of the skull (e.g., forehead, chin, jawline), as well as the presence of plates, pins, or other surgical hardware that may be evidence of FFS (Buchanan 2014; Schall, Rogers, and Deschamps-Braly 2020; Tallman, Kincer, and Plemons 2021). Additionally, some forensic anthropologists suggest cautiously integrating contextual information from the scene, such as personal effects, material evidence, and recovery scene information, into their evaluation of an individual\u2019s social identity (Beatrice and Soler 2016; Birkby, Fenton, and Anderson 2008; Soler and Beatrice 2018; Soler et al. 2019; Tallman, Kincer, and Plemons 2021; Winburn, Schoff, and Warren 2016). The ultimate goal of many skeletal analyses is to make a positive identification on a set of unidentified remains.<\/p>\n<h4 class=\"import-Normal\"><em>Assessment <\/em><em>of Population Affinity<\/em><\/h4>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\"><strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_1236\">Population affinity<\/a><\/strong> is another component of the biological profile. We use the term <em>population affinity<\/em> to refer to the variation seen among modern populations\u2014variation that is both genetic and environmentally driven. The word <em>affinity<\/em> refers to similarities or relationships between individuals. As forensic anthropologists, we compare an unknown individual to multiple reference groups and look for the degree of similarity in observable traits with those groups. As noted previously, population affinity can aid law enforcement in their identification of missing persons or unknown skeletal remains.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Within the field of anthropology, the estimation of population affinity has a contentious history, and early attempts at classification were largely based on the erroneous assumption that an individual\u2019s <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_1238\">phenotype <\/a><\/strong> (outward appearance) was correlated with their innate intelligence and abilities (see Chapter 13 for a more in-depth discussion of the history of the race concept). The use of the term <em>race<\/em> is deeply embedded in the social context of the United States. In any other organism\/living thing, groups divided according to the biological race concept would be defined as a separate subspecies. The major issue with applying the biological race concept to humans is that there are not enough differences between any two populations to separate on a genetic basis. In other words, <em>biological races do not exist in human populations. <\/em>However, the concept of race has been perpetuated and upheld by sociocultural constructs of race.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">The conundrum for forensic anthropologists is the fact that while races do not exist on a biological level, we still socially recognize and categorize individuals based on their phenotype. Clearly, our phenotype is an important factor in not only how we are viewed by others but also how we identify ourselves. It is also a commonly reported variable. Often labeled as \u201crace,\u201d we are asked to report how we self-identify on school applications, government identification, surveys, census reports, and so forth. It follows then that when a person is reported missing, the information commonly collected by law enforcement and sometimes entered into a missing person\u2019s database includes their age, biological sex, stature, and \u201crace.\u201d Therefore, the more information a forensic anthropologist can provide regarding the individual\u2019s physical characteristics, the more he or she can help to narrow the search.<\/p>\n<p class=\"import-Normal\">As an exercise, create a list of all of the women you know who are between the ages of 18 and 24 and approximately 5\u2019 4\u201d to 5\u2019 9\u201d tall. You probably have several dozen people on the list. Now, consider how many females you know who are between the ages of 18 and 24, are approximately 5\u2019 4\u201d to 5\u2019 9\u201d tall, and are Vietnamese. Your list is going to be significantly shorter. That\u2019s how missing persons searches go as well. The more information you can provide regarding a decedent\u2019s phenotype, the fewer possible matches law enforcement are left to investigate. This is why population affinity has historically been included as a part of the biological profile.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\"><span style=\"text-decoration: underline;\">(Put at the beginning of this section<\/span><span style=\"background-color: #ccffcc;\">)In an effort to combat the erroneous assumptions tied to the race concept, forensic anthropologists have attempted to reframe this component of the biological profile. The term <em>race<\/em> is no longer used in casework and teaching. Historically, the word <em>ancestry<\/em> is and was deemed a more appropriate way to describe an individual\u2019s phenotype. However, in more recent years, forensic anthropologists have begun using the term <em>population affinity, <\/em>recognizing that we are basing our analysis on the similarities we see based on the reference samples we have available (Winburn and Algee-Hewitt 2021). An important note here is that it is possible to hinder identifications and harm individuals when tools like estimations of population affinity are misapplied, misinterpreted, or misused. For this reason, the field of forensic anthropology has ongoing conversations about the appropriateness of this analysis in the biological profile (Bethard and DiGangi 2020; Stull et al. 2021).<\/span><\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Traditionally, population affinity was accomplished through a visual inspection of morphological variants of the skull (morphoscopics). These methods focused on elements of the facial skeleton, including the nose, eyes, and cheek bones. However, in an effort to reduce subjectivity, nonmetric cranial traits are now assessed within a statistical framework to help anthropologists better interpret their distribution among living populations (Hefner and Linde 2018). Based on the observable traits, a macromorphoscopic analysis will allow the practitioner to create a statistical prediction of geographic origin. In essence, forensic anthropologists are using human variation in the estimation of geographic origin, by referencing documented frequencies of nonmetric skeletal indicators or macromorphoscopic traits.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Population affinity is also assessed through metric analyses. The computer program Fordisc is an anthropological tool used to estimate different components of the biological profile, including ancestry, sex, and stature. When using Fordisc, skeletal measurements are input into the computer software, and the program employs multivariate statistical classification methods, including discriminant function analysis, to generate a statistical prediction for the geographic origin of unknown remains based on the comparison of the unknown to the reference samples in the software program. Fordisc also calculates the likelihood of the prediction being correct, as well as how typical the metric data is for the assigned group.<\/p>\n<h4 class=\"import-Normal\"><em>Estimating Age-at-Death<\/em><\/h4>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Estimating age-at-death from the skeleton relies on the measurement of two basic physiological processes: (1) growth and development and (2) degeneration (or aging). From fetal development on, our bones and teeth grow and change at a predictable rate. This provides for relatively accurate age estimates. After our bones and teeth cease to grow and develop, they begin to undergo structural changes, or degeneration, associated with aging. This does not happen at such predictable rates and, therefore, results in less accurate or larger age-range estimations.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">During growth and development stages, two primary methods used for estimations of age of subadults (those under the age of 18) are <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_1240\">epiphyseal union<\/a><\/strong> and <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_1244\">dental development.<\/a><\/strong> Epiphyseal union<strong> (<\/strong>or <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_1242\">epiphyseal fusion<\/a><\/strong>) refers to the appearance and closure of the epiphyseal plates between the primary centers of growth in a bone and the subsequent centers of growth (see Figure 15.7). Prior to complete union, the cartilaginous area between the primary and secondary centers of growth is also referred to as the growth plates (Schaefer, Black, and Scheuer 2009). Different areas of the skeleton have documented differences in the appearance and closure of epiphyses, making this a reliable method for aging subadult remains (SWGANTH 2013).<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">As an example of its utility in the identification process, epiphyseal development was used to identify two subadult victims of a fatal fire in Flint, Michigan, in February 2010. The remains represented two young girls, ages three and four. Due to the intensity of the fire, the subadult victims were differentiated from each other through the appearance of the patella, the kneecap. The patella is a bone that develops within the tendon of the quadriceps muscle at the knee joint. The patella begins to form around three to four years of age (Cunningham, Scheuer, and Black 2016, 407\u2013409). In the example above, radiographs of the knees showed the presence of a patella in the four-year-old girl and the absence of a clearly discernible patella in the three-year-old.<\/p>\n<figure style=\"width: 358px\" class=\"wp-caption alignright\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image18-2.png\" alt=\"Cranial cast of child with exposed maxilla and mandible to see developing dentition.\" width=\"358\" height=\"358\" \/><figcaption class=\"wp-caption-text\">Figure 15.12: Dental development in a subadult. Credit: <a href=\"https:\/\/boneclones.com\/product\/5-year-old-human-child-skull-with-mixed-dentition-exposed-BC-189\">5-year-old Human Child Skull with Mixed Dentition Exposed<\/a> by <a href=\"https:\/\/boneclones.com\/\">\u00a9BoneClones<\/a> is used by permission and available here is under a <a href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/\">CC BY-NC 4.0 License<\/a>.<\/figcaption><\/figure>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Dental development begins during fetal stages of growth and continues until the complete formation and eruption of the adult third molars (if present). The first set of teeth to appear are called deciduous or baby teeth. Individuals develop a total of 20 deciduous teeth, including incisors, canines, and molars. These are generally replaced by adult dentition as an individual grows (Figure 15.12). A total of 32 teeth are represented in the adult dental arcade, including incisors, canines, premolars, and molars. When dental development is used for age estimations, researchers use both tooth-formation patterns and eruption schedules as determining evidence. For example, the crown of the tooth forms first followed by the formation of the tooth root. During development, an individual can exhibit a partially formed crown or a complete crown with a partially formed root. The teeth generally begin the eruption process once the crown of the tooth is complete. The developmental stages of dentition are one of the most reliable and consistent aging methods for subadults (Langley, Gooding, and Tersigni-Tarrant 2017, 176\u2013177).<\/p>\n<figure style=\"width: 403px\" class=\"wp-caption alignleft\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image22-3.png\" alt=\"Surfaces of three pubic symphyses: billowy (A) to more flat (B) to rough (C).\" width=\"403\" height=\"224\" \/><figcaption class=\"wp-caption-text\">Figure 15.13: Examples of degenerative changes to the pubic symphysis: (A) young adult; (B) middle adult; (C) old adult. Credit: <a href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/chapter\/__unknown__-5\/\">Example of the progression of degenerative changes to the pubic symphysis (Figure 15.14)<\/a> original to <a href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/\">Explorations: An Open Invitation to Biological Anthropo logy<\/a> by Ashley Kendell is under a <a href=\"https:\/\/creativecommons.org\/licenses\/by-nc-sa\/4.0\/\">CC BY-NC-SA 4.0 License<\/a>. [Original photos by Dr. Julie Fleischman used by permission. Pubic symphyses are curated in the Hartnett-Fulginiti donated skeletal collection. Donation and research consent was provided by next of kin.]<\/figcaption><\/figure>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Degenerative changes in the skeleton typically begin after 18 years of age, with more prominent changes developing after an individual reaches middle adulthood (commonly defined as after 35 years of age in osteology). These changes are most easily seen around joint surfaces of the pelvis, the cranial vault, and the ribs. In this chapter, we focus on the pubic symphysis surfaces of the pelvis and the sternal ends of the ribs, which show metamorphic changes from young adulthood to older adulthood. The <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_1262\">pubic symphysis<\/a> <\/strong>is a joint that unites the left and right halves of the pelvis. The surface of the pubic symphysis changes during adulthood, beginning as a surface with pronounced ridges (called billowing) and flattening with a more distinct rim to the pubic symphysis as an individual ages. As with all metamorphic age changes, older adults tend to develop lipping around the joint surfaces as well as a breakdown of the joint surfaces. The most commonly used method for aging adult skeletons from the pubic symphysis is the Suchey-Brooks method (Brooks and Suchey 1990; Katz and Suchey 1986). This method divides the changes seen with the pubic symphysis into six phases based on macroscopic age-related changes to the surface. Figure 15.13 provides a visual of the degenerative changes that typically occur on the pubic symphysis.<\/p>\n<figure style=\"width: 403px\" class=\"wp-caption alignright\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image12-3.png\" alt=\"Three sternal rib ends demonstrating progressive changes that occur with age.\" width=\"403\" height=\"220\" \/><figcaption class=\"wp-caption-text\">Figure 15.14: Examples of degenerative changes to the sternal rib end: (A) young adult; (B) middle adult; (C) old adult. Images derived from CSU, Chico HIL donated skeletal collection. Credit: <a href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/chapter\/__unknown__-5\/\">Examples of degenerative changes to the sternal rib end (Figure 15.15)<\/a> original to <a href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/\">Explorations: An Open Invitation to Biological Anthropology<\/a> by Alex Perrone is under a <a href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/\">CC BY-NC 4.0 License<\/a>.<\/figcaption><\/figure>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">The sternal end of the ribs, the <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_1246\">anterior <\/a><\/strong> end of the rib that connects via cartilage to the sternum, is also used in age estimations of adults. This method, first developed by M. Y. \u0130\u015fcan and colleagues, considers both the change in shape of the sternal end as well as the quality of the bone (\u0130\u015fcan, Loth, and Wright 1984; \u0130\u015fcan, Loth, and Wright 1985). The sternal end first develops a billowing appearance in young adulthood. The bone typically develops a wider and deeper cupped end as an individual ages. Older adults tend to exhibit bony extensions of the sternal end rim as attaching cartilage ossifies. Figure 15.14 provides a visual of the degenerative changes that typically occur in sternal rib ends.<\/p>\n<h4 class=\"import-Normal\"><em>Estimating Stature<\/em><\/h4>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Stature, or height, is one of the most prominently recorded components of the biological profile. Our height is recorded from infancy through adulthood. Doctor\u2019s appointments, driver's license applications, and sports rosters all typically involve a measure of stature for an individual. As such, it is also a component of the biological profile nearly every individual will have on record. Bioarchaeologists and forensic anthropologists use stature estimation methods to provide a range within which an individual\u2019s biological height would fall. <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_1248\">Biological height<\/a> <\/strong>is a person\u2019s true anatomical height. However, the range created through these estimations is often compared to <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_1264\">reported stature<\/a><\/strong>, which is typically self-reported and based on an approximation of an individual\u2019s true height (Ousley 1995).<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">In June 2015, two men were shot and killed in Granite Bay, California, in a double homicide. Investigators were able to locate surveillance camera footage from a gas station where the two victims were spotted in a car with another individual believed to be the perpetrator in the case. The suspect, sitting behind the victims in the car, hung his right arm out of the window as the car drove away. The search for the perpetrator was eventually narrowed down to two suspects. One suspect was 5\u2019 8\u201d while the other suspect was 6\u2019 4\u201d, representing almost a foot difference in height reported stature between the two. Forensic anthropologists were given the dimensions of the car (for proportionality of the arm) and were asked to calculate the stature of the suspect in the car from measurements of the suspect\u2019s forearm hanging from the window. Approximate lengths of the bones of the forearm were established from the video footage and used to create a predicted stature range. Stature estimations from skeletal remains typically look at the correlation between the measurements of any individual bone and the overall measurement of body height. In the case above, the length of the right forearm pointed to the taller of the two suspects who was subsequently arrested for the homicide.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Certain bones, such as the long bones of the leg, contribute more to our overall height than others and can be used with mathematical equations known as regression equations. <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_1252\">Regression methods <\/a> <\/strong>examine the relationship between variables such as height and bone length and use the correlation between the variables to create a prediction interval (or range) for estimated stature. This method for calculating stature is the most commonly used method (SWGANTH 2012). Figure 15.15 shows the measurement of the bicondylar length of the femur for stature estimations.<\/p>\n<figure style=\"width: 584px\" class=\"wp-caption aligncenter\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image2-3.png\" alt=\"A femur is measured using a wooden osteometric board.\" width=\"584\" height=\"389\" \/><figcaption class=\"wp-caption-text\">Figure 15.15: Image of measurement of the bicondylar length of the femur, often used in the estimation of living stature. Image derived from CSU, Chico HIL donated skeletal collection. Credit: <a href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/chapter\/__unknown__-5\/\">Measurement of the bicondylar length of the femur<\/a> original to <a href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/\">Explorations: An Open Invitation to Biological Anthropology<\/a> by Alex Perrone is under a <a href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/\">CC BY-NC 4.0 License<\/a>.<\/figcaption><\/figure>\n<h4 class=\"import-Normal\"><em>Identification Using Individualizing Characteristics<\/em><\/h4>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">One of the most frequently requested analyses within the forensic anthropology laboratory is assistance with the identification of unidentified remains. While all components of a biological profile, as discussed above, can assist law enforcement officers and medical examiners to narrow down the list of potential identifications, a biological profile will not lead to a <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_1254\">positive identification<\/a><\/strong>. The term <em>positive identification<\/em> refers to a scientifically validated method of identifying previously unidentified remains. Presumptive identifications, however, are not scientifically validated; rather, they are based on circumstances or scene context. For example, if a decedent is found in a locked home with no evidence of forced entry but the body is no longer visually identifiable, it may be presumed that the remains belong to the homeowner. Hence, a presumptive identification.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">The medicolegal system ultimately requires that a positive identification be made in such circumstances, and a presumptive identification is often a good way to narrow down the pool of possibilities. Biological profile information also assists with making a presumptive identification based on an individual\u2019s phenotype in life (e.g., what they looked like). As an example, a forensic anthropologist may establish the following components of a biological profile: white male, between the ages of 35 and 50, approximately 5\u2019 7\u201d to 5\u2019 11.\u201d While this seems like a rather specific description of an individual, you can imagine that this description fits dozens, if not hundreds, of people in an urban area. Therefore, law enforcement can use the biological profile information to narrow their pool of possible identifications to include only white males who fit the age and height outlined above. Once a possible match is found, the decedent can be identified using a method of positive identification.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Positive identifications are based on what we refer to as individualizing traits or characteristics, which are traits that are unique at the individual level. For example, brown hair is not an individualizing trait as brown is the most common hair color in the U.S. But, a specific pattern of dental restorations or surgical implants can be individualizing, because it is unlikely that you will have an exact match on either of these traits when comparing two individuals.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">A number of positive methods are available to forensic anthropologists, and for the remainder of this section we will discuss the following methods: comparative medical and dental radiography and identification of surgical implants.<\/p>\n<figure style=\"width: 165px\" class=\"wp-caption alignleft\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image17-3.png\" alt=\"Radiograph of skull with frontal sinuses visible.\" width=\"165\" height=\"182\" \/><figcaption class=\"wp-caption-text\">Figure 15.16: Example of the unique shape of the frontal sinus. Credit: <a href=\"https:\/\/commons.wikimedia.org\/wiki\/File:Frontal_bone_sinuses.jpg\">Frontal bone sinuses<\/a> by <a href=\"https:\/\/commons.wikimedia.org\/wiki\/User:Alex_Khimich\">Alex Khimich<\/a> is under a <a href=\"https:\/\/creativecommons.org\/licenses\/by-sa\/4.0\/legalcode\">CC BY-SA 4.0 License<\/a>.<\/figcaption><\/figure>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Comparative medical and dental radiography is used to find consistency of traits when comparing antemortem records (medical and dental records taken during life) with images taken postmortem (after death). Comparative medical radiography focuses primarily on features associated with the skeletal system, including trabecular pattern (internal structure of bone that is honeycomb in appearance), bone shape or cortical density (compact outer layer of bone), and evidence of past trauma, skeletal pathology, or skeletal anomalies. Other individualizing traits include the shape of various bones or their features, such as the frontal sinuses (Figure 15.16).<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Comparative dental radiography focuses on the number, shape, location, and orientation of dentition and dental restorations in antemortem and postmortem images. While there is not a minimum number of matching traits that need to be identified for an identification to be made, the antemortem and postmortem records should have enough skeletal or dental consistencies to conclude that the records did in fact come from the same individual (SWGANTH 2010a). Consideration should also be given to population-level frequencies of specific skeletal and dental traits. If a trait is particularly common within a given population, it may not be a good trait to utilize for positive identification.<\/p>\n<figure style=\"width: 354px\" class=\"wp-caption aligncenter\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image16-3.png\" alt=\"A scapula and humerus with a metal shoulder replacement.\" width=\"354\" height=\"231\" \/><figcaption class=\"wp-caption-text\">Figure 15.17: Image of joint replacement in the right shoulder. Credit: <a href=\"https:\/\/naturalhistory.si.edu\/education\/teaching-resources\/written-bone\/skeleton-keys\/todays-bones\">Shoulder replacement<\/a> by <a href=\"https:\/\/www.si.edu\/\">Smithsonian<\/a> [exhibit: Written in Bone, Today\u2019s Bones] <a href=\"https:\/\/www.si.edu\/termsofuse\">is used for educational and non-commercial purposes as outlined by the Smithsonian.<\/a><\/figcaption><\/figure>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Surgical implants or devices can also be used for identification purposes (Figure 15.17). These implements are sometimes recovered with human remains. One of the ways forensic anthropologists can use surgical implants to assist in decedent identification is by providing a thorough analysis of the implant and noting any identifying information such as serial numbers, manufacturer symbols, and so forth. This information can then sometimes be tracked directly to the manufacturer or the place of surgical intervention, which may be used to identify unknown remains (SWGANTH 2010a).<\/p>\n<div class=\"textbox\">\n<h2 class=\"import-Normal\">Special Topic: Trans Doe Task Force<\/h2>\n<p class=\"import-Normal\">The Trans Doe Task Force (TDTF) is a Trans-led nonprofit organization that investigates cases involving LGBTQ+ missing and murdered persons. The organization specifically focuses on transgender and gender-variant cases, providing connections between law enforcement agencies, medical examiner offices, forensic anthropologists, and forensic genetic genealogists to increase the chances of identification. Additionally, the TDTF curates a data repository of missing, murdered, and unclaimed LGBTQ+ individuals, and they continuously try innovative approaches to identify these individuals, whose lived gender identity may not match their biological sex.<\/p>\n<p class=\"import-Normal\">For more information visit <a href=\"https:\/\/transdoetaskforce.org\/\">transdoetaskforce.org<\/a><\/p>\n<\/div>\n<h3 class=\"import-Normal\"><strong>Trauma Analysis<\/strong><\/h3>\n<h4 class=\"import-Normal\"><em>Types of Trauma<\/em><strong><br \/>\n<\/strong><\/h4>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Within the field of anthropology, <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_1256\">trauma<\/a> <\/strong>is defined as an injury to living tissue caused by an extrinsic force or mechanism (Lovell 1997:139). Forensic anthropologists can assist a forensic pathologist by providing an interpretation of the course of events that led to skeletal trauma. Typically, traumatic injury to bone is classified into one of four categories, defined by the trauma mechanism. A trauma mechanism refers to the force that produced the skeletal modification and can be classified as (1) sharp force, (2) blunt force, (3) projectile, or (4) thermal (burning). Each type of trauma, and the characteristic pattern(s) associated with that particular categorization, will be discussed below.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">First, let\u2019s consider s<em>harp-force trauma<\/em>, which is caused by a tool that is edged, pointed, or beveled\u2014for example, a knife, saw, or machete (SWGANTH 2011). The patterns of injury resulting from sharp-force trauma include linear incisions created by a sharp, straight edge; punctures; and chop marks (Figure 15.18; SWGANTH 2011). When observed under a microscope, an anthropologist can often determine what kind of tool created the bone trauma. For example, a power saw cut will be discernible from a manual saw cut.<\/p>\n<figure style=\"width: 602px\" class=\"wp-caption aligncenter\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image21-1.png\" alt=\"Anterior image of a skull with multiple traumatic injuries to forehead.\" width=\"602\" height=\"457\" \/><figcaption class=\"wp-caption-text\">Figure 15.18: Example of sharp-force trauma (sword wound) to the frontal bone. The skull appears sliced with thin lines in two places across the top of the skull. Credit: <a href=\"https:\/\/openverse.org\/image\/909d1b77-ad5f-4cda-be44-6d9b5fbf14b9\/\">Female skull injured by a medieval sword<\/a> by <a href=\"https:\/\/sketchfab.com\/provinciaal_depot_noordholland\">Provinciaal depot voor archeologie Noord-Holland<\/a> is under a <a href=\"https:\/\/creativecommons.org\/licenses\/by-sa\/4.0\/legalcode\">CC BY 4.0 License<\/a>. The original image is a 3D model that can be manipulated on the <a href=\"https:\/\/wordpress.org\/openverse\/image\/909d1b77-ad5f-4cda-be44-6d9b5fbf14b9\/\">openverse website<\/a>.<\/figcaption><\/figure>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Second, <em>blunt-force trauma<\/em> is defined as \u201ca relatively low-velocity impact over a relatively large surface area\u201d (Galloway 1999, 5). Blunt-force injuries can result from impacts from clubs, sticks, fists, and so forth. Blunt-force impacts typically leave an injury at the point of impact but can also lead to bending and deformation in other regions of the bone. Depressions, fractures, and deformation at and around the site of impact are all characteristics of blunt-force trauma (Figure 15.19). As with sharp-force trauma, an anthropologist attempts to interpret blunt-force injuries, providing information pertaining to the type of tool used, the direction of impact, the sequence of impacts, if more than one, and the amount of force applied.<\/p>\n<p>&nbsp;<\/p>\n<figure style=\"width: 578px\" class=\"wp-caption aligncenter\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image30.png\" alt=\"Cranium with two blunt force impacts from a hammer.\" width=\"578\" height=\"803\" \/><figcaption class=\"wp-caption-text\">Figure 15.19: Example of multiple blunt force impacts to the left parietal and frontal bones. There is one hole in the skull with fractured bone around the edges. There are also multiple spots across the back of the skull with depressions of various sizes. Credit: <a href=\"https:\/\/commons.wikimedia.org\/wiki\/File:Skull_hammer_trauma.jpg\">Skull hammer trauma<\/a> by <a href=\"https:\/\/www.nih.gov\/\">the National Institutes of Health<\/a>, Health &amp; Human Services, is in the <a href=\"https:\/\/en.wikipedia.org\/wiki\/Public_domain\">public domain<\/a>. [Exhibit: Visible Proofs: Forensic Views of the Body, U.S. National Library of Medicine, 19th Century Collection, National Museum of Health and Medicine, Armed Forces Institute of Pathology, Washington, D.C.]<\/figcaption><\/figure>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Third, <em>projectile trauma<\/em> refers to high-velocity trauma, typically affecting a small surface area (Galloway 1999, 6). Projectile trauma results from fast-moving objects such as bullets or shrapnel. It is typically characterized by penetrating defects or embedded materials (Figure 15.20). When interpreting injuries resulting from projectile trauma, an anthropologist can often offer information pertaining to the type of weapon used (e.g., rifle vs. handgun), relative size of the bullet (but not the caliber of the bullet), the direction the projectile was traveling, and the sequence of injuries if there are multiple present.<\/p>\n<p>&nbsp;<\/p>\n<figure style=\"width: 462px\" class=\"wp-caption aligncenter\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image5-3.png\" alt=\"Anterior and posterior views of a skull with a gunshot wound.\" width=\"462\" height=\"291\" \/><figcaption class=\"wp-caption-text\">Figure 15.20: Example of projectile trauma with an entrance wound to the frontal bone and exit wound visible on the occipital. A small circular hole is visible in the front of the skull with cracks radiating out from the point of impact. There is a larger hole visible in the back of the skull that is irregular yet circular in shape. Credit: <a href=\"https:\/\/naturalhistory.si.edu\/education\/teaching-resources\/written-bone\/skeleton-keys\/how-bone-biographies-get-written\">Trauma: Gunshot Wounds<\/a> by <a href=\"https:\/\/www.si.edu\/\">Smithsonian<\/a> [exhibit: Written in Bone, How Bone Biographies Get Written] <a href=\"https:\/\/www.si.edu\/termsofuse\">is used for educational and non-commercial purposes as outlined by the Smithsonian.<\/a><\/figcaption><\/figure>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Finally, <em>thermal trauma<\/em> is a bone alteration that results from bone exposure to extreme heat. Thermal trauma can result in cases of house or car fires, intentional disposal of a body in cases of homicidal violence, plane crashes, and so on. Thermal trauma is most often characterized by color changes to bone, ranging from yellow to black (charred) or white (calcined). Other bone alterations characteristic of thermal trauma include delamination (flaking or layering due to bone failure), shrinkage, fractures, and heat-specific burn patterning. When interpreting injuries resulting from thermal damage, an anthropologist can differentiate between thermal fractures and fractures that occurred before heat exposure, thereby contributing to the interpretation of burn patterning (e.g., was the individual bound or in a flexed position prior to the fire?).<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">While there are characteristic patterns associated with the four categories of bone trauma, it is also important to note that these bone alterations do not always occur independently of different trauma types. An individual\u2019s skeleton may present with multiple different types of trauma, such as a projectile wound and thermal trauma. Therefore, it is important that the anthropologist recognize the different types of trauma and interpret them appropriately.<\/p>\n<h3 class=\"import-Normal\"><strong>Timing of Injury<\/strong><\/h3>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Another important component of any anthropological trauma analysis is the determination of the timing of injury (e.g., when did the injury occur). Timing of injury is traditionally split into one of three categories: <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_1260\">antemortem<\/a> <\/strong>(before death), <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_1258\">perimortem<\/a> <\/strong>(at or around the time of death), and <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_1266\">postmortem <\/a><\/strong>(after death). This classification system differs slightly from the classification system used by the pathologist because it specifically references the qualities of bone tissue and bone response to external forces. Therefore, the perimortem interval (at or around the time of death) means that the bone is still fresh and has what is referred to as a green bone response, which can extend past death by several weeks or even months. For example, in cold or freezing temperatures a body can be preserved for extended periods of time, increasing the perimortem interval, while in desert climates decomposition is accelerated, thereby significantly decreasing the postmortem interval (Galloway 1999, 12). Antemortem injuries (occurring well before death and not related to the death incident) are typically characterized by some level of healing, in the form of a fracture callus or unification of fracture margins. Finally, postmortem injuries (occurring after death, while bone is no longer fresh) are characterized by jagged fracture margins, resulting from a loss of moisture content during the decomposition process (Galloway 1999, 16). In general, all bone traumas should be classified according to the timing of injury, if possible. This information will help the medical examiner or pathologist better understand the circumstances surrounding the decedent\u2019s death, as well as events occurring during life and after the final disposition of the body.<\/p>\n<h3 class=\"import-Normal\"><strong>The Role of the Forensic Anthropologist in Trauma Analysis<\/strong><\/h3>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Within the medicolegal system, forensic anthropologists are often called upon by the medical examiner, forensic pathologist, or coroner to assist with an interpretation of trauma. The forensic anthropologist\u2019s main focus in any trauma analysis is the underlying skeletal system\u2014as well as, sometimes, cartilage. Analysis and interpretation of soft tissue injuries fall within the purview of the medical examiner or pathologist. It is also important to note that the main role of the forensic anthropologist is to provide information pertaining to skeletal injury to assist the medical examiner\/pathologist in their final interpretation of injury. Forensic anthropologists do not hypothesize as to the cause of death of an individual. Instead, a forensic anthropologist\u2019s report should include a description of the injury (e.g., trauma mechanism, number of injuries, location, timing of injury); documentation of the injury, which may be utilized in court testimony (e.g., photographs, radiographs, measurements); and, if applicable, a statement as to the condition of the body and state of decomposition, which may be useful for understanding the depositional context (e.g., how long has the body been exposed to the elements; was it moved or in its original location; are any of the alterations to bone due to environmental or faunal exposure instead of intentional human modification).<\/p>\n<h2 class=\"import-Normal\">Taphonomy<\/h2>\n<h2 class=\"import-Normal\"><strong>What Happened to the Remains After Death?<\/strong><\/h2>\n<p class=\"import-Normal\">The majority of the skeletal analysis process revolves around the identity of the deceased individual. However, there is one last, very important question that forensic anthropologists should ask: What happened to the remains after death? Generally speaking, processes that alter the bone after death are referred to as taphonomic changes (refer to Chapter 7 for a discussion regarding taphonomy and the fossil record).<\/p>\n<p class=\"import-Normal\">The term <em>taphonomy<\/em> was originally used to refer to the processes through which organic remains mineralize, also known as fossilization. Within the context of biological anthropology, the term <em>taphonomy<\/em> is better defined as the study of what happens to human remains after death (Komar and Buikstra 2008). Initial factors affecting a body after death include processes such as decomposition and scavenging by animals. However, taphonomic processes encompass much more than the initial period after death. For example, plant root growth can leach minerals from bone, leaving a distinctive mark. Sunlight can bleach human remains, leaving exposed areas whiter than those that remained buried. Water can wear the surface of the bone until it becomes smooth.<\/p>\n<p class=\"import-Normal\">Some taphonomic processes can help a forensic anthropologist estimate the relative amount of time that human remains have been exposed to the elements. For example, root growth through a bone would certainly indicate a body was buried for more than a few days. Forensic anthropologists must be very careful when attempting to estimate time since death based on taphonomic processes because environmental conditions can greatly influence the rate at which taphonomic processes progress. For example, in cold environments, tissue may decay slower than in warm, moist environments.<\/p>\n<p class=\"import-Normal\">Forensic anthropologists must contend with taphonomic processes that affect the preservation of bones. For example, high acidity in the soil can break down human bone to the point of crumbling. In addition, when noting trauma, they must be very careful not to confuse postmortem (after death) bone damage with trauma.<\/p>\n<div style=\"text-align: left;\">\n<table class=\"aligncenter\" style=\"width: 470.25pt;\">\n<caption>Figure 15.21: Table showing taphonomic processes that affect the preservation of bones. A. Rodent gnawing. B. Carnivore damage. C. Burned bone. D. Root etching. E. Weathering. F. Cut marks. Credit: A. <a href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/chapter\/__unknown__-5\/\">Rodent gnawing (Figure 15.26)<\/a>, B. <a href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/chapter\/__unknown__-5\/\">Carnivore damage (Figure 15.27)<\/a>, C. <a href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/chapter\/__unknown__-5\/\">Burned bone (Figure 15.28)<\/a>, D. <a href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/chapter\/__unknown__-5\/\">Root etching (Figure 15.29)<\/a>, E. <a href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/chapter\/__unknown__-5\/\">Weathering (Figure 15.30)<\/a>, and F. <a href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/chapter\/__unknown__-5\/\">Cut marks (Figure 15.30)<\/a>, all original to <a href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/\">Explorations: An Open Invitation to Biological Anthropology<\/a> by Alex Perrone are under a <a href=\"https:\/\/creativecommons.org\/licenses\/by-sa\/4.0\/legalcode\">CC BY-NC 4.0 License<\/a>.<\/caption>\n<thead>\n<tr style=\"height: 52.5pt;\">\n<td class=\"Table1-C\" style=\"padding: 5pt 5pt 5pt 5pt; border: solid #000000 1pt;\">\n<p class=\"import-Normal\" style=\"text-align: center;\">Taphonomic Process<\/p>\n<\/td>\n<td class=\"Table1-C\" style=\"border-top: solid #000000 1pt; border-right: solid #000000 1pt; border-bottom: solid #000000 1pt; border-left: solid #000000 0.75pt; padding: 5pt 5pt 5pt 5pt;\">\n<p class=\"import-Normal\" style=\"text-align: center;\">Definition<\/p>\n<\/td>\n<\/tr>\n<\/thead>\n<tbody>\n<tr class=\"Table1-R\" style=\"height: 190.5pt;\">\n<td class=\"Table1-C\" style=\"border-top: solid #000000 0.75pt; border-right: solid #000000 1pt; border-bottom: solid #000000 1pt; border-left: solid #000000 1pt; padding: 5pt 5pt 5pt 5pt;\">\n<p class=\"import-Normal\" style=\"text-align: center; margin-left: 36pt;\"><strong>Rodent Gnawing<\/strong><\/p>\n<p class=\"import-Normal\" style=\"text-align: center;\"><img class=\"alignnone\" src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image19-2.png\" alt=\"Parallel tooth marks etched by a rodent\u2019s front teeth visible on the end of an animal bone.\" width=\"564\" height=\"422\" \/><\/p>\n<\/td>\n<td class=\"Table1-C\" style=\"border-top: solid #000000 0.75pt; border-right: solid #000000 1pt; border-bottom: solid #000000 1pt; border-left: solid #000000 0.75pt; padding: 5pt 5pt 5pt 5pt;\">\n<p class=\"import-Normal\">When rodents, such as rats and mice, chew on bone, they leave sets of parallel grooves. The shallow grooves are etched by the rodent\u2019s incisors.<\/p>\n<\/td>\n<\/tr>\n<tr class=\"Table1-R\" style=\"height: 166.75pt;\">\n<td class=\"Table1-C\" style=\"border-top: solid #000000 0.75pt; border-right: solid #000000 1pt; border-bottom: solid #000000 1pt; border-left: solid #000000 1pt; padding: 5pt 5pt 5pt 5pt;\">\n<p class=\"import-Normal\" style=\"text-align: center; margin-left: 36pt;\"><strong>Carnivore Damage<\/strong><\/p>\n<p class=\"import-Normal\" style=\"text-align: center;\"><strong><img class=\"alignnone\" src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image23-4.png\" alt=\"Pit marks from the canines of a carnivore visible on the surface of an animal bone.\" width=\"410\" height=\"272\" \/><\/strong><\/p>\n<\/td>\n<td class=\"Table1-C\" style=\"border-top: solid #000000 0.75pt; border-right: solid #000000 1pt; border-bottom: solid #000000 1pt; border-left: solid #000000 0.75pt; padding: 5pt 5pt 5pt 5pt;\">\n<p class=\"import-Normal\">Carnivores may leave destructive dental marks on bone. The tooth marks may be visible as pit marks or punctures from the canines, as well as extensive gnawing or chewing of the ends of the bones to retrieve marrow.<\/p>\n<\/td>\n<\/tr>\n<tr class=\"Table1-R\" style=\"height: 177pt;\">\n<td class=\"Table1-C\" style=\"border-top: solid #000000 0.75pt; border-right: solid #000000 1pt; border-bottom: solid #000000 1pt; border-left: solid #000000 1pt; padding: 5pt 5pt 5pt 5pt;\">\n<p class=\"import-Normal\" style=\"text-align: center; margin-left: 36pt;\"><strong>Burned Bone<\/strong><\/p>\n<p class=\"import-Normal\"><img class=\"alignnone\" src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image20-5.png\" alt=\"Burned animal bone fragments pictured at different stages of thermal damage.\" width=\"512\" height=\"342\" \/><\/p>\n<\/td>\n<td class=\"Table1-C\" style=\"border-top: solid #000000 0.75pt; border-right: solid #000000 1pt; border-bottom: solid #000000 1pt; border-left: solid #000000 0.75pt; padding: 5pt 5pt 5pt 5pt;\">\n<p class=\"import-Normal\">Fire causes observable damage to bone. Temperature and the amount of time bone is heated affect the appearance of the bone. Very high temperatures can crack bone and result in white coloration. Color gradients are visible in between high and lower temperatures, with lower temperatures resulting in black coloration from charring. Cracking can also reveal information about the directionality of the burn.<\/p>\n<\/td>\n<\/tr>\n<tr class=\"Table1-R\" style=\"height: 169.75pt;\">\n<td class=\"Table1-C\" style=\"border-top: solid #000000 0.75pt; border-right: solid #000000 1pt; border-bottom: solid #000000 1pt; border-left: solid #000000 1pt; padding: 5pt 5pt 5pt 5pt;\">\n<p class=\"import-Normal\" style=\"text-align: center; margin-left: 36pt;\"><strong>Root Etching<\/strong><\/p>\n<p class=\"import-Normal\" style=\"text-align: center;\"><img class=\"alignnone\" src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image15-4.png\" alt=\"Animal bone with prominent, discolored grooves where roots leached nutrients from bone\u2019s surface.\" width=\"512\" height=\"342\" \/><\/p>\n<\/td>\n<td class=\"Table1-C\" style=\"border-top: solid #000000 0.75pt; border-right: solid #000000 1pt; border-bottom: solid #000000 1pt; border-left: solid #000000 0.75pt; padding: 5pt 5pt 5pt 5pt;\">\n<p class=\"import-Normal\">Plant roots can etch the outer surface of bone, leaving grooves where the roots attached as they leached nutrients. During this process, the plant\u2019s roots secrete acid that breaks down the surface of the bone.<\/p>\n<p class=\"import-Normal\">\n<\/td>\n<\/tr>\n<tr class=\"Table1-R\" style=\"height: 170.5pt;\">\n<td class=\"Table1-C\" style=\"border-top: solid #000000 0.75pt; border-right: solid #000000 1pt; border-bottom: solid #000000 1pt; border-left: solid #000000 1pt; padding: 5pt 5pt 5pt 5pt;\">\n<p class=\"import-Normal\" style=\"text-align: center; margin-left: 36pt;\"><strong>Weathering<\/strong><\/p>\n<p class=\"import-Normal\"><strong><img class=\"alignnone\" src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image9.png\" alt=\"Cracking and exfoliation of the surface of an animal bone. \" width=\"512\" height=\"342\" \/><\/strong><\/p>\n<\/td>\n<td class=\"Table1-C\" style=\"border-top: solid #000000 0.75pt; border-right: solid #000000 1pt; border-bottom: solid #000000 1pt; border-left: solid #000000 0.75pt; padding: 5pt 5pt 5pt 5pt;\">\n<p class=\"import-Normal\">Many different environmental conditions affect bone. River transport can smooth the surface of the bone due to water abrasion. Sunlight can bleach the exposed surface of bone. Dry and wet environments or the mixture of both types of environments can cause cracking and exfoliation of the surface. Burial in different types of soil can cause discoloration, and exposure can cause degreasing.<\/p>\n<\/td>\n<\/tr>\n<tr class=\"Table1-R\" style=\"height: 169.75pt;\">\n<td class=\"Table1-C\" style=\"border-top: solid #000000 0.75pt; border-right: solid #000000 1pt; border-bottom: solid #000000 1pt; border-left: solid #000000 1pt; padding: 5pt 5pt 5pt 5pt;\">\n<p class=\"import-Normal\" style=\"text-align: center; margin-left: 36pt;\"><strong>Cut Marks<\/strong><\/p>\n<p class=\"import-Normal\" style=\"text-align: left;\"><img class=\"alignnone\" src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image8-2.png\" alt=\"Thin vertical lines and cuts are visible along the bone.