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Anthropology

<OpenstaxParagraph>
	The <OpenstaxTerm>Pliocene epoch</OpenstaxTerm> extended from 5 MYA to 1.8 MYA. Fossils from the Pliocene show evidence of the evolution of hominins that are clearly bipedal. They also show evidence of clear, albeit primitive, cultural behavior. Climatically, the Pliocene was colder than the preceding Miocene, which resulted in changing sea levels and an increase in ice at the poles, opening up some previously inaccessible areas. During this period, North and South America became connected through the Isthmus of Panama, and a land bridge across the Bering Strait appeared between Alaska and Siberia.
</OpenstaxParagraph>
<OpenstaxH3><OpenstaxEm>Ardipithecus ramidus</OpenstaxEm></OpenstaxH3>
<OpenstaxParagraph>
	<OpenstaxTerm><OpenstaxEm>Ardipithecus ramidus</OpenstaxEm></OpenstaxTerm> was found in Ethiopia in 1992 by American paleoanthropologist Tim <OpenstaxTerm>White</OpenstaxTerm> and was dated to about 4.4 MYA. This is the first discovered hominin species to be dated to the Pliocene era. Based on the forward position of the foramen magnum, it can be concluded that <OpenstaxEm>Ardipithecus</OpenstaxEm> was bipedal. Also, the upper arm bones are very small, suggesting that the arms were not used to support weight during locomotion. <OpenstaxEm>Ardipithecus</OpenstaxEm> possesses numerous traits, such as thin dental enamel, evidence of a reduced canine, and an opposable big toe. As a result of the latter trait, many believe that <OpenstaxEm>Ardipithecus</OpenstaxEm> was bipedal on the ground and quadrupedal in the trees. This hypothesis is supported by the fact that the fossil bones were found in relatively heavily forested environments. The reduced canine is a derived trait appearing even earlier than <OpenstaxEm>A. ramidus</OpenstaxEm> and is not what we would typically see in African ape males who have large intimidating canines. Current hypotheses suggest that over time smaller canines became dominant when there became less need to show aggression along with a female preference for males with milder temperaments (Suwa, G., et al. 2021). 
</OpenstaxParagraph>
<OpenstaxFigure id="fig-00003" src="https://openstax.org/apps/archive/20240226.174525/resources/48b8366ccdd6613b9b6d26d6e4e6293dfb8594b9" alt="Partial skeleton laid out on a table. Fewer than a quarter of the bones are present." mediaType="image/jpeg" width="430" height="680" />
<OpenstaxFigureText width="430">
	Figure 4.32 These skeletal remains have been identified as Ardipithecus, the first hominin species discovered that has been dated to the Pliocene Era. (credit: Sailko/Wikimedia Commons, CC BY 3.0)
</OpenstaxFigureText>
<OpenstaxH3>The Robust and Gracile Australopithecines</OpenstaxH3>
<OpenstaxParagraph>
	The next few sections will examine various australopithecine species that had diverse physical characteristics related to morphology of the teeth and skull. Based on these characteristics, paleoanthropologists classified these species into <OpenstaxEm>gracile</OpenstaxEm> and <OpenstaxEm>robust</OpenstaxEm> forms, as illustrated in <a href="#fig-00004">Figure 4.33</a>. <OpenstaxTerm>Gracile species</OpenstaxTerm> had a more pronounced projection of the jaw (<OpenstaxTerm>prognathism</OpenstaxTerm>), less flared cheeks with no sagittal crest, and smaller teeth and jaws. The sagittal crest in the robust australopithecines accommodated large temporalis jaw muscles for chewing tough plant materials.
</OpenstaxParagraph>