\" width=\"512\" height=\"342\" \/><\/p>\n<\/td>\n<td class=\"Table1-C\" style=\"border-top: solid #000000 0.75pt; border-right: solid #000000 1pt; border-bottom: solid #000000 1pt; border-left: solid #000000 0.75pt; padding: 5pt 5pt 5pt 5pt;\">\n<p class=\"import-Normal\">Humans may alter bone by cutting, scraping, or sawing it directly or in the process of removing tissue. The groove pattern\u2014that is, the depth and width of the cuts\u2014can help identify the tool used in the cutting process.<\/p>\n<\/td>\n<\/tr>\n<tr>\n<td><\/td>\n<td><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<h2 class=\"import-Normal\">Ethics and Human Rights<\/h2>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Working with human remains requires a great deal of consideration and respect for the dead. Forensic anthropologists have to think about the ethics of our use of human remains for scientific purposes. How do we conduct casework in the most respectable manner possible? While there are a wide range of ethical considerations to consider when contemplating a career in forensic anthropology, this chapter will focus on two major categories: working with human remains and acting as an expert within the medicolegal system.<\/p>\n<h3 class=\"import-Normal\"><strong>Working with Human Remains<\/strong><\/h3>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Forensic anthropologists work with human remains in a number of contexts, including casework, excavation, research, and teaching. When working with human remains, it is always important to use proper handling techniques. To prevent damage to skeletal remains, bones should be handled over padded surfaces. Skulls should never be picked up by placing fingers in the eye orbits, foramen magnum (hole at the base of the skull for entry of the spinal cord), or through the zygomatic arches (cheekbones). Human remains, whether related to casework, fieldwork, donated skeletal collections, or research, were once living human beings. It is important to always bear in mind that work with remains should be ingrained with respect for the individual and their relatives. In addition to fieldwork, casework, and teaching, anthropologists are often invited to work with remains that come from a bioarchaeological context or from a human rights violation. While this discussion of ethics is not comprehensive, two case examples will be provided below in which an anthropologist must consider the ethical standards outlined above.<\/p>\n<h3 class=\"import-Normal\"><strong>Modern Human Rights Violations<\/strong><\/h3>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Forensic anthropologists may also be called to participate in criminal investigations involving human rights violations. Anthropological investigations may include assistance with identifications, determination of the number of victims, and trauma analyses. In this role, forensic anthropologists play an integral part in promoting human rights, preventing future human rights violations, and providing the evidence necessary to prosecute those responsible for past events. A few ethical considerations for the forensic anthropologist involved in human rights violations include the use of appropriate standards of identification, presenting reliable and unbiased testimony, and maintaining preservation of evidence. For a more comprehensive history of forensic anthropological contributions to human rights violations investigations, see Ubelaker 2018.<\/p>\n<h3 class=\"import-Normal\"><strong>Acting as an Expert in the Medicolegal System<\/strong><\/h3>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">In addition to the ethical considerations involved in working with human skeletal remains, forensic anthropologists must abide by ethical standards when they act as experts within the medicolegal system. The role of the forensic anthropologist within the medicolegal system is primarily to provide information to the medical examiner or coroner that will aid in the identification process or determination of cause and manner of death. Forensic anthropologists also may be called to testify in a court of law. In this capacity, forensic anthropologists should always abide by a series of ethical guidelines that pertain to their interpretation, presentation, and preservation of evidence used in criminal investigations. First and foremost, practitioners should never misrepresent their training or education. When appropriate, outside opinions and assistance in casework should be requested (e.g., consulting a radiologist for radiological examinations or odontologist for dental exams). The best interest of the decedent should always take precedence. All casework should be conducted in an unbiased way, and financial compensation should never be accepted as it can act as an incentive to take a biased stance regarding casework. All anthropological findings should be kept confidential, and release of information is best done by the medical examiner or coroner. Finally, while upholding personal ethical standards, forensic anthropologists are also expected to report any perceived ethical violations committed by their peers.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Ethical standards for the field of forensic anthropology are outlined by the Organization of Scientific Area Committees (OSAC) for Forensic Science, administered by the National Institute of Standards and Technology (NIST). OSAC and NIST recently began an initiative to develop standards that would strengthen the practice of forensic science both in the United States and internationally. OSAC\u2019s main objective is to \u201cstrengthen the nation\u2019s use of forensic science by facilitating the development of technically sound forensic science standards and by promoting the adoption of those standards by the forensic science community\u201d (NIST n.d.). Additionally, OSAC promotes the establishment of best practices and other guidelines to ensure that forensic science findings and their presentation are reliable and reproducible (NIST 2023).<\/p>\n<div class=\"textbox\">\n<h2 class=\"import-Normal\">Special Topic: Native American Graves Protection and Repatriation Act (NAGPRA)<\/h2>\n<p class=\"import-Normal\">There is a long history in the <span style=\"background-color: #00ffff;\">United States<\/span> of systematic disenfranchisement of Native American people, including lack of respect for tribal sovereignty. This includes the egregious treatment of Native American human remains. Over several centuries, thousands of Native American remains were removed from tribal lands and held at institutions in the United States, such as museums and universities.<\/p>\n<p class=\"import-Normal\">In 1990, a landmark human rights federal law, the Native American Graves Protection and Repatriation Act (NAGPRA), spurred change in the professional standards and practice of biological anthropology and archaeology. NAGPRA established a legal avenue to provide protection for and repatriation of Native American remains, cultural items, and sacred objects removed from Federal or tribal lands to Native American lineal descendants, Indian tribes, and Native Hawaiian organizations. Human remains and associated artifacts, curated in museum collections and federally funded institutions, are subject to three primary provisions outlined by the NAGPRA statute: (1) protection for Native graves on federal and private land; (2) recognition of tribal authority on such lands; and (3) the requirement that all Native skeletal remains and associated artifacts be inventoried and culturally affiliated groups be consulted concerning decisions related to ownership and final disposition (Rose, Green, and Green 1996). NAGPRA legislation was enacted to ensure ethical consideration and treatment of Native remains and to improve dialogue between scientists and Native groups.<\/p>\n<ul>\n<li>For more information about NAGPRA, visit the <a href=\"https:\/\/www.usbr.gov\/nagpra\/\" target=\"_blank\" rel=\"noopener\">Bureau of Reclamation NAGPRA website<\/a><\/li>\n<li>To read the text of the law, visit the <a href=\"https:\/\/www.congress.gov\/bill\/101st-congress\/house-bill\/5237\">US Congress NAGPRA law website<\/a>.<\/li>\n<li>For further discussion of NAGPRA history, please see <a href=\"https:\/\/textbooks.whatcom.edu\/tracesarchaeology\/\" target=\"_blank\" rel=\"noopener\"><em>TRACES: <\/em><em>An Open Invitation to <\/em><em>Archaeology <\/em>open textbook website<\/a><em><br \/>\n<\/em><\/li>\n<\/ul>\n<\/div>\n<h2 class=\"import-Normal\"><span style=\"background-color: #ff99cc;\">Becoming a Forensic Anthropologist<\/span><\/h2>\n<p class=\"import-Normal\"><span style=\"background-color: #ff99cc;\">What does it take to be a forensic anthropologist? Forensic anthropologists are first and foremost anthropologists. While many forensic anthropologists have an undergraduate degree in anthropology, they may also major in biology, criminal justice, pre-law, pre-med, and many other related fields. Practicing forensic anthropologists typically have an advanced degree, either a Master\u2019s or Doctoral degree in Anthropology. Additional training and experience in archaeology, the medico-legal system, rules of evidence, and expert witness testimony are also common. Practicing forensic anthropologists are also encouraged to be board-certified through the American Board of Forensic Anthropology (ABFA). Learn more about the field and educational opportunities on the ABFA website: <a class=\"rId111\" style=\"background-color: #ff99cc;\" href=\"https:\/\/www.theabfa.org\/coursework\">https:\/\/www.theabfa.org\/coursework<\/a>.<\/span><\/p>\n<div class=\"textbox shaded\">\n<h2 class=\"import-Normal\">Review Questions<\/h2>\n<ul>\n<li>What is forensic anthropology? What are the seven primary steps involved in a skeletal analysis?<\/li>\n<li>What are the major components of a biological profile? Why are forensic anthropologists often-tasked with creating biological profiles for unknown individuals?<\/li>\n<li>What are the four major types of skeletal trauma?<\/li>\n<li>What is taphonomy, and why is an understanding of taphonomy often critical in forensic anthropology analyses?<\/li>\n<li>What are some of the ethical considerations faced by forensic anthropologists?<\/li>\n<\/ul>\n<\/div>\n<h2>About the Authors<\/h2>\n<p><img class=\"alignleft\" src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image24-4.jpg\" alt=\"A woman with straight blonde hair smiles at the camera. \" width=\"191\" height=\"254\" \/><\/p>\n<h3 class=\"import-Normal\"><strong>Ashley Kendell, Ph.D.<\/strong><\/h3>\n<p class=\"import-Normal\">California State University, Chico, <a class=\"rId113\" href=\"mailto:akendell@csuchico.edu\">akendell@csuchico.edu<\/a><\/p>\n<p class=\"import-Normal\">Dr. Ashley Kendell is currently an associate professor and forensic anthropologist at Chico State. Prior to beginning her position at Chico State, she was a visiting professor at the University of Montana and the forensic anthropologist for the state of Montana. Dr. Kendell obtained her doctorate from Michigan State University, and her research interests include skeletal trauma analysis and digitization and curation methods for digital osteological data. She is also a Registry Diplomate of the American Board of Medicolegal Death Investigators. Throughout her doctoral program, she worked as a medicolegal death investigator for the greater Lansing, Michigan, area and was involved in the investigation of over 200 forensic cases.<\/p>\n<p class=\"import-Normal\"><strong><img class=\"alignleft\" src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image4.jpg\" alt=\"A woman with straight brown hair pulled back smiles at the camera. \" width=\"194\" height=\"258\" \/><\/strong><\/p>\n<h3 class=\"import-Normal\"><strong>Alex Perrone, M.A., M.S.N, R.N., P.H.N.<\/strong><\/h3>\n<p class=\"import-Normal\">Butte Community College, <a class=\"rId115\" href=\"mailto:perroneal@butte.edu\">perroneal@butte.edu<\/a><\/p>\n<p class=\"import-Normal\">Alex Perrone is a lecturer in anthropology at Butte Community College. She is also a Registered Nurse and a certified Public Health Nurse. She is a former Supervisor of the Human Identification Laboratory in the Department of Anthropology at California State University, Chico. Her research interests include bioarchaeology, paleopathology, forensic anthropology, skeletal biology, California prehistory, and public health. She has worked on bioarchaeological and archaeological projects in Antigua, California, Hawaii, Greece, and the UK, and was an archaeological technician for the USDA Forest Service. She assisted with training courses for local and federal law enforcement agencies and assisted law enforcement agencies with the recovery and analysis of human remains.<\/p>\n<p class=\"import-Normal\" data-wp-editing=\"1\"><img class=\"alignleft\" src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image1-1.jpg\" alt=\"A woman with curly brown, shoulder-length hair smiles at the camera.\" width=\"190\" height=\"253\" \/><\/p>\n<h3 class=\"import-Normal\"><strong>Colleen Milligan, Ph.D.<\/strong><\/h3>\n<p class=\"import-Normal\">California State University, Chico, <a class=\"rId117\" href=\"mailto:cfmilligan@csuchico.edu\">cfmilligan@csuchico.edu<\/a><\/p>\n<p class=\"import-Normal\">Dr. Colleen Milligan is a biological and forensic anthropologist with research interests in bioarchaeology, skeletal biology, and forensic anthropology. She has been a Fellow with the Department of Homeland Security and has assisted in forensic anthropology casework and recoveries in the State of Michigan and California. She has also assisted in community outreach programs in forensic anthropology and forensic science, as well as recovery training courses for local, state, and federal law enforcement officers. She is a certified instructor through Peace Officers Standards and Training (POST). Dr. Milligan serves as the current co-director of the Chico State Human Identification Laboratory.<\/p>\n<h2 class=\"import-Normal\">For Further Exploration<\/h2>\n<p><a href=\"https:\/\/www.theabfa.org\/coursework\" target=\"_blank\" rel=\"noopener\">The American Board of Forensic Anthropology (ABFA)<\/a><\/p>\n<p><a href=\"https:\/\/www.aafs.org\/\" target=\"_blank\" rel=\"noopener\">The American Academy of Forensic Sciences (AAFS)<\/a><\/p>\n<p><a href=\"https:\/\/www.nist.gov\/organization-scientific-area-committees-forensic-science\" target=\"_blank\" rel=\"noopener\">The Organization of Scientific Area Committees for Forensic Science (OSAC)<\/a><\/p>\n<p><a href=\"https:\/\/textbooks.whatcom.edu\/tracesarchaeology\/\" target=\"_blank\" rel=\"noopener\">TRACES Bioarchaeology<\/a><\/p>\n<p><a href=\"https:\/\/transdoetaskforce.org\/\" target=\"_blank\" rel=\"noopener\">Trans Doe Task Force<\/a><\/p>\n<h2 class=\"import-Normal\">References<\/h2>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Adams, Bradley J., and Lyle W. Konigsberg, eds. 2008. <em>Recovery, Analysis, and Identification of Commingled Remains<\/em>. Totowa, NJ: Humana Press.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Beatrice, Jared S., and Angela Soler. 2016. \u201cSkeletal Indicators of Stress: A Component of the Biocultural Profile of Undocumented Migrants in Southern Arizona.\u201d <em>Journal of Forensic Sciences <\/em>61 (5): 1164\u20131172.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Berg, Gregory E. 2017. \u201cSex Estimation of Unknown Human Skeletal Remains.\u201d In <em>Forensic Anthropology: A Comprehensive Introduction, Second Edition<\/em>, edited by Natalie R. Langley and MariaTeresa A. Tersigni-Tarrant, 143\u2013159. Boca Raton, FL: CRC Press.<\/p>\n<p class=\"import-Normal\">Bethard, Jonathan D., and Elizabeth A. DiGangi. 2020. \u201cLetter to the Editor\u2014Moving Beyond a Lost Cause: Forensic Anthropology and Ancestry Estimates in the United States.\u201d <em>Journal of Forensic Sciences<\/em> 65 (5): 1791\u20131792.<\/p>\n<p class=\"import-Normal\">Birkby, Walter H., Todd W. Fenton, and Bruce E. Anderson. 2008. \u201cIdentifying Southwest Hispanics Using Nonmetric Traits and the Cultural Profile.\u201d <em>Journal of Forensic Sciences <\/em>53 (1): 29\u201333.<\/p>\n<p class=\"import-Normal\">Blatt, Samantha, Amy Michael, and Lisa Bright. Forthcoming. \u201cBioarchaeology: Interpreting Human Behavior from Skeletal Remains.\u201d In <em>TRACES: <\/em><em>An Open Invitation to <\/em><em>Archaeology<\/em>. https:\/\/textbooks.whatcom.edu\/tracesarchaeology\/.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Brooks, S., and J. M. Suchey. 1990. \u201cSkeletal Age Determination Based on the Os Pubis: A Comparison of the Acs\u00e1di-Nemesk\u00e9ri and Suchey-Brooks Methods.\u201d <em>Human Evolution <\/em>5 (3): 227\u2013238.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Buchanan, Shelby. 2014. \u201cBone Modification in Male to Female Transgender Surgeries: Considerations for the Forensic Anthropologist.\u201d MA thesis, Department of Geography and Anthropology, Louisiana State University, Baton Rouge.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Cunningham, Craig, Louise Scheuer, and Sue Black. 2016. <em>Developmental Juvenile Osteology, Second Edition<\/em>. London: Elsevier Academic Press.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Galloway, Alison, ed. 1999. <em>Broken Bones: Anthropological Analysis of Blunt Force Trauma<\/em>. Springfield, IL: Charles C. Thomas Publisher, LTD.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Hefner, Joseph T., and Kandus C. Linde. 2018. <em>Atlas of Human Cranial <\/em><em>Macromorphoscopic<\/em><em> Traits<\/em>. San Diego: Academic Press.<\/p>\n<p class=\"import-Normal\">\u0130\u015fcan, M. Y., S. R. Loth, and R. K. Wright. 1984. \u201cAge Estimation from the Rib by Phase Analysis: White Males.\u201d <em>Journal of Forensic Sciences <\/em>29 (4): 1094\u20131104.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">\u0130\u015fcan, M. Y., S. R. Loth, and R. K. Wright. 1985. \u201cAge Estimation from the Rib by Phase Analysis: White Females.\u201d <em>Journal of Forensic Sciences <\/em>30 (3): 853\u2013863.Katz, Darryl, and Judy Myers Suchey. 1986. \u201cAge Determination of the Male Os Pubis.\u201d <em>American Journal of Physical Anthropology <\/em>69 (4): 427\u2013435.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Komar, Debra A., and Jane E. Buikstra. 2008. <em>Forensic Anthropology: Contemporary Theory and Practice<\/em>. New York: Oxford University Press.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Langley, Natalie R., Alice F. Gooding, and MariaTeresa Tersigni-Tarrant. 2017. \u201cAge Estimation Methods.\u201d In <em>Forensic Anthropology: A Comprehensive Introduction, Second Edition<\/em>, edited by Natalie R. Langley and MariaTeresa A. Tersigni-Tarrant, 175\u2013191. Boca Raton, FL: CRC Press.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Lovell, Nancy C. 1997. \u201cTrauma Analysis in Paleopathology.\u201d <em>Yearbook of Physical Anthropology<\/em> 104 (S25): 139\u2013170.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Native American Graves Protection and Repatriation Act (NAGPRA) 1990 (25 U.S. Code 3001 et seq.)<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">NIST (National Institute of Standards and Technology). N.d. \u201cThe Organization of Scientific Area Committees for Forensic Science.\u201d Accessed April 18, 2023. <a class=\"rId120\" href=\"https:\/\/www.nist.gov\/topics\/organization-scientific-area-committees-forensic-science\">https:\/\/www.nist.gov\/topics\/organization-scientific-area-committees-forensic-science<\/a>.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Ousley, Stephen. 1995. \u201cShould We Estimate Biological or Forensic Stature?\u201d <em>Journal of Forensic Sciences<\/em> 40(5): 768\u2013773.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Phenice, T. W. 1969. \u201cA Newly Developed Visual Method of Sexing the Os Pubis.\u201d <em>American Journal of Physical Anthropology<\/em> 30 (2): 297\u2013302.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Rose, Jerome C., Thomas J. Green, and Victoria D. Green. 1996. \u201cNAGPRA Is Forever: Osteology and the Repatriation of Skeletons.\u201d <em>Annual Review of Anthropology <\/em>25: 81\u2013103.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Schaefer, Maureen, Sue Black, and Louise Scheuer. <em>Juvenile Osteology: A Laboratory and Field Manua<\/em>l. 2009. San Diego: Elsevier Academic Press.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Schall, Jenna L., Tracy L. Rogers, and Jordan D. Deschamps-Braly. 2020. \u201cBreaking the Binary: The Identification of Trans-women in Forensic Anthropology.\u201d <em>Forensic Science International<\/em> 309: 110220. https:\/\/doi.org\/10.1016\/j.forsciint.2020.110220.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Scientific Working Group for Forensic Anthropology (SWGANTH). 2010a. \u201cPersonal Identification.\u201d Last modified June 3, 2010. <a class=\"rId121\" href=\"https:\/\/www.nist.gov\/sites\/default\/files\/documents\/2018\/03\/13\/swganth_personal_identification.pdf\">https:\/\/www.nist.gov\/sites\/default\/files\/documents\/2018\/03\/13\/swganth_personal_identification.pdf<\/a>.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Scientific Working Group for Forensic Anthropology (SWGANTH). 2010b. \u201cSex Assessment.\u201d Last modified June 3, 2010. <a class=\"rId122\" href=\"https:\/\/www.nist.gov\/sites\/default\/files\/documents\/2018\/03\/13\/swganth_sex_assessment.pdf\">https:\/\/www.nist.gov\/sites\/default\/files\/documents\/2018\/03\/13\/swganth_sex_assessment.pdf<\/a>.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Scientific Working Group for Forensic Anthropology (SWGANTH). 2011. \u201cTrauma Analysis.\u201d Last modified May 27, 2011. <a class=\"rId123\" href=\"https:\/\/www.nist.gov\/sites\/default\/files\/documents\/2018\/03\/13\/swganth_trauma.pdf\">https:\/\/www.nist.gov\/sites\/default\/files\/documents\/2018\/03\/13\/swganth_trauma.pdf<\/a>.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Scientific Working Group for Forensic Anthropology (SWGANTH). 2012. \u201cStature Estimation.\u201d Last modified August 2, 2012. <a class=\"rId124\" href=\"https:\/\/www.nist.gov\/sites\/default\/files\/documents\/2018\/03\/13\/swganth_stature_estimation.pdf\">https:\/\/www.nist.gov\/sites\/default\/files\/documents\/2018\/03\/13\/swganth_stature_estimation.pdf<\/a>.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Scientific Working Group for Forensic Anthropology (SWGANTH). 2013. \u201cAge Estimation.\u201d Last modified January 22, 2013. <a class=\"rId125\" href=\"https:\/\/www.nist.gov\/sites\/default\/files\/documents\/2018\/03\/13\/swganth_age_estimation.pdf\">https:\/\/www.nist.gov\/sites\/default\/files\/documents\/2018\/03\/13\/swganth_age_estimation.pdf<\/a>.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Soler, Angela, and Jared S. Beatrice. 2018. \u201cExpanding the Role of Forensic Anthropology in Humanitarian Crisis: An Example from the USA-Mexico Border. In <em>Sociopolitics of Migrant Death and Repatriation: Perspectives from Forensic Science<\/em>, edited by Krista E. Latham and Alyson J. O\u2019Daniel, 115\u2013128. New York: Springer.<\/p>\n<p class=\"import-Normal\">Soler, Angela, Robin Reineke, Jared Beatrice, and Bruce E. Anderson. 2019. \u201cEtched in Bone: Embodied Suffering in the Remains of Undocumented Migrants.\u201d <em>In<\/em> <em>The Border and Its Bodies: The Embodiment of Risk along the U.S.-M\u00e9xico Line<\/em>, edited by Thomas E. Sheridan and Randall H. McGuire, 173\u2013207. Tucson: University of Arizona Press.<\/p>\n<p class=\"import-Normal\">Stull, Kyra E., Eric J. Bartelink, Alexandra R. Klales, Gregory E. Berg, Michael W. Kenyhercz, Erica N. L\u2019Abb\u00e9, Matthew C. Go, et al.. 2021. \u201cCommentary on: Bethard JD, DiGangi EA. Letter to the Editor\u2014Moving Beyond a Lost Cause: Forensic Anthropology and Ancestry Estimates in the United States. J Forensic Sci. 2020;65(5):1791\u20132. doi: 10.1111\/1556-4029.14513.\u201d <em>Journal of Forensic Sciences <\/em>66 (1): 417\u2013420.<\/p>\n<p class=\"import-Normal\">Tallman, Sean D., Caroline D. Kincer, and Eric D. Plemons. 2022. \u201cCentering Transgender Individuals in Forensic Anthropology and Expanding Binary Sex Estimation in Casework and Research.\u201d Special issue, \u201cDiversity and Inclusion,\u201d <em>Forensic Anthropology<\/em> 5 (2): 161\u2013180.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Tersigni-Tarrant, MariaTeresa A., and Natalie R. Langley. 2017. \u201cHuman Osteology.\u201d In <em>Forensic Anthropology: A Comprehensive Introduction, Second Edition<\/em>, edited by Natalie R. Langley and MariaTeresa A. Tersigni-Tarrant, 81\u2013109. Boca Raton, FL: CRC Press.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Ubelaker, Douglas H. 2018. \u201cA History of Forensic Anthropology.\u201d Special issue, \u201cCentennial Anniversary Issue of AJPA,\u201d <em>American Journal of Physical Anthropology<\/em> 165 (4): 915\u2013923.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">White, Tim D., and Pieter A. Folkens. 2005. <em>The Human Bone Manual<\/em>. Burlington, MA: Elsevier Academic Press.<\/p>\n<p class=\"import-Normal\">Winburn, Allysha P., and Bridget Algee-Hewitt. 2021. \u201cEvaluating Population Affinity Estimates in Forensic Anthropology: Insights from the Forensic Anthropology Database for Assessing Methods Accuracy (FADAMA).\u201d <em>Journal of Forensic Sciences<\/em> 66 (4): 1210\u20131219.<\/p>\n<p class=\"import-Normal\">Winburn, Allysha Powanda, Sarah Kiley Schoff, and Michael W. Warren. 2016. \u201cAssemblages of the Dead: Interpreting the Biocultural and Taphonomic Signature of Afro- Cuban Palo Practice in Florida.\u201d <em>Journal of African Diaspora Archaeology and Heritage <\/em>5 (1): 1\u201337.<\/p>\n<\/div>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_281_1694\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_281_1694\"><div tabindex=\"-1\"><div class=\"__UNKNOWN__\">\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Leslie E. Fitzpatrick, Ph.D., Independent Archaeological Consultants<\/p>\n<p class=\"import-Normal\"><em>This chapter is a revision from \"<\/em><a class=\"rId7\" href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/chapter\/__unknown__-13\/\"><em>Chapter 14: Human Variation: An Adaptive Significance Approach<\/em><\/a><em>\u201d by Leslie E. Fitzpatrick. In <\/em><a class=\"rId8\" href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/\"><em>Explorations: An Open Invitation to Biological Anthropology, first edition<\/em><\/a><em>, edited by Beth Shook, Katie Nelson, Kelsie Aguilera, and Lara Braff, which is licensed under <\/em><a class=\"rId9\" href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\"><em>CC BY-NC 4.0<\/em><\/a><em>. <\/em><\/p>\n<div class=\"textbox textbox--learning-objectives\">\n<header class=\"textbox__header\">\n<h2 class=\"textbox__title\"><span style=\"color: #ffffff;\">Learning Objectives<\/span><\/h2>\n<\/header>\n<div class=\"textbox__content\">\n<ul>\n<li class=\"import-Normal\" style=\"text-indent: 0pt;\">Distinguish between adaptations and adjustments as ways of coping with environmental stressors.<\/li>\n<li class=\"import-Normal\" style=\"text-indent: 0pt;\">Provide examples of adjustments humans use to cope with thermal stressors.<\/li>\n<li class=\"import-Normal\" style=\"text-indent: 0pt;\">Describe how specific patterns of human adaptations and adjustments are correlated to natural selection processes.<\/li>\n<li class=\"import-Normal\" style=\"text-indent: 0pt;\">Summarize the role of solar radiation in variations of human skin tone, and explain why reduced pigmentation is advantageous in northern latitudes.<\/li>\n<li class=\"import-Normal\" style=\"text-indent: 0pt;\">Compare and contrast the various genetic mutations present in Tibetan and Ethiopian populations that allow them to survive at high altitudes.<\/li>\n<li class=\"import-Normal\" style=\"text-indent: 0pt;\">Define the relationship between specific genetic mutations in some human populations and certain infectious diseases, such as the sickle-cell trait mutation and malarial infection.<\/li>\n<\/ul>\n<\/div>\n<\/div>\n<p>As early humans left Africa and spread across the globe, they faced numerous challenges related to their new environments. Beyond genetically influenced changes in physiology as a result of evolution, humans have developed lifestyle strategies to cope with and even thrive in a wide range of habitats. The ways populations of humans met such challenges, coupled with their geographic separation throughout the majority of the last two hundred thousand years, have led to the many forms of adaptation in our species. This chapter focuses on the complexities of modern human variation through the lens of human evolutionary history.<\/p>\n<h2 class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Stress and Homeostasis<\/h2>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">All organisms, including humans, must maintain a baseline of normal functions within their cells, tissues, and organs to survive. This constancy of internal functions is referred to as <strong>homeostasis.<\/strong> Homeostatic regulation, however, may be disrupted by a variety of both external and internal stimuli known as <strong>stressors<\/strong>. Within limits, all organisms have evolved certain physiological mechanisms to respond to stressors in an effort to maintain homeostasis. The range of changes in the physiology (function), morphology (form), and\/or behavior of organisms in response to their environments and potential stressors is regulated by its <strong>phenotypic<\/strong><strong> plasticity<\/strong>. Coping with these stressors led to the development of both <strong>adjustments<\/strong> (behavioral, acclimatory, and developmental) and <strong>adaptations<\/strong>, which are explained in detail in the following sections.<\/p>\n<h2 class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Adjustments and Adaptations<\/h2>\n<h3 class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\"><strong>Adjustments<\/strong><\/h3>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">The term <em>adjustment<\/em> refers to an organism\u2019s nongenetic way of coping with the stressors of its environment. Although adjustments themselves are nongenetic in nature, the ability of an organism to experience or develop an adjustment is based on its phenotypic plasticity, which is linked to its evolutionarily guided genetic potential. Adjustments occur exclusively on the individual level. As such, different individuals within a population may experience a wide range of possible adjustments in response to a similar stressor. In general, the three main forms of adjustment are: behavioral, acclimatory, and developmental.<\/p>\n<h4 class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\"><em>Behavioral Adjustments<\/em><\/h4>\n<figure style=\"width: 390px\" class=\"wp-caption alignleft\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/06\/image3-3.jpg\" alt=\"Underwater photograph of scuba diver exploring the ocean floor.\" width=\"390\" height=\"293\" \/><figcaption class=\"wp-caption-text\">Figure 14.1: Notice the lack of full-spectrum color in this photo of a deep-water diver as well as the diver\u2019s use of specialized equipment, such as a breathing apparatus to deliver gasses for respiration, a bodysuit to ensure thermal regulation, and a flashlight to increase visibility in the low-light setting. Credit: <a href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/chapter\/__unknown__-13\/\">Deep water diver<\/a> by Leslie E. Fitzpatrick is under a <a href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/\">CC BY-NC 4.0 License<\/a>.<\/figcaption><\/figure>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">When you are cold, do you reach for a blanket? When you are warm, do you seek out shelter cooled by an air-conditioning system? If so, you have likely been influenced to do so by the culture in which you were raised. As noted earlier in this textbook, the term <em>culture<\/em> refers to a collection of shared, learned beliefs and behaviors among individuals within a discrete population. <strong>Behavioral adjustments<\/strong> are regarded as cultural responses to environmental stressors. These adjustments are temporary in nature and, since they are nongenetic, must be constantly altered to meet novel situations posed by the environment. For example, divers are able to reach extraordinary depths (in excess of 300 meters below the surface) within the water through the use of a specialized mixture of gasses for breathing, an apparatus for the delivery of the gasses, protective clothing, and gear to increase visibility. The deeper a diver descends, the more atmospheric pressure the diver experiences, resulting in increased levels of potentially toxic byproducts of respiration within the body. In addition, with increased depth there is a decrease in the ambient temperature of the water and a decrease in the availability of light within the visible spectrum. Deep-water divers are well-versed in the environmental stressors of open waters and employ a variety of strategies based on behavioral adjustments to meet such demands. From wearing protective clothing to help maintain the body\u2019s core temperature to waiting at a specific depth for a prescribed period of time to facilitate the expulsion of nitrogen gas that may have accumulated within the bloodstream, divers employ numerous behavioral adjustments to ensure their safety (Figure 14.1). Without these culturally mediated behavioral adjustments, a deep-water diver\u2019s first dive would also be their last.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">In many developing countries, the use of refrigeration for the storage of perishable food products is uncommon; therefore, individuals within these cultures have developed a variety of behavioral adjustment strategies related to food preparation to address possible food spoilage. Through a cross-cultural analysis of spice use in recipes, Paul Sherman and Jennifer Billing (1999) determined that cultures closest to the equator, where temperatures are hotter, tend to use both a greater number and a wider variety of plant-based spices with bacteria-inhibiting phytochemical properties (e.g., garlic and onion). Antimicrobial properties of spices permits the consumption of foods, particularly animal-based protein sources, for a period of time beyond that which would be considered safe. There are some acclimatory adjustment benefits to the use of some pungent spices as well, which are explored in the following section.<\/p>\n<h4 class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\"><em>Acclimatory Adjustments: Thermal Stressors<\/em><\/h4>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\"><strong>Acclimatory adjustments<\/strong> are temporary, reversible changes in an organism\u2019s physiology in response to environmental stressors. Although they are not genetically determined, the range of acclimatory adjustments that an organism is capable of producing is linked to its underlying phenotypic plasticity and the duration and severity of the stressor. A good example of this is the human response to varying ambient temperatures.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">To understand human adjustments, we must first understand the thermodynamic mechanisms through which heat may be gained or lost. The four pathways for this are conduction, convection, evaporation, and radiation (Figure 14.2).<\/p>\n<figure style=\"width: 376px\" class=\"wp-caption aligncenter\"><img class=\"\" src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image11-5.png\" alt=\"Person facing wall with arrows illustrating evaporation, conduction, radiation, and convection.\" width=\"376\" height=\"426\" \/><figcaption class=\"wp-caption-text\">Figure 14.2: Various thermodynamic mechanisms related to heat gain and loss in the human body. This process is decribed in the text below. Credit: <a href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/chapter\/__unknown__-13\/\">Mechanisms of heat transfer (Figure 14.2)<\/a> original to <a href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/\">Explorations: An Open Invitation to Biological Anthropology<\/a> by Mary Nelson is under a <a href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/\">CC BY-NC 4.0 License<\/a>.<\/figcaption><\/figure>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Through <strong>conduction<\/strong> processes, heat will move from a warmer body to a cooler one through direct contact. An example of this is when you accidentally touch a hot cooktop with your hand and the heat is transferred from the cooktop to your skin.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">With <strong>convection<\/strong>, when a warm body is surrounded by a cooler fluid (e.g., air or water), heat will be transferred from the warmer body to the cooler fluid. This is why we will often employ the behavioral adjustment of wearing multiple layers of clothing during the winter in an effort to prevent heat loss to the cooler atmosphere. Conversely, if your body temperature is cooler than that of the air surrounding you, your body will absorb heat.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Depending on your physical condition, most people will begin to sweat around 37.2\u2103 to 37.7\u2103 (98.9\u2109\u201399.9\u2109). Sweating is an example of <strong>evaporation<\/strong>, which occurs when a liquid, such as the water within our bodies, is converted to a gas. Phase conversions, such as those underlying the evaporative processes of transforming liquids to gasses, require energy. In evaporation, this energy is in the form of heat, and the effect is to cool the body.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">The final mechanism for heat loss within the human body is <strong>radiation<\/strong>, through which energy in the form of electromagnetic waves is produced at a wavelength that typically lies below that which is visible to the human eye. Although humans gain and lose heat from their bodies through radiation, this form of heat transfer is not visible. Humans are capable of losing and gaining heat through conduction, convection, and radiation; however, heat may not be gained through evaporation.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">As the ambient temperature decreases, it becomes increasingly difficult for the human body to regulate its core temperature, which is central to the maintenance of homeostasis. When an individual\u2019s body temperature falls below 34.4\u2103 (93.9\u00b0F), the brain\u2019s <strong>hypothalamus<\/strong> becomes impaired, leading to issues with body temperature control. A total loss of the ability to regulate body temperature occurs around 29.4\u2103 (84.9\u00b0F), which may result in death. When the ambient temperature falls below the critical temperature of 31\u2103 (87.8\u00b0F), a nude human body that is at rest will respond with a series of physiological changes to preserve homeostasis (Figure 14.3).<\/p>\n<figure style=\"width: 585px\" class=\"wp-caption aligncenter\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image26-2.jpg\" alt=\"Body outlines illustrate differences in heat maintenance for different ambient environments.\" width=\"585\" height=\"347\" \/><figcaption class=\"wp-caption-text\">Figure 14.3: Example of overall body heat maintenance in cold and warm ambient environments.\u00a0<a href=\"https:\/\/docs.google.com\/document\/d\/1VUDKMBJYS_jNONjLxT04jQN0_z9Ua50BRN6auGSHUuU\/edit\">A full text description of this image is available<\/a>. Credit: <a href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/chapter\/__unknown__-13\/\">Body heat maintenance in cold and warm (Figure 14.3)<\/a> original to <a href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/\">Explorations: An Open Invitation to Biological Anthropology<\/a> by Mary Nelson is under a <a href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/\">CC BY-NC 4.0 License<\/a>.<\/figcaption><\/figure>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">The human body experiences two main types of physiological responses to colder temperatures: those that increase the production of heat and those that seek to retain heat. The production of heat within the body is accomplished through short-term increases in the body\u2019s basal metabolic rate, such as shivering to increase muscular metabolism. An organism\u2019s basic metabolic rate is a measure of the energy required to maintain necessary body processes when the organism is at rest. Increases in basal metabolic rates, such as when we shiver from the cold, require increased consumption of energy-providing nutrients. Of course, such increases in metabolic rates are not infinite, as we may only consume a finite amount of nutrients. As with all <strong>acclimatory adjustments<\/strong>, an increase in the basal metabolic rate is merely temporary.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Of the physiological mechanisms to preserve heat already in the body, the most notable is <strong>vasoconstriction<\/strong>, or the constriction of peripheral capillaries in the skin. The decreased surface area of the capillaries through vasoconstriction results in less heat reaching the surface of the skin where it would be dissipated into the atmosphere. Vasoconstriction also leads to the maintenance of heat near the core of the body where the vital organs are located. As a trade-off, though, individuals are more at risk of cold-related injuries, such as frost-bite, which can lead to tissue necrosis (tissue death) in regions of the body that are most distant from the core (e.g., fingers, toes, nose, ears, cheeks, chin, etc.).<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Just as cold stress presents challenges to maintaining homeostasis, heat does as well. In hot climates, the body will absorb heat from its surroundings (through conduction, convection, and radiation), resulting in potential heat-related disorders, such as heat exhaustion. When the human body is exposed to ambient temperatures above 35\u2103 (95\u00b0F), excess body heat will be lost primarily through evaporative processes, specifically through sweating. All humans, regardless of their environment, have approximately the same number of sweat glands within their bodies. Over time, individuals living in hot, arid environments will develop more sensitive forms of sweat glands resulting in the production of greater quantities of sweat (Best, Lieberman, and Kamilar 2019; Pontzer et al. 2021). In an effort to prevent dehydration due to this form of acclimatory adjustment, there will be an additional reduction in the volume of urine produced by the individual (Pontzer et al. 2021).<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">As noted in the previous section, some cultural groups, particularly those in equatorial regions, add pungent spices to their foods to inhibit the colonization of bacteria (Sherman and Billing 1999). Although adding spices to decrease spoilage rates is a behavioral adjustment, the application of some forms of peppers triggers an acclimatory adjustment as well. Compounds referred to as capsaicinoids are the secondary byproducts of chili pepper plants\u2019 metabolism and are produced to deter their consumption by some forms of fungi and mammals. When mammals, such as humans, consume the capsaicinoids from chili peppers, a burning sensation may occur within their mouths and along their digestive tracts. This burning sensation is the result of the activation of capsaicin receptors along the body\u2019s nerve pathways. Although the peppers themselves may be at ambient temperature so their consumption is not causing any form of body temperature increase, the human body perceives the pepper as elevating its core temperature due to the activation of the capsaicin receptors. This causes the hypothalamus to react, initiating sweating in an attempt to lower body temperature and maintain homeostasis. The increased piquancy (application of pungent spices to food) as a means of inhibiting food-borne bacterial colonization in warm climates, as well as spices\u2019 ability to trigger sweating processes as a method for cooling the body, is an example of the intersection between behavioral and acclimatory adjustments that utilized within certain populations.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">In addition to increased sweat production to maintain homeostasis in excess heat, <strong>vasodilation<\/strong> may occur (Figure 14.4). Vasodilation is an expansion of the capillaries within the skin leading to a more effective transfer of heat from within the body to the exterior to allow conductive, convective, radiative, and evaporative (sweating) processes to occur.<\/p>\n<figure style=\"width: 499px\" class=\"wp-caption aligncenter\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image27-4.png\" alt=\"Side-by-side sketches of capillaries under the skin for heat and cold.\" width=\"499\" height=\"445\" \/><figcaption class=\"wp-caption-text\">Figure 14.4: The vasoconstriction processes occur within the peripheral vascular system when an individual is exposed to cold ambient temperatures and the vasodilation that occurs in warmer environments. <a href=\"https:\/\/docs.google.com\/document\/d\/1VUDKMBJYS_jNONjLxT04jQN0_z9Ua50BRN6auGSHUuU\/edit\">A full text description of this image is available<\/a>. Credit: <a href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/chapter\/__unknown__-13\/\">Vasoconstriction and vasodilation (Figure 14.4)<\/a> original to <a href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/\">Explorations: An Open Invitation to Biological Anthropology<\/a> by Mary Nelson is under a <a href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/\">CC BY-NC 4.0 License<\/a>.<\/figcaption><\/figure>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Physiologically based acclimatory adjustments to hot, dry climates may be complemented by behavioral adjustments as well. For example, individuals in such climates may limit their physical activity during the times of day when the temperature is typically the hottest. Additionally, these individuals may wear loose-fitting clothing that covers much of their skin. The looseness of the clothing allows for air to flow between the clothing and the skin to permit the effective evaporation of sweat. Although it may seem counterintuitive to cover one\u2019s body completely in a hot climate, the covering of the skin keeps the sun\u2019s rays from directly penetrating the skin and elevating the body\u2019s core temperature.<\/p>\n<h4 class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\"><em>Acclimatory Adjustments: Altitudinal Stressors<\/em><\/h4>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">The challenges posed by thermal conditions are but one form of environmental stressor humans must face. High-altitude environments, which are defined as altitudes in excess of 2,400 meters above sea level (masl) or 7,874 feet above sea level (fasl), pose additional challenges to the maintenance of homeostasis in humans. Some of the main stressors encountered by those living within high-altitude environments include decreased oxygen availability, cold temperatures, low humidity, high wind speed, a reduced nutritional base, and increased solar radiation levels. Of these challenges, the most significant is the decreased availability of oxygen.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">To visualize how altitude affects the availability of oxygen, imagine two balloons that are each filled with the same quantity of oxygen molecules. One of these balloons is positioned at sea-level and the other is placed high upon a mountain peak. For the balloon at sea level, there is more atmospheric pressure pressing down on the molecules within this balloon. This leads to the oxygen molecules within the sea level balloon being forced into a more compact organization. In contrast, the mountain peak balloon has less atmospheric pressure pressing down on it. This leads to the oxygen molecules within that balloon spreading out from each other since they are not being forced together quite as strongly. This example highlights the availability of oxygen molecules in each breath than we take in low- versus high-altitude environments. At 5,500 masl (approximately 18,000 fasl), the atmospheric pressure is approximately 50% of its value at sea level (Peacock 1998). At the peak of Mount Everest (8,900 masl or approximately 29,200 fasl), the atmospheric pressure is equivalent to only about 30% of their sea level amounts (Peacock 1998; Figure 14.5).<\/p>\n<figure style=\"width: 482px\" class=\"wp-caption aligncenter\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image21-5.png\" alt=\"Atmospheric pressure decreases in density as a person climbs a mountain and increases in altitude. \" width=\"482\" height=\"418\" \/><figcaption class=\"wp-caption-text\">Figure 14.5: As altitude increases, atmospheric pressure decreases, which allows for more space between air molecules. Credit: <a href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/chapter\/__unknown__-13\/\">Atmospheric pressure (Figure 14.5)<\/a> original to <a href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/\">Explorations: An Open Invitation to Biological Anthropology<\/a> by Mary Nelson is under a <a href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/\">CC BY-NC 4.0 License<\/a>.<\/figcaption><\/figure>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Due to decreased availability of oxygen at higher altitudes, certain acclimatory adjustments are required to ensure the maintenance of homeostasis for individuals other than those who were gestated, born, and raised at high altitude. For these people, their rate of breathing will increase to permit greater quantities of air containing oxygen into the lungs when they ascend into higher altitude environments. An increased speed and depth of breathing, which is referred to as <strong>hyperpnea<\/strong>, is not sustainable indefinitely; thus, the rate of breathing begins to decrease as the person becomes acclimatized to the altitude. During the initial phases of high-altitude-related hyperpnea, the heart begins to beat faster but the amount of blood pushed through during each beat decreases slightly. In addition, the body will divert energy from noncritical bodily functions, such as digestive processes.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Once the atmospheric oxygen reaches the alveoli (small air sacs) in the lungs, it spreads across the alveolar membrane and enters <strong>erythrocytes<\/strong> (red blood cells). As oxygen reaches the alevoli\u2019s erythrocytes, it loosely binds with hemoglobin (an iron-rich protein) contained in the erythrocytes. When the erythrocytes carrying the hemoglobin-bound oxygen molecules reach capillaries where the partial pressure of oxygen is relatively low, oxygen will be released by the hemoglobin so that it is free for diffusion into body cells. Similar to acclimatory adjustments related to thermal conditions (e.g., shivering or sweating), those related to high altitude may not be infinitely sustained due to their energetically expensive nature.<\/p>\n<figure style=\"width: 430px\" class=\"wp-caption alignright\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image24-3.jpg\" alt=\"Newborn lays face down on hospital bedding. Photograph is blue indicating UV light.\" width=\"430\" height=\"323\" \/><figcaption class=\"wp-caption-text\">Figure 14.6: Premature infant born at 30 weeks, 4 days gestation to a mother with altitudinal-induced preeclampsia. Blue light assists the infant\u2019s liver with processing high levels of bilirubin. Credit: <a href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/chapter\/__unknown__-13\/\">Premature infant<\/a> by Leslie E. Fitzpatrick is under a <a href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/\">CC BY-NC 4.0 License<\/a>.<\/figcaption><\/figure>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Although the long-term acclimatory adjustments that an individual from low altitude experiences in a high-altitude environment may permit them to reside there successfully, reproduction within such settings is frequently complicated. With increased altitude comes an increased risk of miscarriage, lower birth weights, and higher infant mortality rates. As the pregnant person\u2019s body seeks to preserve its own homeostasis, there is often a decreased rate and volume of blood flow to the uterus as compared to a pregnant person of similar physiological condition at a lower altitude (Moore, Niermeyer, and Zamudio 1998). This results in a decrease in the amount of oxygen that will be passed through the uterus and placenta to the developing fetus. In addition, pregnant people who experience pregnancy at higher altitudes are more prone to developing preeclampsia (severe elevation of blood pressure), which is linked to increased rates of both fetal and maternal death (Moore, Niermeyer, and Zamudio 1998; Figure 14.6).<\/p>\n<h4 class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\"><em>Developmental Adjustments <\/em><\/h4>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Developmental adjustments occur only in individuals who spent their developmental period (i.e., childhood and adolescence) within a high-altitude environment; they do not apply to those who moved into these environments in the post developmental (i.e., adult) phase. Furthermore, the degree of developmental adjustment within an individual is directly related to their underlying phenotypic plasticity as well as the amount of time during the crucial growth and development period that the individual resides within the challenging environment. Although humans have the remarkable capacity to develop and survive within environments that are not overly conducive to the successful maintenance of homeostasis, there are definitely physiological costs associated with this ability.<\/p>\n<figure style=\"width: 369px\" class=\"wp-caption alignleft\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image18-2.jpg\" alt=\"Two people walking down a street wearing brightly colored woven traditional clothing.\" width=\"369\" height=\"277\" \/><figcaption class=\"wp-caption-text\">Figure 14.7: Two individuals from a high-altitude region of the Peruvian Andes. Credit: <a href=\"https:\/\/commons.wikimedia.org\/wiki\/File:Andahuaylas_Peru-_two_women_walking_down_street.jpg\">Andahuaylas Peru-two women walking down street<\/a> by <a href=\"https:\/\/commons.wikimedia.org\/wiki\/User:ThayneT\">Thayne Tuason<\/a> has been modified (cropped) and is under a <a href=\"https:\/\/creativecommons.org\/licenses\/by\/4.0\/deed.en\">CC BY 4.0 License<\/a>.<\/figcaption><\/figure>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">In general, high-altitude natives tend to grow more slowly and physically mature later than their low-altitude counterparts (Figure 14.7). Lowered growth and maturity rates are linked not only to the increased physiological demands placed on the body due to the decreased partial pressure of oxygen but also to reductions in the quality of the nutritional base at higher altitudes. Increased terrain complexity, elevated solar radiation levels, and higher wind speeds coupled with the lower temperatures and humidity levels found at high altitudes leads to difficulties with growing and maintaining crops and raising livestock. Overall, as altitude rises, the quality of the available nutritional base goes down, which is correlated to a lack of the nutrients necessary to ensure proper physiological growth and development in humans. Thus, even though individuals may be able to develop and grow within high-altitude environments, they may not reach their full genetically mediated growth potential as they would in a lower-altitude environment.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Not all developmental adjustments are linked to environmental pressures such as climate or altitude; rather, some of these adjustments are correlated to sociocultural or behavioral practices. Some of these adjustments may affect the physiological appearance of an individual when they are practiced consistently during the development and growth phases.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Sudden infant death syndrome (SIDS) has no definitive cause; however, the American Academy of Pediatrics published a report in 1992 linking SIDS to infants (under the age of one) sleeping on their stomachs. The \u201cBack to Sleep\u201d campaign championed by the American Academy of Pediatrics helped educate members of the medical community as well as the public that the best sleep position for infants is on their backs (American Academy of Pediatrics 2000).<\/p>\n<\/div>\n<figure id=\"attachment_421\" aria-describedby=\"caption-attachment-421\" style=\"width: 562px\" class=\"wp-caption aligncenter\"><img class=\"wp-image-420\" src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/14.8.jpg\" alt=\"Brachycephaly drawings show a flattened, symmetrical head. Plagiocephaly shows asymmetrical flattening of the skull.\" width=\"562\" height=\"219\" \/><figcaption id=\"caption-attachment-421\" class=\"wp-caption-text\">Figure 14.8: These sketches illustrate a top and side view of brachycephaly (left and middle images, respectively) and plagiocephaly (right image). Credit: Brachycephaly and plagiocephaly original to Explorations: An Open Invitation to Biological Anthropology (2nd ed.) by Mary Nelson is under a <a href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/\">CC BY-NC 4.0 License<\/a>.<\/figcaption><\/figure>\n<div class=\"__UNKNOWN__\">\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Placing infants on their backs to sleep has led to decreased infant mortality (death) rates due to SIDS; however, it has led to an unintended consequence: infant cranial deformation. The cranial deformations experienced by infants who sleep solely on their back tend to manifest in one of two forms: brachycephaly and plagiocephaly (Roby et al. 2012; Figure 14.8). With positional brachycephaly, the back of the infant\u2019s head appears rather uniformly flattened due to repetitive contact with a flat surface, such as a crib mattress or car seat back. In cases of positional plagiocephaly, the back of the infant\u2019s head appears asymmetrically flattened. This asymmetry is typically due to an uneven distribution of mechanical forces resulting from the manner in which the infant\u2019s head is in contact with a flat surface. The forms of cranial deformation resulting from sleep positioning do not affect the infant\u2019s brain development. For many individuals, the appearance of the deformation is minimized during later development. Still, some individuals will maintain the pattern of cranial deformation acquired during their infancy throughout their lives. The unintentional cranial deformation resulting from placing infants on their backs to sleep as a means of preventing SIDS-related deaths is a physiological indicator of a behavioral adjustment.<\/p>\n<\/div>\n<h3 class=\"__UNKNOWN__\"><strong>Adaptations<\/strong><\/h3>\n<div class=\"__UNKNOWN__\">\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">As we have just explored, survival and reproduction at high altitudes present numerous physiological challenges for most humans. The behavioral, acclimatory, and developmental adjustments discussed above are all related to the phenotypic plasticity of the individual; however, most adjustments are temporary in nature and they affect a single individual rather than all individuals within a population. But what if the physiological changes were permanent? What if they affected all members of a population rather than just a single individual? The long-term, microevolutionary (i.e., genetic) changes that occur within a population in response to an environmental stressor are referred to as an adaptation. From an evolutionary standpoint, the term <em>adaptation<\/em> refers to a phenotypic trait (i.e., physiological\/morphological feature or behavior) that has been acted upon by natural selection processes to increase a species\u2019 ability to survive and reproduce within a specific environment. Within the field of physiology, the term <em>adaptation<\/em> refers to traits that serve to restore homeostasis. The physiology-based interpretation of adaptations presumes that all traits serve a purpose and that all adaptations are beneficial in nature; however, this may be a fallacy, since some traits may be present without clear evidence as to their purpose. As such, during the following discussion of various forms of adaptations in human populations, we will focus our attention on phenotypic traits with an evidence-based purpose.<\/p>\n<h4 class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\"><em>Adaptation: <\/em><em>Altitudinal Adaptation<\/em><\/h4>\n<\/div>\n<figure id=\"attachment_421\" aria-describedby=\"caption-attachment-421\" style=\"width: 619px\" class=\"wp-caption aligncenter\"><img class=\"wp-image-421\" src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/14.9.jpg\" alt=\"The Simian Plateau in northeast Africa and Tibetan Plateau in southern Asia.\" width=\"619\" height=\"339\" \/><figcaption id=\"caption-attachment-421\" class=\"wp-caption-text\">Figure 14.9: Highlighted regions feature (from left to right) the Simian (Ethiopian) and Tibetan Plateau high-altitude regions. Credit: <a href=\"https:\/\/commons.wikimedia.org\/wiki\/File:World_Map_of_HVR_adaptation_in_high_altitude_populations.jpg\">World Map of HVR adaptation in high altitude populations<\/a> by Chkuu has been modified (cropped, Andean region color change) and is under <a href=\"https:\/\/creativecommons.org\/licenses\/by-sa\/4.0\/legalcode\">CC BY-SA 4.0 License<\/a>.<\/figcaption><\/figure>\n<div class=\"__UNKNOWN__\">\n<p>As mentioned in the previous section, there is genomic research supporting the evolutionary selection of certain phenotypes and their corresponding genotypes within indigenous high-altitude populations across the globe. The following discussion focuses on two high-altitude indigenous populations from Tibet and Ethiopia (Figure 14.9). Although these populations share many common genetic traits based on relatively similar evolutionary histories influenced by similar environmental stressors, there is support for local genetically based adaptation as well, based on different genes being acted upon by environmental stressors that may be unique to Tibet and Ethiopia (Bigham 2016).<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Tibetan populations have resided in the Tibetan Plateau and Himalayan Mountain regions at elevations exceeding 4,000 masl (13,100 fasl) for at least the past 7,400 years (Meyer et al. 2017). There is evidence of a genetic exchange event involving Tibetan populations and Denisovans around 48,700 years ago, which introduced a haplogroup involving mutations of the <em>EPAS1<\/em> gene (Zhang et al. 2021). The <em>EPAS1<\/em> is involved in the regulation of erythrocytes and hemoglobin. For individuals originating in lower-altitude environments, <em>EPAS1 <\/em>stimulates increased erythrocyte production in high-altitude environments as a temporary acclimatory adjustment. For indigenous high-altitude populations of Tibet, the <em>EPAS1<\/em> gene mutation introduced by Denisovan introgression inhibits increased erythrocyte production, which reduces potential negative effects (e.g., stroke or heart attack) associated with long-term high levels of erythrocyte production (Gray et al. 2022; Zhang et al. 2021). The erythrocyte count of high-altitude Tibetans with the <em>EPAS1<\/em> point mutation is about the same as for individuals residing at sea level.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Populations indigenous to the Semien Plateau of Ethiopia, such as the Oromo and Amhara, share a similar but not identical <em>EPAS1<\/em> point mutation with the Tibetan population (Bigham 2016); however, there is no indication that this mutation was derived from Denisovan introgression. The <em>EPAS1<\/em> mutations occurred independently from each other; however, their effects are still similar in that they permit the Tibetan and Ethiopian populations to survive at high altitudes. Not all adaptations are related to life in high-altitude environments, however. In the following sections, we will address two more general examples of adaptation in human populations: variations in skin color and differences in body build.<\/p>\n<h4 class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\"><em>Adaptation: Skin Tone<\/em><em> Basics<\/em><\/h4>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">When you think about your own skin tone and compare it to members of your family, do you all possess exactly the same shade? Are some members of your family darker than others? What about your friends? Your classmates? Skin tone occurs along a continuum, which is a reflection of the complex evolutionary history of our species. The expression of skin tone is regulated primarily by melanin and hemoglobin. <strong>Melanin<\/strong> is a dark brown-black pigment that is produced by the oxidation of certain amino acids (e.g., tyrosine, cysteine, phenylalanine) in melanocytes. <strong>Melanocytes<\/strong> are specialized cells located in the base layer (stratum basale) of the skin\u2019s epidermis as well as several other areas within the body (Figure 14.10). Within the melanocytes, melanin is produced in the special organelle called a melanosome. Melanosomes serve as sites for the synthesis, storage, and transportation of melanin. Melanosomes transport the melanin particles through cellular projections to epidermal skin cells (keratinocytes) as well as to the base of the growing hair root. In the eye, however, melanin particles produced by the melanosomes remain present within the iris and are not transported beyond their origin location. The two main forms of melanin related to skin, hair, and eye color are eumelanin and pheomelanin. All humans contain both eumelanin and pheomelanin within their bodies; however, the relative expression of these two forms of melanin determines an individual\u2019s overall coloring. Eumelanin is a brown-to-black colored melanin particle while pheomelanin is more pink-to-red colored. Individuals with darker skin or hair color have a greater expression of eumelanin than those with lighter-colored skin and blonde or red hair.<\/p>\n<figure style=\"width: 553px\" class=\"wp-caption aligncenter\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image12-2.jpg\" alt=\"Melanocytes and melanosomes are compared from light and dark skin tones.\" width=\"553\" height=\"436\" \/><figcaption class=\"wp-caption-text\">Figure 14.10: Diagram featuring the relative numbers of melanocytes and melanosomes in light and dark shades of skin tone.\u00a0<a href=\"https:\/\/docs.google.com\/document\/d\/1VUDKMBJYS_jNONjLxT04jQN0_z9Ua50BRN6auGSHUuU\/edit\">A full text description of this image is available<\/a>. Credit: <a href=\"https:\/\/openstax.org\/books\/anatomy-and-physiology-2e\/pages\/5-1-layers-of-the-skin#fig-ch05_01_07\">Skin Pigmentation (Anatomy and Physiology, Figure 5.8)<\/a> by <a href=\"https:\/\/openstax.org\/\">OpenStax<\/a> is under a <a href=\"https:\/\/creativecommons.org\/licenses\/by\/4.0\/\">CC BY 4.0 License<\/a>.<\/figcaption><\/figure>\n<h4 class=\"import-Normal\"><em>Adaptation<\/em><em>: <\/em><em>Melanogenesis <\/em><\/h4>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Although all humans have approximately the same number of melanocytes within their epidermis, the production of melanin by these melanocytes varies. There are two forms of melanogenesis (the process through which melanocytes generate melanin): basal and activated. As discussed previously, the expression of eumelanin and pheomelanin by the melanocytes is genetically regulated through the expression of specific receptors (e.g., <em>MC1R<\/em>) or other melanocyte components (e.g., <em>MFSD12<\/em>)<em>.<\/em> <strong>Basal melanogenesis <\/strong>is dependent upon an individual\u2019s inherent genetic composition and is not influenced by external factors. <strong>Activated melanogenesis<\/strong> occurs in response to ultraviolet radiation (UV) exposure, specifically UV-B (short UV wave) exposure. Increased melanogenesis in response to UV-B exposure serves to provide protection to the skin\u2019s innermost layer called the hypodermis, which lies below the epidermis and dermis (Figure 14.11). Melanin in the skin, specifically eumelanin, effectively absorbs UV-B radiation from light\u2014meaning that it will not reach the hypodermal layer. This effect is often more apparent during periods of the year when people tend to be outside more and the weather is warmer, which leads to most donning fewer protective garments. The exposure of skin to sunlight is, of course, culturally mediated with some cultures encouraging the covering of skin at all times.<\/p>\n<figure style=\"width: 395px\" class=\"wp-caption aligncenter\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image10-6.png\" alt=\"Cross-section of skin illustrating UVA rays penetrate deeper than UVB. \" width=\"395\" height=\"407\" \/><figcaption class=\"wp-caption-text\">Figure 14.11: Penetration of skin layers by UVA and UVB rays. UVB rays penetrate only through the epidermis. UVA rays penetrate much deeper, through the dermis. Credit: <a href=\"https:\/\/cnx.org\/contents\/FPtK1zmh@16.7:RxywCGkA@10\/5-1-Layers-of-the-Skin\">Skin Pigmentation (Anatomy and Physiology, Figure 5.8)<\/a> by<a href=\"https:\/\/openstax.org\/\"> OpenStax<\/a> is under a<a href=\"https:\/\/creativecommons.org\/licenses\/by\/4.0\/\"> CC BY 4.0 License<\/a>.<\/figcaption><\/figure>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">As previously noted in this chapter, hemoglobin is an iron-rich protein that binds with oxygen in the bloodstream. For individuals with lighter-colored skin, blood vessels near the surface of the skin and the hemoglobin contained within those vessels is more apparent than in individuals with darker skin. The visible presence of hemoglobin coupled with the pink-to-red tone of the pheomelanin leads to lighter-skinned individuals having a pale pink skin tone. Individuals with lighter skin more readily absorb UV radiation as their basal melanin expression is directed more toward the production of pheomelanin than eumelanin. But why are there so many variations in skin tone in humans? To answer this question, we now turn toward an exploration of an evolutionary-based adaptation of skin tone as a function of the environment.<\/p>\n<h4 class=\"import-Normal\"><em>Adaptation: <\/em><em>Evolutionary Basis for Skin Tone Variation<\/em><\/h4>\n<figure style=\"width: 337px\" class=\"wp-caption alignleft\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image22-4.png\" alt=\"Table discussing hair and skin, folate and UV rays, leaving Africa, vitamin D, and selective pressures.\" width=\"337\" height=\"843\" \/><figcaption class=\"wp-caption-text\">Figure 14.12: Evolutionary basis for human skin color variation. <a href=\"https:\/\/docs.google.com\/document\/d\/1VUDKMBJYS_jNONjLxT04jQN0_z9Ua50BRN6auGSHUuU\/edit\">A full text description of this image is available<\/a>. Credit: <a href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/chapter\/__unknown__-13\/\">Evolutionary basis for human skin color variation (Figure 14.12)<\/a> original to <a href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/\">Explorations: An Open Invitation to Biological Anthropology<\/a> by Katie Nelson is under a <a href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/\">CC BY-NC 4.0 License<\/a>.<\/figcaption><\/figure>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Skin cancer is a significant concern for many individuals with light skin tone as the cumulative exposure of the epidermis and underlying skin tissues to UV radiation may result in the development of abnormal cells within those tissues, leading to malignancies. Although darker-skinned individuals are at risk for skin cancer as well, they are less likely to develop it due to increased levels of melanin, specifically eumelanin, in their skin. Even though skin cancer is a serious health concern for some individuals, most skin cancers occur in the postreproductive years; therefore, it is improbable that evolutionary forces favoring varying melanin expression levels are related to a selective pressure to avoid such cancers. Furthermore, if avoiding skin cancer were the primary factor driving the evolution of various skin tones, then it reasons that everyone would have the most significant expression of eumelanin possible. So, why do we have different skin tones (Figure 14.12)?<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">The term <strong>cline<\/strong> (introduced in Chapter 13) refers to the continuum or spectrum of gradations (i.e., levels or degrees) from one extreme to another. With respect to skin tone, the various tonal shades occur clinally with darker skin being more prevalent near the equator and gradually decreasing in tone (i.e., decreased melanin production) in more distant latitudes. For individuals who are indigenous to equatorial regions, the increased levels of melanin within their skin provides them with a measure of protection against both sunburn and sunstroke because the melanin is more reflective of UV radiation than hemoglobin. In cases of severe sunburn, eccrine glands are affected, resulting in an individual\u2019s ability to sweat being compromised. As sweat is the body\u2019s most effective means of reducing its core temperature to maintain homeostasis, damage to the eccrine glands may lead to numerous physiological issues related to heat that may ultimately result in death.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Even though avoiding severe sunburn and sunstroke is of great importance to individuals within equatorial regions, this is likely not the primary factor driving the evolutionary selection of darker skin within these regions. It has been proposed that UV radiation\u2019s destruction of <strong>folic acid<\/strong>, which is a form of B-complex vitamin, may have led to the selection of darker skin in equatorial regions. For pregnant people, low levels of folic acid within the body during gestation may lead to defects in the formation of the brain and spinal cord of the fetus. This condition, which is referred to as spina bifida (Figure 14.13), often significantly reduces an infant\u2019s chances of survival without medical intervention. In people producing sperm, low levels of folic acid within the body reduce sperm quantity and quality. Thus, in geographic regions with high UV radiation levels (i.e., equatorial regions), there appears to be an evolutionarily driven correlation between darker skin and fertility.<\/p>\n<figure style=\"width: 364px\" class=\"wp-caption alignright\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image19-2-1.jpg\" alt=\"Infant with a bulging spinal cord above the lower spine.\" width=\"364\" height=\"294\" \/><figcaption class=\"wp-caption-text\">Figure 14.13: Infant with open neural tube defect in lower (lumbar) region of the spine (right). A close-up of the open neural tube defect within the spinal column (left) shows the dura matter, which is ordinarily protected within the spine, is exposed on the surface of the skin. The spinal cord sits near the surface, when it should be protected within the spinal column. Credit: <a href=\"https:\/\/commons.wikimedia.org\/wiki\/File:Spina-bifida.jpg\">Spina-bifida<\/a> by the <a href=\"https:\/\/www.cdc.gov\/\">Centers for Disease Control and Prevention<\/a> is in the <a href=\"https:\/\/en.wikipedia.org\/wiki\/Public_domain\">public domain<\/a>.<\/figcaption><\/figure>\n<p>If darker skin tone is potentially correlated to more successful reproduction, then why do lighter shades of skin exist? One hypothesis is that there is a relationship between lighter skin tone and vitamin D synthesis within the body. When skin is exposed to the UV-B radiation waves in sunlight, a series of chemical reactions occur within the epidermis leading to the production of vitamin D3, which is a fat-soluble vitamin that assists the body with absorbing calcium and phosphorus in the small intestine. These nutrients are among those that are critical for the proper growth and maintenance of bone tissue within the body. In the absence of adequate minerals, particularly calcium, bone structure and strength will be compromised, leading to the development of rickets during the growth phase. Rickets is a disease affecting children during their growth phase. It is characterized by inadequately calcified bones that are softer and more flexible than normal. Individuals with rickets will develop a true bowing of their legs, which may affect their mobility (Figure 14.14). In addition, deformation of pelvic bones in people who may become pregnant may occur as a result of rickets, leading to complications with reproduction. In adults, a deficiency in vitamin D3 will often result in osteomalacia, which is a general softening of the bones due to inadequate mineralization. As noted, a variety of maladies may occur due to the inadequate production or absorption of vitamin D3, as well as the destruction of folate within the human body. Therefore, from an evolutionary perspective, natural selection should favor a skin tone that is best suited to a given environment.<\/p>\n<figure style=\"width: 263px\" class=\"wp-caption alignleft\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image9-2-1.jpg\" alt=\"Historic photo of three young children each with visible lower limb curvature.\" width=\"263\" height=\"315\" \/><figcaption class=\"wp-caption-text\">Figure 14.14: Children with rickets in various developmental stages. Credit: <a href=\"https:\/\/wellcomecollection.org\/works\/m3eu5snb\">Rachitis, stages of development for children<\/a> [slide numbers 7181 and 7182; photo number: M0003399] by <a href=\"https:\/\/wellcomecollection.org\/\">Wellcome Collection<\/a> is under a <a href=\"https:\/\/creativecommons.org\/licenses\/by\/4.0\/\">CC BY 4.0 License<\/a>.<\/figcaption><\/figure>\n<p>In general, the trend related to lighter skin pigmentation further from the equator follows a principle called <strong>Gloger\u2019s Rule<\/strong>. This rule states that within the same species of mammals the more heavily pigmented individuals tend to originate near the equator while lighter-pigmented members of the species will be found in regions further from the equator. Gloger\u2019s Rule applies latitudinally; however, it does not appear to hold for certain human populations near the poles. Specifically, it does not apply to the Inuit people (Figure 14.15), who are indigenous to regions near the North Pole and currently reside in portions of Canada, Greenland, Alaska, and Denmark. The Inuit have a darker skin tone that would not be anticipated under the provisions of Gloger\u2019s Rule. The high reflectivity of light off of snow and ice, which is common in polar regions, necessitates the darker skin tone of these individuals to prevent folic acid degradation just as it does for individuals within equatorial regions. The consumption of vitamin D\u2013rich foods, such as raw fish, permits the Inuit to reside at high latitudes with darker skin tone while preventing rickets.<\/p>\n<h4 class=\"import-Normal\"><em>Adaptation: <\/em><em>Shape and Size Variations<\/em><\/h4>\n<figure style=\"width: 353px\" class=\"wp-caption alignright\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image6-3-1.jpg\" alt=\"Historic photo of a person carrying a very large fish laid on a pack.\" width=\"353\" height=\"296\" \/><figcaption class=\"wp-caption-text\">Figure 14.15: Copper Inuk (from Bernard Harbour, Nunavut) with lake trout on his back (1915). Credit: <a href=\"https:\/\/commons.wikimedia.org\/wiki\/File:Copper_Inuk_with_lake_trout_on_his_back_near_Bernard_Harbour_(51007).jpg\">Copper Inuk with lake trout on his back near Bernard Harbour, Northwest Territories (Nunavut)<\/a> (1915) by George H. Wilkins is under a <a href=\"https:\/\/creativecommons.org\/licenses\/by-sa\/4.0\/deed.en\">CC BY-SA 4.0 License<\/a>. This image is part of the Photographic Archives of the Canadian Museum of History.<\/figcaption><\/figure>\n<p>In addition to natural selection playing a role in the determination of melanin expression, it plays a significant role in the determination of the shape and size of the human body. As previously discussed, the most significant thermodynamic mechanism of heat loss from the body is radiation. At temperatures below 20\u2103 (68\u2109), the human body loses around 65% of its heat to radiative processes; however, the efficiency of radiation is correlated to the overall body shape and size of the individual. There is a direct correlation between the ratio of an object\u2019s surface area to mass and the amount of heat that may be lost through radiation. For example, two objects of identical composition and mass are heated to the same temperature. One object is a cube and the other is a sphere. Which object will cool the fastest? Geometrically, a sphere has the smallest surface area per unit mass of any three-dimensional object, so the sphere will cool more slowly than the cube. In other words, the smaller the ratio of the surface area to mass an object has, the more it will retain heat. With respect to the cube in our example, mass increases by the cube, but surface area may increase only by the square, so size will affect the mass to surface area ratio. This, in general, holds true for humans, as well.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">In regions where temperatures are consistently cold, the body shape and size of individuals indigenous to the area tend to be more compact. These individuals have a relatively higher body mass to surface area (i.e., skin) than their counterparts from equatorial regions where the average temperatures are considerably warmer. Individuals from hot climates, such as the Fulani (Figure 14.16a) of West Africa, have limbs that are considerably longer than those of individuals from cold climates, such as the Inuit of Greenland (Figure 14.16b). Evolutionarily, the longer limbs of individuals from equatorial regions (e.g., the Fulani) provide a greater surface area (i.e., lower body mass to surface area ratio) for the dissipation of heat through radiative processes. In contrast, the relatively short limbs of Arctic-dwelling people, such as the Inuit, allows for the retention of heat because there is a decreased surface area through which heat may radiate away from the body.<\/p>\n<figure style=\"width: 385px\" class=\"wp-caption aligncenter\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image20-2.jpg\" alt=\"Person on left is stocky, person on right has a narrow body breadth.\" width=\"385\" height=\"570\" \/><figcaption class=\"wp-caption-text\">Figure 14.16: The individual on the left is typical of one adapted to a cold environment where the conservation of heat in the body\u2019s core is of critical importance.The individual on the right could be adapted to a tropical environment where the rapid dispersal of heat is necessary to maintain homeostasis. Credit: <a href=\"https:\/\/commons.wikimedia.org\/wiki\/File:Greenland_1999_(01).jpg\">Greenland 1999 (01)<\/a> by <a href=\"https:\/\/commons.wikimedia.org\/wiki\/User:Vadeve\">Vadeve<\/a> has been designated to the <a href=\"https:\/\/creativecommons.org\/share-your-work\/public-domain\/cc0\/\">public domain (CC0)<\/a>.<\/figcaption><\/figure>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">As described above, there are certain trends related to the general shape and size of human bodies in relation to the thermal conditions. To better describe these trends, we turn to a couple of general principles that are applicable to a variety of species beyond humans. <strong>Bergmann\u2019s Rule<\/strong> predicts that as average environmental temperature decreases, populations are expected to exhibit an increase in weight and a decrease in surface area (Figure 14.17a). Also, within the same species of homeothermic animals, the relative length of projecting body parts (e.g., nose, ears, and limbs) increases in relation to the average environmental temperature (Figure 14.17b). This principle, referred to as <strong>Allen\u2019s Rule<\/strong>, notes that longer, thinner limbs are advantageous for the radiation of excess heat in hot environments and shorter, stockier limbs assist with the preservation of body heat in cold climates. A measure of the crural index (crural index = tibia length <span style=\"font-size: NaNpt; color: #; text-decoration: none;\">\u00f7 <\/span>femur length) of individuals from various human populations provides support for Allen\u2019s Rule since this value is lower in individuals from colder climates than it is for those from hot climates. The crural indices for human populations vary directly with temperature, so individuals with higher crural index values are generally from regions with a warmer average environmental temperature. Conversely, the crural indices are lower for individuals from regions where there are colder average temperatures.<\/p>\n<figure style=\"width: 533px\" class=\"wp-caption aligncenter\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image16-6.png\" alt=\"Illustration of an elk (left) and gazelle (right).\" width=\"533\" height=\"319\" \/><figcaption class=\"wp-caption-text\">Figure 14.17a: These organisms are representative of Bergmann\u2019s rule. The animal on the left depicts an ungulate from a cooler environment with increased body weight and decreased surface area, compared to the slender ungulate on the right. Credit: <a href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/chapter\/__unknown__-13\/\">Bergmann\u2019s Rule (Figure 14.16a)<\/a> original to <a href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/\">Explorations: An Open Invitation to Biological Anthropology<\/a> by Mary Nelson is under a <a href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/\">CC BY-NC 4.0 License<\/a>.<\/figcaption><\/figure>\n<figure style=\"width: 521px\" class=\"wp-caption aligncenter\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image14-4.png\" alt=\"Three types of rabbits with different ear and forelimb lengths.\" width=\"521\" height=\"264\" \/><figcaption class=\"wp-caption-text\">Figure 14.17b: These animals are representative of Allen\u2019s rule. The rabbit on the left comes from a cooler environment and is compact with short limbs and ears. The rabbit on the right comes from a warm environment and has long and lanky limbs and ears. The rabbit in the middle has ears and limbs that are in-between the other two. Rabbits do not sweat like humans; heat is dissipated primarily through their ears. Credit: <a href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/chapter\/__unknown__-13\/\">Allen\u2019s Rule (Figure 14.16b)<\/a> original to <a href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/\">Explorations: An Open Invitation to Biological Anthropology<\/a> by Mary Nelson is under a <a href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/\">CC BY-NC 4.0 License<\/a>.<\/figcaption><\/figure>\n<figure style=\"width: 627px\" class=\"wp-caption alignleft\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image17-6.png\" alt=\"Four noses with varying heights, arches, and nostril breadth.\" width=\"627\" height=\"237\" \/><figcaption class=\"wp-caption-text\">Figure 14.18: Human nasal morphological variation as influenced by four major climate-based adaptive zones: hot-dry, hot-wet, cold-dry, and cold-wet. The four noses in this figure vary in shape in relation to their respective climate-based adaptive zones. Credit: <a href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/chapter\/__unknown__-13\/\">Human nasal morphological variation (Figure 14.17)<\/a> original to <a href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/\">Explorations: An Open Invitation to Biological Anthropology<\/a> by Mary Nelson is under a <a href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/\">CC BY-NC 4.0 License<\/a>.<\/figcaption><\/figure>\n<p>Nasal shape and size (Figure 14.18) is another physiological feature affected by our ancestors\u2019 environments. The selective role of climate in determining human nasal variation is typically approached by dividing climates into four adaptive zones: hot-dry, hot-wet, cold-dry, and cold-wet (Maddux et al. 2016). A principal role of the nasal cavity is to condition (i.e., warm and humidify) ambient air prior to its reaching the lungs. Given this function of the nasal cavity, it is anticipated that different nasal shapes and sizes will be related to varying environments. In cold-dry climates, an individual\u2019s nasal cavity must provide humidification and warmth to the dry air when breathing in through the nose (Noback et al. 2011). Also, in that type of climate, the nasal cavity must conserve moisture and minimize heat loss during when the individual exhales through the nose (Noback et al. 2011). From a physiological stress perspective, this is a stressful event.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Conversely, in hot-wet environments, there is no need for the nasal cavity to provide additional moisture to the inhaled air nor is there a need to warm the air or to preserve heat within the nasal cavity (Noback et al. 2011). So, in hot-wet climates, the body is under less physiological stress related to the inhalation of ambient air than in cold-dry climates. As with most human morphological elements, the shape and size of the nasal cavity occurs along a cline. Due to the environmental stressors of cold-dry environments requiring the humidification and warming of air through the nasal cavity, individuals indigenous to such environments tend to have taller (longer) noses with a reduced nasal entrance (nostril opening) size (Noback et al. 2011). This general shape is referred to as leptorrhine, and it allows for a larger surface area within the nasal cavity itself for the air to be warmed and humidified prior to entering the lungs (Maddux et al. 2016). In addition, the relatively small nasal entrance of leptorrhine noses serves as a means of conserving moisture and heat (Noback et al. 2011). Individuals indigenous to hot-wet climates tend to have platyrrhine nasal shapes, which are shorter with broader nasal entrances (Maddux et al. 2016). Since individuals in hot-wet climates do not need to humidify and warm the air entering the nose, their nasal tract is shorter and the nasal entrance wider to permit the effective cooling of the nasal cavity during respiratory processes.<\/p>\n<h4 class=\"import-Normal\"><em>Adaptation: Infectious Disease<\/em><\/h4>\n<p class=\"import-Normal\">Throughout our evolutionary journey, humans have been exposed to numerous infectious diseases. In the following section, we will explore some of the evolutionary-based adaptations that have occurred in certain populations in response to the stressors presented by select infectious diseases. One of the primary examples of natural selection processes acting on the human genome in response to the presence of an infectious disease is the case of the relationship between the sickle-cell anemia trait and malaria, introduced in Chapter 4.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Malaria is a zoonotic disease (an infectious disease transmitted between animals and humans; it is covered in more detail in Chapter 16). It is caused by the spread of the parasitic protozoa from the genus <em>Plasmodium <\/em>(Figure 14.19). These unicellular, eukaryotic protozoa are transmitted through the bite of a female <em>Anopheles<\/em> mosquito. During the bite process, the protozoan parasites present within an infected mosquito\u2019s saliva enter a host\u2019s bloodstream where they are transported to the liver. Within the liver, the parasites multiply and are eventually released into the bloodstream, where they infect erythrocytes. Once inside the erythrocytes, the parasites reproduce until they exceed the cell\u2019s storage capacity, causing it to burst and release the parasites into the bloodstream once again. This replication cycle continues as long as there are viable erythrocytes within the host to infect.<\/p>\n<figure style=\"width: 518px\" class=\"wp-caption aligncenter\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image13-1-1.jpg\" alt=\"Life cycle stages of Malaria parasite.\" width=\"518\" height=\"511\" \/><figcaption class=\"wp-caption-text\">Figure 14.19: Life cycle of the malaria parasite.\u00a0<a href=\"https:\/\/docs.google.com\/document\/d\/1VUDKMBJYS_jNONjLxT04jQN0_z9Ua50BRN6auGSHUuU\/edit\">A full text description of this image is available<\/a>. Credit: <a href=\"https:\/\/commons.wikimedia.org\/wiki\/File:Malaria_parasite_life_cycle-NIAID.jpg\">Malaria parasite life cycle-NIAID<\/a> by <a href=\"https:\/\/www.niaid.nih.gov\/\">NIH National Institute of Allergy and Infectious Diseases<\/a> is in the <a href=\"https:\/\/en.wikipedia.org\/wiki\/Public_domain\">public domain<\/a>.<\/figcaption><\/figure>\n<p class=\"import-Normal\">General complications from malaria infections include the following: enlargement of the spleen (due to destruction of infected erythrocytes); lower number of thrombocytes (also called platelets, required for coagulation\/clotting of blood); high levels of bilirubin (a byproduct of hemoglobin breakdown in the liver) in the blood; jaundice (yellowing of the skin and eyes due to increased blood bilirubin levels); fever; vomiting; retinal (eye) damage; and convulsions (seizures). In 2020, there were 241 million cases of malaria reported globally, with 95% of those cases originating in Africa (World Health Organization 2021). In sub-Saharan Africa, where incidents of malaria are the highest in the world, 125 million pregnancies are affected by malaria, resulting in 200,000 infant deaths (Hartman, Rogerson, and Fischer 2013). Pregnant people who become infected during the gestational process are more likely to have low-birthweight infants due to prematurity or growth restriction inside the uterus (Hartman, Rogerson, and Fischer 2013). After birth, infants born to malaria-infected pregnant people are more likely to develop infantile anemia (low red-blood cell counts), a malaria infection that is not related to the maternal malarial infection, and they are more likely to die than infants born to non-malaria-infected pregnant people (Hartman, Rogerson, and Fischer 2013).<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">For children and adolescents whose brains are still developing, there is a risk of cognitive (intellectual) impairment associated with some forms of malaria infections (Fernando, Rodrigo, and Rajapakse 2010). Given the relatively high rates of morbidity (disease) and mortality (number of deaths) associated with malaria, it is plausible that this disease may have served as a selective pressure during human evolution. Support for natural selection related to malaria resistance is related to genetic mutations associated with sickle cell, thalassemia, glucose-6-phosphate dehydrogenase (G6PD) deficiency, and the absence of certain antigens (molecules capable of inducing an immune response from the host) on erythrocytes. For the purposes of this text, we will focus our discussion on the relationship between sickle cell disease and malaria.<\/p>\n<figure style=\"width: 312px\" class=\"wp-caption alignright\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image15-2-1.jpg\" alt=\"Normal (round) and sickle (crescent-shaped) red blood cells flow through a blood vessel. \" width=\"312\" height=\"499\" \/><figcaption class=\"wp-caption-text\">Figure 14.20: Normal and sickled erythrocytes. Normal red blood cells are round and can easily flow freely through blood vessels. Abnormal, or cicle, blood cells are half moon shaped and can easily become entangled and block blood flow. Sickle cells have abnormal hemoglobin that form strands that cause the sickle shape. The Credit: <a href=\"https:\/\/commons.wikimedia.org\/wiki\/File:Sickle_cell_01.jpg\">Sickle cell 01<\/a> by <a href=\"https:\/\/www.nhlbi.nih.gov\/health\/sickle-cell-disease\">The National Heart, Lung, and Blood Institute (NHLBI)<\/a> is in the <a href=\"https:\/\/en.wikipedia.org\/wiki\/Public_domain\">public domain<\/a>.<\/figcaption><\/figure>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\"><strong>Sickle cell disease<\/strong> is a group of genetically inherited blood disorders characterized by an abnormality in the shape of the hemoglobin within erythrocytes. It is important to note that there are multiple variants of hemoglobin, including, but not limited to the following: A, D, C, E, F, H, S, Barts, Portland, Hope, Pisa, and Hopkins. Each of these variants of hemoglobin may result in various conditions within the body; however, for the following explanation we will focus solely on variants A and S.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Individuals who inherit a mutated gene (hemoglobin with a sickled erythrocyte variety, HbS) on chromosome 11 from both parents will develop sickle cell anemia, which is the most severe form of the sickle cell disease family (Figure 14.20). The genotype of an individual with sickle cell anemia is HbSS; whereas, an individual without sickle cell alleles has a genotype of HbAA representing two normal adult hemoglobin type A variants. Manifestations of sickle cell anemia (HbSS) range from mild to severe, with some of the more common symptoms being anemia, blood clots, organ failure, chest pain, fever, and low blood-oxygen levels. In high-income countries with advanced medical care, the median life expectancy of an HbSS individual is around 60 years; however, in low-income countries where advanced medical care is scarce, as many as 90% of children with sickle cell disease perish before the age of five (Longo et al. 2017).<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Considering that advanced medical care was not available during much of human evolutionary history, it stands to reason that the majority of individuals with the HbSS genotype died before the age of reproduction. If that is the case though, why do we still have the HbS variant present in modern populations? As covered earlier in this textbook, the genotype of an individual is composed of genes from both biological parents. In the case of an individual with an HbSS genotype, the sickle cell allele (HbS) was inherited from each of the parents. For individuals with the heterozygous genotype of HbSA, they have inherited both a sickle cell allele (HbS) and a normal hemoglobin allele (HbA). Heterozygous (HbSA) individuals who reside in regions where malaria is endemic may have a selective advantage. They will experience a sickling of some, but not all, of their erythrocytes. As discussed in the following paragraph, HbSA heterozygous individuals are less likely to die from malaria infections than their HbAA counterparts. Unlike an individual with the HbSS genotype, someone with HbSA may experience some of the symptoms listed above; however, they are generally less severe.