<OpenstaxFigure id="fig-00004" src="https://openstax.org/apps/archive/20240226.174525/resources/c1e3705b05faab34119bfeed3b716e0de543caf5" alt="Two skulls, one identified as “Robust australopithecine” and the other as “Gracile australopithecine.” The Robust specimen has a ridge of bone along the top of the skull, identified as a sagittal crest. The Gracile specimen displays pronounced projection of the face." mediaType="image/png" width="1367" height="841" />
<OpenstaxFigureText width="1367">
	Figure 4.33 Australopithecine species are classified as either robust or gracile. A defining feature of the robust species is the sagittal crest visible on the Paranthropus boisei skull on the left. Gracile species, such as A. afarensis, on the right, display more pronounced projection of the face (prognathism). (credit: left, Rama/Wikimedia Commons, Public Domain; right, “Australopithecus afarensis Fossil Hominid (Pliocene, Eastern Africa) 1” by James St. John/flickr, CC BY 2.0)
</OpenstaxFigureText>
<OpenstaxParagraph>
	Species considered to be the gracile include <OpenstaxEm>Australopithecus anamensis</OpenstaxEm>, <OpenstaxEm>A. afarensis</OpenstaxEm>, <OpenstaxEm>A. africanus</OpenstaxEm>, <OpenstaxEm>A</OpenstaxEm>. <OpenstaxEm>garhi</OpenstaxEm>, and <OpenstaxEm>A. sediba</OpenstaxEm>. The <OpenstaxTerm>robust australopithecines</OpenstaxTerm> (classified under the genus <OpenstaxEm>Paranthropus</OpenstaxEm>) include <OpenstaxEm>Paranthropus robustus</OpenstaxEm>, <OpenstaxEm>P. boisei</OpenstaxEm>, and <OpenstaxEm>P. aethiopicus</OpenstaxEm>. The gracile species emerged around 4 MYA and disappeared 2 MYA, while robust species continued to exist for another million years. The next sections will first take a look at some of the gracile forms of australopithecine, followed by the robust forms.
</OpenstaxParagraph>
<OpenstaxH3><OpenstaxEm>Australopithecus africanus</OpenstaxEm></OpenstaxH3>
<OpenstaxParagraph>
	<OpenstaxTerm><OpenstaxEm>Australopithecus africanus</OpenstaxEm></OpenstaxTerm> was the first australopithecine discovered, in 1924, and was described by Australian anatomist and anthropologist Raymond <OpenstaxTerm>Dart</OpenstaxTerm>, who found the fossil in a box of fossils sent to him by lime quarry workers at a site called <OpenstaxTerm>Taung</OpenstaxTerm> in South Africa. The most notable specimen in the box was a skull from a child, which Dart had to chip away from the stone it was embedded in. It took Dart four years to separate the teeth. The skull is now known as the Taung skull or Taung child. Dart argued that the Taung child represents “an extinct race of apes intermediate between living anthropoids and man” (Wayman 2011). He noted that the skull was long and narrow, not rounded as in modern humans, and its brain averaged a mere 422 cc, equivalent to a chimpanzee. However, the Taung child did not possess brow ridges, had circular orbits, and had minimal prognathism as well as small canines and no <OpenstaxTerm>diastema</OpenstaxTerm> (space in the jaw for large canines to be positioned when the mouth closes). These latter traits are all analogous to modern humans. Most importantly, Dart noted that the forward position of the foramen magnum indicated that the skull was poised on top of the vertebral column, suggesting bipedalism and an upright posture.
</OpenstaxParagraph>
<OpenstaxFigure id="fig-00005" src="https://openstax.org/apps/archive/20240226.174525/resources/64dcb8978eede23417c347327b4ac3141ed8e232" alt="Partial skull with a number of human-like features, including small canines, minimal projection of the jaw, and no brow ridges." mediaType="image/jpeg" width="600" height="800" />