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">As noted earlier, the mechanism through which <em>Plasmodium<\/em> protozoan parasites replicate involves human erythrocyte cells. However, due to their sickled shape, as well as the presence of an abnormally shaped protein within the cell, the parasites are unable to replicate effectively in the erythrocyte cells coded for by the HbS allele (Cyrklaff et al. 2011). An individual who has an HbSA genotype and an active malaria infection will become ill with the disease to a lesser extent than someone with an HbAA genotype, which increases their chances of survival. Although normal erythrocytes (regulated by the HbA allele) allow for parasite replication, they are not able to replicate in HbS erythrocytes of the heterozygote. So, individuals with the HbSA genotype are more likely to survive a malaria infection than an individual who is HbAA. Although individuals with the HbSA genotype may endure some physiological complications related to the sickling of some of their erythrocytes, their morbidity and mortality rates are lower than they are for HbSS members of the population. The majority of individuals who are heterozygous or homozygous for the HbS trait have ancestors who originated in sub-Saharan Africa, India, Saudi Arabia, and regions in South and Central America, the Mediterranean (Turkey, Greece, and Italy), and the Caribbean (Centers for Disease Control and Prevention 2017; Figure 14.21).<\/p>\n<figure style=\"width: 511px\" class=\"wp-caption aligncenter\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image23-3.png\" alt=\"Map illustrating distribution of sickle cell and associated erythrocytic abnormalities for Africa and Asia.\" width=\"511\" height=\"306\" \/><figcaption class=\"wp-caption-text\">Figure 14.21: Distribution of sickle cell and associated erythrocytic abnormalities for Africa and Asia. Credit: <a href=\"https:\/\/commons.wikimedia.org\/wiki\/File:Red_Blood_Cell_abnormalities.png\">Red Blood Cell abnormalities<\/a> by Armando Moreno Vranich has been designated to the <a href=\"https:\/\/creativecommons.org\/share-your-work\/public-domain\/cc0\/\">public domain (CC0)<\/a>.<\/figcaption><\/figure>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">With respect to the history of these regions, during the early phases of settlement horticulture was the primary method of crop cultivation. Typically performed on a small scale, horticulture is based on manual labor and relatively simple hand tools rather than the use of draft animals or irrigation technologies. Common in horticulture is <em>swidden<\/em>, or the cutting and burning of plants in woodland and grassland regions. The swidden is the prepared field that results following a slash-and-burn episode. This practice fundamentally alters the soil chemistry, removes plants that provide shade, and increases the areas where water may pool. This anthropogenically altered landscape provides the perfect breeding ground for the <em>Anopheles<\/em> mosquito, as it prefers warm, stagnant pools of water (Figure 14.22).<\/p>\n<figure style=\"width: 561px\" class=\"wp-caption aligncenter\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image5-6.png\" alt=\"Horticulture encourages mosquitos, increasing malaria. Balancing selection maintains normal and sickle cell alleles.\" width=\"561\" height=\"468\" \/><figcaption class=\"wp-caption-text\">Figure 14.22: The effects of human horticultural activities on the balancing selection of populations in relation to sickle cell disease genotype variants. <a href=\"https:\/\/docs.google.com\/document\/d\/1VUDKMBJYS_jNONjLxT04jQN0_z9Ua50BRN6auGSHUuU\/edit\">A full text description of this image is available<\/a>. Credit: <a href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/chapter\/__unknown__-13\/\">Sickle cell disease (Figure 14.21)<\/a> original to <a href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/\">Explorations: An Open Invitation to Biological Anthropology<\/a> by Katie Nelson is a collective work under a <a href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/\">CC BY-NC 4.0 License<\/a>. [Includes two horticulture illustrations by Mary Nelson, <a href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/\">CC BY-NC 4.0<\/a>; <a href=\"https:\/\/commons.wikimedia.org\/wiki\/File:Sickle_cell_anemia.jpg\">Sickle cell anemia<\/a> by <a href=\"https:\/\/en.wikibooks.org\/wiki\/User:Pkleong\">Pkleong<\/a> at <a href=\"https:\/\/en.wikibooks.org\/wiki\/\">English Wikibooks<\/a> (modified), <a href=\"https:\/\/creativecommons.org\/share-your-work\/public-domain\/cc0\/\">public domain (CC0)<\/a>.]<\/figcaption><\/figure>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Although swidden agriculture was historically practiced across the globe, it became most problematic in the regions where the <em>Anopheles<\/em> mosquito is endemic. These areas have the highest incidence rates of malaria infection. Over time, the presence of the <em>Anopheles<\/em> mosquito and the <em>Plasmodium<\/em> parasite that it transmitted acted as a selective pressure, particularly in regions where swidden agricultural practices were common, toward the selection of individuals with some modicum of resistance against the infection. In these regions, HbSS and HbSA individuals would have been more likely to survive and reproduce successfully. Although individuals and populations are far more mobile now than they have been throughout much of history, there are still regions where we can see higher rates of malaria infection as well as greater numbers of individuals with the HbS erythrocyte variant. The relationship between malaria and the selective pressure for the HbS variant is one of the most prominent examples of natural selection in the human species within recent evolutionary history.<\/p>\n<h4 class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\"><span style=\"background-color: #ff9900;\"><em>Adaptation: Lactase Persistence <\/em><\/span><\/h4>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">With the case of sickled erythrocytes and their resistance to infection by malaria parasites, there is strong support for a cause-and-effect-style relationship linked to natural selection. Although somewhat less apparent, there is a correlation between lactase persistence and environmental challenges. Lactase-phlorizin hydrolase (LPH) is an enzyme that is primarily produced in the small intestine and permits the proper digestion of lactose, a disaccharide (composed of two simple sugars: glucose and galactose) found in the milk of mammals. Most humans will experience a decrease in the expression of LPH following weaning, leading to an inability to properly digest lactose. Generally, LPH production decreases between the ages of two and five and is completely absent by the age of nine (Dzialanski et al. 2016). For these individuals, the ingestion of lactose may lead to a wide variety of gastrointestinal ailments, including abdominal bloating, increased gas, and diarrhea. Although the bloating and gas are unpleasant, the diarrhea caused by a failure to properly digest lactose can be life-threatening if severe enough due to the dehydration it can cause. Some humans, however, are able to produce LPH far beyond the weaning period.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Individuals who continue to produce LPH have what is referred to as the <strong>lactase persistence <\/strong>trait. The lactase persistence trait is encoded for a gene called <em>LCT<\/em>, which is located on human chromosome 2 (Ranciaro et al. 2014; see also Chapter 3). From an evolutionary and historical perspective, this trait is most commonly linked to cultures that have practiced cattle domestication (Figure 14.23). For individuals in those cultures, the continued expression of LPH may have provided a selective advantage. During periods of environmental stress, such as a drought, if an individual is capable of successfully digesting cow\u2019s milk, they have a higher chance of survival than someone who suffers from diarrhea-linked dehydration due to a lack of LPH. Although the frequency of the lactase persistence trait is relatively low among African agriculturalists, it is high among pastoralist populations that are traditionally associated with cattle domestication, such as the Tutsi and Fulani, who have frequencies of 90% and 50%, respectively (Tishkoff et al. 2007).<\/p>\n<figure style=\"width: 632px\" class=\"wp-caption aligncenter\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image4-4.png\" alt=\"Map depicting the percentage of adults with lactase persistence in the eastern hemisphere.\" width=\"632\" height=\"497\" \/><figcaption class=\"wp-caption-text\">Figure 14.23: Interpolated map depicting the percentage of adults with the lactase persistence genotype in indigenous populations of Africa, Europe, Asia, and Australia. Circles denote sample locations. Credit: <a href=\"https:\/\/commons.wikimedia.org\/wiki\/File:Lactose_tolerance_in_the_Old_World.svg\">Lactose tolerance in the Old World<\/a> by <a href=\"https:\/\/commons.wikimedia.org\/wiki\/User:Joe_Roe\">Joe Roe<\/a> is under a <a href=\"https:\/\/creativecommons.org\/licenses\/by\/4.0\/legalcode\">CC BY 4.0 License<\/a>.<\/figcaption><\/figure>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Cattle domestication began around 11,000 years ago in Europe (Beja-Pereira et al. 2006) and 7,500 to 9,000 years ago in the Middle East and North Africa (Tishkoff et al. 2007). Based on human genomic studies, it is estimated that the mutation for the lactase persistence trait occurred around 2,000 to 20,000 years ago for European populations (Tishkoff et al. 2007). For African populations, the lactase persistence trait emerged approximately 1,200 to 23,000 years ago (Gerbault et al. 2011). This begs the question: Is this mutation the same for both populations? It appears that the emergence of the lactase persistence mutation in non-European populations, specifically those in East Africa (e.g., Tutsi and Fulani), is a case of <strong>convergent evolution<\/strong>. With convergent evolution events, a similar mutation may occur in species of different lineages through independent evolutionary processes. Based on our current understanding of the genetic mutation pathways for the lactase persistence trait in European and African populations, these mutations are not representative of a shared lineage. In other words, just because a person of European origin and a person of African origin can each digest milk due to the presence of the lactase-persistence trait in their genotypes, it does not mean that these two individuals inherited it due to shared common ancestry.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Is it possible that the convergent evolution of similar lactase-persistence traits in disparate populations is merely a product of genetic drift? Or is there evidence for natural selection? Even though 23,000 years may seem like a long time, it is but a blink of the proverbial evolutionary eye. From the perspective of human evolutionary pathways, mutations related to the <em>LCT<\/em> gene have occurred relatively recently. Similar genetic changes in multiple populations through genetic drift processes, which are relatively slow and directionless, fail to accumulate as rapidly as lactase-persistence traits (Gerbault et al. 2011). The widespread accumulation of these traits in a relatively short period of time supports the notion that an underlying selective pressure must be driving this form of human evolution. Although to date no definitive factors have been firmly identified, it is thought that environmental pressures are likely to credit for the rapid accumulation of the lactase-persistence trait in multiple human populations through convergent evolutionary pathways.<\/p>\n<div class=\"textbox\">\n<h2 class=\"import-Normal\">Special Topic: Skin Tone Genetic Regulation<\/h2>\n<p class=\"import-Normal\">The melanocortin 1 receptor (<em>MC1R<\/em>) gene acts to control which types of melanin (eumelanin or pheomelanin) are produced by melanocytes. The <em>MC1R<\/em> receptor is located on the surface of the melanocyte cells (Quillen et al. 2018). Activation of the <em>MC1R <\/em>receptors may occur through exposure to specific environmental stimuli or due to underlying genetic processes. Inactive or blocked <em>MC1R <\/em>receptors result in melanocytes producing pheomelanin. If the <em>MC1R<\/em> gene receptors are activated, then the melanocytes will produce eumelanin. Thus, individuals with activated <em>MC1R<\/em> receptors tend to have darker-pigmented skin and hair than individuals with inactive or blocked receptors.<\/p>\n<p class=\"import-Normal\">The alleles of another gene, the major facilitator, superfamily domain-containing protein 12 (<em>MFSD12<\/em>) gene, affect the expression of melanocytes in a different way than the <em>MC1R<\/em> gene. Instead of affecting the activation of melanocyte receptors, the <em>MFSD12<\/em> alleles indirectly affect the membranes of melanocyte lysosomes (Quillen et al. 2018). The melanocyte\u2019s lysosomes are organelles containing digestive enzymes, which ultimately correlate to varying degrees of pigmentation in humans. Variations in the membranes of the melanocyte lysosomes ultimately correlate to differing degrees of pigmentation in humans.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Ancestral <em>MFSD12 <\/em>allele variants are present in European and East Asian populations and are associated with lighter pigmentation of the skin (Crawford et al. 2017; Quillen et al. 2018). In addition, this ancestral variant is also associated with Tanzanian, San, and Ethiopian populations of Afro-Asiatic ancestry (Crawford et al. 2017; Quillen et al. 2018). In contrast, the more derived (i.e., more recent) allele variants that are linked to darker skin tones are more commonly present in East African populations, particularly those of Nilo-Saharan descent (Crawford et al. 2017; Quillen et al. 2018). The notion that ancestral alleles of <em>MFSD12<\/em> are associated with lighter skin pigmentation is in opposition to the commonly accepted idea that our pigmentation was likely darker throughout early human evolution (Crawford et al. 2017; Quillen et al. 2018). Due to the complexity of the human genome, <em>MFSD12<\/em> and <em>MC1R <\/em>are but two examples of alleles affecting human skin tone. Furthermore, there is genetic evidence suggesting that certain genomic variants associated with both darker and lighter skin color have been subject to directional selection processes for as long as 600,000 years, which far exceeds the evolutionary span of <em>Homo sapiens sapiens<\/em> (Crawford et al. 2017; Quillen et al. 2018).<\/p>\n<\/div>\n<p>&nbsp;<\/p>\n<\/div>\n<h2 class=\"__UNKNOWN__\">Human Variation: Our Story Continues<\/h2>\n<div class=\"__UNKNOWN__\">\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">From the time that the first of our species left Africa, we have had to adjust and adapt to numerous environmental challenges. The remarkable ability of human beings to maintain homeostasis through a combination of both nongenetic (adjustments) and genetic (adaptations) means has allowed us to occupy a remarkable variety of environments, from high-altitude mountainous regions to the tropics near the equator. From adding piquant, pungent spices to our foods as a means of inhibiting food-borne illnesses due to bacterial growth to donning garments specially suited to local climates, behavioral adjustments have provided us with a nongenetic means of coping with obstacles to our health and well-being. Acclimatory adjustments, such as sweating when we are warm in an attempt to regulate our body temperature or experiencing increased breathing rates as a means of increasing blood oxygen levels in regions where the partial pressure of oxygen is low, have been instrumental in our survival with respect to thermal and altitudinal environmental challenges. For some individuals, developmental adjustments that were acquired during their development and growth phases (e.g., increased heart and lung capacities for individuals from high-altitude regions) provide them with a form of physiological advantage not possible for someone who ventures to such an environmentally challenging region as an adult. Genetically mediated adaptations, such as variations in the pigmentation of our skin, have ensured our evolutionary fitness across all latitudes.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Will the human species continue to adjust and adapt to new environmental challenges in the future? If past performance is any measure of future expectations, then the human story will continue as long as we do not alter our environment to the point that the plasticity of our behavior, physiological, and morphological boundaries is exceeded. In the following chapters, you will explore additional information about our saga as a species. From the concept of race as a sociocultural construct to our epidemiological history, the nuances of evolutionary-based human variation are always present and provide the basis for understanding our history and our future as a species.<\/p>\n<div class=\"textbox shaded\">\n<h2 class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Review Questions<\/h2>\n<ul>\n<li class=\"import-Normal\" style=\"text-indent: 0pt;\">Detail at least two examples of how natural selection has influenced human variation. Specifically, what was the selective pressure that may have led to a preference for a specific trait and how is that trait related to an increased level of fitness?<\/li>\n<li class=\"import-Normal\" style=\"text-indent: 0pt;\">Why is reduced pigmentation of the skin advantageous for individuals from northern latitudes? What role does darker skin pigmentation serve for individuals near the equator? What is the relationship between skin pigmentation and fitness?<\/li>\n<li class=\"import-Normal\" style=\"text-indent: 0pt;\">What are some of the risks associated with pregnancy at high altitude? Compare and contrast the various genetic mutations of the indigenous Tibetan and Ethiopian high-altitude populations. In your answer, specifically address the issue of pregnancy at high altitudes.<\/li>\n<li class=\"import-Normal\" style=\"text-indent: 0pt;\">What is the relationship between the sickle cell mutation and the <em>Plasmodium<\/em> parasite? Would having the HbSA genotype still be advantageous in a region where such parasites are not common? Why or why not?<\/li>\n<\/ul>\n<\/div>\n<p>&nbsp;<\/p>\n<h2 class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Key Terms<strong><br \/>\n<\/strong><\/h2>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\"><strong>Acclimatory adjustm<\/strong><strong>ents<\/strong>: Processes by which an individual organism adjusts in order to maintain homeostasis in response to environmental challenges.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\"><strong>Activated melanogenesis<\/strong>: Increase in melanin production in response to ultraviolet radiation (UV) exposure.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\"><strong>Adaptation<\/strong>: Alteration in population-level gene frequencies related to environmentally induced selective pressures; leads to a greater level of fitness for a population related to a specific environment.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\"><strong>Adjustment<\/strong>: Nongenetic-based ways in which organisms adjust to environmental stressors.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\"><strong>Allen\u2019s Rule<\/strong>: Due to thermal adaptation, homeothermic animals have body volume-to-surface ratios that vary inversely with the average temperature of their environment. In cold climates, the anticipated ratio is high; in warm climates, it is low.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\"><strong>Basal melanogenesis<\/strong>: Genetically mediated, non-environmentally influenced base melanin level.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\"><strong>Behavioral adjustments<\/strong>: An individual\u2019s culturally mediated responses to an environmental stressor in an effort to maintain homeostasis.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\"><strong>Bergmann\u2019s Rule<\/strong>: For a broadly distributed monophyletic group, species and populations of smaller size tend to be found in environments with warmer climates and those of larger size tend to be found in ones that are colder.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\"><strong>Cline<\/strong>: A continuum of gradations (i.e., degrees or levels) of a specific trait.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\"><strong>Conduction<\/strong>: Mechanism of heat transfer between objects through direct contact.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\"><strong>Convection<\/strong>: Movement of heat away from a warm object to the cooler surrounding fluid (i.e., gas or liquid).<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\"><strong>Convergent evolution<\/strong>: Evolutionary process whereby organisms that are not closely related independently evolve similar traits as a product of adaptation to similar evolutionary parameters.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\"><strong>Erythrocyte<\/strong>: Red blood cell; most common form of blood cell; the principle means of transporting oxygen throughout the circulatory system.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\"><strong>Evaporation<\/strong>: Mechanism of heat transfer whereby liquid is transformed into a gas, utilizing energy (e.g., heat).<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\"><strong>Folic acid<\/strong>: Form of B complex vitamin necessary for proper fetal development.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\"><strong>Gloger\u2019s Rule<\/strong>: For mammals of the same species, those with more darkly pigmented forms tend to be found closer to the equator and those with lighter forms are found in regions further from the equator.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\"><strong>Homeostasis<\/strong>: Condition of optimal functioning for an organism.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\"><strong>Hyperpnea<\/strong>: Increased depth and rate of respiration.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\"><strong>Hypothalamus<\/strong>: Small portion of the human brain responsible for body temperature regulation.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\"><strong>Lactase persistence<\/strong>: Genetic mutation permitting the continued production of lactase-phlorizin hydrolase enzyme in the small intestine past the weaning period.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\"><strong>Melanin<\/strong>: Black-brown pigment produced by melanocytes; one of the primary pigments in skin.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\"><strong>Melanocytes<\/strong>: Specialized cells that produce melanin.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\"><strong>Phenotypic plasticity<\/strong>: Ability of one genotype to produce more than one phenotype dependent on environmental conditions.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\"><strong>Radiation<\/strong>: Mechanism of heat transfer involving electromagnetic energy being emitted from an object.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\"><strong>Sickle cell disease<\/strong>: A group of genetically inherited blood disorders characterized by an abnormality in the shape of the hemoglobin within erythrocytes (red blood cells).<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\"><strong>Stressor<\/strong>: Any stimulus resulting in an imbalance in an organism\u2019s homeostatic balance.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\"><strong>Vasoconstriction<\/strong>: Narrowing of the blood vessels due to contractions of the muscular vessel walls.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\"><strong>Vasodilation<\/strong>: Dilation of the blood vessels due to relaxation of the muscular vessel walls.<\/p>\n<h2 class=\"import-Normal\">About the Author<strong><br \/>\n<\/strong><\/h2>\n<p class=\"import-Normal\"><strong><img class=\"alignleft\" src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image25-1-1.jpg\" alt=\"A woman stands in front of museum statues imitating the statues' gestures with a hand over the stomach.\" width=\"272\" height=\"204\" \/><\/strong><\/p>\n<h3 class=\"import-Normal\">Leslie E. Fitzpatrick, Ph.D., RPA<\/h3>\n<p class=\"import-Normal\">Independent Archaeological Consultants<\/p>\n<p class=\"import-Normal\">Lfitzpatrick@iac-llc.net<\/p>\n<p class=\"import-Normal\">Leslie Fitzpatrick is an historical archaeologist with Independent Archaeological Consultants based in Dover, New Hampshire. She earned a PhD in Anthropology from the University of Wyoming (2017), an MA in Anthropology from Georgia State (2012), and a BS in Mechanical Engineering from Georgia Tech (2000). Her primary research focus is the stable-isotope analysis of human remains as a means of interpreting past mobility and diet profiles for both modern and archaeological populations. In addition to her work as a historical archaeologist in New England, she has worked as a bioarchaeologist at field sites in Germany, Spain, Croatia, Mexico, Peru, and throughout the United States.<\/p>\n<h2 class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">For Further Exploration<strong><br \/>\n<\/strong><\/h2>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\"><strong>Homeostasis<\/strong><\/p>\n<p class=\"import-Normal\">Baptista, Vander. 2006. \u201c<a href=\"https:\/\/doi.org\/10.1152\/advan.00075.2006\" target=\"_blank\" rel=\"noopener\">Starting Physiology: Understanding Homeostasis<\/a>.\u201d <em>Advances in Physiology Education<\/em> 30: 263\u2013264.<\/p>\n<p class=\"import-Normal\">Goldstein, David S., and Bruce McEwen. 2002. \u201c<a href=\"https:\/\/doi.org\/10.1080\/102538902900012345\" target=\"_blank\" rel=\"noopener\">Allostasis, Homeostats, and the Nature of Stress<\/a>.\u201d <em>The International Journal on the Biology of Stress<\/em> 5 (1): 55\u201358.<\/p>\n<p class=\"import-Normal\"><strong>General Clinal Variation and Genetic Exchange<\/strong><\/p>\n<p class=\"import-Normal\">Delhey, Kaspar. 2019. \u201c<a href=\"https:\/\/doi.org\/10.1111\/brv.12503\" target=\"_blank\" rel=\"noopener\">A Review of Gloger's Rule, an Ecogeographical Rule of Colour: Definitions, Interpretations and Evidence<\/a>.\u201d <em>Biological Reviews<\/em> 94 (4): 1294\u20131316.<\/p>\n<p class=\"import-Normal\">Feng, Yuanqing, Michael A. McQuillan, and Sarah A. Tishkoff. 2021. \u201c<a href=\"https:\/\/doi.org\/10.1093\/hmg\/ddab007\" target=\"_blank\" rel=\"noopener\">Evolutionary Genetics of Skin Pigmentation in African Populations<\/a>.\u201d <em>Human Molecular Genetics<\/em> 30 (R1): R88\u2013R97.<\/p>\n<p class=\"import-Normal\">Hu, Hao, Nayia Petousi, Gustavo Glusman, Yao Yu, Ryan Bohlender, Tsewang Tashi, Jonathan M. Downie, et al. 2017. \u201c<a href=\"https:\/\/doi.org\/10.1371\/journal.pgen.1006675\" target=\"_blank\" rel=\"noopener\">Evolutionary History of Tibetans Inferred from Whole-Genome Sequencing<\/a>.\u201d <em>PLoS Genetics <\/em>13 (4): e1006675. .<\/p>\n<p class=\"import-Normal\">Jablonski, Nina G. 2021. \u201c<a href=\"https:\/\/doi.org\/10.1002\/ajpa.24200\" target=\"_blank\" rel=\"noopener\">Skin Color and Race<\/a>.\u201d Special issue, \u201cRace Reconciled II: Interpreting and Communicating Biological Variation and Race in 2021,\u201d <em>American Journal of Physical Anthropology<\/em> 175 (2): 437\u2013447.<\/p>\n<p class=\"import-Normal\">Pritchard, Jonathan K., Joseph K. Pickrell, and Graham Coop. 2010. \u201c<a href=\"https:\/\/doi.org\/10.1016\/j.cub.2009.11.055\" target=\"_blank\" rel=\"noopener\">The Genetics of Human Adaptation: Hard Sweeps, Soft Sweeps, and Polygenic Adaptation<\/a>.\u201d <em>Current Biology<\/em> 20 (4): R208\u2013R215.<\/p>\n<p class=\"import-Normal\">Sankararaman, Sriram, Swapan Mallick, Nick Patterson, and David Reich. 2016. \u201c<a href=\"https:\/\/doi.org\/10.1016\/j.cub.2016.03.037\" target=\"_blank\" rel=\"noopener\">The Combined Landscape of Denisovan and Neanderthal Ancestry in Present-Day Humans<\/a>.\u201d <em>Current Biology<\/em> 26 (9): 1241\u20131247.<\/p>\n<p class=\"import-Normal\"><strong>Lactase Persistence<\/strong><\/p>\n<p class=\"import-Normal\">HHMI BioInteractive. 2021. \u201c<a href=\"https:\/\/www.biointeractive.org\/classroom-resources\/making-fittest-got-lactase-co-evolution-genes-and-culture\" target=\"_blank\" rel=\"noopener\">The Making of the Fittest: Got Lactase? The Co-evolution of Genes and Culture<\/a>.\u201d Accessed April 7, 2023.<\/p>\n<p class=\"import-Normal\"><strong>Malaria and Sickle Cell Anemia<\/strong><\/p>\n<p class=\"import-Normal\">Bill and Melinda Gates Foundation. 2022. \u201c<a href=\"https:\/\/www.gatesfoundation.org\/our-work\/programs\/global-health\/malaria\" target=\"_blank\" rel=\"noopener\">Malaria<\/a>.\u201d Accessed April 7, 2023.<\/p>\n<p class=\"import-Normal\">Centers for Disease Control and Prevention. 2022. \u201c<a href=\"https:\/\/www.cdc.gov\/parasites\/malaria\/index.html\" target=\"_blank\" rel=\"noopener\">Malaria<\/a>.\u201d Accessed April 7, 2023.<\/p>\n<p class=\"import-Normal\">HHMI BioInteractive. 2020. \u201c<a href=\"https:\/\/www.biointeractive.org\/classroom-resources\/making-fittest-natural-selection-humans\" target=\"_blank\" rel=\"noopener\">The Making of the Fittest: Natural Selection in Humans<\/a>.\u201d 2020. Accessed April 7, 2023.<\/p>\n<p class=\"import-Normal\">National Institutes of Health: National Center for Advancing Translational Sciences. \u201c<a href=\"https:\/\/rarediseases.info.nih.gov\/diseases\/8614\/sickle-cell-anemia\" target=\"_blank\" rel=\"noopener\">Sickle Cell Anemia<\/a>.\u201d Accessed April 7, 2023.<\/p>\n<p class=\"import-Normal\">World Health Organization. 2022. \u201c<a href=\"https:\/\/www.who.int\/news-room\/fact-sheets\/detail\/malaria\" target=\"_blank\" rel=\"noopener\">Malaria<\/a>.\u201d Accessed April 7, 2023.<\/p>\n<p class=\"import-Normal\"><strong>Rickets and Bone Health<\/strong><\/p>\n<p class=\"import-Normal\">National Institutes of Health: National Center for Advancing Translational Sciences. \u201c<a href=\"https:\/\/rarediseases.info.nih.gov\/diseases\/5700\/rickets\" target=\"_blank\" rel=\"noopener\">Rickets<\/a>.\u201d Accessed April 7, 2023.<\/p>\n<p class=\"import-Normal\">Talmadge, D. W., and R. V. Talmadge. 2007. \u201cCalcium Homeostasis: How Bone Solubility Relates to All Aspects of Bone Physiology.\u201d <em>Journal of Musculoskeletal and Neuronal Interactions <\/em>7 (2): 108\u2013112.<\/p>\n<p class=\"import-Normal\"><strong>Skin Color<\/strong><\/p>\n<p class=\"import-Normal\">HHMI BioInteractive. 2020. \u201c<a href=\"https:\/\/www.biointeractive.org\/classroom-resources\/biology-skin-color\" target=\"_blank\" rel=\"noopener\">The Biology of Skin Color<\/a>.\u201d Accessed April 7, 2023<\/p>\n<h2 class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">References<\/h2>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">American Academy of Pediatrics, Task Force on Infant Sleep Position and Sudden Infant Death Syndrome. 2000. \u201cChanging Concepts of Sudden Infant Death Syndrome: Implications for Infant Sleeping Environment and Sleep Position.\u201d <em>Pediatrics<\/em> 105 (3): 650\u2013656.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Beja-Pereira, Albano, David Caramelli, Carles Lalueza-Fox, Cristiano Vernesi, Nuno Ferrand, Antonella Casoli, Felix Goyache, et al. 2006. \u201cThe Origin of European Cattle: Evidence from Modern and Ancient DNA.\u201d <em>PNAS <\/em>103 (21): 8113\u20138118.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Best, Andre, Daniel E. Lieberman, and Jason M. Kamilar. 2019. \u201cDiversity and Evolution of Human Eccrine Sweat Gland Density.\u201d <em>Journal of Thermal Biology<\/em> 84: 331\u2013338.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Bigham, Abigail W. 2016. \u201c<a href=\"https:\/\/www.cdc.gov\/ncbddd\/sicklecell\/data.html\" target=\"_blank\" rel=\"noopener\">Genetics of Human Origin and Evolution: High-Altitude Adaptations<\/a>.\u201d <em>Current Opinion in Genetics &amp; Development<\/em> 41: 8\u201313.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Centers for Disease Control and Prevention. 2017. \u201cData &amp; Statistics on Sickle Cell Disease.\u201d <em>Centers for Disease Control and Prevention<\/em> website, August 9. Accessed April 7, 2023. .<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Crawford, Nicholas G., Derek E. Kelly, Matthew E. B. Hansen, Marcia H. Beltrame, Shaohua Fan, Shanna L. Bowman, Ethan Jewett, et al. 2017. \u201cLoci Associated with Skin Pigmentation Identified in African Populations.\u201d <em>Science<\/em> 358 (6365): 1\u201349.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Cyrkalff, Marek, Cecilia P. Sanchez, Nicole Kilian, Curille Bisseye, Jacques Simpore, Friedrich Frischknecht, and Michael Lanzer. 2011. \u201cHemoglobins S and C Interfere with Actin Remodeling in <em>Plasmodium <\/em><em>falciparum<\/em>-Infected Erythrocytes.\u201d <em>Science<\/em> 334 (6060): 1283\u20131286.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Dzialanski, Zbigniew, Michael Barany, Peter Engfeldt, Anders Magnuson, Lovisa A. Olsson, and Torbj\u04e7rn K. Nilsson. 2016. \u201cLactase Persistence versus Lactose Intolerance: Is There an Intermediate Phenotype?\u201d <em>Clinical Biochemistry<\/em> 49 (2016): 248\u2013252.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Fernando, Sumadya D., Chaturaka Rodrigo, and Senaka Rajapakse. 2010. \u201cThe \u2018Hidden\u2019 Burden of Malaria: Cognitive Impairment Following Infection.\u201d <em>Malaria Journal<\/em> 9 (366): 1\u201311.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Gerbault, Pascale, Anke Liebert, Yuval Itan, Adam Powell, Mathias Currat, Joachim Burger, Dallas M. Swallow, and Mark G. Thomas. 2011. \u201cEvolution of Lactase Persistence: An Example of Human Niche Construction.\u201d <em>Philosophical Transactions of the Royal Society B: Biological Sciences <\/em>366 (1566): 863\u2013877.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Gray, Olivia A., Jennifer Yoo, D\u00e9bora R. Sobriera, Jordan Jousma, David Witnosky, Noboru J. Sakabe, Ying-Jie Ping, et al. 2022. \u201cA Pleiotropic Hypoxia-Sensitive <em>EPAS1<\/em> Enhancer Is Disrupted by Adaptive Alleles in Tibetans.\u201d <em>Science Advances <\/em>8 (47): 1\u201313.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Hartman, T. K., S. J. Rogerson, and P. R. Fischer. 2013. \u201cThe Impact of Maternal Malaria on Newborns.\u201d <em>Annals of Tropical Paediatrics<\/em> 30 (4): 271\u2013282.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Longo, Dan L., Fr\u00e9d\u00e9ric B. Piel, Martin H. Steinberg, and David C. Rees. 2017. \u201cSickle Cell Disease.\u201d <em>The New England Journal of Medicine<\/em> 376 (16): 1561\u20131573.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Maddux, Scott D., Todd R. Yokley, Bohumil M. Svoma, and Robert G. Franciscus. 2016. \u201cAbsolute Humidity and the Human Nose: A Reanalysis of Climate Zones and Their Influence on Nasal Form and Function.\u201d <em>American Journal of Physical Anthropology <\/em>161 (2): 309\u2013320.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Meyer, M. C., M. S. Alexander, Z. Wang, D. L. Hoffmann, J. A. Dahl, D. Degering, W. R. Haas, and F. Schl\u00fctz. 2017. \u201cPermanent Human Occupation of the Central Tibetan Plateau in the Early Holocene.\u201d <em>Science <\/em>355 (6320): 64\u201367.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Moore, Lorna G., Susan Niermeyer, and Stacy Zamudio. 1998. \u201cHuman Adaptation to High Altitude: Regional and Life-Cycle Perspectives.\u201d <em>Yearbook of Physical Anthropology<\/em> 41: 25\u201364.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Noback, Marlijn L., Katerina Harvati, and Fred Spoor. 2011. \u201cClimate-Related Variation of the Human Nasal Cavity.\u201d <em>American Journal of Physical Anthropology<\/em> 145 (4): 599\u2013614.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Peacock, A. J. 1998. \u201cABC of Oxygen: Oxygen at High Altitude.\u201d <em>BMJ<\/em> 317 (7165): 1063\u20131066.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Pontzer, Herman, Mary H. Brown, Brian M. Wood, David A. Raichlen, Audax Z.P. Madbulla, Jacob A. Harris, Holly Dunsworth, et al. 2021. \u201cEvolution of Water Conservation in Humans.\u201d <em>Current Biology<\/em> 31 (8): 1804\u20131810.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Quillen, Ellen E., Heather L. Norton, Esteban J. Parra, Frida Loza-Durazo, Khai C. Ang, Florin Mircea Illiescu, Laurel N. Pearson, et al. 2019. \u201cShades of Complexity: New Perspectives on the Evolution and Genetic Architecture of Human Skin.\u201d <em>Yearbook<\/em><em> of Physical Anthropology <\/em>168 (S67): 4\u201326.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Ranciaro, Alessia, Michael C. Campbell, Jibril B. Hirbo, Wen-Ya Ko, Alain Froment,<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Paolo Anagnostou, Maritha J. Kotze,<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">et al. 2014. \u201cGenetic Origins of Lactase Persistence and the Spread of Pastoralism in Africa.\u201d <em>American Journal of Human Genetics <\/em>94 (4): 496\u2013510.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Roby, Brianne Barnett, Marsha Finkelstein, Robert J. Tibesar, and James D. Sidman. 2012. \u201cPrevalence of Positional Plagiocephaly in Teens Born after the \u2018Back to Sleep\u2019 Campaign.\u201d <em>Otolaryn<\/em><em>g<\/em><em>ology<\/em><em>\u2014Head and Neck Surgery<\/em> 146 (5): 823\u2013828.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Sherman, Paul W., and Jennifer Billing. 1999. \u201cDarwinian Gastronomy: Why We Use Spices.\u201d <em>BioScience <\/em>49 (6): 453\u2013463.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Tishkoff, Sarah A., Floyd A. Reed, Alessia Ranciaro, Benjamin F. Voight, Courtney C. Babbitt, Jesse S. Silverman, Kweli Powell, et al. 2007. \u201cConvergent Adaptation of Human Lactase Persistence in Africa and Europe.\u201d <em>Nature Genetics<\/em> 39 (1): 31\u201340.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">World Health Organization. 2021. \u201c<a href=\"https:\/\/www.who.int\/teams\/global-malaria-programme\/reports\/world-malaria-report-2021\" target=\"_blank\" rel=\"noopener\">World Malaria Report 2021<\/a>.\u201d <em>World Health Organization<\/em> website, December 4, 2022. Accessed April 7, 2023.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Zhang, Xinjun, Kelsey E. Witt, Mayra M. Ba\u00f1uelos, Amy Ko, Kai Yuan, Shuhua Xu, Rasmus Nielsen, and Emilia Huerta-Sanchez. 2021. \u201cThe History and Evolution of Denisovan-<em>EPAS1<\/em> Haplotype in Tibetans.\u201d <em>PNAS Biological Sciences<\/em> 118 (22): 1\u20139.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">\n<\/div>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_281_2568\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_281_2568\"><div tabindex=\"-1\"><\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_281_1698\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_281_1698\"><div tabindex=\"-1\"><div class=\"__UNKNOWN__\">\n<p class=\"import-Normal\">Mary P. Dinsmore, Ph.D., Loyola University Chicago<\/p>\n<p class=\"import-Normal\">Ilianna E. Anise, M.S.<\/p>\n<p class=\"import-Normal\">Rebekah J. Ellis, M.S.<\/p>\n<p class=\"import-Normal\">Jacob B. Kraus, Ph.D. Candidate, University of Wisconsin\u2013Madison<\/p>\n<p class=\"import-Normal\">Karen B. Strier, Ph.D., University of Wisconsin\u2013Madison<\/p>\n<p class=\"import-Normal\"><em>This chapter <\/em><em>is a revision from <\/em><a class=\"rId7\" href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/chapter\/primate-conservation-3\/\"><em>\"Appendix B: Primate Conservation\"<\/em><\/a><em> by Mary P. Dinsmore, Ilianna E. Anise, Rebekah J. Ellis, Amanda J. Hardie, Jacob B. Kraus, and Karen B. Strier. In <\/em><a class=\"rId8\" href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/\"><em>Explorations: An Open Invitation to Biological Anthropology, first edition<\/em><\/a><em>, edited by Beth Shook, Katie Nelson, Kelsie Aguilera, and Lara Braff, which is licensed under <\/em><a class=\"rId9\" href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\"><em>CC BY-NC 4.0<\/em><\/a><em>.<\/em><\/p>\n<div class=\"textbox textbox--learning-objectives\">\n<header class=\"textbox__header\">\n<h2 class=\"textbox__title\"><span style=\"color: #ffffff;\">Learning Objectives<\/span><\/h2>\n<\/header>\n<div class=\"textbox__content\">\n<ul>\n<li>Describe the current conservation status of the world\u2019s primates and the criteria that researchers and conservationists use to make these assessments.<\/li>\n<li>Recognize the many threats that negatively impact primate survival.<\/li>\n<li>Identify how these threats uniquely affect primates because of characteristics like slow growth rates, long interbirth intervals, strong social bonds, and cultural behavior.<\/li>\n<li>Distinguish the many ways in which primates are significant to ecological processes, our understanding of human evolution, human cultures, and local economies.<\/li>\n<li>Illustrate the ways that people, wherever they may live, can work to protect primates.<\/li>\n<\/ul>\n<\/div>\n<\/div>\n<p>We are field primatologists interested in understanding nonhuman primates (henceforth, simply \u201cprimates\u201d) in their natural environments and in contributing to their conservation. Our research has focused on a diversity of primate species that occur in a wide range of habitats throughout the tropics; however, these species and their habitats are subject to many similar threats. As human populations continue to grow (Figure B.1), primates are being pushed out of their natural home ranges and forced to occupy increasingly smaller and more isolated patches of land. Humans and primates are sharing more spaces with one another, making it easier for primates to be hunted or captured and for diseases to spread from humans to primates (and vice versa). Even when primates are not directly threatened by human activities, human-induced climate change is altering local ecosystems at an alarming rate. Local political instability exacerbates all of these problems. Our research has caused us to think about these issues on a daily basis, both in the field and at home. Understanding how these threats affect the primates we have studied is a very important part of what we do. Ultimately, the research of field primatologists is important for documenting the status of wild primate populations and for understanding how primates respond to these threats in order to gain insight into efforts that can help improve their chances of survival in an uncertain future.<\/p>\n<p>&nbsp;<\/p>\n<figure style=\"width: 587px\" class=\"wp-caption aligncenter\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/06\/image6-11.png\" alt=\"Global population by region, with projection of 11 billion by 2100.\" width=\"587\" height=\"363\" \/><figcaption class=\"wp-caption-text\">Figure B1: Caption: World population growth by region. Global populations are projected to approach 11 billion people by 2100 (UN Population Division 2019). <a href=\"https:\/\/docs.google.com\/document\/d\/1VUDKMBJYS_jNONjLxT04jQN0_z9Ua50BRN6auGSHUuU\/edit\">A full text description of this image is available<\/a>. Credit: <a class=\"rId11\" href=\"https:\/\/ourworldindata.org\/world-population-growth\">World population by region<\/a> by <a class=\"rId12\" href=\"https:\/\/ourworldindata.org\/\">Our World in Data<\/a> [Source Gapminder (v6), HYDE (v3.2) &amp; UN (2019)] accessed June 6, 2022 is used under a <a class=\"rId13\" href=\"https:\/\/creativecommons.org\/licenses\/by\/4.0\/deed.en_US\">CC BY 4.0 License<\/a>.<\/figcaption><\/figure>\n<p class=\"import-Normal\">This appendix begins with a review of the current status of primates and the criteria used in these assessments. We then describe the major threats to primates, explain why primates are important, and consider what can be done to improve their chances of survival. We conclude with a brief consideration of the future for primates.<\/p>\n<h2 class=\"import-Normal\">Current Conservation Status of Nonhuman Primates <strong><br style=\"clear: both;\" \/><\/strong><\/h2>\n<h3 class=\"import-Normal\"><strong>Diversity of Primates<\/strong><\/h3>\n<p class=\"import-Normal\">The order Primates is one of the most diverse groups of mammals on the planet, with over 528 species in 81 different genera currently recognized (IUCN SSC Primate Specialist Group 2022). In the last few decades new genera, species, and subspecies of primates have been recognized\u2014sometimes as a result of new discoveries and new data but also because of revisions to taxonomic classification systems based on different species concepts (Groves 2014; Lynch Alfaro et al. 2012; Rylands and Mittermeier 2014).<\/p>\n<figure style=\"width: 725px\" class=\"wp-caption aligncenter\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image3-8.png\" alt=\"World map shows threats to primates.\" width=\"725\" height=\"372\" \/><figcaption class=\"wp-caption-text\">Figure B.2: Global distribution of primates and their main threats within the four major primate regions. For each region, the top circle represents the proportion of species impacted by specific threat types; the bottom circle represents the total number of species (in black) and threatened species (in red). <a href=\"https:\/\/docs.google.com\/document\/d\/1VUDKMBJYS_jNONjLxT04jQN0_z9Ua50BRN6auGSHUuU\/edit\">A full text description of this image is available<\/a>. Credit: Main threats and conservation status within each of the four primate regions based on IUCN data <a class=\"rId15\" href=\"https:\/\/advances.sciencemag.org\/content\/3\/1\/e1600946\">(Figure 2)<\/a> by Fern\u00e1ndez et al. (2022) is used with permission under a <a class=\"rId16\" href=\"https:\/\/creativecommons.org\/licenses\/by\/4.0\/deed.en_US\">CC BY 4.0 License<\/a>.<\/figcaption><\/figure>\n<figure style=\"width: 211px\" class=\"wp-caption alignleft\"><img class=\"\" src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image8-7.jpg\" alt=\"Male mountain gorilla peers through leaves.\" width=\"211\" height=\"270\" \/><figcaption class=\"wp-caption-text\">Figure B.3: Mountain gorilla (Gorilla beringei beringei) in Bwindi Impenetrable National Park, Uganda. This endangered species has suffered tremendously due to habitat destruction, poaching, political unrest, and war (Kalpers et al. 2003). Credit: <a class=\"rId18\" href=\"https:\/\/www.flickr.com\/photos\/rod_waddington\/34907123722\/in\/photostream\/\">Mountain Gorilla Bwindi<\/a> by <a class=\"rId19\" href=\"https:\/\/www.flickr.com\/photos\/rod_waddington\/\">Rod Waddington<\/a> is used under a <a class=\"rId20\" href=\"https:\/\/creativecommons.org\/licenses\/by-sa\/2.0\/\">CC BY-SA 2.0 License. <\/a><\/figcaption><\/figure>\n<p>Wild primates occur in 90 countries around the world, but two-thirds of all species are found in only four countries: Brazil, Madagascar, Democratic Republic of Congo, and Indonesia (Estrada et al. 2017; Estrada et al. 2018). An estimated 66% of primate species are threatened with extinction (Fern\u00e1ndez et al. 2022; Figure B.2). Yet despite this discouraging statistic, there are a growing number of populations recovering as a result of research and conservation efforts. For example, the population of mountain gorillas (Figure B.3) initially studied by Dian Fossey in Rwanda in 1967 has grown from 250 gorillas in 1981 to 339 in 2008. The increase is a result of ongoing research and conservation efforts that include highly controlled ecotourism (Robbins et al. 2011). Similarly, one population of northern muriqui monkeys (Figure B.4)\u2014which inhabits a small, privately owned forest fragment in southeastern Brazil\u2019s Atlantic Forest\u2014increased from about 50 individuals to nearly 350 individuals as a result of increased habitat protection over the course of the Muriqui Project of Caratinga (https:\/\/www.facebook.com\/pg\/ProjetoMuriquiCaratinga), a long-term field study initiated nearly 40 years ago by one of the authors of this appendix (Strier and Mendes 2012). Although the population has declined by about \u2153 in the past five years, it is still 4\u20135 times larger than it was 40 years ago (Strier 2021a).<em><br style=\"clear: both;\" \/><\/em><\/p>\n<figure style=\"width: 456px\" class=\"wp-caption aligncenter\"><img class=\"\" src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image17-4.jpg\" alt=\"Female northern muriqui with infant in a tree.