<OpenstaxFigureText width="600">
	Figure 4.34 This partial skull is from a specimen known as the Taung child. The species, Australopithecus africanus, displays traits that resemble modern humans in some ways but not others. (credit: Daderot/Wikimedia Commons, Public Domain)
</OpenstaxFigureText>
<OpenstaxH3><OpenstaxEm>Australopithecus afarensis</OpenstaxEm></OpenstaxH3>
<OpenstaxParagraph>
	In 1973, a good portion of a skeleton (about 40 percent) was found in the <OpenstaxTerm>Afar region</OpenstaxTerm> of Ethiopia by American paleoanthropologist Donald <OpenstaxTerm>Johanson</OpenstaxTerm>. He called the skeleton <OpenstaxTerm>Lucy</OpenstaxTerm>, after a Beatles song. It was dated to around 3.75–2.8 MYA and was determined to be a member of the species <OpenstaxEm>Australopithecus afarensis</OpenstaxEm>. Like all fossils recently discovered, Lucy was given an identification or accession number, KNM-AL-288. The KNM acronym stands for the Kenya National Museum, where the fossil is housed, and AL stands for the Afar locality where the fossil was found. Since then, more specimens of this species have been found in Kenya, Tanzania, and Ethiopia, all in East Africa.
</OpenstaxParagraph>
<OpenstaxFigure id="fig-00006" src="https://openstax.org/apps/archive/20240226.174525/resources/d844ce3bb363543fb33842cda54f5107a6df82eb" alt="Young girl standing next to a skeleton that is slightly taller than she is. The arms, fingers, and toes of the skeleton are all much longer than those of a human being." mediaType="image/jpeg" width="557" height="800" />
<OpenstaxFigureText width="557">
	Figure 4.35 This child stands next to a recreated skeleton of A. afarensis. The long arms and long, curved fingers and toes of A. afarensis are apparent. (credit: “Australopithecus afarensis Fossil Hominid (Lucy Skeleton) (Hadar Formation, Pliocene, 3.2 Ma; Hadar Area, Afar Triangle, Northern Ethiopia, Eastern Africa) 2” by James St. John/flickr, CC BY 2.0)
</OpenstaxFigureText>
<OpenstaxParagraph>
	<OpenstaxEm>Australopithecus afarensis</OpenstaxEm> is dated from 3.9 to 2.9 MYA with an endocranial capacity of around 400 cc, which is approximately the same as a common chimpanzee. There are two morphological features that provide evidence that <OpenstaxEm>A. afarenis</OpenstaxEm> moved more like a great ape than a human. First, it had arms that were substantially longer than modern humans’. Long arms are generally found in animals that hang from branches, suggesting that <OpenstaxEm>A. afarensis</OpenstaxEm> also exhibited this behavior. Also, <OpenstaxEm>A. afarensis</OpenstaxEm> possesses finger and toe bones that are long and curved, another characteristic of animals that hang from branches. However, there is one important morphological feature of <OpenstaxEm>A. afarensis</OpenstaxEm> that suggests that this species may have moved somewhat like modern humans. The shape of <OpenstaxEm>A. afarensis</OpenstaxEm>’s pelvis (hip bones) looks substantially more like a modern human’s than it does an ape’s. Instead of the hip bones being long and narrow, they are short and wide. Most paleoanthropologists believe that this change in pelvic shape indicates that <OpenstaxEm>A. afarensis</OpenstaxEm> moved like modern humans do, on two legs. While <OpenstaxEm>A. afarensis</OpenstaxEm> may have locomoted bipedally, the morphological differences between <OpenstaxEm>A. afarensis</OpenstaxEm> and modern humans suggest they did not move in exactly the same way. Current consensus is that <OpenstaxEm>A. afarensis</OpenstaxEm> was both tree dwelling and bipedal. Other anatomical evidence of bipedalism includes a more anterior position of the foramen magnum and the angle of the femoral head and neck.