\" width=\"456\" height=\"342\" \/><figcaption class=\"wp-caption-text\">Figure B.4: A female northern muriqui (Brachyteles hypoxanthus) with infant at the Feliciano Miguel Abdala Private Natural Heritage Reserve near Caratinga, Minas Gerais, Brazil. Credit: A female northern muriqui (Brachyteles hypoxanthus) with infant at the Feliciano Miguel Abdala Private Natural Heritage Reserve outside of Caratinga, Brazil by A.J. Hardie, courtesy of <a class=\"rId22\" href=\"https:\/\/www.preservemuriqui.org.br\/\">Projeto Muriqui de Caratinga<\/a>, is used by permission and available here under a <a class=\"rId23\" href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/\">CC BY-NC 4.0 License<\/a>.<\/figcaption><\/figure>\n<h3 class=\"import-Normal\"><strong>International Union for the Conservation of Nature (IUCN)<\/strong><\/h3>\n<p class=\"import-Normal\">In conservation, it is crucial to have a global standard to assess and recognize the conservation status of species. The International Union for the Conservation of Nature (IUCN) formed the Red List for Threatened Species in 1994 to determine species extinction risks (IUCN 2022). Scientists submit assessments of species to the IUCN, which are subsequently categorized based on the size and distribution of species\u2019 numbers and available habitat. The categories range from \u201cdata deficient,\u201d when not enough is known, to \u201cleast concern,\u201d \u201cnear threatened,\u201d \u201cvulnerable,\u201d \u201cendangered,\u201d \u201ccritically endangered,\u201d \u201cextinct in the wild,\u201d and \u201cextinct.\u201d Threatened species are classified as \u201cvulnerable,\u201d \u201cendangered,\u201d or \u201ccritically endangered,\u201d with the most critically endangered species being those whose numbers are fewer than 250 mature individuals and continuing to decline or whose habitats are severely fragmented (Figure B.5; IUCN 2022).<\/p>\n<div class=\"textbox\">\n<p class=\"import-Normal\"><strong>Critically Endangered (CR)<\/strong>: Facing an extremely high risk of extinction in the wild due to any of the following:<\/p>\n<ul>\n<li class=\"import-Normal\">Reduction in population size of 80%\u201390% over the last ten years or three generations, depending on the causes and reversibility of the reductions;<\/li>\n<li class=\"import-Normal\">Extent of occurrence &lt;100 km<sup>2 <\/sup>or area of occupancy &lt;10 km<sup>2 <\/sup>or both;<\/li>\n<li class=\"import-Normal\">Population size estimated to number fewer than 250 mature individuals and to be declining or unevenly distributed;<\/li>\n<li class=\"import-Normal\">Population size estimated to number fewer than 50 mature individuals;<\/li>\n<li class=\"import-Normal\">Probability of extinction within ten years or three generations is at least 50%.<\/li>\n<\/ul>\n<p class=\"import-Normal\"><strong>Endangered (EN)<\/strong>: Facing a very high risk of extinction in the wild due to any of the following:<\/p>\n<ul>\n<li class=\"import-Normal\">Reduction in population size of 50%\u201370% over the last ten years or three generations, depending on the causes and reversibility of the reductions;<\/li>\n<li class=\"import-Normal\">Extent of occurrence &lt;5000 km<sup>2 <\/sup>or area of occupancy &lt;500 km<sup>2 <\/sup>or both;<\/li>\n<li class=\"import-Normal\">Population size estimated to number fewer than 2,500 mature individuals and to be declining or unevenly distributed;<\/li>\n<li class=\"import-Normal\">Population size estimated to number fewer than 250 mature individuals;<\/li>\n<li class=\"import-Normal\">Probability of extinction within 20 years or five generations is at least 20%.<\/li>\n<\/ul>\n<p class=\"import-Normal\"><strong>Vulnerable (VU)<\/strong>: Facing a high risk of extinction in the wild due to any of the following:<\/p>\n<ul>\n<li class=\"import-Normal\">Reduction in population size of 30%\u201350% over the last ten years or three generations, depending on the causes and reversibility of the reductions;<\/li>\n<li class=\"import-Normal\">Extent of occurrence &lt;20,000 km<sup>2 <\/sup>or area of occupancy &lt;2000 km<sup>2 <\/sup>or both;<\/li>\n<li class=\"import-Normal\">Population size estimated to number fewer than 10,000 mature individuals and to be declining or unevenly distributed;<\/li>\n<li class=\"import-Normal\">Population size estimated to number fewer than 1,000 mature individuals;<\/li>\n<li class=\"import-Normal\">Probability of extinction within 100 years is at least 10%.<\/li>\n<\/ul>\n<\/div>\n<p><span style=\"color: #082166;\"><span class=\"very-tight\"><em>Figure B.5: International Union for Conservation of Nature (IUCN) Criteria for Threatened Taxa. Credit: International Union for Conservation of Nature (IUCN) Criteria for Threatened Taxa by Mary P. Dinsmore et al., updated from Strier 2011, with data simplified and condensed from IUCN Species Survival Commission (2012), is under a <span style=\"color: #ff0000;\"><a class=\"rId24\" style=\"color: #ff0000;\" href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/\"><span style=\"color: #ba0606;\">CC BY-NC 4.0 License<\/span><\/a><\/span>.<\/em><\/span>\u00a0<\/span><\/p>\n<p>&nbsp;<\/p>\n<\/div>\n<div class=\"__UNKNOWN__\">\n<div><\/div>\n<div style=\"text-align: left;\">The IUCN has a committee specifically dedicated to primates, the IUCN Species Survival Commission (SSC) Primate Specialist Group. This group collaborates with the International Primatological Society (IPS), Conservation International (CI), and the Bristol Zoological Society (BZS) every two years to publish \u201cPrimates in Peril: The World\u2019s 25 Most Endangered Primates.\u201d These lists are created at IPS open meetings and are intended to focus attention on all endangered primates by highlighting the plights of some of the most critically endangered (Mittermeier et al. 2022).<\/div>\n<h3 class=\"import-Normal\"><strong>Identifying Priorities in Primate Conservation <\/strong><\/h3>\n<figure style=\"width: 387px\" class=\"wp-caption alignright\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image5-5.jpg\" alt=\"A male Bornean orangutan with large padded cheeks.\" width=\"387\" height=\"257\" \/><figcaption class=\"wp-caption-text\">Figure B.6: A male Bornean orangutan (Pongo pygmaeus). This species\u2019s large size and close genetic relatedness to humans make them appealing to the public, such that they are categorized as a \u201ccharismatic species.\u201d Credit: <a class=\"rId26\" href=\"https:\/\/www.flickr.com\/photos\/ekilby\/12627089413\/in\/photolist-odBzse-kePx4n-kePeW6-keP8La-kePhGX-keRfZf-kePYuT-o63SWa-odTw3k-nVPEL5-5uzcjG-nWq1oU-odApvx-nVPmcd-odAB9c-keQJKY-kePbSF-keNTRX-J6E6zP-JBjDrS-JSWPZL-J6KPYB-JVfZNe-6QTZh3-nBsRDJ-keQZuC-byu\">Bornean Orangutan Wide Face<\/a> by <a class=\"rId27\" href=\"https:\/\/www.flickr.com\/photos\/ekilby\/\">Eric Kilby<\/a> is used under a <a class=\"rId28\" href=\"https:\/\/creativecommons.org\/licenses\/by-sa\/2.0\/\">CC BY-SA 2.0 License<\/a>.<\/figcaption><\/figure>\n<p>It is important to consider extinction risk in making conservation decisions, thus the IUCN Red list and the \u201cPrimates in Peril\u201d reports are factors in deciding how to allocate resources and funding. Some primate species are found only in biodiversity hot spots or in areas that contain high levels of species diversity and include primates that are endemic to the area and genetically unique (Sechrest et al. 2002). Hot spots are often considered conservation priorities because protecting these areas can result in the protection of large numbers of species. In addition, some conservation organizations focus on highly charismatic primate species (e.g., primates that are large, closely related to humans, or well-known from zoos) to garner attention and resources for conservation (Figure B.6). However, dramatic declines of charismatic species indicate that charisma is not enough (Estrada et al. 2017). In making conservation decisions, primatologists may also consider the importance of genetically unique primates\u2014such as the aye-aye (<em>Daubentonia madagascariensis<\/em>), the last remaining species within its genus\u2014in order to preserve evolutionary history (Strier 2011a).<\/p>\n<h2 class=\"import-Normal\">Threats to Primates<\/h2>\n<h3 class=\"import-Normal\"><strong>Hunting, Poaching, and Wildlife Trade<\/strong><\/h3>\n<p class=\"import-Normal\">Hunting represents one of the most critical threats to primates (Figure B.7). Bushmeat, which is the meat of wild animals, has historically been a staple diet in many societies. However, human population growth and economic development have increased the commercialization of bushmeat hunting (Estrada et al. 2017). The availability and use of shotguns has also dramatically increased the quantity of carcasses that hunters capture (Cronin et al. 2015). A study in the Ivory Coast indicated that primates are preferentially targeted for bushmeat hunting by economically reliant hunters, as primate meat is more likely to be sold in markets compared to smaller species (such as rodents), possibly due to its demand as a luxury product for those in nearby urban environments (Bachman et al. 2020). In one market on the Liberia\/Ivory Coast border, Ryan Covey and Scott McGraw (2014) estimated that the carcasses of nearly 9,500 primates (from at least nine different species) were sold per year, resulting in an almost 3% annual reduction in the local primate population.<\/p>\n<figure id=\"attachment_554\" aria-describedby=\"caption-attachment-554\" style=\"width: 386px\" class=\"wp-caption alignleft\"><img class=\"wp-image-546\" src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/B7.jpg\" alt=\"A gelada with a wire snare around its neck.\" width=\"386\" height=\"283\" \/><figcaption id=\"caption-attachment-554\" class=\"wp-caption-text\">Figure B.7: A female gelada (Theropithecus gelada) with a snare around its neck in central Ethiopia. Many rural hunters rely on snare traps, which are easier to construct and more affordable than firearms and can be equally lethal (Noss 1998; Tumusiime et al. 2010). Credit: A female gelada (<em>Theropithecus gelada<\/em>) with a snare around its neck in central Ethiopia by Kadie Callingham is used by permission and available here under a <a class=\"rId30\" href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/\">CC BY-NC 4.0 License<\/a>.<\/figcaption><\/figure>\n<p class=\"import-Normal\">Not all primates are hunted specifically for food. Biomedical researchers use primates as models for understanding human biology and as test subjects for the development of vaccines, drugs, and hormones (Conaway 2011). Many of these experiments require large numbers of primates; therefore biomedical facilities often require a continuous supply of primates. Between 2007 and 2008, a single biomedical laboratory purchased roughly 4,000 nocturnal monkeys for over 100,000 USD through a network of 43 traders across Brazil, Colombia, and Peru (Maldonado, Nijman, and Bearder 2009). Although the use of apes in biomedical research has been severely reduced and\/or banned in many countries, such as Austria, New Zealand, the United Kingdom, and the United States (Aguilera, Perez Gomez, and DeGrazia 2021), the use of other primates to study disease transmission, incubation, vaccine effectiveness, and similar topics is still ongoing and has recently been widespread in studying SARS-CoV-2 (Corbett et al. 2020; Lu et al. 2020; Stammes et al. 2021).<\/p>\n<p class=\"import-Normal\">Aside from biomedical research, captured primates are both legally and illegally sold to pet owners, zoos, tourist centers, and circuses. In Peru, it is estimated that, as recently as 2015, hundreds of thousands of primates are illegally traded every year, comparable to levels of trade prior to a 1973 national ban on primate exportation (Shanee, Mendoza, and Shanee 2017). Once captured, primates may spend over a week in transit from a rural village to a coastal market. To make the transportation of primates more manageable, common trafficking strategies include sedation, asphyxiation, electrocution, and the removal of teeth. As these conditions severely affect the health of the trafficked primates, many perish during the journey while others die within the hands of authorities. Out of the 77 greater slow lorises (<em>Nycticebus coucang<\/em>) confiscated from a single wildlife trader in Indonesia, 22 died from either trauma or from the severity of their wounds (Fuller et al. 2018). Even when primates are successfully confiscated from wildlife traders, authorities sometimes resell or gift these animals to friends and family (Shanee, Mendoza, and Shanee 2017).<\/p>\n<p class=\"import-Normal\">A growing concern of primate conservationists is the use of social media to convey harmful images of primates. People posting on social media sites, such as Instagram, TikTok, Facebook, and YouTube, who show videos and photos of primates dressed in human clothing, tourists engaging with primates while traveling, and \u201cfunny\u201d or \u201ccute\u201d photos of primates as pets, may not realize the negative impact their posts can have. The sharing of this content, coupled with comments expressing the desire to own the subject as a pet, can motivate further harvesting of these species from the wild (Clarke et al. 2019; Norconk et al. 2019). After a video depicting a pygmy slow loris (<em>Nycticebus<\/em> <em>pygmaeus<\/em>) being \u201ctickled\u201d went viral in 2009, and another depicting a slow loris eating rice went viral in 2012, international confiscations of slow lorises increased (Nekaris et al. 2013).<\/p>\n<p class=\"import-Normal\">To help curb illegal trafficking of animals, the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) was established in 1973 and ratified in 1975. Under this treaty, the 183 participating countries work together to both regulate the international trade of wildlife and to prevent the overexploitation of wild populations. While only some primates are listed as endangered or threatened under the Endangered Species Act (ESA), all primates are listed under CITES. According to the CITES database, more than 450,000 live primates were traded over the past 15 years (CITES n.d.). However, as the CITES database only includes information formally reported by each country, the real number of primates involved is likely to be much higher.<\/p>\n<h3 class=\"import-Normal\"><strong>Disease<\/strong><\/h3>\n<p class=\"import-Normal\">Disease has become a critical threat to human and nonhuman primates alike (Nunn and Altizer 2006). Shifting temperatures, unpredictable precipitation, crowding in fragmented habitats, and more frequent human contact can contribute to increased disease transmission among primates (Nunn and Gillespie 2016). Mosquito populations often thrive in this environment and are vectors of diseases that affect both humans and primates, such asZika virus, yellow fever, and malaria (Lafferty 2009). Disease outbreaks have the potential to severely reduce primate populations. In 2016 and 2017, a large yellow fever outbreak devastated several populations of the brown howler monkeys (<em>Alouatta guariba<\/em>) and other species in the Atlantic forest of Brazil (Fernandes et al. 2017; Strier et al. 2017; Possamai et al. 2022). Ebola outbreaks have similarly diminished populations of African apes; in 2003 and 2004, an outbreak killed up to 5,000 endangered western gorillas (<em>Gorilla gorilla<\/em>; Bermejo et al. 2006) and severely reduced populations of chimpanzees (<em>Pan troglodytes<\/em>; Leroy et al. 2004) in Gabon and the Republic of Congo.<\/p>\n<p class=\"import-Normal\">Human encroachment into primate habitats as a result of agricultural expansion, resource extraction, or even through irresponsible ecotourism or research practices can introduce novel pathogens into both human and primate populations (Strier 2017). Due to our close shared lineage, many diseases are communicable between humans and primates, such as Ebola, HIV, tuberculosis, herpes, and other common ailments. Close contact and primate handling are often the most direct ways in which these diseases are transmitted. However, poor hygiene practices, improper waste disposal, and primate provisioning (<em>e.g.<\/em> providing food resources to primates) contribute to disease susceptibility in primates (Wallis and Lee 1999). For example, two groups of olive baboons (<em>Papio cynocephalus anubis<\/em>) living in the Masai Mara Game Reserve in Kenya contracted tuberculosis from foraging at contaminated garbage dumps near the tourist lodge (Tarara et al. 1985). Recently with the proliferation of social media, tourists are coming into close contact with charismatic primate species, such as orangutans, in an effort to capture engaging photographs. Such close contact with varied populations is yet another driver for possible increased disease transmission (Molyneaux et al. 2021). Transmission of diseases through increased human contact can have devastating effects on primate populations that have not built any resistance (Laurance 2015).<\/p>\n<h3 class=\"import-Normal\"><strong>Habitat<\/strong><strong> Loss, Fragmentation, and Degradation<\/strong><\/h3>\n<figure style=\"width: 400px\" class=\"wp-caption alignleft\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image14-6.jpg\" alt=\"Cows stand in a field of papaya trees with sparse foreground.\" width=\"400\" height=\"300\" \/><figcaption class=\"wp-caption-text\">Figure B.8: Cattle graze in a newly formed papaya plantation, which was once forested land in Montagne des Fran\u00e7ais, Madagascar. Credit: Cattle graze in papaya plantation, once forested land, in Montagne des Fran\u00e7ais, Madagascar by Mary P. Dinsmore is under a <a class=\"rId32\" href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/\">CC BY-NC 4.0 License<\/a>.<\/figcaption><\/figure>\n<p class=\"import-Normal\">The geographic distribution of many primate species has been severely limited by habitat loss. A recent analysis showed human demands for biological resources threaten 81% of primate species, followed by demands for agricultural land (80%) and residential and commercial development (32%; see Fern\u00e1ndez et al. 2022). Habitat loss is not new and has affected the distribution of some primate species, including golden snub-nosed monkeys (<em>Rhinopithecus roxellana<\/em>), for thousands of years (Wang et al. 2014). However, our ever-growing need for food, water, and other natural resources has drastically decreased primate habitats globally (Figure B.8). From 2000 to 2013, roughly 220,000 km<sup>2<\/sup> of tropical forest have been completely deforested in the Brazilian Amazon alone (Tyukavina et al. 2017). Since the start of oil palm development in Indonesia\u2019s Ketapang District in 1994, over 65% of habitats without government protection have been allocated to the oil palm industry (Carlson et al. 2012). Habitat loss can lead to increased human-primate conflict. After a 2004 tsunami destroyed large areas of natural habitat on India\u2019s Nicobar Islands, local farmers witnessed increased crop raiding by long-tailed macaques (<em>Macaca fascicularis<\/em>; Velankar et al. 2016). In Saudi Arabia, expanding cities and improper waste disposal practices contributed to the formation of unusually large urban troops of Hamadryas baboons (<em>Papio hamadryas<\/em>) that are less fearful of humans than troops surveyed in rural areas (Biquand et al. 1994). Even within protected areas, primate habitats are rapidly declining. In South Asia, 36% of surveyed protected areas had more than half of their habitat modified for human use, many of which experienced near-total habitat transformation (Clark et al. 2013). In a protected area in northern Madagascar that houses the last remaining population of the critically endangered Northern sportive lemur (<em>Lepilemur septentrionalis<\/em>), forest cover was reduced from 76% to 24% in a 60-year time frame (Dinsmore et al. 2021a).<\/p>\n<figure style=\"width: 338px\" class=\"wp-caption alignright\"><img class=\"\" src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image19-6.jpg\" alt=\"An area of forest cut and burned.\" width=\"338\" height=\"254\" \/><figcaption class=\"wp-caption-text\">Figure B.9: Forest cleared for cattle ranching in the province of Manab\u00ed, Ecuador. Cattle ranching is currently the main driver of deforestation in South American countries (Steinweg et al. 2016). Credit: Forest cleared for cattle ranching in the province of Manab\u00ed, Ecuador, by Irene Duch-Latorre, courtesy of <a class=\"rId34\" href=\"https:\/\/www.proyectowashu.org\/\">Proyecto Washu<\/a>, is used by permission and available here under a <a class=\"rId35\" href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/\">CC BY-NC 4.0 License<\/a>.<\/figcaption><\/figure>\n<p class=\"import-Normal\">Habitat fragmentation compounds the effects of habitat loss. Whereas habitat loss reduces the total area in which primates can survive, habitat fragmentation divides large, contiguous primate habitats into smaller isolated patches (Figure B.9). The construction of road networks cutting through savannas, forests, and other primate habitats is a key driver of this fragmentation. Within the next half-century, over 25,000,000 km of new roads are expected to be built, many of which will be located in developing nations through primate habitats (Laurance et al. 2014). By fragmenting habitats, it becomes increasingly challenging for primates (particularly arboreal primates) to disperse between isolated habitat patches. While only 0.1% of black-and-white snub-nosed monkey (<em>Rhinopithecus bieti<\/em>) habitat was lost to the construction of China National Highway 214, movement between habitat patches on either side of the highway was reduced by over 20% (Clauzel et al. 2015). In the long run, habitat fragmentation can force primate populations into genetic bottlenecks, which occur when populations become so small that genetic diversity in them is severely reduced. In the forest fragments of Manaus, Brazil, groups of pied tamarins (<em>Sanguins bicolor<\/em>) that historically formed one biological population were found to harbor only a subset of the genetic diversity previously exhibited in the region (Farias et al. 2015). Furthermore, primates living in fragments with scarce resources experience elevated levels of stress, which can also have long-term consequences on the health of individuals and populations (Rimbach et al. 2014).<\/p>\n<figure style=\"width: 317px\" class=\"wp-caption alignleft\"><img class=\"\" src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image18-6.jpg\" alt=\"A truck on a dirt road with bags of charcoal in its bed.\" width=\"317\" height=\"238\" \/><figcaption class=\"wp-caption-text\">Figure B.10: An industrial-sized truck leaves the Montagne des Fran\u00e7ais region in Madagascar, with dozens of bags of charcoal in tow to be delivered to a nearby town. Much of sub-Saharan Africa still relies on fuelwoods as a main source of energy for cooking and heating, acting as strong drivers of forest degradation (Hosonuma et al. 2012). Credit: An industrial-sized truck with charcoal leaves Montagne des Fran\u00e7ais region, Madagascar, by Mary P. Dinsmore is under a <a class=\"rId37\" href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/\">CC BY-NC 4.0 License<\/a>.<\/figcaption><\/figure>\n<p class=\"import-Normal\">Aside from habitat loss, other drivers of habitat degradation may affect primate populations. For example, streams can carry toxic chemicals used for agriculture into local habitats where they are either directly or indirectly consumed by primates. In Uganda, chimpanzees (<em>Pan troglodytes<\/em>) living within the Sebitoli Forest have been spotted with facial and limb deformities that are suspected of being related to their exposure to pesticides and herbicides used by local tea farmers (Krief et al. 2017). Additionally, invasive species that outcompete native species and alter habitats can affect primate behaviors. In Madagascar, southern bamboo lemurs (<em>Hapalemur meridionalis<\/em>) spent less time feeding in forests dominated by invasive Melaleuca trees (<em>Melaleuca quinquenervia<\/em>) than in forests without these trees (Eppley et al. 2015). Lastly, fuelwood and charcoal are still widely used throughout sub-Saharan Africa to produce heat and energy for cooking. Heavy reliance on these resources can result in degradation of primate habitat, fragmentation, and overall forest loss (Figure B.10).<\/p>\n<h3 class=\"import-Normal\"><strong>Climate Change<\/strong><\/h3>\n<figure style=\"width: 272px\" class=\"wp-caption alignright\"><img class=\"\" src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image20-4.jpg\" alt=\"An uprooted tree with a large hole lies on the forest floor.\" width=\"272\" height=\"363\" \/><figcaption class=\"wp-caption-text\">Figure B.11: An old-growth tree is uprooted after Cyclone Enawo made landfall in northeast Madagascar in March 2017. Hurricanes and cyclones may become stronger with global climate change and often alter ecosystems in ways that negatively affect primates in these regions (Dinsmore, Strier, and Louis 2018). Credit: Old-growth tree uprooted after Cyclone Enawo, Madagascar, by Mary P. Dinsmore is under a <a class=\"rId39\" href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/\">CC BY-NC 4.0 License<\/a>.<\/figcaption><\/figure>\n<p class=\"import-Normal\">The ramifications of climate change, many of which are just beginning to be documented, can be unpredictable and cause a range of consequences for biodiversity, compounding preexisting threats facing primates, as each decade is warmer than the last (IPCC 2022). On a large scale, the deleterious effects of climate change can make primates\u2019 current environments inhospitable. Additionally, climate change alters the flowering and fruiting seasons of many plants, requiring dietary flexibility from the organisms that rely on their production (Anderson et al. 2012). Many primates are not capable of this adjustment and would need to shift their habitat range to cope. Arboreal primates have already been observed to shift the utilization of their habitats due to climate change, especially by spending more time on the ground (Eppley et al. 2022). Unfortunately, habitat loss and fragmentation make these range shifts impossible for many species without human assistance in the form of translocations. Compounding this, primates have relatively slow life-histories, often producing only one offspring at a time, and their extended juvenile period results in minimal evolutionary adaptation to change (Campos et al. 2017; Bernard and Marshall 2020). Primates are projected to have some of the most restricted ranges due to climate change (Schloss, Nu\u00f1ez, and Lawler 2012), forcing them to utilize a variety of possible, nonpreferred habitats.<\/p>\n<figure style=\"width: 309px\" class=\"wp-caption alignleft\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image13-4.jpg\" alt=\"A small lemur with a research collar clings to a tree. \" width=\"309\" height=\"309\" \/><figcaption class=\"wp-caption-text\">Figure B. 12: A northern sportive lemur (Lepilemur septentrionalis), a Critically Endangered species, rests in a tree at Montagne des Fran\u00e7ais, Madagascar. Credit: A northern sportive lemur (<em>Lepilemur septentrionalis<\/em>), Montagne des Fran\u00e7ais, Madagascar, by Mary P. Dinsmore is under a <a class=\"rId41\" href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/\">CC BY-NC 4.0 License<\/a>.<\/figcaption><\/figure>\n<p class=\"import-Normal\">Rapidly changing climate also causes other extreme weather events in primate areas. Due to climate change, hurricanes and cyclones are increasing in severity. On a small or local scale, these stochastic environmental events are more fine-tuned and the severity can differ depending on the primate species, which can directly impact populations or their habitats (Figure B.11). For example, spider monkeys (<em>Ateles geoffroyi yucatanensis<\/em>) were not severely affected after two hurricanes hit Mexico but still exhibited behavioral plasticity by spending more time resting, feeding on leaves, and gathering in smaller subgroups than they did before the hurricanes (Schaffner et al. 2012). Some species, such as the critically endangered northern sportive lemur (<em>Lepilemur septentrionalis<\/em>), which has an estimated population of ~87 individuals, exhibited behavioral plasticity after a Category 4 cyclone (Figure B.12; Bailey et al. 2020; Dinsmore et al. 2021b). However, stochastic weather events can still severely impact the species by causing the direct death of individuals in an already-small population, reducing overall population totals and genetic diversity (Dinsmore et al. 2021b). Species that are not threatened or that have large, intact ranges are not likely to be greatly affected by localized climatic conditions, but they may nonetheless experience local devastation and even extinction (Strier 2017).<\/p>\n<div class=\"textbox shaded\">\n<h2 class=\"import-Normal\">Dig Deeper: The COVID-19 Pandemic<\/h2>\n<p class=\"import-Normal\">Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus that causes COVID-19, was first recorded in December of 2019 and has infected millions of people since then. Although humans have been the primary focus during this global pandemic, other animals, such as minks, cats, fruit bats, and nonhuman primates can also be infected (Oude Munnink et al. 2021). Human-to-animal transmission of diseases like COVID-19 is a process most commonly known as \u201czooanthroponosis\u201d or \u201creverse zoonosis\u201d (Messenger, Barnes, and Gray 2014). For example, in January 2021, western lowland gorillas at the San Diego Zoo in California were confirmed to have contracted SARS-CoV-2 (USDA 2021).<\/p>\n<p class=\"import-Normal\">Apart from the direct risks that respiratory viruses bring to nonhuman primates, the COVID-19 pandemic also brought economic crisis and limited human presence in conservation areas.The reduction in human mobility due to the pandemic is being referred to as \u201canthropause\u201d\u2014a term coined to represent the temporary diminishment of the human footprint. However, this reduction in movement halted conservation action on the ground, potentially increasing poaching and the wildlife trade by people who rely more heavily on natural resources due to global market stress (Rutz et al. 2020). Given the interactions among the multiple consequences of the COVID-19 pandemic, many scientists fear that increased poaching pressure could push some primates, especially the great apes, closer to extinction (Casal and Singer 2021).<\/p>\n<\/div>\n<div class=\"textbox shaded\">\n<h2 class=\"import-Normal\">Dig Deeper: Extinction Vortex<\/h2>\n<p class=\"import-Normal\"><strong><br style=\"clear: both;\" \/><\/strong>The many threats facing primates that we have listed here are interrelated: as they interact with one another, they create what is known as an <em>extinction vortex<\/em> (Figure B.13; Gilpin and Soul\u00e9 1986). Habitat fragmentation and loss, hunting, climate change, and disease compound to reduce primate populations at a greater rate than when any one factor acts alone. Small populations living in isolated fragments of habitat are disconnected from the rest of their species and are therefore more vulnerable to inbreeding effects. Daniel Brito and colleagues (2008) found that many populations of the critically endangered northern muriqui (<em>Brachyteles hypoxanthus<\/em>) residing in the remaining fragments of the Atlantic Forest would experience genetic decay with the possibility of extinction over the next 50 generations if management practices are not put into place. Slow life histories resulting in long interbirth intervals push many primate species farther into the extinction vortex. Shifting demographics can have dire consequences for primates, thrusting them into a cycle that is hard to break once entered. With the continued presence of threats, many species have a difficult time recovering (Brook et al. 2008; Strier 2011a).<\/p>\n<p>&nbsp;<\/p>\n<figure style=\"width: 595px\" class=\"wp-caption aligncenter\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image2-6.jpg\" alt=\"A drawing illustrates the extinction vortex.\" width=\"595\" height=\"446\" \/><figcaption class=\"wp-caption-text\">Figure B.13: A model of the extinction vortex (Strier 2021b: see ch. 4 study guide). The extinction vortex shows the threats and pressures that work simultaneously to threaten populations. These pressures are often exacerbated by the compounding effects they have on each other. Once a population has entered the vortex, this cascade of events can prevent recovery, resulting in extinction. Credit: <a class=\"rId43\" href=\"https:\/\/routledgetextbooks.com\/textbooks\/9780367222888\/student.php\">A model of the extinction vortex<\/a> drawn by Karen B. Strier (Strier 2021b), adapted from Gilpin and Soul\u00e9 1986, is available here under a <a class=\"rId44\" href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/\">CC BY-NC 4.0 License<\/a>.<\/figcaption><\/figure>\n<\/div>\n<h2 class=\"import-Normal\">Primate Significance<\/h2>\n<p class=\"import-Normal\">As threats to primates continue to widen in scale, increase in severity, and compound with each other, it is imperative to highlight the variety of ways that primates are important not only to their ecosystems but to humans as well. Below we denote four specific areas of primate significance: ecological, bioanthropological, cultural, and economic. Understanding the value of primates can help strengthen conservation actions.<\/p>\n<h3 class=\"import-Normal\"><strong>Ecological Significance <\/strong><strong>of Primates<\/strong><\/h3>\n<p class=\"import-Normal\">Primates play a key role within their ecosystems, often acting as important contributors to forest community structure by aiding in seed dispersal and pollination of angiosperms and other plant species. Variability in traits such as diet, gut anatomy, and movement patterns influence the spatial landscape of dispersed seeds (Russo and Chapman 2011). Frugivorous primates that range widely are considered the greatest contributors to the dispersal of seeds, as they often either swallow seeds whole, as is common for most Neotropical frugivorous primates (Figure B.14), or spit seeds out, as is common for primates with cheek pouches in Africa and Asia. These primates can augment the diversification and regeneration of forest communities by traveling long distances after consuming fruit and depositing seeds away from the parent plant within heterogeneous landscapes (Strier 2017; Terborgh 1983). Frugivory and seed dispersal are critical plant-animal relationships (Russo 2017). Bach Thanh Hai and colleagues (2018) found that yellow-cheeked crested gibbons (<em>Nomascus<\/em> <em>gabriellae<\/em>) in Southeast Asia were the most effective seed disperser for the Pacific walnut tree. Gibbons dispersed seeds via consumption anywhere from 4 m to 425 m from the parent tree. Seeds defecated by gibbons had higher germination and success rates than those spit by macaques in the same forest.<\/p>\n<figure style=\"width: 343px\" class=\"wp-caption alignleft\"><img class=\"\" src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image9-4.jpg\" alt=\"Feces with intact seeds on the ground with twigs and leaves.\" width=\"343\" height=\"257\" \/><figcaption class=\"wp-caption-text\">Figure B.14: Fecal matter with seeds from the large-bodied northern muriqui (Brachyteles hypoxanthus). When primates consume fruit, they often swallow whole seeds that they then disperse via their dung. Credit: Fecal matter with seeds from the large-bodied northern muriqui (<em>Brachyteles hypoxanthus<\/em>) by Amanda J. Hardie, courtesy of <a class=\"rId46\" href=\"https:\/\/www.preservemuriqui.org.br\/\">Projeto Muriqui de Caratinga<\/a>, is used by permission and available here under a <a class=\"rId47\" href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/\">CC BY-NC 4.0 License<\/a>.<\/figcaption><\/figure>\n<p>Some species of primate may also act as pollinators for local plant species. These primates are attracted to the nectar and flowers of the plant, which often leave pollen on their faces and fur, subsequently spreading pollen to conspecifics when the primate moves to a new location. Some primates may have coevolved a plant-pollinator relationship. Data indicate that the black-and-white ruffed lemur (<em>Varecia<\/em> <em>variegata<\/em>) is reliant on the nectar of the traveler\u2019s palm (<em>Ravenala<\/em> <em>madagascariensis<\/em>) during specific times of the year when food is scarce. When eating this nectar, pollen can stick to the ruff of these lemurs\u2019 necks. This, along with the notion that no other species visit the travel\u2019s palm during these times of the year, indicate that this plant species may be dependent on nonflying mammals for pollination (Kress et al. 1994).<\/p>\n<p class=\"import-Normal\">By acting as seed dispersers and pollinators, primates can aid in the reproductive success, regeneration, and diversification of plants within their ecosystems. The significance of these relationships is only becoming more apparent as habitats continue to be fragmented and destroyed. As habitats dwindle, the ability to regenerate healthy forest systems is crucial to the health and survival of tropical forest systems worldwide (Stier 2017).<\/p>\n<h3 class=\"import-Normal\"><strong>Bioanthropological Significance <\/strong><strong>of Primates<\/strong><\/h3>\n<p class=\"import-Normal\">The study of nonhuman primates has been an integral component of anthropology for many decades (Riley 2020). Even before Sherwood Washburn advocated in <em>The New Physical Anthropology<\/em> (1951) that primates could be studied as living reference for hominin behaviors, anthropologists like Margaret Mead recognized that studies of wild primates contribute to biological and sociocultural anthropology in many ways (Strier 2011b). Primatology in Japan, the U.S., and Europe grew out of a desire to better understand ourselves. Thus, research in the 1960s and 1970s largely focused on species such as chimpanzees (<em>Pan spp.<\/em>) or baboons (<em>Papio spp.<\/em>) that are closely related to humans phylogenetically or live in environments similar to those occupied by early hominins (Haraway 1991; Strum and Fedigan 1999; Washburn 1973). Since those early days, biological anthropological primatology has broadened to include primates from around the world (Strier 2003, 2018a). The inclusion of diverse taxa from what were then-understudied regions challenged notions of \u201ctypical\u201d primate behavior.<\/p>\n<p class=\"import-Normal\">Anthropologists draw from primate studies to explore the many facets of human behavior and evolution. For example, studies demonstrating the tool-using capabilities of wild chimpanzees (<em>Pan troglodytes<\/em>) and capuchin monkeys (<em>Sapajus spp., <\/em>formerly<em> Cebus spp.<\/em>) show that similar ecological pressures and intelligence (not just phylogenetic relatedness to humans) contribute to tool-using behaviors (Fragaszy et al. 2004; Inoue-Nakamura and Matsuzawa 1997). Similarly, studies of modern primate morphology are frequently used to assess how locomotor style or behaviors (such as foraging) are related to anatomy, and this knowledge can then be used to assess the skeletal and dental anatomy of fossil hominins. Living primates provide a comparative sample with which we deepen our understanding of the evolutionary mechanisms that shaped human evolution.<\/p>\n<h3 class=\"import-Normal\"><strong>Cultural Significance <\/strong><strong>of Primates<\/strong><\/h3>\n<p class=\"import-Normal\">For as long as our species has existed, groups of people have lived alongside nonhuman primates and engaged with them in varying ways (Fuentes 2012). The development and expansion of the field of ethnoprimatology, the study of the human-primate interface, has encouraged researchers from sociocultural anthropology and primatology to investigate these points where primates and humans interact and influence each other in surprising ways (Fuentes 2012; Riley 2020; Sponsel 1997). Primates are viewed by many as exceptional animals for the ways in which they reflect elements of humanness, enticing thousands of people to observe their exhibits at zoos and sanctuaries throughout the world. However, the significance of these animals to diverse cultures goes beyond anthropocentrism and touches on aspects of ecology, religion, and social systems. Primates are common figures in religion and myth, appearing sometimes as gods or deities themselves (e.g., the Hindu deity Hanuman) and sometimes as mediators between the human and spirit realms (Alves, Barboza, and de Medeiros Silva Souto 2017; Peterson 2017; Wheatley 1999). Primates have additional cultural significance as figures in folklore and legend, and they are often ascribed human-like characteristics in many of these narratives (Cormier 2017). These stories often inform local taboos that may discourage the consumption of particular species or deforestation of particular areas (Osei-Tutu 2017; Roncal, Bowler, and Gilmore 2018; Sicotte 2017).<\/p>\n<p class=\"import-Normal\">The role that primates play in human cultures is complex and varies significantly with local history, religious practice, and economies. Among the Awa Guaj\u00e1 of eastern Amazonia, for example, primates are considered a part of the humans\u2019 extended kin network and are protected as such, yet they also constitute an important source of dietary protein and are hunted regularly (Cormier 2003). In other primate habitat countries, such as Bali, primates play a significant role in religious practice. Long-tailed macaques (<em>Macaca fascicularis<\/em>) in Bali are frequently found in the forests surrounding Hindu temples and will consume offerings left by residents and tourists once festivals or rituals are concluded (Fuentes 2010; Wheatley 1999). These macaques are seen by some as mediators between the natural world and the spiritual world that transports offerings from one realm to another (Wheatley 1999). Investigating how local residents view primates\u2014for example, whether species are considered sacred or not\u2014is a vital component of conservation programs in these areas (Peterson and Riley 2017). Studying the interface between human and nonhuman primates, as well as considering what factors (e.g., local religious practices, taboos, etc.) influence these interactions, can lead to more holistic conservation planning and implementation.<\/p>\n<h3 class=\"import-Normal\"><strong>Economic Significance<\/strong><strong> of Primates<\/strong><\/h3>\n<p class=\"import-Normal\">One of the most concrete ways that primates can benefit people is through the potential to stimulate local economies from ecotourism. Ecotourism differs from traditional tourism in three main ways: it focuses on nature-based attractions, it provides learning opportunities, and its tourism management practices adhere to economic and ecological sustainability (Fennell and Weaver 2005). Primates are charismatic megafauna, meaning that they are large animals (oftentimes mammals) that elicit mass appeal. They have the possibility to draw tourists, which can in turn bring revenue to lower-income communities found near primate habitats. This attraction from tourists, along with revenue-sharing, can then stimulate local populations to have more positive attitudes toward protected areas and become more invested in the well-being and protection of primates and their habitats (Archabald and Naughton-Treves 2001).<\/p>\n<figure style=\"width: 415px\" class=\"wp-caption alignright\"><img class=\"\" src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image10-9.png\" alt=\"Several tourists observe and photograph a monkey in a tree.\" width=\"415\" height=\"278\" \/><figcaption class=\"wp-caption-text\">Figure B.15: Tourists observing a black-and-white snub-nosed monkey (Rhinopithecus bieti) from a distance, in southwest China. Although nature-based tourism generates revenue for local communities and primate conservation, it can overhabituate primates, changing their natural behaviors. Credit: Tourists observing a black-and-white snub-nosed monkey (<em>Rhinopithecus bieti<\/em>) in southwest China by Danhe Yang is used by permission and available here under a <a class=\"rId50\" href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/\">CC BY-NC 4.0 License<\/a>.<\/figcaption><\/figure>\n<p>Perhaps one of the greatest success stories of nature-based tourism revolves around the mountain gorillas (<em>Gorilla<\/em> <em>beringei<\/em> <em>beringei<\/em>) of Rwanda. After internal conflict plagued Rwanda during the 1990s, the Virungas area developed gorilla-based tourism as a means to aid in socioeconomic development and to bring stability to the region. This process not only helped to increase mountain gorilla populations but was also able to generate enough income to cover the operation costs of three national parks (Maekawa et al. 2013). Research indicated that low-income individuals living around Parc National des Volcans in Rwanda could garner direct income as well as nonfinancial benefits (such as the development of schools and hospitals) from gorilla tourism in the region (Spenceley et al. 2010). Ecotourism success has also been preliminarily observed in the Amazonias region in Brazil. The Mamirau\u00e1 Sustainable Development Reserve began to let tourists visit groups of uakaris (<em>Cacajao<\/em> spp.) in 2019. Data indicated that although the program was new, tourists had a high success rate (&gt;70%) of observing these rare primates, and researchers believe that these educational encounters will help promote uakari conservation while also driving economic possibilities for the local human populations (Lebr\u00e3o et al. 2021).<\/p>\n<p class=\"import-Normal\">Although ecotourism has the potential to alleviate poverty situations for local populations and aid in the overall sustainability of natural habitats, it can also bring a suite of new problems to areas. It can overcrowd national parks and overhabituate primates (Figure B.15), increase potential disease transfer between humans and primates, and exacerbate corruption, which often pulls money away from local communities (Hvenegaard 2014; Muehlenbein et al. 2010).<\/p>\n<h2 class=\"import-Normal\">What Can Be Done?<\/h2>\n<h3 class=\"import-Normal\"><strong>Role of Research<\/strong><\/h3>\n<p class=\"import-Normal\">Systematic and long-term research studies provide some of the most foundational and necessary information for the conservation of endangered primates (Kappeler and Watts 2012). Research provides critical data on essential and preferred feeding resources, life history parameters and reproduction rates, territoriality, the carrying capacity of habitats, and solitary or group social dynamics. Within the last few decades, researchers have also begun to stress the acute need for studies investigating how various primates are responding to human disturbances; how climate change is affecting the behavior, range, and habitat of these species; and the significance of primate biodiversity hotspots (Brown and Yoder 2015; Chapman and Peres 2001; Estrada et al. 2018). Understanding these aspects will provide crucial information for practitioners to make the most effective and species-specific conservation decisions.<\/p>\n<p class=\"import-Normal\">Long-term studies on primate species provide some of the most conclusive information on changes occurring to populations in the face of anthropogenic disturbances and climate change. They also provide a suite of direct and indirect conservation contributions to endangered species, and the continual monitoring of populations can deter deleterious anthropogenic actions, allowing for population growth and forest regeneration. For example, the Northern Muriqui Project of Caratinga in Minas Gerais, Brazil, has documented growth of both the muriqui population and the regeneration of the forest via secondary succession (Strier 2010). The project has also invested in future research and conservation by training more than 65 Brazilian students, as well as providing stable jobs for local people, stimulating the local community, and alleviating reliance on forest products for income and survival (Strier 2010; Strier and Boubli 2006; Strier and Mendes 2012). Several other long-term primate studies all over the world have seen similar positive impacts and conservation successes (Kappeler and Watts 2012).<\/p>\n<p class=\"import-Normal\">The implementation of novel research techniques can also aid in the conservation of primates and their ecosystems. Remote sensing, a technique that gathers information about the environment using satellites, aircraft, or drones, has recently been applied in primate conservation efforts (reviewed in Strier 2021b: see Box 1.3). Another remote-sensing method called LiDAR (Light Detection and Ranging) has been used to generate 3D images of a forest canopy and quantify how canopy height and forest maturity influences movement patterns of three neotropical primates (McLean et al. 2016). The use of high-resolution camera traps both on the ground and in the canopy have become widespread and invaluable in their ability to aid primatologists and conservationists in surveying rare populations, establishing population counts, and assessing behavior (Pebsworth and LaFleur 2014). Camera traps became particularly important in allowing field research to continue during the \u201canthropause\u201d of 2020, as human mobility was limited during the onset of the COVID-19 pandemic (Blount et al. 2021).<\/p>\n<p class=\"import-Normal\">Research is also imperative for making important decisions regarding translocations and reintroductions of animals. Without knowledge of the species\u2019 social ecology, demography, and unique learned behaviors\u2014also known as primate traditions or cultures\u2014successful translocations and reintroductions from captive populations would not be possible. Researchers and conservationists must recognize these dynamics when making the difficult decision to reintroduce or move populations and factor in how these dynamics may shift or affect the resident population after management. The most notable case of effective translocation and reintroduction is that of the golden lion tamarin (<em>Leontopithecus<\/em> <em>rosalia<\/em>). Over 30 zoos contributed 146 captive-born individuals to be reintroduced into Brazil, providing essential information on nutrition and health that aided in reintroduction strategies. Additionally, in 1994, isolated individuals in forest fragments were successfully translocated into protected regions in order to increase gene flow, which through the exchange of genes, introduces more genetic variation into the next generation (Kierulff et al. 2012).<\/p>\n<h3 class=\"import-Normal\"><strong>Nongovernmental Organizations (NGOs) and Community-Based Conservation Work<\/strong><\/h3>\n<p class=\"import-Normal\">Conservation NGOs have a long-standing history of working to save endangered species from going extinct. These organizations often target primates for their work because of their ability to act as umbrella species, supporting the conservation of many species found within their ecosystems. Over the past 30 years, conservation NGOs have begun to move away from a preservation-based mindset that focused on excluding humans from using protected areas. The 1990s ushered in a shift toward community-based conservation (CBC), which instead aimed to work with local people living near targeted natural environments to establish sustainable practices (Horwich and Lyon 2007). CBC strategies involving the installation of visual and acoustic deterrents, barriers, and buffers around human settlements can also help reduce human-primate conflict (Hockings 2016). CBC has shown success in terms of reducing hunting and deforestation in many regions including the Manas Biosphere Reserve in Assam, India, as well as in the cloud forests of Peru from the work of the Yellow Tailed Woolly Monkey Project (Horwich et al. 2012; Shanee et al. 2007). Although CBC has seen conservation successes, many warn that it should not be a panacea for all conservation goals but, rather, one mechanism among many when attempting to conserve endangered species (Reibelt and Nowack 2015; Scales 2014).<\/p>\n<p class=\"import-Normal\">Reforestation is widely becoming one of the most practical ways in which NGOs aid in primate conservation. Organizations often collaborate with communities to establish nurseries to grow saplings, which can then be transplanted strategically to reforest certain parts of primate habitats or create habitat corridors between forest fragments. Madagascar Biodiversity Partnership, an NGO with four field sites throughout Madagascar, has planted over 5,166,000 trees from 2010 to August of 2022 (Edward E. Louis Jr., personal communication, 7,15,22 ). These efforts have been shown to be successful, as lemurs have been observed in reforested regions where they had previously not been seen when trees were more sparse. <strong><br style=\"clear: both;\" \/><\/strong><\/p>\n<div class=\"textbox\">\n<h2 class=\"import-Normal\"><strong>Special Topic: What Can Readers of this Book Do?<\/strong><\/h2>\n<p class=\"import-Normal\">It may be difficult to imagine how an individual living thousands of miles away can aid in the conservation of primates and their habitats, but in fact there are several small steps that people all over the world can take to make a difference. Many local zoos contribute to in situ conservation work as well as maintain species survival plans in order to increase diversity among zoo populations. We recommend readers visit their local zoos to learn about what actions zoos take to aid in the conservation of primates and how they can get involved in these activities.<\/p>\n<p class=\"import-Normal\">One tangible action that can be done is to reduce the purchasing of products that contain nonsustainable ingredients. The demand for cheap oil has increased in recent years for commercial products such as peanut butter, chocolate, soaps, and shampoos, among many others. As such, palm oil plantations have expanded into wildlife habitat throughout Southeast Asia, especially in Borneo and Sumatra, the last remaining habitats of orangutans (<em>Pongo<\/em> <em>spp<\/em>.) and many other species of primates. This, coupled with other local pressures such as hunting and peat fires, resulted in the IUCN upgrading the Borneo orangutan\u2019s (<em>Pongo<\/em> <em>pygmaeus<\/em>) conservation status to Critically Endangered in 2016. Although data suggest that orangutans will nest within agroindustrial environments, they will only do so with natural forest patches nearby (Ancrenaz et al. 2014). Reducing individual consumption of palm oil or choosing sustainable oil products can help reduce the overall demand and drive producers to commit to more environmentally friendly practices. This can hopefully slow the conversion of naturally forested landscapes into agroindustrial environments.<\/p>\n<p class=\"import-Normal\">As previously noted, the proliferation of social media has spurred the desire to photograph animals in close proximity (Pearce and Moscardo 2015). We recommend that readers who visit native primate environments resist engaging with primates in an attempt to take \u201cselfies\u201d with animals. Repeated encounters with travelers and tourists can overhabituate primates and put them in danger of contracting (and transmitting) diseases (Geffroy et al. 2015). Paying for photos with primates can also exacerbate the illegal pet trade because local people will be incentivized to harvest primate infants from wild populations, adversely affecting primate densities and social group dynamics. While it may be popular to try to take the most engaging \u201cselfie\u201d with a wild animal, it is best to just admire these animals from afar (Figure B.16).<\/p>\n<p>&nbsp;<\/p>\n<figure style=\"width: 441px\" class=\"wp-caption aligncenter\"><img class=\"\" src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image16-6.jpg\" alt=\"Four students looking up, pointing, and using binoculars.\" width=\"441\" height=\"294\" \/><figcaption class=\"wp-caption-text\">Figure B.16: Students on a field course observe and record data on primates in the canopy at El Zota field station in Costa Rica. Credit: Students in the canopy at El Zota field station, Costa Rica, by Mary P. Dinsmore, courtesy of <a class=\"rId52\" href=\"https:\/\/www.gobroadreach.com\/\">Broadreach Global Summer Adventures, Inc.<\/a>, is used by permission and available here under a <a class=\"rId53\" href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/\">CC BY-NC 4.0 License<\/a>.<\/figcaption><\/figure>\n<p class=\"import-Normal\">Lastly, readers can aid in primate conservation by resisting sharing social media videos depicting primates in nonnative habitats. Videos of primates engaging with humans often spark the popularity of these animals as pets. The desire for these animals can lead to an influx in illegal pet harvesting and trading, the mistreatment of wild animals in domestic settings, and the belief that these animals are not endangered since others own them as pets (Nekaris et al. 2013). Educating one\u2019s self and others, coupled with a refusal to share these \u2018cute\u2019 videos, can help reduce the market for primates to be captured for the illegal pet trade.<\/p>\n<\/div>\n<h2 class=\"import-Normal\">Further Perspectives<\/h2>\n<p class=\"import-Normal\">As anthropogenic and natural disturbances continue to intensify in range and scale, the future status of the world\u2019s primates is increasingly dire. However, researchers, conservationists, and the general public are attempting to understand how primates respond to these disturbances, what actions can be done to mitigate further disturbances, how to establish sustainable relationships between humans and primates, and what small actions each individual can do to aid these processes.<\/p>\n<p class=\"import-Normal\">Regardless of our cultural or political views, we think it is valid to ask ourselves as researchers, conservationists, and students: What is the value of Earth\u2019s biological diversity, and what are our obligations to nonhuman primates, our closest living ancestors? Although scientists and conservationists often argue that there is inherent value in maintaining the world\u2019s biodiversity, we propose that primates have a special significance that goes beyond their intrinsic contribution to biodiversity. The concept that species and systems can provide a suite of benefits to humans is known as ecosystem services (Cardinale et al. 2012; Kremen 2005). These services are often classified into four categories: provisioning (e.g., food), regulating (e.g., water-quality regulating), cultural (e.g., recreation and aesthetic), and supporting services (e.g., nutrient cycling) (Harrison et al. 2014; Mace et al. 2011; Millennium Ecosystem Assessment 2005). Following this approach, we propose that understanding the value of primates and their habitats in terms of their ecological, bioanthropological, cultural\u2013historical, and economic contributions can aid in the long-term conservation of these endangered species. Recognizing the connections and continuities between ourselves and other primates is the first critical step toward caring about their future and making it part of our own.<\/p>\n<div class=\"textbox shaded\">\n<h2 class=\"import-Normal\">Review Questions <strong><br \/>\n<\/strong><\/h2>\n<ul>\n<li class=\"import-Normal\">What criteria do researchers and conservationists use to identify the conservation status of primate populations and species?<\/li>\n<li class=\"import-Normal\">What are the main threats facing primates today, and how do the combined impacts of these threats uniquely affect primates?<\/li>\n<li class=\"import-Normal\">What do you think a world without primates would look like? Consider their unique significance and the various roles they play in ecology, human evolutionary and cultural history, and local economies. How would the absence of primates affect ecosystems, other animals, and humans?<\/li>\n<li class=\"import-Normal\">Considering all the other problems in the world today, should primate conservation be a high priority? What are the arguments to support prioritizing primate conservation?<\/li>\n<li class=\"import-Normal\">How can you contribute to primate conservation in your everyday life?<\/li>\n<\/ul>\n<\/div>\n<h2 class=\"import-Normal\">About the Authors <strong><br \/>\n<\/strong><\/h2>\n<p class=\"import-Normal\" data-wp-editing=\"1\"><img class=\"alignleft\" src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image1-7.jpg\" alt=\"A woman with blond hair smiles at the camera.\" width=\"249\" height=\"320\" \/><\/p>\n<h3 class=\"import-Normal\"><strong>Mary P. Dinsmore, Ph.D<\/strong><\/h3>\n<p class=\"import-Normal\">Loyola University Chicago, <a class=\"rId55\" href=\"mailto:mdinsmore@luc.edu\">mdinsmore@luc.edu<\/a><\/p>\n<p class=\"import-Normal\">Mary P. Dinsmore, Ph.D. is an Assistant Teaching Professor in the School of Environmental Sustainability at Loyola University Chicago. Mary\u2019s interest in primatology began when she was working as a research assistant in Peru with saddleback tamarins (<em>Saguinus fuscicollis<\/em>) and in Madagascar with greater bamboo lemurs (<em>Prolemur simus<\/em>). It was during these experiences that she saw firsthand the immense impacts that humans had on primate habitats and became interested in human-wildlife conflict and conservation. Her dissertation work explored the consequences of anthropogenic and natural disturbances on the habitat and behavior of the northern sportive lemur (<em>Lepilemur septentrionalis<\/em>). She received funding for her work from the Primate Action Fund of Conservation International and African Studies Department of UW\u2013Madison.<\/p>\n<p class=\"import-Normal\">Mary received her BS and BA from the University of Portland in 2009, her MS from the University of Wisconsin\u2013Madison in 2014, and her Ph.D. from the University of Wisconsin-Madison in 2020. She currently teaches courses at Loyola University Chicago on Biodiversity and Biogeography, Mammalogy, and Human Dimensions of Conservation.<\/p>\n<p class=\"import-Normal\"><img class=\"alignleft\" src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image4-8.png\" alt=\"A woman with black hair holds a small mammal wearing gloves.\" width=\"225\" height=\"300\" \/><\/p>\n<h3 class=\"import-Normal\"><strong>Ilianna E. Anise, M.S.<\/strong><\/h3>\n<p class=\"import-Normal\">University of Wisconsin\u2013Madison, ilianna.anise@wisc.edu<\/p>\n<p class=\"import-Normal\">Ilianna E. Anise received her M.S. in Integrative Biology at the University of Wisconsin\u2013Madison in 2022. In her masters research, she used social network analysis to detect the timing of a group fission using behavioral data that had been collected on wild northern muriquis and considered the implications of this method for conservation management. During the writing of the first edition of this appendix, she was supported by an Advanced Opportunity Fellowship, the Department of Integrative Biology, and Teaching Assistantships at University of Wisconsin-Madison.<\/p>\n<p class=\"import-Normal\">Ilianna received her BA in biology and environmental science from Drew University. She found her passion for fieldwork while participating in a small mammal demography research project as an undergraduate student.<\/p>\n<p class=\"import-Normal\"><img class=\"alignleft wp-image-558\" src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/rebekah_ellis_headshot_2019-768x548-1.jpg\" alt=\"A woman with blond hair smiles.\" width=\"225\" height=\"161\" \/><\/p>\n<h3 class=\"import-Normal\"><strong>Rebekah J. Ellis, M.S.<\/strong><\/h3>\n<p class=\"import-Normal\">Rebekah J. Ellis received her M.S degree from the Department of Anthropology at the University of Wisconsin\u2013Madison. Rebekah received her BA in anthropology and psychology from the University of Texas at Austin. She has studied the behavior of neotropical primates at field sites in Eastern Costa Rica and the Ecuadorian Amazon. At her time at UW\u2013Madison, Rebekah assisted in teaching an introductory course covering the subdisciplines of cultural, archeological, and biological anthropology and her research utilized social network analysis to explore the social behavior of neotropical primates.<\/p>\n<p class=\"import-Normal\"><img class=\"alignleft\" src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image7-14.png\" alt=\"A man with glasses and a full beard smiles and looks off to the side.\" width=\"225\" height=\"338\" \/><\/p>\n<h3 class=\"import-Normal\"><strong>Jacob B. Kraus, B.A., Ph.D. student<\/strong><\/h3>\n<p class=\"import-Normal\">University of Wisconsin\u2013Madison, <a class=\"rId59\" href=\"mailto:jbkraus2@wisc.edu\">jbkraus2@wisc.edu<\/a><\/p>\n<p class=\"import-Normal\">Jacob B. Kraus is a Ph.D. candidate and teaching assistant in the Department of Integrated Biology at the University of Wisconsin\u2013Madison and a member of the Strier Lab. His interest in primatology began while studying the ecology and behavior of Gelada monkeys (<em>Theropithecus gelada<\/em>) as a field assistant for the Guassa Gelada Research Project (GGRP) in Ethiopia. He is broadly interested in the behavioral thermoregulation strategies that primates, and other social mammals, employ in high-altitude habitats. Jacob\u2019s current research is focused on how the sociality of Yunnan snub-nosed monkeys (<em>Rhinopithecus bieti<\/em>) affects their microhabitat selection and grooming behaviors. His work has been funded by the Department of Integrative Biology.<\/p>\n<p class=\"import-Normal\">Jacob received his BA in Biology from Reed College. Prior to attending UW\u2013Madison, Jacob interned at the Smithsonian Conservation Biology Institute (SCBI), where he worked on various remote-sensing and habitat-survey projects.<\/p>\n<p class=\"import-Normal\"><img class=\"alignleft\" src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image12-10.png\" alt=\"A woman with glasses and brown hair smiles at the camera.\" width=\"213\" height=\"300\" \/><\/p>\n<h3 class=\"import-Normal\"><strong>Karen B. Strier, Ph.D.<\/strong><\/h3>\n<p class=\"import-Normal\">University of Wisconsin\u2013Madison, <a class=\"rId61\" href=\"mailto:kbstrier@wisc.edu\">kbstrier@wisc.edu<\/a><\/p>\n<p class=\"import-Normal\"><a class=\"rId62\" href=\"https:\/\/strierlab.anthropology.wisc.edu\/\">https:\/\/strierlab.anthropology.wisc.edu\/<\/a><\/p>\n<p class=\"import-Normal\">Karen B. Strier is Vilas Research Professor and Irven DeVore Professor of Anthropology at the University of Wisconsin\u2013Madison. She received her BA (1980) from Swarthmore College, and MA (1981) and PhD (1986) from Harvard University. She has been studying the endangered northern muriqui monkey in the Brazilian Atlantic forest since 1982. She is a fellow of the U.S. National Academy of Sciences, the American Academy of Arts and Sciences, and the American Association for the Advancement of Science. She was awarded an Honorary Doctorate of Science from the University of Chicago and Distinguished Primatologist Awards from the American Primatological Society and the Midwestern Primate Interest Group. She has received various research, teaching, and service awards from the University of Wisconsin\u2013Madison. She holds Lifetime Honorary Memberships from the Brazilian Primatological Society, the Latin American Primatological Society, the Margot Marsh Biodiversity Foundation Award for Excellence in Primate Conservation, and the Premio Muriqui from the Reserva Biosfera da Mata Atlantica. She has authored or coauthored more than 100 publications; and authored two books, including <em>Primate Behavioral Ecology, 6th edition <\/em>(2021b). She served as the President of the International Primatological Society from 2016 to 2022.<\/p>\n<h2 class=\"import-Normal\">For Further Exploration <strong><br \/>\n<\/strong><\/h2>\n<p>For those interested in gaining hands-on experience with primates, we recommend visiting Primate Info Net, where a list of field school opportunities and professional, educational, and volunteer positions are posted regularly. These listings can be found <a href=\"https:\/\/primate.wisc.edu\/primate-info-net\/the-pin-career-groups-jobs-volunteer-opportunities-degree-and-other-programs\/\">here<\/a>:<\/p>\n<p>To learn more about reducing the spread of potentially harmful images of primates, access <a href=\"https:\/\/humanprimateinteractions.files.wordpress.com\/2022\/06\/6b42c-hpi-imagery-guidelines.pdf\"><em>Best Practice Guidelines for Responsible Images of Non-Human Primates<\/em><\/a>, written by The Primate Specialist Group of the International Union for the Conservation of Nature (IUCN):<\/p>\n<h2 class=\"import-Normal\">References<\/h2>\n<p class=\"import-Normal\">Aguilera, Bernardo, Javiera Perez Gomez, and David DeGrazia. 2021. \u201cShould Biomedical Research with Great Apes Be Restricted? A Systematic Review of Reasons.\u201d <em>BMC Medical Ethics<\/em> 22. doi: https:\/\/doi.org\/10.1186\/s12910-021-00580-z.<\/p>\n<p class=\"import-Normal\">Alves, R\u00f4mulo Romeu N\u00f3brega, Raynner Rilke Duarte Barboza, and Wedson de Medeiros Silva Souto. 2017. \u201cPrimates in Mythology.\u201d In <em>The International Encyclopedia of Primatology<\/em>, edited by Agust\u00edn Fuentes, 1149\u20131154. Hoboken, NJ: John Wiley and Sons. https:\/\/doi.org\/10.1002\/9781119179313.wbprim0173.<\/p>\n<p class=\"import-Normal\">Ancrenaz, Marc, Felicity Oram, Laurentius Ambu, Isabelle Lackman, Eddie Ahmad, Hamisah Elahan, Harjinder Kler, Nicola K. Abram, and Erik Meijaard. 2014. \u201cOf Pongo, Palms, and Perceptions: A Multidisciplinary Assessment of Bornean Orangutans <em>Pongo<\/em> <em>pygmaeus<\/em> in an Oil Palm Context.\u201d <em>Oryx<\/em> 49 (3): 465\u2013472. https:\/\/doi.org\/10.1017\/S0030605313001270.<\/p>\n<p class=\"import-Normal\">Archabald, Karen, and Lisa Naughton-Treves. 2001. \u201cTourism Revenue-Sharing around National Parks in Uganda: Early Efforts to Identify and Reward Local Communities.\u201d <em>Environmental<\/em> <em>Conservation<\/em> 28 (2): 135\u2013149. https:\/\/doi.org\/10.1017\/S0376892901000145.<\/p>\n<p class=\"import-Normal\">Bachmann, Mona Estrella, Martin Reinhardt Nielsen, Heather Cohen, Dagmar Haase, Joseph A. K. Kouassi, Roger Mundry, and Hjalmar S. Kuehl. 2020. \u201cSaving Rodents, Losing Primates: Why We Need Tailored Bushmeat Management Strategies.\u201d <em>People and Nature<\/em> 2: 889\u2013902. https:\/\/doi.org\/10.1002\/pan3.10119.<\/p>\n<p class=\"import-Normal\">Bailey, Carolyn A., Timothy M. Sefczek, Brittani A. D. Robertson, Lucile Rasoamazava, Val\u00e9rie F. Rakotomalala, Jean D. N. Andriamadison, Fran\u00e7ois Randrianasolo,<\/p>\n<p class=\"import-Normal\">Aubin Andriajaona, and Edward E. Louis, Jr. 2020. \u201cA Re-evaluation of the Northern Sportive Lemur (<em>Lepilemur septentrionalis<\/em>) Population at Montagne des Fran\u00e7ais, and a Review of Its Current State of Conservation in the Protected Area.\u201d <em>Primate Conservation<\/em> 34: 53\u201359.<\/p>\n<p class=\"import-Normal\">Bermejo, Magdalena, Jose Domingo Rodriguez-Teijeiro, German Illera, and Peter D. Walsh. 2006. \u201cEbola Outbreak Killed 5,000 Gorillas.\u201d <em>Science <\/em>314 (5805): 1564. https:\/\/doi.org\/10.1126\/science.1133105.<\/p>\n<p class=\"import-Normal\">Bernard, Andrew M., and Andrew J. Marshall. 2020. \u201cAssessing the State of Knowledge of Contemporary Climate Change and Primates.\u201d <em>Evolutionary Anthropology<\/em> 29 (6): 317\u2013331. https:\/\/doi.org\/10.1002\/evan.21874.<\/p>\n<p class=\"import-Normal\">Biquand, S., A. Boug, V. Biquand-Guyot, and J. P. Gautier. 1994. \u201cManagement of Commensal Baboons in Saudi Arabia.\u201d <em>Revue d\u2019Ecologie, Terre et Vie, Soci\u00e9t\u00e9 nationale de protection de la nature<\/em> 49 (3): 213\u2013222.<\/p>\n<p class=\"import-Normal\">Blount, J. David., Mark W. Chynoweth, Austin M. Green, and \u00c7a\u011fan H. \u015eekercio\u011flu. 2021.<\/p>\n<p class=\"import-Normal\">\u201cReview: COVID-19 Highlights the Importance of Camera Traps for Wildlife Conservation Research and Management.\u201d<em> Biological Conservation<\/em> 256: 108984. https:\/\/doi.org\/10.1016\/j.biocon.2021.108984.<\/p>\n<p class=\"import-Normal\">Brito, Daniel, Carlos E. V. Grelle, and Jean Phillipe Boubli. 2008. \u201cIs the Atlantic Forest Protected Area Network Efficient in Maintaining Viable Populations of\u00a0<em>Brachyteles hypoxanthus<\/em>?\u201d <em>Biodiversity and Conservation <\/em>17 (13): 3255\u20133268. https:\/\/doi.org\/10.1007\/s10531-008-9427-z.<\/p>\n<p class=\"import-Normal\" style=\"background-color: #ffffff; color: #ffffff;\"><span style=\"color: #000000;\">Brook, Barry W., Navjot S. Sodhi, and Corey J. A. Bradshaw. 2008. \u201cSynergies among Extinction Drivers under Global Change.\" <em>Trends in Ecology and Evolution <\/em>23 (8): 453\u2013460. https:\/\/doi.org\/<a class=\"rId65\" style=\"color: #000000;\" href=\"https:\/\/doi.org\/10.1016\/j.tree.2008.03.011\">10.1016\/j.tree.2008.03.011<\/a>.<\/span><\/p>\n<p class=\"import-Normal\">Brown, Jason L., and Anne D. Yoder. 2015. \u201cShifting Ranges and Conservation Challenges for Lemurs in the Face of Climate Change.\u201d <em>Ecology and Evolution <\/em>5 (6): 1131\u20131142. https:\/\/doi.org\/10.1002\/ece3.1418.<\/p>\n<p class=\"import-Normal\">Campos, Fernando A., William F. Morris, Susan C. Alberts, Jeanne Altmann, Diane K. Brockman, Marina Cords, Anne Pusey, Tara S. Stoinski, Karen B. Strier, and Linda M. Fedigan. 2017. \u201cDoes Climate Variability Influence the Demography of Wild Primates? Evidence from Long-Term Life-History Data in Seven Species.\" <em>Globe Change Biology <\/em>23 (11): 1\u201315. https:\/\/doi.org\/10.1111\/gcb.13754.<\/p>\n<p class=\"import-Normal\">Cardinale, B. J., J. Emmett Duffy, Andrew Gonzalez, David U. Hopper, Charles Perrings, Patrick Venail, Anita Narwani, et al. 2012. \u201cBiodiversity Loss and Its Impact on Humans.\u201d <em>Nature <\/em>486 (7401): 59\u201367. https:\/\/doi.org\/10.1038\/nature11148.<\/p>\n<p class=\"import-Normal\">Carlson, Kimberly M., Lisa M. Curran, Dessy Ratnasari, Alice M. Pittman, Britaldo S. Soares-Filho, Gregory P. Asner, Simon N. Trigg, David A. Gaveau, Deborah Lawrence, and Herman O. Rodrigues. 2012. \u201cCommitted Carbon Emissions, Deforestation, and Community Land Conversion from Oil Palm Plantation Expansion in West Kalimantan, Indonesia.\u201d <em>Proceedings of the National Academy of Sciences<\/em> 109 (19): 7559\u20137564. https:\/\/doi.org\/10.1073\/pnas.1200452109.<\/p>\n<p class=\"import-Normal\">Casal, Paula, and Peter Singer. 2021. \u201cThe Threat of Great Ape Extinction from COVID-19.\u201d <em>Journal of Animal Ethics <\/em>11 (2): 6\u201311. https:\/\/doi.org\/10.5406\/janimalethics.11.2.0006.<\/p>\n<p class=\"import-Normal\">Chapman, Colin A., and Carlos A. Peres. 2001. \u201cPrimate Conservation in the New Millennium: The Role of Scientists.\u201d <em>Evolutionary Anthropology<\/em> 10 (1): 16\u201333. https:\/\/doi.org\/10.1002\/1520-6505(2001)10:1&lt;16::AID-EVAN1010&gt;3.0.CO;2-O.CITES. N.d. \u201cCITES Trade Database.\u201d Accessed July 22, 2018. https:\/\/trade.cites.org\/en\/cites_trade\/#.<\/p>\n<p class=\"import-Normal\">Clark, Natalie E., Elizabeth H. Boakes, Philip J. K. McGowan, Georgina M. Mace, and Richard A. Fuller. 2013. \u201cProtected Areas in South Asia Have Not Prevented Habitat Loss: A Study Using Historical Models of Land-Use Change.\u201d <em>PLoS ONE<\/em> 8 (5):e65298. https:\/\/doi.org\/10.1371\/journal.pone.0065298.<\/p>\n<p class=\"import-Normal\">Clarke, Tara A., Kim E. Reuter, Marni LaFleur, and Melissa S. Schaefer. 2019. \u201cA Viral Video and Pet Lemurs on Twitter.\u201d<em> PLoS ONE<\/em> 14(1): e0208577. https:\/\/doi.org\/10.1371\/journal.pone.0208577.<\/p>\n<p class=\"import-Normal\">Clauzel, Celine, Deng Xiqing, Wu Gongsheng, Patrick Giraudoux, and Li Li. 2015. \u201cAssessing the Impact of Road Developments on Connectivity across Multiple Scales: Application to Yunnan Snub-Nosed Monkey Conservation.\u201d <em>Biological Conservation<\/em> 192: 207\u2013217. https:\/\/doi.org\/10.1016\/j.biocon.2015.09.029.<\/p>\n<p class=\"import-Normal\">Conaway, Eileen. 2011. \u201cBioidentical Hormones: An Evidence-Based Review for Primary Care Providers.\u201d <em>The Journal of the American Osteopathic Association<\/em> 111 (3): 153\u2013164.<\/p>\n<p class=\"import-Normal\">Corbett, Kizzmekia S., Barbara Flynn, Kathryn E. Foulds, Joseph R. Francica, Seyhan Boyoglu-Barnum, Anne P. Werner, Britta Flach, et al. 2020. \u201cEvaluation of the mRNA-1273 Vaccine against SARS-CoV-2 in Nonhuman Primates.\u201d <em>The New England Journal of Medicine<\/em> 383: 1544\u20131555. https:\/\/doi.org\/10.1056\/NEJMoa2024671.<\/p>\n<p class=\"import-Normal\">Cormier, Loretta A. 2003. <em>Kinship with Monkeys: The Guaj\u00e1 Foragers of Eastern Amazonia. <\/em>New York: Columbia University Press.<\/p>\n<p class=\"import-Normal\">Cormier, Loretta A. 2017. \u201cPrimates in Folklore.\u201d In <em>The International Encyclopedia of Primatology<\/em>, edited by Agust\u00edn Fuentes, 1139\u20131146. Hoboken, NJ: John Wiley and Sons. https:\/\/doi.org\/10.1002\/9781119179313.wbprim0285.<\/p>\n<p class=\"import-Normal\">Covey, Ryan, and W. Scott McGraw. 2014. \u201cMonkeys in a West African Bushmeat Market: Implications for Cercopithecid Conservation in Eastern Liberia.\u201d <em>Tropical Conservation Science<\/em> 7 (1): 115\u2013125. https:\/\/doi.org\/10.1177\/194008291400700103.<\/p>\n<p class=\"import-Normal\">Cronin, Drew T., Stephen Woloszynek, Wayne A. Morra, Shaya Honarvar, Joshua M. Linder, Mary Katherine Gonder, Michael P. O\u2019Connor, and Gail W. Hearn. 2015. \u201cLong-term Urban Market Dynamics Reveal Increased Bushmeat Carcass Volume Despite Economic Growth and Proactive Environmental Legislation on Bioko Island, Equatorial Guinea.\u201d <em>PLoS ONE<\/em> 10 (7): e0134464. https:\/\/doi.org\/10.1371\/journal.pone.0134464.<\/p>\n<p class=\"import-Normal\">Dinsmore, Mary P., Edward E. Louis Jr., Daniel Georges Randriamahazomana, Ali Hachim, John R. Zaonarivelo, and Karen B. Strier. 2016. \u201cVariation in Habitat and Behavior of the Northern Sportive Lemur (<em>Lepilemur septentrionalis<\/em>) at Montagne des Fran\u00e7ais, Madagascar.\u201d <em>Primate Conservation<\/em> 30: 73\u201388.<\/p>\n<p class=\"import-Normal\">Dinsmore, Mary P., Karen B. Strier, and Edward E. Louis Jr. 2018. \u201cThe Impacts of Cyclone Enawo and Anthropogenic Disturbances on the Habitat of Northern Sportive Lemurs (<em>Lepilemur<\/em> <em>septentrionalis<\/em>) in Northern Madagascar.\u201d <em>American Journal of Physical Anthropology<\/em> 165 (2): 68.<\/p>\n<p class=\"import-Normal\">Dinsmore, Mary P., Karen B. Strier, and Edward E. Louis Jr. 2021a. \u201cAnthropogenic Disturbances and Deforestation of Northern Sportive Lemur (<em>Lepilemur septentrionalis<\/em>) Habitat at Montagne des Fran\u00e7ais, Madagascar.\u201d <em>Primate Conservation<\/em> 35: 125\u2013138.<\/p>\n<p class=\"import-Normal\">Dinsmore, Mary P., Karen B. Strier, and Edward E. Louis Jr. 2021b. \u201cThe Influence of Seasonality, Anthropogenic Disturbances, and Cyclonic Activity on the Behavior of Northern Sportive Lemurs (<em>Lepilemur septentrionalis<\/em>) at Montagne des Fran\u00e7ais, Madagascar.\u201d American Journal of Primatology 83: e23333. https:\/\/doi.org\/10.1002\/ajp.23333.<\/p>\n<p class=\"import-Normal\">Eppley, Timothy M., Giuseppe Donati, Jean Baptiste Ramanamanjato, Faly Randriatafika, Laza N. Andriamandimbiarisoa, David Rabehevitra, Robertin Ravelomanantsoa, and J\u00f6rg U. Ganzhorn. 2015. \u201cThe Use of an Invasive Species Habitat by a Small Folivorous Primate: Implications for Lemur Conservation in Madagascar.\u201d <em>PLoS ONE<\/em> 10 (11): e0140981. https:\/\/doi.org\/10.1371\/journal.pone.0140981.<\/p>\n<p class=\"import-Normal\">Eppley, Timothy M., Selwyn Hoeks, Colin A. Chapman, J\u00f6rg U. Ganzhorn, Katie Hall, Megan E. Owen, Dara B. Adams, et al. 2022. \u201cFactors influencing terrestriality in primates of the Americas and Madagascar.\u201d PNAS 119 (42): e2121105119. https:\/\/doi.org\/10.1073\/pnas.2121105119.<\/p>\n<p class=\"import-Normal\">Estrada, Alejandro, Paul A. Garber, Russell A. Mittermeier, Serge Wich, Sidney Gouveia, Ricardo Dobrovolski, K. A. I. Nekaris, et al. 2018. \u201cPrimates in Peril: The Significance of Brazil, Madagascar, Indonesia, and the Democratic Republic of the Congo for Global Primate Conservation.\u201d <em>PeerJ<\/em> 6: e4869. https:\/\/doi.org\/10.7717\/peerj.4869.<\/p>\n<p class=\"import-Normal\">Estrada, Alejandro, Paul A. Garber, Anthony B. Rylands, Christian Roos, Eduardo Fernandez-Duque, Anthony Di Fiore, K. Anne-Isola Nekaris, et al. 2017. \u201cImpending Extinction Crisis of the World\u2019s Primates: Why Primates Matter.\u201d <em>Science Advances<\/em> 3 (229): 1\u201316. https:\/\/doi.org\/10.1126\/sciadv.1600946.<\/p>\n<p class=\"import-Normal\">Farias, Izeni P., Wancley G. Santos, Marcelo Gordo, and Tomas Hrbek. 2015. \u201cEffects of Forest Fragmentation on Genetic Diversity of the Critically Endangered Primate, the Pied Tamarin (<em>Saguinus<\/em> <em>Bicolor<\/em>): Implications for Conservation.\u201d <em>Journal of Heredity<\/em> 106 (S1): 512\u2013521. https:\/\/doi.org\/10.1093\/jhered\/esv048.<\/p>\n<p class=\"import-Normal\">Fennell, David, and David Weaver. 2005. \u201cThe Ecotourium Concept and Tourism-Conservation Symbiosis.\u201d <em>Journal<\/em> <em>of<\/em> <em>Sustainable<\/em> <em>Tourism<\/em> 13(4): 373\u2013390. https:\/\/doi.org\/10.1080\/09669580508668563.<\/p>\n<p class=\"import-Normal\">Fernandes, Natalia C. C. A., Mariana Sequetin Cunha, Juliana Mariotti Guerra, Rodrigo Albergaria Ressio, Cinthya dos Santos Cirqueira, Silvia D\u2019Andretta Iglezias, Julia de Carvalho, Emerson L. L. Aruajo, Jose-Luiz Catao-Dias, and Josue Diaz-Delgado. 2017. \u201cOutbreak of Yellow Fever among Nonhuman Primates, Espirito Santo, Brazil, 2017.\u201d <em>Emerging Infectious Diseases <\/em>23 (12): 2038\u20132041. https:\/\/doi.org\/10.3201\/eid2312.170685.<\/p>\n<p class=\"import-Normal\">Fern\u00e1ndez, David, Daphne Kerhoas, Andrea Dempsey, Josephine Billany, Gr\u00e1inne McCabe, and Elitsa Argirova. 2022. \u201cThe Current Status of the World\u2019s Primates: Mapping Threats to Understand Priorities.\u201d <em>International Journal of Primatology<\/em> 433: 15\u201339. https:\/\/doi.org\/10.1007\/s10764-021-00242-2.<\/p>\n<p class=\"import-Normal\">Fragaszy, Dorothy, Patr\u00edcia Izar, Elisabetta Visalberghi, Eduardo B. Ottoni, and Marino Gomes de Oliveira. 2004. \u201cWild Capuchin Monkeys (<em>Cebus libidinosus<\/em>) Use Anvils and Stone-Pounding Tools.\u201d <em>American Journal of Primatology<\/em> 64 (4): 359\u2013366. https:\/\/doi.org\/10.1002\/ajp.20085.<\/p>\n<p class=\"import-Normal\">Fuentes, Agust\u00edn. 2010. \u201cNatural Cultural Encounters in Bali: Monkeys, Temples, Tourists, and Ethnoprimatology.\u201d <em>Cultural Anthropology<\/em> 25 (4): 600\u2013624. https:\/\/doi.org\/10.1111\/j.1548-1360.2010.0170.x<\/p>\n<p class=\"import-Normal\">Fuentes, Agust\u00edn. 2012. \u201cEthnoprimatology and the Anthropology of the Human-Primate Interface.\u201d <em>Annual Review of Anthropology<\/em> 41: 101\u2013117. https:\/\/doi.org\/10.1148\/annurev-anthro-092611-145808.<\/p>\n<p class=\"import-Normal\">Fuller, Grace, Wilhelmina Frederica Eggen, Wirdateti Wirdateti, and K. A. I. Nekaris. 2018. \u201cWelfare Impacts of the Illegal Wildlife Trade in a Cohort of Confiscated Greater Slow Lorises, Nycticebus Coucang.\u201d <em>Journal of Applied Animal Welfare Science<\/em> 21 (3): 224\u2013238. https:\/\/doi.org\/10.1080\/10888705.2017.1393338.<\/p>\n<p class=\"import-Normal\">Geffroy, Benjamin, Diogo S. M. Samia, Eduardo Bessa, and Daniel T. Blumstein. 2015. \u201cHow Nature-Based Tourism Might Increase Prey Vulnerability to Predators.\u201d <em>Trends in Ecology &amp; Evolution<\/em> 30 (12): 755\u2013765.<\/p>\n<p class=\"import-Normal\">Gilpin, Michael E., and Michael E. Soul\u00e9. 1986. \u201cMinimum Viable Populations: Processes of Species Extinction.\u201d In\u00a0<em>Conservation Biology: The Science of Scarcity and Diversity<\/em>, edited by Michael E. Soul\u00e9, 19\u201334. Sunderland, UK: Sinauer and Associates.<\/p>\n<p class=\"import-Normal\">Groves, Colin P. 2014. \u201cPrimate Taxonomy: Inflation or Real?\u201d <em>Annual Review of Anthropology<\/em> 43: 27\u201336. https:\/\/doi.org\/10.1146\/annurev-anthro-102313-030232.<\/p>\n<p class=\"import-Normal\">Hai, Bach Thanh, Jin Chen, Kim R. McConkey, and Salindra K. Dayananda. 2018. \u201cGibbons (<em>Nomascus<\/em> <em>gabriellae<\/em>) Provide Key Seed Dispersal for the Pacific Walnut (<em>Dracontomelon<\/em> <em>dao<\/em>), in Asia\u2019s Lowland Tropical Forest.\u201d <em>Acta<\/em> <em>Oecologica<\/em> 88: 71\u201379. https:\/\/doi.org\/10.1016\/j.actao.2018.03.011.<\/p>\n<p class=\"import-Normal\">Haraway, Donna. 1991. <em>Simians, Cyborgs, and Women: The Reinvention of Nature<\/em>. New York: Routledge.<\/p>\n<p class=\"import-Normal\">Harrison, P. A., P. M. Barry, G. Simpson, J. R. Haslett, M. Blicharska, M. Bucur, R. Dunford, et al. 2014. \u201cLinkages between Biodiversity Attributes and Ecosystem Services: A Systematic Review.\u201d <em>Ecosystem<\/em> <em>Services<\/em> 9: 191\u2013203. https:\/\/doi.org\/10.1016\/j.ecoser.2014.05.006.<\/p>\n<p class=\"import-Normal\" style=\"background-color: #ffffff; color: #ffffff;\"><span style=\"color: #000000;\">Hockings, Kimberly J. 2016. \u201cMitigating Human-Nonhuman Primate Conflict.\u201d In <em>The International Encyclopedia of Primatology<\/em>, edited by Agust\u00edn Fuentes, 820\u2013828. Hoboken, NJ: John Wiley and Sons. https:\/\/doi.org\/10.1002\/9781119179313.wbprim0053.<\/span><\/p>\n<p class=\"import-Normal\">Horwich, Robert H., and Jonathan Lyon. 2007. \u201cCommunity Conservation: Practitioners\u2019 Answer to Critics.\u201d <em>Oryx<\/em> 41 (3): 376\u2013385. https:\/\/doi.org\/10.1017\/S0030605307001010.<\/p>\n<p class=\"import-Normal\">Horwich, R. H., J. Lyon, and A. Bose. 2012. \u201cPreserving Biodiversity and Ecosystems: Catalyzing Conservation Contagion.\u201d In <em>Deforestation around the World<\/em>, edited by P. Moutinho, 283\u2013318. Rijeka, Croatia: InTech.<\/p>\n<p class=\"import-Normal\">Hosonuma, Noriko, Martin Herold, Veronique de Sy, Ruth S. de Fries, Maria Brockhaus, Louis Verchot, Arild Angelsen, and Erika Romijn. 2012. \u201cAn Assessment of Deforestation and Forest Degradation Drivers in Developing Countries.\u201d <em>Environmental Research Letters<\/em> 7 (4). https:\/\/doi.org\/10.1088\/1748-9326\/7\/4\/044009.<\/p>\n<p class=\"import-Normal\">Hvenegaard, Glen. 2014. \u201cEconomic Aspects of Primate Tourism Associated with Primate Conservation.\u201d In <em>Primate Tourism: A Tool for Conservation<\/em><em>?<\/em>, edited by Anne E. Russon and Janette Wallis, 259\u2013277. Cambridge, UK: Cambridge University Press.<\/p>\n<p class=\"import-Normal\">Inoue-Nakamura, Noriko, and Tetsuro Matsuzawa. 1997. \u201cDevelopment of Stone Tool Use by Wild Chimpanzees (<em>Pan troglodytes<\/em>).\u201d <em>Journal of Comparative Psychology<\/em> 111 (2): 159\u2013173.<\/p>\n<p class=\"import-Normal\">IPCC. 2022. \u201cClimate Change 2022: Impacts, Adaptation and Vulnerability. Contribution of Working Group II to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change,\u201d edited by H.-O. P\u00f6rtner, D. C. Roberts, M. Tignor, E. S. Poloczanska, K. Mintenbeck, A. Alegr\u00eda, M. Craig, S. Langsdorf, S. L\u00f6schke, V. M\u00f6ller, A. Okem, B. Rama. Cambridge<ins>, UK:<\/ins> Cambridge University Press. https:\/\/doi.org\/10.1017\/9781009325844.<\/p>\n<p class=\"import-Normal\">IUCN. 2012. \u201cIUCN Red List Categories and Criteria: Version 3.1.\u201d Technical Report, 32. Gland, Switzerland and Cambridge, UK: IUCN.<\/p>\n<p class=\"import-Normal\">IUCN. 2022.\u00a0\u201cThe\u00a0IUCN Red List of Threatened Species: Version 2021-3.\u201d Accessed June 6, 2022. <a class=\"rId66\" href=\"https:\/\/www.iucnredlist.org\">https:\/\/www.iucnredlist.org<\/a>.<\/p>\n<p class=\"import-Normal\">IUCN SSC Primate Specialist Group. 2022. \u201cGlobal Non-Human Primate Diversity.\u201d Accessed June 6, 2022. <a class=\"rId67\" href=\"https:\/\/www.primate-sg.org\/primate_diversity_by_region\/\">https:\/\/www.primate-sg.org\/primate_diversity_by_region\/<\/a>.<\/p>\n<p class=\"import-Normal\" style=\"background-color: #ffffff; color: #ffffff;\"><span style=\"color: #000000;\">Kalpers, Jos\u00e9, Elizabeth A. Williamson, Martha M. Robbins, Alastair Mcneilage, Augustin Nzamurambaho, Ndakasi Lola, and Ghad Mugiri. 2003. \u201cGorillas in the Crossfire: Population Dynamics of the Virunga Mountain Gorillas over the Past Three Decades.\u201d\u00a0<em>Oryx<\/em>\u00a037 (3): 326\u2013337. https:\/\/doi.org\/10.1017\/S0030605303000589.<\/span><\/p>\n<p class=\"import-Normal\"><span style=\"color: #000000;\">Kappeler, Peter M., and David P.<\/span> Watts. 2012. <em>Long-term Field Studies of Primates<\/em>. New York: Springer.<\/p>\n<p class=\"import-Normal\">Kierulff, M. C. M., C. R. Ruiz-Miranda, P. Procopio de Oliveira, B. B. Beck, A. Martins, J. M. Dietz, D. M. Rambaldi, and A. J. Baker. 2012. \u201cThe Golden Lion Tamarin <em>Leontopithecus rosalia<\/em>: A Conservation Success Story.\u201d <em>International Zoo Yearbook<\/em> 46 (1): 36\u201345. https:\/\/doi.org\/10.1111\/j.1748-1090.2012.00170.x.<\/p>\n<p class=\"import-Normal\">Kremen, Claire. 2005. \u201cManaging Ecosystem Services: What Do We Need to Know about Their Ecology?\u201d <em>Ecology Letters<\/em> 8 (5): 468\u2013479. https:\/\/doi.org\/10.1111\/j.1461-0248.2005.00751.x.<\/p>\n<p class=\"import-Normal\">Kress, John, George E. Schatz, Michael Andrianifahanana, and Hilary Simons Morland. 1994. \u201cPollination of<em> Ravenala madagascariensis<\/em> (<em>Strelitziaceae<\/em>) by Lemurs in Madagascar: Evidence for an Archaic Coevolution System?\u201d <em>American Journal of Botany<\/em> 81 (5): 542\u2013551. https:\/\/doi.org\/10.1002\/j.1537-2197.1994.tb15483.x.<\/p>\n<p class=\"import-Normal\">Krief, Sabrina, Philippe Berny, Francis Gumisiriza, R\u00e9gine Gross, Barbara Demeneix, Jean Baptiste Fini, Colin A. Chapman, Lauren J. Chapman, Andrew Seguya, and John Wasswa. 2017. \u201cAgricultural Expansion as Risk to Endangered Wildlife: Pesticide Exposure in Wild Chimpanzees and Baboons Displaying Facial Dysplasia.\u201d <em>Science of <span style=\"color: #000000;\">the Total Environment<\/span><\/em><span style=\"color: #000000;\"> 598: 647\u2013656. https:\/\/doi.org\/10.1016\/j.scitotenv.2017.04.113.<\/span><\/p>\n<p class=\"import-Normal\" style=\"background-color: #ffffff; color: #ffffff;\"><span style=\"color: #000000;\">Lafferty, Kevin D. 2009. \u201cThe Ecology of Climate Change and Infectious Diseases.\u201d <em>Ecology <\/em>90 (4): 888\u2013900. doi: <a class=\"rId68\" style=\"color: #000000;\" href=\"https:\/\/doi.org\/10.1890\/08-0079.1\">https:\/\/doi.org\/10.1890\/08-0079.1<\/a>.<\/span><\/p>\n<p class=\"import-Normal\" style=\"background-color: #ffffff; color: #ffffff;\"><span style=\"color: #000000;\">Laurance, William F. 2015. \u201cEmerging Threats to Tropical Forests.\u201d <em>Annals of the Missouri Botanical Garden <\/em>100 (3): 159\u2013169. doi: https:\/\/doi.org\/<a class=\"rId69\" style=\"color: #000000;\" href=\"https:\/\/doi.org\/10.3417\/2011087\">10.3417\/2011087<\/a>.<\/span><\/p>\n<p class=\"import-Normal\">Laurance, William F., Gopalasamy Reuben Clements, Sean Sloan, Christine S. O\u2019Connell, Nathan D. Mueller, Miriam Goosem, Oscar Venter, et al. 2014. \u201cA Global Strategy for Road Building.\u201d <em>Nature<\/em> 513 (7517): 229\u2013232. https:\/\/doi.org\/10.1038\/nature13717.<\/p>\n<p class=\"import-Normal\">Lebr\u00e3o, Cynthia, Lana Mignone Viana Rosa, Fernanda P. Paim, Pedro M. Nassar, Hani R. El Bizri, and Felipe Ennes Silva. 2021. \u201cCommunity-Based Ecotourism and Primate Watching as a Conservation Tool in the Amazon Rainforest.\u201d <em>International Journal of Primatology<\/em> 42<strong>: <\/strong>523\u2013527. doi: https:\/\/doi.org\/10.1007\/s10764-021-00226-2.<\/p>\n<p class=\"import-Normal\">Leroy, Eric M., Pierre Rouquet, Pierre Formenty, Sandrine Souquiere, Annelisa Kilbourne, Jean-Marc Froment, Magdalena Bermejo, et al. 2004. \u201cMultiple Ebola Virus Transmission Events and Rapid Decline of Central African Wildlife.\u201d <em>Science <\/em>303 (5656): 387\u2013390. https:\/\/doi.org\/10.1126\/science.1092528.<\/p>\n<p class=\"import-Normal\">Lu, Shuaiyao, Yuan Zhao, Wenhai Yu, Yun Yang, Jiahong Gao, Junbin Wang, Dexuan Kuang, et al. 2020. \u201cComparison of Nonhuman Primates Identified the Suitable Model for COVID-19.\u201d <em>Signal Transduction and Targeted Therapy<\/em> 5<strong>: <\/strong>157. https:\/\/doi.org\/10.1038\/s41392-020-00269-6.<\/p>\n<p class=\"import-Normal\">Lynch Alfaro, Jessica W., Jos\u00e9 de Sousa E. Silva Jr., and Anthony B. Rylands. 2012. \u201cHow Different Are Robust and Gracile Capuchin Monkeys? An Argument for the Use of <em>Sapajus <\/em>and <em>Cebus<\/em>.\u201d <em>American Journal of Primatology<\/em> 74 (4): 273\u2013286. https:\/\/doi.org\/10.1002\/ajp.22007.<\/p>\n<p class=\"import-Normal\">Mace, Georgina M., Ken Norris, and Alastair H. Fitter. 2011. \u201cBiodiversity and Ecosystem Services: A Multilayered Relationship.\u201d <em>Trends in Ecology and Evolution<\/em> 27 (1): 19\u201326. https:\/\/doi.org\/10.1016\/j.tree.2011.08.006.<\/p>\n<p class=\"import-Normal\">Maekawa, Miko, Annette Lanjouw, Eugene Rutagarama, and Douglas Sharp. 2013. \u201cMountain Gorilla Tourism Generating Wealth and Peace in Post-Conflict Rwanda.\u201d <em>Natural Resources Forum<\/em> 37 (2): 127\u2013137. https:\/\/doi.org\/10.1111\/1477-8947.12020.<\/p>\n<p class=\"import-Normal\">Maldonado, Angela M., Vincent Nijman, and Simon K. Bearder. 2009. \u201cTrade in Night Monkeys <em>Aotus<\/em> <em>Spp<\/em>. in the Brazil-Colombia-Peru Tri-Border Area: International Wildlife Trade Regulations Are Ineffectively Enforced.\u201d <em>Endangered Species Research<\/em> 9 (2): 143\u2013149. https:\/\/doi.org\/10.3354\/esr00209.<\/p>\n<p class=\"import-Normal\">McLean, Kevin A., \u200b\u200bAnne M. Trainor, Gregory P. Asner, Margaret C. Crofoot, Mariah E. Hopkins, Christina J. Campbell, Roberta E. Martin, et al. 2016. \u201cMovement Patterns of Three Arboreal Primates in a Neotropical Moist Forest Explained by LiDAR Estimated Canopy Structure.\u201d <em>Landscape Ecology <\/em>31: 1849\u20131862. https:\/\/doi.org\/10.1007\/s10980-016-0367-9.<\/p>\n<p class=\"import-Normal\">Messenger, Ali M., Amber N. Barnes, and Gregory C. Gray. 2014. \u201cReverse Zoonotic Disease Transmission (Zooanthroponosis): A Systematic Review of Seldom-Documented Human Biological Threats to Animals.\u201d <em>PLoS One <\/em>9 (2): e89055. https:\/\/doi.org\/10.1371\/journal.pone.0089055.<\/p>\n<p class=\"import-Normal\">Millenium Ecosystem Assessment. 2005. <em>Ecosystems and Human Well-Being: Synthesis<\/em>. Washington, DC: World Resources Institute.<\/p>\n<p class=\"import-Normal\">Mittermeier, Russel A., Kim E. Reuter, Anthony B. Rylands, Leonardo Jerusalinsky, Christoph Schwitzer, Karen B. Strier, Jonah Ratsimbazafy, and Tatyana Humle, eds. 2022.<em>Primates in Peril: The World\u2019s 25 Most Endangered Primates 2022\u20132023.<\/em> Washington, DCVA: IUCN SSC Primate Specialist Group (PSG), International Primatological Society (IPS), Re:wild.<\/p>\n<p class=\"import-Normal\">Molyneaux, A., E. Hankinson, M. Kaban, M. S. Svensson, S. M. Cheyne, and V. Nijman. 2021. \u201cPrimate Selfies and Anthropozoonotic Diseases: Lack of Rule Compliance and Poor Risk Perception Threatens Orangutans.\u201d <em>Folia Primatologica<\/em> 92: 296\u2013305. https:\/\/doi.org\/10.1159\/000520371.<\/p>\n<p class=\"import-Normal\">Muehlenbein, Michael P., Leigh A. Martinez, Andrea A. Lemke, Laurentius Ambu, Senthilvel Nathan, Sylvia Alsisto, and Rosman Sakong. 2010. \u201cUnhealthy Travelers Present Challenges to Sustainable Primate Ecotourism.\u201d <em>Travel<\/em> <em>Medicine and<\/em> <em>Infectious<\/em> <em>Disease<\/em> 8 (3): 169\u2013175. https:\/\/doi.org\/10.1016\/j.tmaid.2010.03.004.<\/p>\n<p class=\"import-Normal\">Nekaris, Anne-Isola, Nicola Campbell, Tim G. Coggins, E. Johanna Rode, and Vincent Nijman. 2013. \u201cTickled to Death: Analysing Public Perceptions of \u2018Cute\u2019 Videos of Threatened Species (Slow Loris\u2013<em>Nycticebus<\/em> <em>spp<\/em>.) on Web 2.0 Sites.\u201d <em>PLoS<\/em> <em>ONE<\/em> 8(7): e69215. https:\/\/doi.org\/10.1371\/journal.pone.0069215.<\/p>\n<p class=\"import-Normal\">Norconk, Marilyn A., Sylvia Atsalis, Gregg Tully, Ana Maria Santillan, Si\u00e2n Waters, Cheryl D. Knott, Stephan R. Ross, Sam Shanee, and Daniel Stiles. 2019. \u201cReducing the Primate Pet Trade: Actions of Primatologists.\u201d <em>American Journal of Primat<\/em>ology 82: e23079. https:\/\/doi.org\/10.1002\/ajp.23079.<\/p>\n<p class=\"import-Normal\">Noss, Andrew J. 1998. \u201cThe Impacts of Cable Snare Hunting on Wildlife Populations in the Forests of the Central African Republic.\u201d <em>Conservation Biology<\/em> 12 (2): 390\u2013398.<\/p>\n<p class=\"import-Normal\">Nunn, Charles L., and Sonia Altizer. 2006. <em>Infectious Diseases in Primates. <\/em>Oxford, UK: Oxford University Press.<\/p>\n<p class=\"import-Normal\">Nunn, Charles L., and Thomas R. Gillespie. 2016. \u201cInfectious Disease and Primate Conservation.\u201d In <em>An Introduction to Primate Conservation<\/em>, edited by Serge A. Wich and Andrew J. Marshall, 157\u2013174. Oxford, UK: Oxford University Press.<\/p>\n<p class=\"import-Normal\">Osei-Tutu, Paul. 2017. \u201cTaboos as Informal Institutions of Local Resource Management in Ghana: Why They Are Complied With or Not.\u201d <em>Forest Policy and Economics<\/em> 85 (1): 114\u2013123. https:\/\/doi.org\/10.1016\/j.forpol.2017.09.009.<\/p>\n<p class=\"import-Normal\">Oude Munnink, Bas B., Reina S. Sikkema, David F. Nieuwenhuijse, Robert Jan Molenaar, Emmanuelle Munger, Richard Molenkamp, Arco van der Spek, et al. 2021. \u201cTransmission of SARS-CoV-2 on Mink Farms Between Humans and Mink and Back to Humans.\u201d <em>Science <\/em>371 (6525): 172\u2013177. https:\/\/doi.org\/10.1126\/science.abe5901.<\/p>\n<p class=\"import-Normal\">Pearce, John, and Gianna Moscardo. 2015. \u201cSocial Representations of Tourist Selfies: New Challenges for Sustainable Tourism.\u201d In <em>BEST EN Think Tank X, The Environment-People Nexus in Sustainable Tourism: Finding the Balance<\/em>,\u00a0<ins> <\/ins>59\u201373. BEST EN Think Tank XV, 17\u201321 June 2015, Skukuza, Mpumalanga, South Africa.