</OpenstaxParagraph>
<OpenstaxH3><OpenstaxEm>Australopithecus garhi</OpenstaxEm></OpenstaxH3>
<OpenstaxParagraph>
	Also found in Ethiopia, <OpenstaxTerm><OpenstaxEm>Australopithecus garhi</OpenstaxEm></OpenstaxTerm> is dated to approximately 2.5 MYA. Its cranial capacity is slightly greater than <OpenstaxEm>A. afarensis</OpenstaxEm>, at 450 cc. <OpenstaxEm>Australopithecus</OpenstaxEm> <OpenstaxEm>garhi</OpenstaxEm> has incisors that are larger than those of any of the known australopithecines or <OpenstaxEm>Homo</OpenstaxEm>. The function of the large incisors is not yet known. The most exciting aspect of <OpenstaxEm>A. garhi</OpenstaxEm> is that it provides evidence of the earliest use of stone tools by a hominin. Specifically, <OpenstaxEm>A. garhi</OpenstaxEm> fossils were found with fossil bones of ruminants, such as antelopes, that displayed numerous cut marks. Cut marks are made on bones by the process of removing meat from the bones with stone or metal tools. Based on this finding, biological anthropologists have hypothesized that <OpenstaxEm>A. garhi</OpenstaxEm> used some type of stone tool for butchering.
</OpenstaxParagraph>
<OpenstaxH3><OpenstaxEm>Australopithecus sediba</OpenstaxEm></OpenstaxH3>
<OpenstaxParagraph>
	In 2008, the clavicle bone of <OpenstaxTerm><OpenstaxEm>Australopithecus sediba</OpenstaxEm></OpenstaxTerm> was discovered by Matthew <OpenstaxTerm>Berger</OpenstaxTerm>, the nine-year-old son of American paleontologist Lee Berger, in Malapa, South Africa. Further excavation in a cave feature uncovered two partial skeletons, one of an adult female and the other a younger juvenile. <OpenstaxEm>A. sediba</OpenstaxEm> is considered an important species because it appears in the fossil record around the time of the first emergence of the genus <OpenstaxEm>Homo</OpenstaxEm> around 2 mya. The classification of <OpenstaxEm>A. sediba</OpenstaxEm> was initially difficult to determine, due to its complex overlapping features, which include humanlike spine, pelvis, hands, and teeth and a chimpanzee-like foot. This combination of traits suggests both tree climbing and bipedal adaptations. After studying the characteristics collectively, anthropologists classified <OpenstaxEm>A. sediba</OpenstaxEm> as a species of <OpenstaxEm>Australopithecus</OpenstaxEm>. It is considered a direct ancestor of <OpenstaxEm>Homo erectus and Homo ergaster</OpenstaxEm>, which are discussed in Chapter 5, The Genus <OpenstaxEm>Homo</OpenstaxEm> and the Emergence of Us . It is believed that <OpenstaxEm>A. sediba</OpenstaxEm> could be a descendent of <OpenstaxEm>A. africanus</OpenstaxEm>, which suggests the species may be a dead end within the lineage to humans. Its classification and relationship with the genus <OpenstaxEm>Homo</OpenstaxEm> will likely remain highly debated.
</OpenstaxParagraph>
<OpenstaxFigure id="fig-00007" src="https://openstax.org/apps/archive/20240226.174525/resources/aca88ba8b322e2f00cbde82fe3b02c23601c411a" alt="Collection of bones, including a portion of a spine." mediaType="image/jpeg" width="800" height="600" />
<OpenstaxFigureText width="800">
	Figure 4.36 These bones are from Australopithecus sediba, which displays a humanlike spine and pelvis but a chimpanzee-like foot. (credit: Phiston/Wikimedia Commons, CC BY 3.0)
</OpenstaxFigureText>
<OpenstaxH3><OpenstaxEm>Paranthropus robustus</OpenstaxEm></OpenstaxH3>
<OpenstaxParagraph>