<\/p>\n<p class=\"import-Normal\">Pebsworth, Paula A., and Marni LaFleur. 2014. \u201cAdvancing Primate Research and Conservation through the Use of Camera Traps: Introduction to the Special Issue.\u201d <em>International Journal of Primatology<\/em> 35 (5): 825\u2013840. https:\/\/doi.org\/10.1007\/s10764-014-9802-4.<\/p>\n<p class=\"import-Normal\">Peterson, Jeffrey V. 2017. \u201cPrimates in World Religions (Buddhism, Christianity, Hinduism, Islam).\u201d In <em>The International Encyclopedia of Primatology<\/em>, edited by Agust\u00edn Fuentes, 1171\u20131177. Hoboken, NJ: John Wiley and Sons. https:\/\/doi.org\/10.1002\/9781119179313.wbprim0122.<\/p>\n<p class=\"import-Normal\">Peterson, Jeffrey V., and Erin P. Riley. 2017. \u201cSacred Monkeys? An Ethnographic Perspective on Macaque Sacredness in Balinese Hinduism.\u201d In <em>Ethnoprimatology: A Practical Guide to Research at the Human-Nonhuman Primate Interface<\/em>, edited by Kerry M. Dore, Erin P. Riley, and Agust\u00edn Fuentes, 206\u2013218. Cambridge, UK: Cambridge University Press.<\/p>\n<p class=\"import-Normal\">Possamai, Carla B., Fabiano Rodrigues de Melo, S\u00e9rgio Lucena Mendes, and Karen B. Strier. 2022. \u201cDemographic Changes in an Atlantic Forest Primate Community Following a Yellow Fever Outbreak.\u201d <em>American Journal of Primatology<\/em> 84 (9): e23425. https:\/\/doi.org\/10.1002\/ajp.23425.<\/p>\n<p class=\"import-Normal\">Reibelt, L. M., and J. Nowack. 2015. \u201cEditorial: Community-Based Conservation in Madagascar, the \u2018Cure-All\u2019 Solution? <em>Madagascar Conservation &amp; Development<\/em> 10 (1): 3\u20135. https:\/\/doi.org\/10.4314\/mcd.v10i1.S1.<\/p>\n<p class=\"import-Normal\">Riley, Erin P. 2020. <em>The Promise of Contemporary Primatology<\/em>. New York: Routledge.<\/p>\n<p class=\"import-Normal\">Rimbach, Rebecca, Andr\u00e9s Link, Andr\u00e9s Montes-Rojas, Anthony Di Fiore, Michael Heistermann, and Eckhard W. Heymann. 2014. \u201cBehavioral and Physiological Responses to Fruit Availability of Spider Monkeys Ranging in a Small <span style=\"color: #000000;\">Forest Fragment.\u201d <em>American Journal of Primatology<\/em> 76 (11): 1049\u20131061. https:\/\/doi.org\/10.1002\/ajp.22292.<\/span><\/p>\n<p class=\"import-Normal\" style=\"background-color: #ffffff; color: #ffffff;\"><span style=\"color: #000000;\">Robbins, Martha M., Markye Gray, Katie A. Fawcett, Felicia B. Nutter, Prosper Uwingeli, Innocent Mburanumwe, Edwin Kagoda, et al. 2011. \u201cExtreme Conservation Leads to Recovery of the Virunga Mountain Gorillas.\u201d <em>PLoS ONE <\/em>6 (6): e19788. https:\/\/doi.org\/10.1371\/journal.pone.0019788.<\/span><\/p>\n<p class=\"import-Normal\"><span style=\"color: #000000;\">Roncal, Carla Mere, Mark Bowler, and Michael P. Gilmore. 2018. \u201cThe Ethnoprimatology of the Maijuna of the Peruvian Amazon and Implications for Primate Conservation.\u201d<em> Journal of Ethnobiology and Ethnomedicine<\/em> 14 (19). https:\/\/doi.org\/10<\/span>.1186\/s13002-018-0207-x.<\/p>\n<p class=\"import-Normal\">Russo, Sabrina E. 2017. \u201cSeed Dispersal.\u201d In <em>The International Encyclopedia of Primatology<\/em>, edited by Agust\u00edn Fuentes, 1265\u20131269. Hoboken, NJ: John Wiley and Sons.<\/p>\n<p class=\"import-Normal\">Russo, Sabrina, and Colin Chapman. 2011. \u201cPrimate Seed Dispersal: Linking Behavioral Ecology with Forest Community Structure.\u201d In <em>Primates<\/em> <em>in<\/em> <em>Perspective<\/em>, edited by Christina Campbell, Agust\u00edn Fuentes, Katherine McKinnon, Simon Bearder, and Rebecca Stumpf, 523\u2013534. New York: Oxford University Press.<\/p>\n<p class=\"import-Normal\">Rutz, Christian, Matthias-Claudio Loretto, Amanda E. Bates, Sarah C. Davidson, Carlos M. Duarte, Walter Jetz, Mark Johnson, et al. 2020. \u201cCOVID-19 Lockdown Allows Researchers to Quantify Effects of Human Activity on Wildlife.\u201d <em>Nature Ecology &amp; Evolution <\/em>4: 1156\u20131159. https:\/\/doi.org\/10.1038\/s41559-020-1237-z.<\/p>\n<p class=\"import-Normal\">Rylands, Anthony B., and Russell A. Mittermeier. 2014. \u201cPrimate Taxonomy: Species and Conservation.\u201d <em>Evolutionary Anthropology<\/em> 23 (1): 8\u201310. https:\/\/doi.org\/10.1002\/evan.21387.<\/p>\n<p class=\"import-Normal\">Scales, I. R. 2014. \u201cThe Future of Biodiversity Conservation and Environmental Management in Madagascar: Lessons from the Past and Challenges Ahead.\u201d In <em>Conservation and Environmental Management in Madagascar<\/em>, edited by I. R. Scales, 342\u2013360. London: Routledge.<\/p>\n<p class=\"import-Normal\">Schaffner, Colleen M., Luisa Rebecchini, Gabriel Ramos-Fernandez, Laura G. Vick, and Filippo Aureli. 2012. \u201cSpider Monkeys (<em>Ateles geoffroyi yucatenensis<\/em>) Cope with the Negative Consequences of Hurricanes Through Changes in Diet, Activity Budget, and Fission-Fusion Dynamics.\u201d <em>International Journal of Primatology<\/em> 33: 922-936. https:\/\/doi.org\/10.1007\/s10764-012-9621-4.<\/p>\n<p class=\"import-Normal\">Schloss, Carrie A., Tristan A. Nu\u00f1ez, and Joshua J. Lawler. 2012. \u201cDispersal Will Limit Ability of Mammals to Track Climate Change in the Western Hemisphere.\u201d <em>PNAS<\/em> 109 (22): 8606\u20138611. https:\/\/doi.org\/<a class=\"rId70\" href=\"https:\/\/doi.org\/10.1073\/pnas.1116791109\">10.1073\/pnas.1116791109<\/a>.<\/p>\n<p class=\"import-Normal\">Sechrest, W., Thomas M. Brooks, Gustavo A. B. da Fonseca, William R. Konstant, Russel A. Mittermeier, Andy Purvis, Anthony B. Rylands, and John L. Gittleman. 2002. \u201cHot Spots and the Conservation of Evolutionary History.\u201d <em>Proceedings of the National Academy of Sciences<\/em> 99 (4): 2067\u20132071. https:\/\/doi.org\/10.1073\/pnas.251680798.<\/p>\n<p class=\"import-Normal\">Shanee, Noga, A. Patricia Mendoza, and Sam Shanee. 2017. \u201cDiagnostic Overview of the Illegal Trade in Primates and Law Enforcement in Peru.\u201d <em>American Journal of Primatology<\/em> 79 (11): 1\u201312. https:\/\/doi.org\/10.1002\/ajp.22516.<\/p>\n<p class=\"import-Normal\">Shanee, N., S. Shanee, and A. M. Maldonado. 2007. \u201cConservation Assessment and Planning for the Yellow-Tailed Woolly Monkey (<em>Oreonax flavicauda<\/em>) in Peru.\u201d <em>Wildlife Biology in Practice<\/em> 3 (2): 73\u201382. https:\/\/doi.org\/10.2461\/wbp.2007.3.9.<\/p>\n<p class=\"import-Normal\">Sicotte, Pascale. 2017. \u201cSocial Taboos.\u201d In <em>The International Encyclopedia of Primatology<\/em>, edited by Agust\u00edn Fuentes, 1319\u20131321. Hoboken, NJ: John Wiley and Sons. https:\/\/doi.org\/10.1002\/9781119179313.wbprim0117.<\/p>\n<p class=\"import-Normal\">Spenceley, Anna, Straton Habyalimana, Ritah Tusabe, and Donnah Mariza. 2010. \u201cBenefits to the Poor from Gorilla Tourism in Rwanda.\u201d <em>Development<\/em> <em>Southern<\/em> <em>Africa<\/em> 27 (5): 647\u2013662. https:\/\/doi.org\/10.1080\/0376835X.2010.522828.<\/p>\n<p class=\"import-Normal\">Sponsel, Leslie E. 1997. \u201cThe Human Niche in Amazonia: Explorations in Ethnoprimatology.\u201d In <em>New World Primates: Ecology, Evolution, and Behavior, <\/em>edited by W. Kinzey, 143\u2013165. New York: Aldine de Gruyter.<\/p>\n<p class=\"import-Normal\">Stammes, Marieke A., Ji Hyun Lee, Lisette Meijer, Thibaut Naninck, Lara A. Doyle-Meyers, Alexander G. White, H. Jacob Borish, et al. 2021. \u201cMedical Imaging of Pulmonary Disease in SARS-CoV-2-Exposed Non-human Primates.\u201d Trends in Molecular Medicine 28 (2): 123\u2013142. https:\/\/doi.org\/10.1016\/j.molmed.2021.12.001.<\/p>\n<p class=\"import-Normal\">Steinweg, Tim, Barbara Kuepper, and Gabriel Thoumi. 2016. <em>Economic Drivers of Deforestation<\/em>. Washington, DC: Chain Reaction Research. Accessed March 12, 2023. <a class=\"rId71\" href=\"https:\/\/chainreactionresearch.com\/wp-content\/uploads\/2016\/08\/economic-drivers-of-deforestation-crr-160803-final1.pdf\">https:\/\/chainreactionresearch.com\/wp-content\/uploads\/2016\/08\/economic-drivers-of-deforestation-crr-160803-final1.pdf<\/a>.<\/p>\n<p class=\"import-Normal\">Strier, Karen B. 1994. \u201cMyth of the Typical Primate.\u201d <em>American Journal of Physical Anthropology<\/em> 37 (S19): 233\u2013271. https:\/\/doi.org\/10.1002\/ajpa.13303700609.<\/p>\n<p class=\"import-Normal\">Strier, Karen B. 2003. \u201cPrimatology Comes of Age: 2002 AAPA Luncheon Address.\u201d <em>Yearbook of Physical Anthropology<\/em> 46: 2\u201313.<\/p>\n<p class=\"import-Normal\">Strier, Karen B. 2010. \u201c Long-term Field Studies: Positive Impacts and Unintended Consequences.\u201d <em>American Journal of Primatology<\/em> 72 (9): 772\u2013778. https:\/\/doi.org\/10.1002\/ajp.20830.<\/p>\n<p class=\"import-Normal\">Strier, Karen B. 2011a. \u201cConservation.\" In <em>Primates in Perspective<\/em>, edited by Christina Campbell, Agust\u00edn Fuentes, Katherine C. MacKinnon, Simon K. Bearder, and Rebecca M. Stumpf, 664\u2013675. New York: Oxford University Press.<\/p>\n<p class=\"import-Normal\">Strier, Karen B. 2011b. \u201cWhy Anthropology Needs Primatology.\u201d <em>General Anthropology<\/em> 18 (1): 1\u20138.<\/p>\n<p class=\"import-Normal\">Strier, Karen B. 2017. <em>Primate Behavioral Ecology: Fifth Edition<\/em>. New York: Routledge.<\/p>\n<p class=\"import-Normal\">Strier, Karen B. 2018a. \"Primate Social Behavior.\" <em>American Journal of Physical Anthropology<\/em> 165 (4): 801\u2013812.<\/p>\n<p class=\"import-Normal\">Strier, Karen B. 2018b. \u201cWhat Climate Change Means for Primates and Primatology.\u201d Paper presented at the 87th Annual Meeting of American Association of Physical Anthropologists, Austin, Texas, April 11\u201314, 2018.<\/p>\n<p class=\"import-Normal\">Strier, Karen B. 2021a. \u201cThe Limits of Resilience.\u201d <em>Primates<\/em> 62: 861\u2013868. https:\/\/doi.org\/10.1007\/s10329-021-00953-3.<\/p>\n<p class=\"import-Normal\">Strier, Karen B. 2021b. <em>Primate Behavioral Ecology<\/em>. 6th ed. New York: Routledge.<\/p>\n<p class=\"import-Normal\">Strier, Karen B., and Jean Philippe Boubli. 2006. \u201cA History of Long-term Research and Conservation of Northern Muriquis (<em>Brachyteles<\/em> <em>hypoxanthus<\/em>) at the Esta\u00e7\u00e3o Biol\u00f3gica de Caratinga\/RPPN-FMA.\u201d <em>Primate Conservation <\/em>20: <span style=\"color: #000000;\">53\u201363. https:\/\/doi.org\/10.1896\/0898-6207.20.1.53.<\/span><\/p>\n<p class=\"import-Normal\" style=\"background-color: #ffffff; color: #ffffff;\"><span style=\"color: #000000;\">Strier, Karen B., and S\u00e9rgio L. Mendes. 2012. \u201cThe Northern Muriqui (<em>Brachyteles hypoxanthus<\/em>):Lessons on Behavioral Plasticity and Population Dynamics from a Critically Endangered Species.\u201d In\u00a0<em>Long-term Field Studies of Primates<\/em>, edited by Peter M. Kappeler and David P. Watts, 125\u2013140. Berlin, Heidelberg: Springer.<\/span><\/p>\n<p class=\"import-Normal\" style=\"background-color: #ffffff; color: #ffffff;\"><span style=\"color: #000000;\">Strier, Karen B., Carla B. Possamai, Fernanda P. Tabacow, Alcides Pissinatti, Andre M. Lanna, Fabiano Rodrigues de Melo, Leandro Moreira, et al<em>.<\/em> 2017. \u201cDemographic Monitoring of Wild Muriqui Populations: Criteria for Defining Priority Areas and Monitoring Intensity.\u201d <em>PLoS ONE<\/em> 12 (12): e0188922. https:\/\/doi.org\/10.1371\/journal.pone.0188922.<\/span><\/p>\n<p class=\"import-Normal\"><span style=\"color: #000000;\">Strum, Shirley C., and Linda M. Fedigan. 1999. \u201cTheory, Method, Gender, and Culture: What Changed Our Views of Primate Society.\u201d In<em> The New Physical Anthropology: Science, Humanism, and Critical Reflection, <\/em>edited by S. C. Strum, D. G. Lindburg, and D. A<\/span>. Hamburg, 67\u2013105. New Jersey: Prentice Hall.<\/p>\n<p class=\"import-Normal\">Tarara, R., M. A. Suleman, R. Sapolsky, M. J. Wabomba, and J. G. Else. 1985. \u201cTuberculosis in Wild Olive Baboons (<em>Papio cynocephalus anubis<\/em>) in Kenya.\u201d <em>Journal of Wildlife Diseases<\/em> 21 (2): 137\u2013140. https:\/\/doi.org\/<a class=\"rId72\" href=\"https:\/\/doi.org\/10.7589\/0090-3558-21.2.137\">10.7589\/0090-3558-21.2.137<\/a>.<\/p>\n<p class=\"import-Normal\">Terborgh, J. 1983. <em>Five New World Primates: A Study in Comparative Ecology<\/em>. Princeton: Princeton University Press.<\/p>\n<p class=\"import-Normal\">Tumusiime, David Mwesigye, Gerald Eilu, Mnason Tweheyo, Mnason Tweheyo, and Fred Babweteera. 2010. \u201cWildlife Snaring in Budongo Forest Reserve, Uganda.\u201d <em>Human Dimensions of Wildlife<\/em> 15 (2): 129\u2013144. https:\/\/doi.org\/10.1080\/10871200903493899.<\/p>\n<p class=\"import-Normal\">Tyukavina, Alexandra, Matthew C. Hansen, Peter V. Potapov, Stephen V. Stehman, Kevin Smith-Rodriguez, Chima Okpa, and Ricardo Aguilar. 2017. \u201cTypes and Rates of Forest Disturbance in Brazilian Legal Amazon, 2000\u20132013.\u201d <em>Science Advances<\/em> 3 (4): 1\u201316. https:\/\/doi.org\/10.1126\/sciadv.1601047.<\/p>\n<p class=\"import-Normal\">UN Population Division. 2017. \u201cWorld Population Prospects: The 2017 Revision.\u201d Accessed January 2, 2019. https:\/\/esa.un.org\/unpd\/wpp\/publications\/files\/wpp2017_keyfindings.pdf.<\/p>\n<p class=\"import-Normal\">USDA [United States Department of Agriculture]. 2021. \u201cConfirmation of COVID-19 in Gorillas at California Zoo.\u201d <em>Animal and Plant Health Inspection Service<\/em> website. Accessed June 15, 2022. https:\/\/www.aphis.usda.gov\/aphis\/newsroom\/stakeholder-info\/sa_by_date\/sa-2021\/sa-01\/ca-gorillas-sars-cov-2.<\/p>\n<p class=\"import-Normal\">Velankar, Avadhoot D., Honnavalli N. Kumara, Arijit Pal, Partha Sarathi Mishra, and Mewa Singh. 2016. \u201cPopulation Recovery of Nicobar Long-tailed Macaque <em>Macaca fascicularis umbrosus<\/em> following a Tsunami in the Nicobar Islands, India.\u201d <em>PLoS ONE<\/em> 11(2): e0148205. https:\/\/doi.org\/10.1371\/journal.pone.0148205.<\/p>\n<p class=\"import-Normal\">Wallis, Janette, and D. Rick Lee. 1999. \u201cPrimate Conservation: The Prevention of Disease Transmission.\u201d <em>International Journal of Primatology <\/em>20 (6): 803\u2013826. https:\/\/doi.org\/10.1023\/A:1020879700286.<\/p>\n<p class=\"import-Normal\">Wang, Chengliang, Xiaowei Wang, Xiaoguang Qi, Songtao Guo, Haitao Zhao, Wei Wei, and Baoguo Li. 2014. \u201cInfluence of Human Activities on the Historical and Current Distribution of Sichuan Snub-Nosed Monkeys in the Qinling Mountains, China.\u201d <em>Folia Primatologica<\/em> 85 (6): 343\u2013357.<\/p>\n<p class=\"import-Normal\">Washburn, Sherwood L. 1951. \u201cSection of Anthropology: The New Physical Anthropology.\u201d <em>Transactions of the New York Academy of Sciences<\/em> 13 (7): 298\u2013304.<\/p>\n<p class=\"import-Normal\">Washburn, Sherwood L.1973. \u201cThe Promise of Primatology.\u201d <em>American Journal of Physical Anthropology <\/em>38 (2): 177\u2013182.<\/p>\n<p class=\"import-Normal\">Wheatley, Bruce P. 1999. <em>The Sacred Monkeys of Bali<\/em>. New York: Waveland.<\/p>\n<h2 class=\"import-Normal\">Acknowledgments<\/h2>\n<p class=\"import-Normal\">We are grateful to the University of Wisconsin\u2013Madison for the various sources of funding that enabled us to write this Appendix, including Teaching Assistantships from the department of Integrative Biology (to JBK) and a Vilas Research Professorship (to KBS). We are grateful to A.J. Hardy for their significant contributions to the previous addition of this appendix, Irene Duch Latorre for her photograph and helpful additions, and to Kadie Callingham and Danhe Yang for the use of their photographs. We thank the editors of this volume for inviting our contribution and for the helpful comments that they and anonymous reviewers provided.<\/p>\n<\/div>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_281_1699\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_281_1699\"><div tabindex=\"-1\"><div class=\"__UNKNOWN__\">\n<p class=\"import-Normal\" style=\"text-align: left;\">Kristin Snopkowski, Ph.D., Boise State University<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;\"><em>This chapter is a revision from \"<\/em><a class=\"rId7\" href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/chapter\/__unknown__-17\/\"><em>Appendix C:<\/em><\/a><a class=\"rId8\" href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/chapter\/__unknown__-17\/\"><em> Human Behavioral Ecology<\/em><\/a><em>\u201d by Kristin Snopkowski. <\/em><a class=\"rId9\" href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/\"><em>In Explorations: An Open Invitation to Biological Anthropology, first edition<\/em><\/a><em>, edited by Beth Shook, Katie Nelson, Kelsie Aguilera, and Lara Braff, which is licensed under <\/em><a class=\"rId10\" href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\"><em>CC BY-NC 4.0<\/em><\/a><em>. <\/em><\/p>\n<div class=\"textbox textbox--learning-objectives\">\n<header class=\"textbox__header\">\n<h2 class=\"textbox__title\"><span style=\"color: #ffffff;\">Learning Objectives<\/span><\/h2>\n<\/header>\n<div class=\"textbox__content\">\n<ul>\n<li class=\"import-Normal\" style=\"text-indent: 18pt;\">Define human behavioral ecology.<\/li>\n<li class=\"import-Normal\" style=\"text-indent: 18pt;\">Describe the types of behaviors that human behavioral ecologists study.<\/li>\n<li class=\"import-Normal\" style=\"text-indent: 18pt;\">Explain why humans share food.<\/li>\n<li class=\"import-Normal\" style=\"text-indent: 18pt;\">Identify how human behavioral ecology contributes to contemporary world issues.<\/li>\n<\/ul>\n<\/div>\n<\/div>\n<figure style=\"width: 311px\" class=\"wp-caption alignright\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/06\/image1-12.png\" alt=\"Man walking among destruction resulting from tsunami.\" width=\"311\" height=\"213\" \/><figcaption class=\"wp-caption-text\">Figure C.1: Aftermath of the 2004 Asian Tsunami in Sri Lanka. Credit: <a href=\"https:\/\/commons.wikimedia.org\/wiki\/File:Pictures_from_bus_13.jpg\">Pictures from bus 13<\/a> by <a href=\"https:\/\/www.sarvodaya.org\">Sarvodaya Shramadana<\/a> is under a <a href=\"https:\/\/creativecommons.org\/licenses\/by\/2.0\/legalcode\">CC BY 2.0 License<\/a>.<\/figcaption><\/figure>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">On December 26, 2004, an earthquake in the Indian Ocean resulted in a tsunami that killed over 200,000 people in at least a dozen different countries (Figure C.1; Editors of Encyclopedia Britannica 2018). In the aftermath, 30% of households in the United States donated an estimated $2.78 billion to help the victims (Center on Philanthropy at Indiana University 2008). At the same time, despite being one of the wealthiest countries in the world, the United States has over a million children who experience homelessness each year (National Center for Homeless Education 2017). Why is it that sometimes humans work together to help those in need, but at other times, humans struggle to solve basic problems? The field of Human Behavioral Ecology seeks to understand this and many other questions to learn why humans behave the way they do. <strong>Human Behavioral Ecology<\/strong> is the field of anthropology that explores how evolutionary history and ecological factors combine to influence human behavior.<\/p>\n<h2 class=\"import-Normal\">Human Behavioral Ecology<\/h2>\n<h3 class=\"import-Normal\"><strong>Evolutionary History<\/strong><\/h3>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Natural selection is the force of evolution by which individuals with heritable traits that result in greater survival and reproduction have more offspring than individuals without those traits. By having more offspring (specifically, offspring who themselves survive and reproduce), these heritable traits become more common in future generations. As an example, hominin brain size has increased dramatically over the past two million years. <span style=\"background-color: #ffff00;\">Our ancestors with larger brains were better able to survive and reproduce than those with smaller brains, possibly because they were better able to acquire food or navigate the social complexities of living in a large<\/span> group (Dunbar 1998; Parker and Gibson 1979).<\/p>\n<figure style=\"width: 305px\" class=\"wp-caption alignleft\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image2-11.png\" alt=\"Plate of dessert items.\" width=\"305\" height=\"210\" \/><figcaption class=\"wp-caption-text\">Figure C.2: Sample of sweets to celebrate Diwali, a Hindu festival of lights. Credit: <a href=\"https:\/\/commons.wikimedia.org\/wiki\/File:Diwali_sweets_India_2009.jpg\">Diwali sweets India 2009<\/a> by <a href=\"https:\/\/www.flickr.com\/people\/14772187@N00\">robertsharp<\/a> is under a <a href=\"https:\/\/creativecommons.org\/licenses\/by\/2.0\/legalcode\">CC BY 2.0 License<\/a>.<\/figcaption><\/figure>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Human behavioral ecology uses the theory of evolution by natural selection to understand how modern behaviors were advantageous in our <strong>evolutionary history<\/strong>. For most of human history, humans lived as hunter-gatherers, meaning they collected or hunted food; they typically resided in small communities with individuals related through blood or marriage; and they had no access to modern medicines or other modern conveniences. It is useful to think about this environment\u2014which is much different than how humans live today\u2014to help us understand how current behaviors may have evolved. For example, humans today enjoy consuming food high in fats and sugars (Figure C.2; see Chapter 16). In the past, eating fatty and sugary food was a good survival strategy since food was limited in this environment and these foods contained a lot of calories. Over time, those individuals who sought out these foods were probably better able to survive and reproduce, resulting in a population of people today who have preferences for these foods. In modern environments, where food is abundant, this preference has likely contributed to the obesity epidemic, which increases people\u2019s risk of cardiovascular diseases and no longer improves people\u2019s ability to survive and reproduce.<\/p>\n<h3 class=\"import-Normal\"><strong>Ecology<\/strong><\/h3>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">In addition to evolutionary history, the field of human behavioral ecology also focuses on the influence of ecology. <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_950\">Ecology<\/a><\/strong> is defined as one\u2019s physical environment, including types of resources, predators, terrain, and weather, as well as one\u2019s social environment, including the behaviors of other individuals and cultural rules. For example, if one lives in an environment where there are abundant fruit trees, then the diet likely includes fruit. Since fruits are easy to acquire, children can engage in food gathering at young ages. In contrast, in environments like the Arctic, where there are fewer plant resources, the diet focuses more on hunting and fishing. Since these skills take longer to acquire, children may only be able to contribute to their own subsistence at older ages. One\u2019s environment influences the behaviors in which individuals engage, such as children\u2019s foraging.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Another component of ecology is one\u2019s social environment, including cultural rules. Throughout the world, different cultures have quite different norms of behavior. For instance, in some societies marriages are required to be monogamous, meaning that a marriage is between just two individuals. This is a cultural norm in the United States, and it is illegal to violate this rule. In other societies, marriages can occur between one man and several women or one woman and several men, referred to as polygyny and polyandry respectively. Across the world, polyandry tends to be quite rare, and in cultures with polyandrous marriage, polygynous and monogamous marriages also occur. The age difference of married people frequently depends on the type of marriages allowed in their culture. In cultures with polygynous marriage, the age difference between husbands and wives tends to be larger than it is in monogamous cultures, as the men who are able to attract additional wives tend to have high status or wealth and are typically older than the women who are available for marriage. In cultures with fraternal polyandry, defined as the marriage of one woman to a set of brothers, marriage typically occurs when the eldest brother is ready to marry and he typically marries a woman close in age. This results in the wife being older than some of her husbands, with the exception of the eldest one. The environment (both physical and social) influences one\u2019s behavioral options, and human behavioral ecologists examine how one\u2019s ecology influences people\u2019s behavior. In Figure C.3, we see a visual depiction of the field of human behavioral ecology, using evolutionary history and ecology (physical environment plus culture) to explain modern human behavior.<\/p>\n<figure style=\"width: 567px\" class=\"wp-caption aligncenter\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image4-9.png\" alt=\"Equation representing human behavioral ecology.\" width=\"567\" height=\"178\" \/><figcaption class=\"wp-caption-text\">Figure C.3: Human Behavioral Ecology. Credit: <a class=\"rId20\" href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/chapter\/__unknown__-17\/\">Human Behavioral Ecology (Figure C.3)<\/a> original to <a class=\"rId21\" href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/\">Explorations: An Open Invitation to Biological Anthropology<\/a> by Katie Nelson is under a <a class=\"rId22\" href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/\">CC BY-NC 4.0 License<\/a>.<\/figcaption><\/figure>\n<h3 class=\"import-Normal\"><strong>Both Genes and Environment Influence Behavior<\/strong><\/h3>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">While physical characteristics (like height) are clearly heritable, we also know that they depend on the environment. When children grow up with poor nutrition and do not ingest enough calories, their growth is stunted. At the same time, if parents are both tall, then their child is more likely to be tall as well. Physical traits are the result of both genes and environment. Behavior is the same\u2014dependent on both genes and environment. While there are no genes for specific behaviors, behavioral tendencies do show some level of heritability. Personality disorders, for instance, may be partially heritable, but it also depends on the environment in which a child is raised, where child neglect or sexual abuse may increase the risk of personality disorders (Johnson et al. 1999).<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Human behavioral ecologists assume that even though there are not genes for specific behaviors, genes may influence behavioral tendencies. Additionally, behaviors are flexible and people use information from the environment to determine under which conditions they should behave in particular ways. For example, the <em>ability<\/em> to cooperate has evolved over evolutionary time, but whether or not an individual cooperates in a particular instance likely depends on the situation. Research shows that people are more likely to cooperate if: (1) their behavior is known to others (that is to say their identity is <em>not<\/em> anonymous); (2) it will improve their reputation; or (3) they will be punished for not cooperating (Andreoni and Petrie 2004; Fehr and Fischbacher 2003; Milinski, Semmann, and Krambeck 2002).<\/p>\n<h2 class=\"import-Normal\">How Can Human Behavioral Ecology Help Us Understand Altruism?<\/h2>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\"><strong>Altruism<\/strong> is defined as providing a benefit to someone without expecting anything in return. A perfect example is donating money to tsunami victims. From an evolutionary perspective, it seems that providing benefits to others would be disadvantageous for one\u2019s own survival and reproduction, as resources given to others are resources that cannot be used for oneself. But people do engage in altruistic behaviors, so how can the field of human behavioral ecology help us understand this behavior? We will use the example of food sharing to think about different ways that human behavioral ecologists have examined this question. In many small-scale hunter-gatherer societies, people share food extensively with other people living in their communities. This sharing is most widespread when the item is a hunted animal, which can typically feed many people. Just as giving away money seems counterintuitive, so does giving away food. So, why do people in these foraging communities share so much food with each other?<\/p>\n<h3 class=\"import-Normal\"><strong>Kin Selection<\/strong><\/h3>\n<figure style=\"width: 412px\" class=\"wp-caption alignleft\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image8-10.png\" alt=\"Family sitting on the ground communally eating.\" width=\"412\" height=\"274\" \/><figcaption class=\"wp-caption-text\">Figure C.4: Lao family eating together. Credit: <a class=\"rId24\" href=\"https:\/\/commons.wikimedia.org\/wiki\/File:Lao_Mangkong_family_eats_together.JPG\">Lao Mangkong family eats together<\/a> by <a class=\"rId25\" href=\"https:\/\/commons.wikimedia.org\/wiki\/User:BigBrotherMouse\">BigBrotherMouse<\/a> is modified (faces blurred) and under a <a class=\"rId26\" href=\"https:\/\/creativecommons.org\/licenses\/by-nc-sa\/4.0\/\">CC BY-NC-SA 4.0 License<\/a>.<\/figcaption><\/figure>\n<p>One of the first explanations for why humans share food is that they are sharing with their close family members. <strong>Kin selection<\/strong> proposes that individuals help kin, even at a cost to themselves, because this help is directed at individuals with whom they share genes. Genes that result in a person acting altruistically toward close kin would have become more frequent over time if individuals sharing that gene are more successful than those not sharing that gene (Hamilton 1964). Taking this perspective is described as a <em>gene\u2019s eye view. <\/em>Since family members share genes, this may explain why kin help one another. Figure C.4 shows a Lao family eating together. It is very common around the world for families to share food with one another. In many small-scale societies, people share food with family members but also with those who are not family members. Kin selection helps explain some food sharing, but it doesn\u2019t explain all food sharing.<\/p>\n<h3 class=\"import-Normal\"><strong>Reciprocal Altruism<\/strong><\/h3>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Another potential explanation for why humans share food is that they are engaging in <strong>reciprocal altruism<\/strong>, meaning that an individual shares food today with the expectation of repayment at some point in the future (Trivers 1971). This can work well, unless the person who receives the help chooses not to reciprocate in the future. In this case, the original sharer does not obtain anything in return. To maintain these relationships, it is important that individuals have the opportunity to share with one another repeatedly and that if one person chooses not to reciprocate, the original sharer terminates their sharing.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Reciprocal altruism is even more likely to occur if the value of the food is greater to the person receiving the food than the person sharing the food. For instance, imagine that you have an entire pizza. After you eat several slices, you are no longer hungry and the next piece of pizza has little value to you. In contrast, if you are hungry, receiving a slice of pizza from a friend would mean a lot to you. In this case, the person giving a piece of pizza after already eating their fill is giving away something of little value, but the person receiving a slice of pizza when they are hungry is receiving something with substantial value. If the following week the roles are reversed, then in both cases, the person receiving the food has received something of greater value than the person who gave it away.<\/p>\n<figure style=\"width: 370px\" class=\"wp-caption alignright\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image6-7.jpg\" alt=\"A person jumping from a boat while spearing a whale with a harpoon.\" width=\"370\" height=\"214\" \/><figcaption class=\"wp-caption-text\">Figure C.5: A Lamalera whale-spearer jumps from a boat, spearing a whale in Lembata Island, East Nusa Tenggara Province. Credit: <a class=\"rId28\" href=\"https:\/\/commons.wikimedia.org\/wiki\/File:Lamafa_(spearer)_jumping_from_peledang_boat_to_a_whale.jpg\">Lamafa (spearer) jumping from peledang boat to a whale<\/a> by Bambang Budi Utomo is in the <a class=\"rId29\" href=\"https:\/\/en.wikipedia.org\/wiki\/Public_domain\">public domain<\/a> in Indonesia.<\/figcaption><\/figure>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">This makes sense in the case of sharing hunted meat as well. In environments without refrigeration technology or in highly mobile groups where food storage is not feasible, the killing of a large animal will result in leftover meat. Sharing that meat with hungry community members has a lot of value to those receiving the meat. Then, at some point in the future, the person who received the meat may successfully hunt and share with others. Figure C.5 displays an Indigenous hunting party from Malaysia. Food is widely shared in small-scale societies, particularly when the item is large in size and when there is a lot of uncertainty around when the next successful hunt will occur (Gurven 2004). But, as with other skilled activities, some individuals are better hunters than others and acquire more meat than others consistently, so why would highly skilled hunters give more food to low-skilled hunters than will be reciprocated (e.g., Gurven et al. 2000)? Again, reciprocal altruism is one piece of the story but cannot explain all sharing behavior.<\/p>\n<\/div>\n<div class=\"__UNKNOWN__\">\n<h3><strong>Costly Signaling<\/strong><\/h3>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Another possible explanation for why people share food, particularly meat in small-scale societies, is because they want to signal their foraging abilities and generosity (Smith and Bliege Bird 2000). One way to communicate to others your inherent qualities is to do something that is hard to fake. For instance, telling someone that you are a good hunter is not as convincing as hunting a difficult-to-acquire animal and sharing it with them. If someone is a poor hunter, it will be difficult for them to successfully hunt, so sharing hunted meat demonstrates one\u2019s abilities. The hunter who provides resources to the community is likely viewed as generous, allowing them to attract mates, friends, and allies. <strong>Costly signaling theory <\/strong>argues that a signaller produces a costly display (e.g., shares hunted meat) to communicate honest information about themselves to others (e.g., I am a generous, skilled hunter). Costly signals can occur across species for a variety of purposes, but this example may help us understand why people share food with unrelated others who are unlikely to reciprocate.<\/p>\n<figure style=\"width: 430px\" class=\"wp-caption alignright\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image9-7.jpg\" alt=\"A green turtle swimming.\" width=\"430\" height=\"304\" \/><figcaption class=\"wp-caption-text\">Figure C.6: Green turtle. Credit: <a class=\"rId31\" href=\"https:\/\/www.flickr.com\/photos\/usfwspacific\/12197897325\/\">Green turtle<\/a><a class=\"rId32\" href=\"https:\/\/www.flickr.com\/photos\/usfwspacific\/12197897325\/\"> Palmyra Atoll National Wildlife Refuge<\/a> by Kydd Pollock, The Nature Conservancy, <a class=\"rId33\" href=\"https:\/\/www.flickr.com\/people\/52133016@N08\">US Fish and Wildlife Service Pacific Region<\/a> is under a <a class=\"rId34\" href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/2.0\/\">CC BY-NC 2.0 License<\/a>.<\/figcaption><\/figure>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Among the Melanesian Meriam Islanders, turtles (Figure C.6) are hunted at two times of year; during the turtles\u2019 feeding\/mating season, which is risky and unpredictable, and during the turtles\u2019 nesting season, which is low risk and relatively easier. Turtles hunted during the feeding\/mating season are typically shared widely in the community, while turtles hunted during the nesting season are consumed by a small number of households. This suggests that more people know about high-risk hunts, which may result in hunters gaining more prestige for their successful hunts. Evidence also shows that hunters involved in high-risk hunting gain social and reproductive benefits, such as having children earlier and having more sexual (or reproductive) partners (Smith, Bliege Bird, and Bird 2003). While some sharing behavior may be best explained by a desire to display one\u2019s skills to gain reputational benefits, it cannot explain all sharing behavior and likely works in conjunction with the other hypotheses described above.<\/p>\n<h3 class=\"import-Normal\"><strong>What Does Food Sharing Tell Us about Altruism?<\/strong><\/h3>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Examining these three explanations of sharing behavior\u2014kin selection, reciprocal altruism, and costly signaling (Figure C.7)\u2014helps explain a lot of sharing seen around the world, but donating money to tsunami victims is still hard to understand. Most donors from the United States were not related to the victims of the tsunami; donors probably did not expect reciprocation; and because the donors and receivers did not know each other, reputational benefits would have been limited to people who were made aware of the donation. While some charitable giving may be explained by the tax incentives, the donations to the tsunami victims were so extensive that it seems unlikely to be the main explanation. There are other hypotheses that have not been discussed here, but they also suffer from the inability to fully explain all examples of altruistic behavior. People commonly state that they donate because \u201cit makes them feel good.\u201d While helping others does make people feel good, this likely evolved because those that had the feel-good sensation helped others (like their family members) resulting in greater survival and reproduction. The \u201cfeel good\u201d sensation is a <strong>proximate <\/strong><strong>explanation<\/strong>, the immediate reason for the behavior, while human behavioral ecology seeks to understand the <strong>ultimate explanation<\/strong>, the deep evolutionary reason that this trait led to increased survival and reproduction. In the case of donating money to people living on the other side of the world, our modern environment (allowing us to help people living so far away) may lead us to act in ways that were adaptive in our evolutionary past but may not improve our survival or reproduction today.<\/p>\n<h4>Explanations of food sharing:<\/h4>\n<ol>\n<li><strong>Kin selection:<\/strong> Helping family members who share the same genes.<\/li>\n<li><strong>Reciprocal altruism:<\/strong> Sharing food with someone with the expectation that they will reciprocate at some point in the future.<\/li>\n<li><strong>Costly signaling:<\/strong> Providing food to others to display one's foraging skill and generosity to improve one's reputation or social standing.<\/li>\n<\/ol>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">At the same time, we struggle to solve the problem of homelessness across the United States. Using evolutionary theory may help us understand why people are unable to come together to eliminate this problem. Eradicating homelessness would be costly, would require the cooperation of lots of individuals (no single individual or small group can solve it on their own), and would be ongoing. This type of long-lasting commitment to help unrelated strangers may be difficult to acquire from large numbers of people.<\/p>\n<h2 class=\"import-Normal\">How Can Human Behavioral Ecology Help Us Understand the World?<\/h2>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Throughout this appendix, I have been discussing one of the main research areas in Human Behavioral Ecology: cooperation and sharing. Two other prominent areas of research for Human Behavioral Ecologists include production and reproduction. Production research explores how people acquire the resources that they need. Some research in this area has examined which items people choose to include in their diets and how long people spend foraging. This research has shown that people do not simply acquire any food resource in their environment; instead they make strategic decisions based on the food options available and the possible nutrients gained. Research on reproduction includes an examination of how people choose mates, make reproductive choices, invest in children, and acquire help to raise offspring. This line of research has shown that human mothers need help from others to raise offspring, and this help can come from a variety of sources, including the child\u2019s father, grandmothers, older siblings, grandfathers, or others (Hrdy 2009; Sear and Mace 2008). This is quite different from our nonhuman primate relatives, for whom almost all offspring care is given by mothers. These research areas capture many behaviors we faced in our evolutionary history: How did we obtain food, how did we distribute that food once we had it, and how did we make mating and reproductive decisions? All of the topics examined in the field of human behavioral ecology are closely linked to survival and reproduction and to understanding how the environment influences decision making.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Some common misperceptions about human behavioral ecology cause skepticism of this type of research. Some critiques have argued that studying the evolution of human behavior is problematic because of <strong>biological determinism<\/strong>, the idea that all behaviors are innate, determined by our genes. If behaviors are innate, then we cannot hold people accountable for their actions. But this is a misunderstanding. As mentioned previously, both genes and the environment influence behavior. Individuals may have a tendency to behave in a particular way, but behaviors are flexible. Also, there is no guarantee that everyone behaves in perfectly optimal ways. Over evolutionary time, those who behaved in ways that resulted in more successful offspring had a greater representation of genes in the next generation, but in each generation we have variation in environments, genotypes, phenotypes, and behaviors on which selection can act.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Another common misconception is that by studying human behavior, human behavioral ecologists are providing justifications for those behaviors. The <strong>naturalistic fallacy<\/strong> describes the incorrect belief that what occurs in nature is what <em>ought to be<\/em>. This is a fallacy because it is absolutely not the goal of researchers in this field. For instance, some researchers study human violence. It is wrong to assume that by studying violence, the researchers believe that violence is an acceptable behavior or is justifiable. It is easy to slip into this misconception.<\/p>\n<h3 class=\"import-Normal\"><strong>Modern Applications<\/strong><\/h3>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">While it may seem that the field of human behavioral ecology is more concerned about our evolutionary past than our present, there are many contemporary issues that human behavioral ecology can help us solve. One area that human behavioral ecologists have focused on is climate change (Schradin 2021). In many ways, solving the climate crisis is similar to that of homelessness; it requires many people to come together and sacrifice for the benefit of all. Evidence has shown that people are more likely to sacrifice for others' benefit when their good deeds are known, their actions improve their reputation, or their failure to act produces negative consequences, like increased taxes (Milinski et al. 2002). By focusing on these motivators, policy makers may be able to leverage people to minimize their carbon usage, although current progress achieving targets has seen limited success. Researchers have also used evolutionary theory to improve handwashing rates around the world (Curtis 2013), reduce the obesity epidemic (Pepper and Nettle 2014), ease conflicts (de Waal 2000), and improve cooperation (Boyd and Richerson 1992).<\/p>\n<div class=\"textbox\">\n<h2 class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Special Topic: Fertility Research in Human Behavioral Ecology<\/h2>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">To understand how human behavior has evolved through time and responds to local environments, human behavioral ecologists collect data on populations across the world. Globally, people are choosing to have fewer children than in the past. Some countries are still dealing with overpopulation, but an even larger number are dealing with<strong> population aging<\/strong> and fear of depopulation. Understanding decisions about how many children to have is important in today\u2019s world and is the focus of my research. To examine how family size is changing, researchers calculate <strong>total fertility rate<\/strong>, which is specific to a given year and is calculated as the total number of children that would be born to a female if she were to give birth at that particular year\u2019s age-specific fertility rate for each age. This is a value that represents the fertility of females at all ages in a particular year but does not represent any particular person (since a real person experiences fertility across many years). I conducted fieldwork in rural Bolivia, a place where the total fertility rate was approximately 6 children per woman in 1970 but fell to only 3 children per woman by 2013 (World Bank 2022). By interviewing people who live in communities that are undergoing rapid changes in fertility rates, I attempt to understand how people make decisions about family size.<\/p>\n<figure style=\"width: 306px\" class=\"wp-caption alignleft\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image7-2-1.jpg\" alt=\"A woman walks on an unpaved street.\" width=\"306\" height=\"338\" \/><figcaption class=\"wp-caption-text\">Figure C.7: Conducting fieldwork in Bolivia. Credit: Conducting fieldwork in Bolivia original to Explorations: An Open Invitation to Biological Anthropology (2nd ed.) by Kristin Snopkowski is under a <a class=\"rId38\" href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/\">CC BY-NC 4.0 License<\/a>.<\/figcaption><\/figure>\n<p>Figure C.8 shows me walking from house to house during my fieldwork in Bolivia. My interviews with over 500 Bolivian women found that those who had more education or those who expected their children to go further in school had fewer children and that family size was similar across groups of friends (Snopkowski and Kaplan 2014). While the conflict between work and childcare is particularly difficult for parents in postindustrialized contexts, in this rural Bolivian community, most women were able to integrate their daily work with childcare. For instance, a woman may own a shop where she could engage in childcare and run the shop simultaneously. To fully understand human behavior cross-culturally, we need to examine many different societies. Using large datasets collected in 45 different countries, my collaborator and I were able to examine how factors such as education and wealth may have different effects on fertility across the world (Colleran and Snopkowski 2018). Our results showed that in every country surveyed, more education for women was associated with having fewer children, but the effect of wealth varied. In countries with high fertility, more wealth typically associated with more children, but in countries with low fertility, more wealth was typically associated with fewer children. These results show that as people have access to more education and choose to educate themselves and their children, small families will become the norm everywhere in the world.<\/p>\n<\/div>\n<div class=\"textbox shaded\">\n<h2 class=\"import-Normal\">Review Questions <strong><br \/>\n<\/strong><\/h2>\n<ul>\n<li class=\"import-Normal\">In human behavioral ecology, human behavior is the result of the interaction among which two factors?<\/li>\n<li class=\"import-Normal\">What are the three main explanations for why people in small-scale societies share food extensively?<\/li>\n<li class=\"import-Normal\">Describe the difference between a proximate and an ultimate explanation and include an example of each.<\/li>\n<li class=\"import-Normal\">What are two misconceptions about human behavioral ecology?<\/li>\n<li class=\"import-Normal\">What contemporary world issues can human behavioral ecology help us solve?<\/li>\n<\/ul>\n<\/div>\n<h2 class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\"><strong>Key Terms<br \/>\n<\/strong><\/h2>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\"><strong>Altruism<\/strong>: Providing a benefit to someone else at a cost to oneself, without expecting future reciprocation.