	Thirteen years after Raymond Dart’s discovery, South African paleontologist and medical doctor Robert <OpenstaxTerm>Broom</OpenstaxTerm> discovered <OpenstaxTerm><OpenstaxEm>Paranthropus robustus</OpenstaxEm></OpenstaxTerm> at a site called <OpenstaxTerm>Kromdraai</OpenstaxTerm> in South Africa. The most obvious difference between Dart’s and Broom’s respective fossils, <OpenstaxEm>A. africanus</OpenstaxEm> and <OpenstaxEm>P. robustus</OpenstaxEm>, is that the morphology of Broom’s fossil is much larger. Its features include a sagittal crest and a flared zygomatic arch for the attachment of a large temporalis muscle for chewing a diet reliant on hard nuts and seeds. This interpretation was further supported by scanning electron microscopy (SEM), which was used to evaluate the markings etched into the teeth. As the teeth increased in size the incisors and canines shrank, giving <OpenstaxEm>Paranthropus</OpenstaxEm> a flatter face with less projection of the jaw. There are some who argue that depending on the environment and locale, some <OpenstaxEm>Paranthropus</OpenstaxEm> may have been omnivores, with varied diets similar to those of <OpenstaxEm>H. ergaster</OpenstaxEm>. (Lee-Thorp, Thackeray, and van der Merwe 2000).
</OpenstaxParagraph>
<OpenstaxH3><OpenstaxEm>Paranthropus boisei</OpenstaxEm></OpenstaxH3>
<OpenstaxParagraph>
	Following in Broom’s footsteps, other scientists began searching for fossils in East Africa. Beginning in 1931, Kenyan and British paleoanthropologist Louis <OpenstaxTerm>Leakey</OpenstaxTerm> and his wife, Mary <OpenstaxTerm>Leakey</OpenstaxTerm>, worked in what is known as the <OpenstaxTerm>Eastern Rift Valley</OpenstaxTerm>, which is a 1,200-mile trough extending through Ethiopia, Kenya, and Tanzania. They searched for almost 30 years before they found their first hominin fossil, <OpenstaxTerm><OpenstaxEm>Paranthropus boisei</OpenstaxEm></OpenstaxTerm> (OH-5)—originally classified as <OpenstaxTerm><OpenstaxEm>Zinjanthropus boisei</OpenstaxEm></OpenstaxTerm>—in 1959. It is often referred to as the hyper-robust hominin because of its mohawk of bone on the top of the skull. Other features include a low or absent forehead, a flat face, large jaws, and large attachment sites over the entire skull for chewing muscles.
</OpenstaxParagraph>
<OpenstaxH3><OpenstaxEm>Paranthropus aethiopicus</OpenstaxEm></OpenstaxH3>
<OpenstaxParagraph>
	We have little knowledge about <OpenstaxTerm><OpenstaxEm>Paranthropus aethiopicus</OpenstaxEm></OpenstaxTerm> (shown in <a href="#fig-00008">Figure 4.37</a>), which has been dated to about 2.5 MYA and is referred to as the “black skull.” It is believed that this species falls somewhere between the robust and gracile australopithecines, having characteristics of both. The species was discovered in Ethiopia in 1967 by a French expedition team headed by Camille Arambourg and Yves Coppens.
</OpenstaxParagraph>
<OpenstaxFigure id="fig-00008" src="https://openstax.org/apps/archive/20240226.174525/resources/7db2a2f8de20230f24ba58556edb421a73c49569" alt="Partial skull displaying a pronounced sagittal crest, brow ridges, and large eye sockets" mediaType="image/jpeg" width="800" height="754" />
<OpenstaxFigureText width="800">
	Figure 4.37 Much remains to be learned about Paranthropus aethiopicus, which has characteristics of both the robust and gracile australopithecines. (credit: “Paranthropus aethiopicus (Fossil Hominid) (Nachukui Formation, Upper Pliocene, 2.5 Ma; Lomekwi, Lake Turkana Area, Kenya) 3” by James St. John/flickr, CC BY 2.0)
</OpenstaxFigureText>