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\"><strong>Biological determinism<\/strong>: The idea that behaviors are determined exclusively by genes.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt;\"><strong>Costly signaling theory<\/strong>: A theory by which individuals provide honest signals about personal attributes through costly displays.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\"><strong>Ecology<\/strong>: The physical and social environment, including food resources, predators, terrain, weather, social rules, behavior of other people, and cultural rules.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\"><strong>Evolutionary history<\/strong>: An understanding of how traits (including behaviors) may be the result of natural selection in our hominin past.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\"><strong>Human Behavioral Ecology<\/strong>: The field of anthropology that explores how ecological factors and evolutionary history combine to influence how humans behave.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\"><strong>Kin selection<\/strong>: A type of natural selection whereby people help relatives, which can evolve because people are helping other individuals with whom they share genes.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\"><strong>Naturalistic fallacy<\/strong>: The incorrect belief that what occurs is what ought to be.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\"><strong>Population aging<\/strong>: An increase in the number and proportion of people who are over the age of 60.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\"><strong>Proximate explanation<\/strong>: The mechanism that is immediately responsible for an event.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\"><strong>Reciprocal altruism<\/strong>: Helping behavior that occurs because individuals expect that any help they provide will be reciprocated in the future.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\"><strong>Total fertility rate<\/strong>: the number of children a hypothetical female would have at the end of their reproductive period if they experienced fertility rates of a given year for each year of their reproductive period and were not subject to mortality. It represents the fertility of all females in a given year. It is reported as children per woman.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\"><strong>Ultimate explanation<\/strong>: An explanation for an event that is further removed than a proximate explanation but provides a greater insight or understanding. In human behavioral ecology, ultimate explanations usually describe how a behavior is linked to reproduction and survival.<\/p>\n<h2 class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">About the Author <strong><br \/>\n<\/strong><\/h2>\n<h2 class=\"import-Normal\"><img class=\"alignleft\" src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image5-11.png\" alt=\"Head and shoulders of a woman with shoulder length, light brown hair.\" width=\"273\" height=\"228\" \/><\/h2>\n<h2 class=\"import-Normal\"><strong>Kristin Snopkowski, Ph.D.<\/strong><\/h2>\n<p class=\"import-Normal\">Boise State University, <a class=\"rId40\" href=\"mailto:kristinsnopkowski@boisestate.edu\">kristinsnopkowski<\/a><a class=\"rId41\" href=\"mailto:kristinsnopkowski@boisestate.edu\">@boisestate.edu<\/a><\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Kristin Snopkowski is Associate Professor of Anthropology at Boise State University specializing in human behavioral ecology. Her research examines reproductive decisions, including how many children people have, how other family members influence fertility decisions, and the interaction between females and males in negotiating these decisions. She has conducted field work in Bolivia and Peru, interviewing women about their reproductive choices, and has been analyzing data sets from around the world to understand how environmental factors influence these decisions worldwide. She has published more than 15 peer-reviewed journal articles and co-edited the special issue <em>The Behavioral Ecology of the Family. <\/em><\/p>\n<h2 class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">For Further Exploration<strong><br \/>\n<\/strong><\/h2>\n<p>Barrett, Louise, Robin Dunbar, and John Lycett. 2002. <em>Human Evolutionary Psychology. <\/em>Princeton: Princeton University Press.<\/p>\n<p>Cronk, Lee, and Beth L. Leech. 2013. <em>Meeting at Grand Central: Understanding the Social and Evolutionary Roots of Cooperation. <\/em>Princeton: Princeton University Press.<\/p>\n<p>Low, Bobbi S. 2015. <em>Why Sex Matters: A Darwinian Look at Human Behavior.<\/em> Princeton: Princeton University Press.<\/p>\n<p>Raihani, Nichola. 2021. <em>The Social Instinct: How Cooperation Shaped the World<\/em>. New York: St. Martin\u2019s Press.<\/p>\n<h2 class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">REFERENCES<\/h2>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Andreoni, James, and Ragan Petrie. 2004. \u201cPublic Goods Experiments without Confidentiality: A Glimpse into Fund-Raising.\u201d <em>Journal of Public Economics<\/em> 88 (7-8): 1605\u20131623. https:\/\/doi.org\/10.1016\/S0047-2727(03)00040-9.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Boyd, Robert, and Peter J. Richerson. 1992. \u201cPunishment Allows the Evolution of Cooperation (or Anything Else) in Sizable Groups.\u201d <em>Ethology and Sociobiology<\/em> 13 (3): 171\u2013195. Center on Philanthropy at Indiana University. 2008. \u201cKey Findings about Charitable Giving.\u201d Accessed June 26, 2023. <a class=\"rId42\" href=\"https:\/\/scholarworks.iupui.edu\/bitstream\/handle\/1805\/5775\/copps_2005_key_findings.pdf?sequence=1&amp;isAllowed=y\">https:\/\/scholarworks.iupui.edu\/bitstream\/handle\/1805\/5775\/copps_2005_key_findings.pdf?sequence=1&amp;isAllowed=y<\/a>.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Colleran, Heidi, and Kristin Snopkowski. 2018. \u201cVariation in Wealth and Educational Drivers of Fertility Decline across 45 Countries.\u201d <em>Population Ecology<\/em> 60: 155\u2013169. https:\/\/doi.org\/10.1007\/s10144-018-0626-5.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Curtis, Valerie. 2013. <em>Don\u2019t Look, Don\u2019t Touch, Don\u2019t Eat<\/em>. Chicago: University of Chicago Press.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">de Waal, Frans B. M. 2000. \u201cPrimates\u2014A Natural Heritage of Conflict Resolution.\u201d <em>Science<\/em> 289 (5479): 586\u2013590. https:\/\/doi.org\/10.1126\/science.289.5479.586.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Dunbar, Robin I. M. 1998. \u201cThe Social Brain Hypothesis.\u201d <em>Evolutionary Anthropology<\/em> 6 (5): 178\u2013190.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Editors of Encyclopaedia Britannica. 2018. \u201cIndian Ocean Tsunami of 2004.\u201d <em>Encyclopaedia <\/em><em>Britannica<\/em>. Accessed June 26, 2023. <a class=\"rId43\" href=\"https:\/\/www.britannica.com\/event\/Indian-Ocean-tsunami-of-2004\">https:\/\/www.britannica.com\/event\/Indian-Ocean-tsunami-of-2004<\/a>.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Fehr, Ernst, and Urs Fischbacher. 2003. \u201cThe Nature of Human Altruism.\u201d <em>Nature<\/em> 425: 785\u2013791.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Gurven, Michael. 2004. \u201cReciprocal Altruism and Food-Sharing Decisions among Hiwi and Ache Hunter-Gatherers.\u201d <em>Behavioral Ecology and Sociobiology<\/em> 56 (4): 366\u2013380. https:\/\/doi.org\/10.1007\/s00265-004-0793-6.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Gurven, Michael, Wesley Allen-Arave, Kim Hill, and Magdalena Hurtado. 2000. \u201c\u2018It\u2019s a Wonderful Life\u2019: Signaling Generosity among the Ache of Paraguay.\u201d <em>Evolution and Human <\/em><em>Behavior<\/em> 21 (4): 263\u2013282.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Hamilton, W. D. 1964. \u201cThe Genetical Evolution of Social Behaviour I &amp; II.\u201d <em>Journal of <\/em><em>Theoretical Biology<\/em> 7 (1): 1\u201352.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Hrdy, Sarah Blaffer. 2009. <em>Mothers and Others: The Evolutionary Origins of Mutual Understanding<\/em>. Cambridge, MA: The Belknap Press of Harvard University Press.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Johnson, Jeffrey G., Patricia Cohen, Jocelyn Brown, Elizabeth M. Smailes, and David P. Bernstein. 1999. \u201cChildhood Maltreatment Increases Risk for Personality Disorders during Early Adulthood.\u201d <em>Archives of General Psychiatry<\/em> 56 (7): 600\u2013606. https:\/\/doi.org\/10.1001\/archpsyc.56.7.600.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Milinski, Manfred, Dirk Semmann, and Hans-J\u00fcrgen Krambeck. 2002. \u201cReputation Helps Solve the \u2018Tragedy of the Commons.\u2019\u201d <em>Nature<\/em> 415: 424\u2013426.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">National Center for Homeless Education. 2017. \u201cFederal Data Summary: School Years 2013\u20132014 to 2015\u20132016.\u201d Accessed June 26, 2023. https:\/\/nche.ed.gov\/wp-content\/uploads\/2018\/11\/data-comp-1314-1516.pdf.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Parker, Sue Taylor, and Kathleen Rita Gibson. 1979. \u201cA Developmental Model for the Evolution of Language and Intelligence in Early Hominids.\u201d <em>Behavioral and Brain Sciences<\/em> 2 (3): 367\u2013381. https:\/\/doi.org\/10.1017\/S0140525X0006307X.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Pepper, Gillian V., and Daniel Nettle. 2014. \u201cOut-of-Control Mortality Matters: The Effect of Perceived Uncontrollable Mortality Risk on a Health-Related Decision.\u201d <em>PeerJ<\/em> 2: e459. https:\/\/doi.org\/10.7717\/peerj.459.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Schradin, Carsten. 2021. \u201cCorona, Climate Change, and Evolved Human Behavior\u201d <em>Trends in Ecology &amp; Evolution<\/em> 36 (7): 569-572.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Sear, Rebecca, and Ruth Mace. 2008. \u201cWho Keeps Children Alive? A Review of the Effects of Kin on Child Survival.\u201d <em>Evolution and Human Behavior<\/em> 29 (1): 1\u201318. https:\/\/doi.org\/10.1016\/j.evolhumbehav.2007.10.001.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Smith, Eric Alden, and Rebecca L. Bliege Bird. 2000. \u201cTurtle Hunting and Tombstone Opening: Public Generosity as Costly Signaling.\u201d <em>Evolution and Human Behavior<\/em> 21 (4): 245\u2013261. <a class=\"rId44\" href=\"https:\/\/doi.org\/10.1016\/S1090-5138(00)00031-3\">https:\/\/doi.org\/10.1016\/S1090-5138(00)00031-3<\/a>.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Smith, Eric Alden, Rebecca Bliege Bird, and Douglas W. Bird. 2003. \u201cThe Benefits of Costly Signaling: Meriam Turtle Hunters.\u201d <em>Behavioral Ecology<\/em> 14 (1): 116\u2013126. <a class=\"rId45\" href=\"https:\/\/doi.org\/10.1093\/beheco\/14.1.116\">https:\/\/doi.org\/10.1093\/beheco\/14.1.116<\/a>.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Snopkowski, Kristin, and Hillard Kaplan. 2014. \u201cA Synthetic Biosocial Model of Fertility Transition: Testing the Relative Contribution of Embodied Capital Theory, Changing Cultural Norms, and Women\u2019s Labor Force Participation.\u201d <em>American Journal of Physical Anthropology<\/em> 154 (3): 322\u2013333. https:\/\/doi.org\/10.1002\/ajpa.22512.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Trivers, Robert L. 1971. \u201cThe Evolution of Reciprocal Altruism.\u201d <em>The Quarterly Review of <\/em><em>Biology<\/em> 46 (1): 35\u201357. https:\/\/doi.org\/10.1086\/406755.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">World Bank. 2022. \u201cFertility Rate, Total (Births per Woman): Bolivia.\u201d The World Bank Group. Accessed November 15, 2022. <a class=\"rId46\" href=\"https:\/\/data.worldbank.org\/indicator\/SP.DYN.TFRT.IN?locations=BO\">https:\/\/data.worldbank.org\/indicator\/SP.DYN.TFRT.IN?locations=BO<\/a>.<\/p>\n<\/div>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_281_1700\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_281_1700\"><div tabindex=\"-1\"><div class=\"__UNKNOWN__\">\n<p class=\"import-Normal\">Robyn Humphreys, MSc., University of Cape Town<\/p>\n<p class=\"import-Normal\"><em>This appendix is a revision of the \u201c<\/em><a class=\"rId7\" href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/chapter\/__unknown__-16\/\"><em>Chapter 11 Special Topics: Ancient DNA<\/em><\/a><em>\u201d by Robyn Humphreys<\/em><em>. In <\/em><a class=\"rId8\" href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/\"><em>Explorations: An Open Invitation to Biological Anthropology, first edition<\/em><\/a><em>, edited by Beth Shook, Katie Nelson, Kelsie Aguilera, and Lara Braff, which is licensed under <\/em><a class=\"rId9\" href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\"><em>CC BY-NC 4.0<\/em><\/a><em>. <\/em><\/p>\n<div class=\"textbox textbox--learning-objectives\">\n<header class=\"textbox__header\">\n<h2 class=\"textbox__title\"><span style=\"color: #ffffff;\">Learning Objectives<\/span><\/h2>\n<\/header>\n<div class=\"textbox__content\">\n<ul>\n<li>Describe the challenges in recovering and sequencing ancient DNA.<\/li>\n<li>Explain how the Denisovans were discovered and what we have learned about them based on their aDNA.<\/li>\n<li>Describe the relationships between Neanderthals, Denisovans, and modern humans based on aDNA evidence.<\/li>\n<li>Explain how DNA can provide insights into the population structure of hominin groups of the past.<\/li>\n<\/ul>\n<\/div>\n<\/div>\n<p>Ancient DNA (aDNA) has provided us with new insights into our evolutionary history that cannot be garnered from the fossil record alone. For example, it has assisted with the discovery of the Denisovans, for whom little fossil evidence is available. It has helped us better understand, and make inferences about, the evolution of and relationships among Neanderthals, Denisovans, and modern humans. It has also helped to answer some very important questions about what happened when modern humans migrated out of Africa and encountered these European\/Asian hominins, as we will discuss in this appendix.<\/p>\n<h2 class=\"import-Normal\">Sequencing Ancient Genomes<\/h2>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">The first successful sequencing of aDNA from an archaic hominin took place in 1997 with the sequencing of mitochondrial DNA (mtDNA) from a Neanderthal-type specimen from Feldhofer Cave. mtDNA is ideal for aDNA studies because it is more abundant than nuclear DNA in our cells. This mitochondrial sequence provided evidence that Neanderthals belonged in a clade separate from modern humans and that their mtDNA was four times more different from modern humans than modern human mtDNA was from each other (Krings et al. 1997).<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Sequencing of nuclear DNA would not occur until more than ten years later. The first nuclear genomic sequence representing Neanderthals was produced by sequencing three individuals and using their sequences to create a composite draft Neanderthal genome (Green et al. 2010). The first high-coverage sequence of a single Neanderthal was that of a female Neanderthal who lived in Siberia, followed by another high-coverage sequence from a female Neanderthal whose remains were found in the Vidja cave in Croatia (Pr\u00fcfer et al. 2014). <strong>H<\/strong><strong>igh-coverage sequence<\/strong><strong>s<\/strong> are produced when the genome has been sequenced multiple times, which ensures that the sequences are a true reflection of the genomic sequence and not due to errors that occur during the process of sequencing.<\/p>\n<h2 class=\"import-Normal\">Collecting and Sequencing aDNA<\/h2>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">While aDNA can be collected from many different sources (e.g., soft tissue, hair, paleo feces, soils, and sediments), when studying ancient hominins it is most often collected from bone and teeth. Because extraction of aDNA requires destruction of part of the tissue, and the morphology of the skeletal element might be informative, care needs to be taken when deciding what is sampled. Multiple samples are often taken to allow repeat sequencing and demonstrate reproducibility of results. All samples must be minimally handled to avoid contamination.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\"><strong>Endogenous aDNA<\/strong>, or DNA that was present in the tissue before the body decomposed, are usually in fragments 100 to 300 base pairs (bp) long due to degradation, and thus difficult to study. Sometimes DNA from other sources, known as <strong>exogenous DNA,<\/strong> are also found in samples. Some examples include DNA from microbes or modern human contamination (Figure D.1).<\/p>\n<figure style=\"width: 521px\" class=\"wp-caption aligncenter\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/06\/image2-8-1.png\" alt=\"A test tube with different types of DNA - see the caption for the full list.\" width=\"521\" height=\"338\" \/><figcaption class=\"wp-caption-text\">Figure D.1: The different types of DNA you may find after DNA extraction is performed on bone or other samples. In the sample you can see microbial DNA, modern human contamination DNA (both exogenous DNA), and endogenous hominin aDNA. Credit: <a class=\"rId11\" href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/chapter\/__unknown__-16\/\">DNA extraction (Figure 11.12)<\/a> original to <a class=\"rId12\" href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/\">Explorations: An Open Invitation to Biological Anthropology<\/a> by Robyn Humphreys is under a <a class=\"rId13\" href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/\">CC BY-NC 4.0 License<\/a>.<\/figcaption><\/figure>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">There are also modifications that occur to aDNA due to chemical reactions. For example, <strong>deamination<\/strong> results in Cytosine (C) to Thymine (T) conversions, which occur mostly at the 5\u2019 end <strong>(5 prime end) <\/strong>of the DNA fragment. This in turn results in Guanine (G) to Adenine (A) substitutions on the 3\u2019 end <strong>(3 prime end) <\/strong>of the DNA fragment. These sequence changes in aDNA might not reflect the original hominin sequence, yet these changes can be helpful when differentiating between aDNA and modern human DNA contamination. The environment plays a significant role, as DNA preserves well in cold conditions such as permafrost. aDNA has also been recovered from material found in drier environments under special conditions. Factors such as water percolation, salinity, pH, and microbial growth all affect the preservation of aDNA.<\/p>\n<p class=\"import-Normal\">The bone that best preserves DNA after death is the petrous portion of the temporal bone. This forms part of the skull and protects the inner ear. Due to its high density, the petrous portion preserves DNA very well. Thus, it is possible to get DNA from older and less well-preserved individuals when using the petrous portion. Compared to other bones, the petrous portion not only preserves DNA better but also allows for the extraction of more DNA. The petrous portion can yield up to 100 times more DNA than other bones (Pinhasi et al. 2015)<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Initially the short fragments and degraded nature of aDNA posed a big problem with the usual polymerase chain reaction (PCR) procedures used to sequence DNA. But, the advent of <strong>high<\/strong>-<strong>throughput sequencin<\/strong><strong>g<\/strong> has revolutionized sequencing the genomes of ancient hominins. High-throughput sequencing allows for the parallel sequencing of many fragments of DNA in one reaction, without prior knowledge of the target sequence. In this way, the maximum amount of available aDNA can be sequenced. Because the high-throughput sequencing method does not discriminate between endogenous aDNA and exogenous DNA, it is important to either ensure that there is as little contamination as possible and\/or use methods that allow for differentiation of the target aDNA.<\/p>\n<h2 class=\"import-Normal\">The Discovery of Denisovans<\/h2>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Denisovans, named after the Siberian cave in which they were discovered, are a distinct group of hominins that were identified through aDNA. Analysis of the ancient mtDNA from teeth and bone fragments revealed they had haplotypes outside the range of variation of modern humans and Neanderthals. The phalanx bone from which the DNA of the Denisovan was recovered did not have traits that indicated that it was another species. A<strong> haplotype<\/strong> is a set of genetic variants located on a single stretch of the genome. Shared or similar haplotypes can be used to identify ancestral relationships and to differentiate groups. Dubbed lineage X, the mtDNA sequence from these fossils suggested that Denisovans diverged from modern humans and Neanderthals.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Subsequent high-coverage sequence of a Denisovan (Denisovan 3) nuclear genome showed that Denisovans are a sister group to Neanderthals and thus more closely related to them than indicated by the mtDNA data (Brown et al. 2016). Because mtDNA and nuclear DNA have different patterns of inheritance, they can paint different pictures about the relationships between two groups. The Denisovans are now thought to have a mtDNA sequence derived from an ancient hominin group that hybridized with Denisovans and introduced the mtDNA sequence.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Sequences from three other Denisovans (Denisovan 2, 4, and 8) that provide insight into how old the specimens are, along with the usual dating methods (such as radio carbon dating and uranium dating), show that Denisovans occupied the Denisovan cave from around 195 kya to 52 kya to 76 kya. DNA can assist with dating because, compared to older sequences, younger sequences will have accumulated more mutations from the putative common ancestral sequence. Thus, it is possible to conclude from sequence data, that Denisovan 2 is 54.2 kya to 99.4 kya older than Denisovan 3, and 20.6 kya to 37.7 kya older than Denisovan 8. Molecular data indicates that Neanderthals and Denisovans separated between 381 kya and 473 kya and that the branch leading to Denisovans and modern humans diverged around 800 kya. Denisovans are also more closely related to another set of fossils found in the cave Sima de los Huesos dated to 430 kya. Thus, the split between Neanderthals and Denisovans must have occurred before 430 kya (Meyer et al. 2016).<\/p>\n<h2 class=\"import-Normal\">What Can We Learn About Population Structure of the Neanderthals and Denisovans from aDNA?<\/h2>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Ancient DNA has helped us understand the demographics of Neanderthals and Denisovans and make inferences about population size and history. Three lines of evidence suggest that these groups had small populations toward the end of their existence.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">The first line of evidence uses <strong>coalescent<\/strong> methods. This process is used to determine which population dynamics in the past are most likely to give rise to the genetic sequences we have, and it allows us to understand population changes of the past, including recombination, population subdivision, and variable population size.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">The second indicator that Neanderthals and Denisovans had smaller population sizes is that these groups carried many deleterious (or harmful) genomic variants. Genomic variants are considered deleterious when the change in genomic sequence alters the amino acid sequence of a protein and affects the function of the protein; such variants are known as <strong>nonsynonymous mutations<\/strong>. By contrast, <strong>s<\/strong><strong>ynonymous mutations<\/strong> that occur in protein-coding regions of the genome do not change the amino acid sequence nor affect the proteins produced. Denisovans and Neanderthals have a higher ratio of nonsynonymous to synonymous mutations when compared to contemporary modern human populations. This is indicative of a small population size, because if the population were larger, natural selection would have acted on these deleterious variants and weeded them out.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">A third indicator of small population size is that the Neanderthals sequenced thus far have low levels of <strong>heterozygosity<\/strong>. Heterozygosity is measured by looking at how often two different <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_738\">alleles<\/a><\/strong> are found within a certain stretch of DNA. When you find many regions on the genome with different alleles, there is a high level of heterozygosity. When you find very few positions where there are two different alleles, this indicates a low level of heterozygosity. Both Neanderthals and Denisovans appear to have low levels of heterozygosity, indicating smaller population sizes. Ancient Neanderthal genomes also revealed that there were consanguineous relations (mating relationships between two closely related Neanderthals). This was determined by looking at the stretches of<strong> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_1464\">homozygosity<\/a><\/strong> in a female neanderthal\u2019s genome that were longer than expected and could not be explained by small population size alone.<\/p>\n<h2 class=\"import-Normal\">Sequencing Archaic Genomes to Understand Modern Humans<\/h2>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Not only did the sequencing of archaic genomes allow us to learn more about Neanderthals and Denisovans, it gave us important insights into our own evolution. Previously the human genome was only compared to our closest living relatives, the great apes, which helped us identify unique derived genomic changes that occurred since humans split from our last common ancestor with chimpanzees. Neanderthal and Denisovan genomes provide another set of comparative samples that might help us identify changes unique to modern humans that occurred after our split from the last common ancestor with Neanderthals\/Denisovans. These changes may help account for our success as a species.<\/p>\n<h2 class=\"import-Normal\">Hybridization Between Hominin Groups<\/h2>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">aDNA also provides insight into interactions between modern humans migrating out of Africa and other hominins that evolved in Europe and Asia. One of the hypotheses tested was this: if <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_1461\">hybridization<\/a><\/strong> between modern humans and Neanderthals occurred, Neanderthals would have shared more genomic variants with some modern human populations than with others. When this was tested, the data showed that Neanderthals shared more genomic variants with Europeans and Asians than with African individuals (Sankararaman 2016). This difference in relatedness was significant, indicating that there had been hybridization between Neanderthals and modern humans.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">From the genetic data, we know that Europeans have a smaller proportion of Neanderthal-derived genes than East Asians do (Pr\u00fcfer et al. 2017). Thus, there was more admixture into ancestral East Asian populations than into ancestral European populations. Oceanians (Melanesians, Australian aborigines, and other Southeast Asian islanders) have a higher proportion of their DNA derived from Denisovans and longer stretches of Denisovan DNA. DNA in chromosomes get exchanged and experience <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_281_690\">genetic recombination<\/a>, <\/strong>whereby <strong>introgressed<\/strong> regions (inherited from different species or taxon) are broken down into smaller segments each generation. Thus, longer stretches of introgressed DNA indicate that hybridization occurred more recently. Genetic analysis shows that the admixture event between the Denisovan and human ancestors of these populations is more recent than the admixture events between Neanderthals and modern humans.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">To determine whether shared sequences are a result of introgression or more ancient substructure, researchers use <strong>d<\/strong><strong>ivergence time<\/strong><strong>:<\/strong> a measure of how long two sequences have been changing independently. The longer the two sequences have been changing independently, the more differences they will accumulate, which will result in a longer divergence time. By measuring the divergence time between the introgressed regions in modern human genomes and the Neanderthal sequences, researchers can calculate that the shared sequences are recent as well as date to when the two taxa made secondary contact. This is well after the initial population split between modern humans and Neanderthals. There has been gene flow from Neanderthals and Denisovans into modern human populations, between Neanderthals and Denisovans, and from modern humans into Neanderthals.<\/p>\n<p class=\"import-Normal\">There is variation in how much of the Neanderthal genome is represented in the modern human population. Individuals outside of Africa usually have 1% to 4% of their genome derived from Neanderthals. Approximately 30% of the Neanderthal genome is represented in modern human genomes, altogether.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Introgressed genes have signatures that allow us to identify them and differentiate them from parts of the genome that are not introgressed. This can be identified in at least three ways. First, in this case, if the sequence is more similar to the Neanderthal sequence (i.e.,fewer sequence differences from the Neanderthal than the African modern human), it is likely that it is derived from a Neanderthal. Second, what is the divergence time between the allele and the same allele in a Neanderthal? If it is shorter than the divergence time between humans and Neanderthal, then the gene is most likely introgressed. An example of this can be seen in Figure D.2. Third, consider whether the allele that meets the first two criteria and is identified as possibly being introgressed can be found at higher frequencies in populations outside of Africa.<\/p>\n<figure style=\"width: 752px\" class=\"wp-caption aligncenter\"><img src=\"https:\/\/opentextbooks.concordia.ca\/explorations\/wp-content\/uploads\/sites\/57\/2023\/08\/image1-5-1.jpg\" alt=\"Three DNA sequences for comparison.\" width=\"752\" height=\"184\" \/><figcaption class=\"wp-caption-text\">Figure D.2: The middle (b) DNA sequence is that of a modern human with an introgressed genomic region (DNA inherited from a more recent Neanderthal ancestor, highlighted in yellow). This DNA sequence is compared to (c) a human sequence with no introgression and (a) a Neanderthal sequence. The introgressed region of DNA can be recognized because it has more sequence similarity with that of neanderthal DNA, indicating that region has had a shorter divergence time from a Neanderthal ancestor. Credit: <a class=\"rId15\" href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/chapter\/__unknown__-16\/\">Introgressed Neanderthal DNA in a modern human genome (Figure 11.14)<\/a> original to <a class=\"rId16\" href=\"https:\/\/pressbooks-dev.oer.hawaii.edu\/explorationsbioanth\/\">Explorations: An Open Invitation to Biological Anthropology<\/a> by Robyn Humphreys is under a <a class=\"rId17\" href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/\">CC BY-NC 4.0 License<\/a>.<\/figcaption><\/figure>\n<p class=\"import-Normal\">Examining the genomes of modern humans, we can see that there are regions of the genome with no Neanderthal and Denisovan genomic variants. These are known as Neanderthal or Denisovan introgression deserts. There are also overlaps between regions in the human genome that are Neanderthal and Denisovan deserts, which might indicate genomic incompatibilities between modern humans and these groups, resulting in those genes being selected against in the modern human genome. We can also infer that hybridization may itself have been a barrier to gene flow because there is a significant reduction in introgression on the X chromosome and around genes that are disproportionately expressed in the testes compared to other tissue groups. This could indicate that hybridization between modern humans and Neanderthals may have resulted in male hybrid infertility.<\/p>\n<p class=\"import-Normal\">Because of the climate in Africa, it has been difficult or impossible to extract aDNA from African fossil remains. However, analysis of genomes of modern African populations indicate that there was admixture between modern humans and other hominins within Africa (see Figure D.2).<\/p>\n<h2 class=\"import-Normal\">Confirmed Fossil Hybrids<\/h2>\n<p class=\"import-Normal\">Another line of evidence concerns hybrids. A first-generation hybrid is called an F1 hybrid; it is the direct offspring of two lineages that have been evolving independently over an extended period. A second-generation hybrid (F2) would be the offspring of two F1 hybrids. A backcrossed individual is the result of an F1 or F2 hybrid mating with an individual from one of the parental populations. An example of a backcross would be when a Neanderthal-human hybrid produces offspring with a human; their offspring would be considered a first-generation backcrossed hybrid (B1). Sequencing of aDNA from fossil material has confirmed that hybridization between different hominins has occurred, supporting the introgression data from recent populations.<\/p>\n<p class=\"import-Normal\">The sequencing of Oase 1, a suspected hybrid based on skeletal morphology, showed that it had a Neanderthal ancestor as recently as six to eight generations back. He would thus be considered a backcrossed individual. The recent sequencing of a 13-year-old Denisovan female showed that she was the F1 hybrid offspring of a Neanderthal mother (from whom she inherited Neanderthal mtDNA) and a Denisovan father. While these are only two examples of individuals who are confirmed hybrids, many other remains show some indication of gene flow between hominins.<\/p>\n<h2 class=\"import-Normal\">The Future of Genetic Studies<\/h2>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">We are continuing to learn how introgressed genes affect modern humans. Combining phenotypic and genetic information, Neanderthal-derived genes have been associated with diverse traits, ranging from thes skin's sun sensitivity to excessive blood clotting by certain individuals. Interesting research has also shown that introgressed alleles might produce different gene expression profiles when compared to non-introgressed alleles. However, there is a lot of research still to be done to fully understand the effects of introgression on modern populations and how it might have assisted modern humans who migrated out of Africa.<\/p>\n<div class=\"textbox shaded\">\n<h2 class=\"import-Normal\" style=\"margin-left: 36pt;\">Review Questions <strong><br \/>\n<\/strong><\/h2>\n<ul>\n<li>What are three reasons that ancient DNA is so difficult to study?<\/li>\n<li>What are introgressed regions of DNA? What insights do studying introgression provide about early hominins?<\/li>\n<li>Diagram our current understanding of Denisovan, Neanderthal, and modern human lineages based on ancient DNA.<\/li>\n<li>How can ancient DNA help us understand Neanderthal demographics?<\/li>\n<\/ul>\n<\/div>\n<h2 class=\"import-Normal\">Key Terms<\/h2>\n<p class=\"import-Normal\"><strong>5 prime end<\/strong>: A nucleic acid strand that terminates at the chemical group attached to the fifth carbon in the sugar-ring.<\/p>\n<p class=\"import-Normal\"><strong>3 prime end<\/strong>: A nucleic acid strand that terminates at the hydroxyl (-OH) chemical group attached to the third carbon in the sugar-ring.<\/p>\n<p class=\"import-Normal\"><strong>Allele<\/strong>: Each of two or more alternative forms of a gene that arise by mutation and are found at the same place on a chromosome.<\/p>\n<p class=\"import-Normal\"><strong>C<\/strong><strong>oalescent<\/strong><strong> methods<\/strong>: These are models which allow for inference of how genetic variants sampled from a population may have originated from a common ancestor<\/p>\n<p class=\"import-Normal\"><strong>Deamination<\/strong>: The chemical process that results in the conversion of Cytosine to uracil, which results in Cytosine to Thymine conversions during sequencing.<\/p>\n<p class=\"import-Normal\"><strong>Divergence time<\/strong>: A measure of how long two genomic sequences have been changing independently.<\/p>\n<p class=\"import-Normal\"><strong>Endogenous aDNA<\/strong>: A form of ancient DNA in which DNA originates from the specimen being examined.<\/p>\n<p class=\"import-Normal\"><strong>Exogenous DNA<\/strong>: DNA that originates from sources outside of the specimen you are trying to sequence.<\/p>\n<p class=\"import-Normal\"><strong>Genetic recombination<\/strong>: This is the process of exchange of DNA between two strands to produce new sequence arrangements.<\/p>\n<p class=\"import-Normal\"><strong>Haplotype<\/strong>: A set of genetic variants located on a single stretch of the genome. This unique combination of variants on a stretch of the genome can be used to differentiate groups that will have different combinations of variants.<\/p>\n<p class=\"import-Normal\"><strong>Heterozygosity<\/strong>: A measure of how many genes within a diploid genome are made up of more than one variant for a gene.<\/p>\n<p class=\"import-Normal\"><strong>H<\/strong><strong>igh-coverage sequence<\/strong><strong>s<\/strong>: These are genomic sequences which have been sequenced multiple times to ensure that the sequence produced is a true reflection of the genomic sequence, and reduce the likelihood that the sequence has sequencing errors as a result of the sequencing process.<\/p>\n<p class=\"import-Normal\"><strong>H<\/strong><strong>igh<\/strong>-<strong>throughput sequencing<\/strong>: DNA sequencing technologies developed in the early 21st century that are capable of sequencing many DNA molecules at a time.<\/p>\n<p class=\"import-Normal\"><strong>Homozygosity<\/strong>: A measure of how many genes within a diploid genome are made up of more than the same variant for a gene.<\/p>\n<p class=\"import-Normal\"><strong>Hybridization<\/strong>: Mating between two genetically differentiated groups (or species).<\/p>\n<p class=\"import-Normal\"><strong>Introgressed genes<\/strong>: This is the movement of genes from one species to the gene pool of another species through hybridization between the species and backcross into the parental population by hybrid offspring.<\/p>\n<p class=\"import-Normal\"><strong>Nonsynonymous mutations<\/strong>: These are changes that occur in the protein-coding region of the genome and result in a change in amino acid sequence of the protein being produced.<\/p>\n<p class=\"import-Normal\"><strong>S<\/strong><strong>ynonymous mutations<\/strong>: Mutations that occur in the protein-coding region of the genome but do not result in a change in amino acid sequence of the protein being produced.<\/p>\n<h2 class=\"import-Normal\">About the Author<\/h2>\n<h3 class=\"import-Normal\"><strong>Robyn Humphreys, MSc.<\/strong><\/h3>\n<p class=\"import-Normal\">University of the Western Cape, rhumphreys@uwc.ac.za<\/p>\n<p class=\"import-Normal\">Robyn Humphreys is a biological anthropologist based in the archaeology department at the University of Cape Town. Her MSc focused on the role of hybridization in human evolution. She is now pursuing her Ph.D., which will involve looking at the relationship between archaeologists and communities in relation to research on human remains from historical sites in Cape Town.<\/p>\n<h2 class=\"import-Normal\">For Further Exploration<\/h2>\n<p>Fu, Qiaomei, Mateja Hajdinjak, Oana Teodora Moldovan, Silviu Constantin, Swapan Mallick, Pontus Skoglund, Nick Patterson, et al. 2015. \u201cAn Early Modern Human from Romania with a Recent Neanderthal Ancestor.\u201d <em>Nature<\/em> 524 (7564): 216.<\/p>\n<p>P\u00e4\u00e4bo, Svante. 2011. \u201cDNA Clues to Our Inner Neanderthal.,\u201d TED Talk by Svante P\u00e4\u00e4bo, August 2011. Last accessed May 7, 2023. <a class=\"rId18\" href=\"https:\/\/www.ted.com\/talks\/svante_paeaebo_dna_clues_to_our_inner_neanderthal?language=en\">https:\/\/www.ted.com\/talks\/svante_paeaebo_dna_clues_to_our_inner_neanderthal?language=en<\/a>.<\/p>\n<h2 class=\"import-Normal\">References<\/h2>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Beyin, Amanuel. 2011. \u201cUpper Pleistocene Human Dispersals out of Africa: A Review of the Current State of the Debate.\u201d <em>International Journal of Evolutionary Biology<\/em> 2011: Article ID 615094. https:\/\/doi.org\/10.4061\/2011\/615094.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Brown, Samantha, Thomas Higham, Viviane Slon, Svante P\u00e4\u00e4bo, Matthias Meyer, Katerina Douka, Fiona Brock, et al. 2016. \u201cIdentification of a New Hominin Bone from Denisova Cave, Siberia, Using Collagen Fingerprinting and Mitochondrial DNA Analysis.\u201d <em>Science Reports<\/em> 6: 23559. https:\/\/doi.org\/10.1038\/srep23559.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Green, Richard E., Johannes Krause, Adrian W. Briggs, Tomislav Maricic, Udo Stenzel, Martin Kircher, Nick Patterson, et al. 2010. \u201cA Draft Sequence of the Neanderthal Genome.\u201d <em>Science<\/em> 328 (5979): 710\u2013722.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Krings, Matthias, Anne Stone, Ralf W. Schmitz, Heike Krainitzki, Mark Stoneking, and Svante P\u00e4\u00e4bo. 1997. \u201cNeanderthal DNA Sequences and the Origin of Modern Humans.\u201d <em>Cell<\/em> 90 (1): 19\u201330.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Meyer, Matthias, Juan-Luis Arsuaga, Cesare de Filippo, Sarah Nagel, Ayinuer Aximu-Petri, Birgit Nickel, Ignacio Mart\u00ednez, et al. 2016. \u201cNuclear DNA Sequences from the Middle Pleistocene Sima de los Huesos Hominins.\u201d <em>Nature<\/em> 531: 504\u2013507.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Pinhasi, Ron, Daniel Fernandes, Kendra Sirak, Mario Novak, Sarah Connell, Song\u00fcl Alpaslan-Roodenberg, Fokke Gerritsen, et al. 2015. \u201cOptimal Ancient DNA Yields from the Inner Ear Part of the Human Petrous Bone.\u201d <em>PLoS One<\/em> 10 (6): e0129102. https:\/\/doi.org\/10.1371\/journal.pone.0129102.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Pr\u00fcfer, Kay, Fernando Racimo, Nick Patterson, Flora Jay, Sriram Sankararaman, Susanna Sawyer, Anja Heinze, et al. 2014. \u201cThe Complete Genome Sequence of a Neanderthal from the Altai Mountains.\u201d <em>Nature <\/em>505 (7481): 43\u201349.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Pr\u00fcfer, Kay, Cesare De Filippo, Steffi Grote, Fabrizio Mafessoni, Petra Korlevi\u0107, Mateja Hajdinjak, Benjamin Vernot, et al. 2017. \u201cA High-Coverage Neandertal Genome from Vindija Cave in Croatia.\u201d Science <em>358 (6363): <\/em>655\u2013658.<\/p>\n<p class=\"import-Normal\" style=\"margin-left: 0pt; text-indent: 0pt;\">Sankararaman, Sriram, Swapan Mallick, Nick Patterson, and David Reich. 2016. \"The Combined Landscape of Denisovan and Neanderthal Ancestry in Present-Day Humans.\" <em>Current Biology<\/em> 26 (9): 1241\u20131247.<\/p>\n<\/div>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_281_1702\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_281_1702\"><div tabindex=\"-1\"><\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_281_1704\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_281_1704\"><div tabindex=\"-1\"><\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_281_1705\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_281_1705\"><div tabindex=\"-1\"><p>Crucial thanks are offered to Rachel Harris, the Scholarly Publishing Librarian in the Concordia Library, for her continuing assistance and advice as well as the allocation and coordination of the grant given to the student, Lola Leus.\u00a0 Many thanks and sincere appreciation are extended to Lola for her excellent contributions with her work on this project. Finally, I wish to thank the Students in ANTH 203, Fall 2023 for their engagement and the resulting project reports on this text.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_281_800\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_281_800\"><div tabindex=\"-1\"><p>Species that are regarded as human, directly ancestral to humans, or very closely related to humans.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_281_1708\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_281_1708\"><div tabindex=\"-1\"><div>\n<p>\u00a0As you may have noticed, the textbook for this course is an Open Educational Resource (OER). This means you have free and unrestricted access to all the material, with no need to purchase a costly textbook. As students in the <em>Culture and Biology<\/em> course, you will be assigned to critically analyze sections of the textbook. You will also be encouraged to bring your own research into the discussion, enriching the learning experience for yourself and others. Your active engagement with the textbook is not just for your benefit; it could lead to content that may be included in future editions of the textbook. This is a unique opportunity to collaborate with your peers and contribute to an academic project that will be more relevant to students in Quebec, Canada, and beyond.<\/p>\n<\/div>\n<p>As you read through each chapter, you'll notice highlighted sections. These highlights represent a colour-coded system of recommended edits from the previous semester. These edits are designed to improve the textbook's clarity, relevance, and educational value. Our focus was on five key factors:<\/p>\n<p><span style=\"background-color: #ccffcc\">Condense\/re-phrase<\/span> : Recommended by the professor, this factor addresses the issue of redundancy and overly lengthy text. We aimed to simplify the chapters by condensing and rephrasing content.<\/p>\n<p><span style=\"background-color: #ff99cc\">Eliminate<\/span> : Suggested to remove irrelevant or unnecessary information, this factor helps to focus the chapters on essential content.<\/p>\n<p><span style=\"background-color: #ff9900\">Refer to other chapters<\/span>: Due to frequent repetition across chapters, we decided that referring to other chapters that had already covered certain information would reduce length and redundancy.<\/p>\n<p><span style=\"background-color: #00ffff\">Replace with information from Canada\/Quebec<\/span>: One of the project's main objectives was to include content more relevant to students in Quebec and Canada. We identified sections where information could be replaced with content specific to these regions.<\/p>\n<p><span style=\"background-color: #ffff00\">Assumptions<\/span>: This factor was suggested to address the presentation of theories as established facts by the authors of the chapters. As students, it is crucial for us to understand that theories are a set of ideas used to explain facts, but they are not the final explanations and should not be presented with absolute certainty. In biological anthropology, theories are ideas that have yet to be disproven! Presenting theories as facts can hinder our comprehensive understanding of the past, which requires considering multiple perspectives.<\/p>\n<p>These edits were made during the initial stages of the project, marking the first steps in what will become a series of outstanding contributions by students. The colour-coding system you see is not a permanent structure; it serves as a draft to guide and inspire further enhancements and revisions. This is an evolving project, and your input is essential in shaping it into a resource that truly reflects the needs and perspectives of its readers. We strongly encourage you to engage deeply with the textbook, offering your valuable analysis and ideas. Your contributions have the potential to enrich the content, making it more relevant and effective for current and future students.<\/p>\n<p>You may notice some sections where only the paragraph title is highlighted. This indicates that the following content would be highlighted in the same colour, but we opted not to, in order to avoid overwhelming the textbook with too many colours. You may also come across sentences that are both in parentheses and underlined (<span style=\"text-decoration: underline\">example<\/span>). These are personal suggestions open to interpretation. Like the colour-coded edits, these sentences are not final; they are included to encourage further engagement with the textbook. We invite you to reflect on these suggestions and consider how they might be expanded, revised, or even re-imagined.<\/p>\n<p>This textbook is a living document, continually shaped by those who engage with it. Your insights and analyses are crucial in making it more relevant and significant. By challenging assumptions and sharing your unique perspectives, you enhance not only your own learning but also the future of this textbook. 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