4.7.3 Pliocene Hominins

1 What Is Anthropology?

1.1 The Study of Humanity, or "Anthropology Is Vast"

1.1.1 The Heart of Anthropology: Central Narrative and Commitments

1.1.2 Central Commitment #1: Exploring Sociocultural Diversity

1.1.3 Central Commitment #2: Understanding How Societies Hold Together

1.1.4 Central Commitment #3: Examining the Interdependence of Humans and Nature

1.2 The Four-Field Approach: Four Approaches within the Guiding Narrative

1.2.1 Biological Anthropology

1.2.2 Archaeology

1.2.3 Cultural Anthropology

1.2.4 Linguistic Anthropology

1.2.5 How the Four Fields Work Together: The Example of Race

1.3 Overcoming Ethnocentrism

1.3.1 Enculturation and Ethnocentrism

1.3.2 Primitivism and Orientalism

1.4 Western Bias in Our Assumptions about Humanity

1.4.1 Primitivism and Orientalism in Popular Culture

1.4.2 The Bias of Backwardness

1.5 Holism, Anthropology’s Distinctive Approach

1.5.1 Society as an Integrated Whole

1.5.2 Sources of Contradiction, Conflict, and Change

1.6 Cross-Cultural Comparison and Cultural Relativism

1.6.1 Relativism Is Not “Anything Goes”

1.6.2 Morality, Activism, and Cultural Relativism

1.7 Reaching for an Insider’s Point of View

1.7.1 The Challenge of Representing Others

1.7.2 Collaborative Methods of Representation

1.7.3 Working across Cultures toward Common Goals

1.7.4 Suggested Readings

2 Methods: Cultural and Archaeological

2.1 Archaeological Research Methods

2.1.1 Archaeological Techniques

2.1.2 Archaeological Dating Methods

2.2 Conservation and Naturalism

2.2.1 Early Efforts

2.2.2 Salvage Anthropology

2.2.3 Museum Collections

2.2.4 Interpretation and Voice

2.3 Ethnography and Ethnology

2.3.1 The Development of Ethnography and Ethnology

2.3.2 Perspective and Interpretation in Ethnography

2.4 Participant Observation and Interviewing

2.4.1 Participant Observation

2.4.2 Interviewing Informants

2.4.3 Ethical Considerations

2.5 Quantitative and Qualitative Analysis

2.5.1 Differences between Quantitative and Qualitative Information

2.5.2 Modeling

2.5.3 The Science of Anthropology

2.6 Collections

2.6.1 Archives

2.6.2 Three-Dimensional Collections

2.6.3 Ownership

2.6.4 Suggested Readings

3 Culture Concept Theory: Theories of Cultural Change

3.1 The Homeyness of Culture

3.2 The Winkiness of Culture

3.3 The Elements of Culture

3.3.1 Culture Is What We Make

3.3.2 Culture Is What We Do

3.3.3 Culture Is What We Think

3.4 The Aggregates of Culture

3.4.1 Symbols

3.4.2 Ritual

3.4.3 Social Structure

3.5 Modes of Cultural Analysis

3.5.1 Evolution, Adaptation, and Historical Particularism

3.5.2 Functionalism

3.5.3 Structuralism

3.5.4 Ontology

3.6 The Paradoxes of Culture

3.6.1 Paradox 1: Culture Is Continuous, but It Changes

3.6.2 Paradox 2: Culture Is Bounded but Mobile

3.6.3 Paradox 3: Culture Is Consensual but Contested

3.6.4 Paradox 4: Culture Is Shared, but It Varies

3.6.5 Suggested Readings

4 Biological Evolution and Early Human Evidence

4.1 What Is Biological Anthropology?

4.1.1 Looking to the Deep Past

4.1.2 Exploring What It Means to Be Human

4.2 What’s in a Name? The Science of Taxonomy

4.2.1 Defining the Science of Taxonomy

4.2.2 Defining a Species

4.3 It’s All in the Genes! The Foundation of Evolution

4.3.1 The Units of Life

4.3.2 Gregor Mendel and the Laws of Heredity

4.3.3 Mendelian Inheritance in Humans

4.4 Evolution in Action: Past and Present

4.4.1 Early Evolutionists and the Fixity of Species

4.4.2 Charles Darwin’s Role in Changing Views of the Natural World

4.4.3 Understanding Darwin’s Theory of Natural Selection

4.5 What Is a Primate?

4.5.1 What Is a Primate?

4.5.2 Primate Behavioral Variation

4.5.3 Explaining Primate Success

4.5.4 Primate Classification and Taxonomy

4.6 Origin of and Classification of Primates

4.6.1 Understanding Concepts of Time

4.6.2 Fossils and Dating Methods

Question	Answer
a space or gap between the canines and the other teeth that allows for the upper and lower teeth to bite together.	diastema
projection of the face, as seen in many nonhuman primates and early hominins.	prognathism