Ch 10 Early Hominin Origins and Evolution – Flashcards

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The earliest pre-australopithecine species found in central Africa with possible evidence of bipedalism.
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Sahelanthropus tchadensis
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The pre-australopithecines lived between ___ mya.
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7-4
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The australopithecines lived between ___ mya.
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4-1
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These three things do not define a hominin: (They evolved long after the first hominins appeared.)
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Speech/advanced cognition/complex material culture
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Hominins have two obligate behaviors:
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bipedal locomotion/nonhoning chewing
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This is the foundational behavior of the Hominini.
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Bipedalism
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Bipedalism preceded most attributes associated with humans and with human behavior by ____ of years.
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millions
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The 7 distinguishing characteristics in the skeleton that are associated with bipedalism:
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foramen magnum/s shaped spine/short ilium/long legs/inward knees/longitudinal foot arch/non opposable hallux
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The position of this reflects the fact that the hominin carries its head atop its body.
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Foramen magnum
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This part of hominin anatomy generally reflects changes that coincide with the shift from quadrupedalism to bipedalism.
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shortened ilium and pelvis
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The reason that the gluteal muscles were reconfigured.
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stabilize the hip
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Bipeds have distinctively ___ ___ which provide the ability to stride and to do so with minimal energy.
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Long legs
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This helps to place the feet below the body's center of gravity.
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inward knees
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This reflects the use of this digit in helping propel the body forward.
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non opposable hallux
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This acts as a kind of shock absorber, allowing the foot to sustain the demanding forces of body weight.
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longitudinal arch
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Hominin canines wear on the ___ instead of the ___.
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tips/backs
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Humans ___ food more than apes do.
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crush
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Apes use their molars more for ___, reflecting their plant-heavy diet.
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slicing
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Hominins have evolved ___ enamel, while apes have evolved ___ enamel, reflecting their different diets.
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thick/thin
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When did humans and chimps split?
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9 mya
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The human side of the evolutionary tree, after humans and chimps split.
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Hominins
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The 5 distinguishing characteristics that reflect nonhoning chewing:
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blunt nonprojecting canine/small canine/no diastema/wear on canines and third premolars/cusps on lower third premolar equal size
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A pre-australopithecine species found in East Africa that displayed some of the earliest evidence of bipedalism.
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Orrorin Tugenensis
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An early pre-australopithecine species from the late Miocene to the early Pliocene; shows evidence of a preihoning complex, a primitive trait intermediate between apes and modern humans.
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Ardipithecus Kadabba
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A later pre-australopithecine species from the late Miocene to the early Pliocene; shows evidence of both bipedalism and arboreal activity but no indication of the primitive perihoning complex.
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Ardipithecus ramidus
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The oldest species of australopithecine from East Africa and a likely ancestor to Au. afarensis.
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Australopithecus anamensis
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An early australopithecine from East Africa that had a brain size equivalent to a modern chimpanzee's and is thought to be a direct human ancestor.
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Australopithecus afarensis
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An australopithecine from East Africa that had a unique flat face and was contemporaneous with Au. afarensis.
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Australopithecus platyops
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Synonym for Australopithecus.
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Kenyanthropus
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A late australopithecine from East Africa that was contemporaneous with Au. africanus and Au. aethiopicus and was the likely ancestor to the Homo lineage.
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Australopithecus garhi
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The stone tool culture associated with H. Habilis and, possibly, Au. garhi, including primitive chopper tools.
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Oldowan complex
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The oldest part of the first stone tools were created and used, beginning with the Oldowan Complex.
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Lower Paleolithic
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An early robust australopithecine from East Africa, with the hallmark physical traits of large teeth, large face, and massive muscle attachments on the cranium.
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Australopithecus aethiopicus
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A later robust autralopithecine from East Africa that was contemporaneous with Au. robustus and Au. africanus and had the robust cranial traits, including large teeth, large face, and heavy muscle attachments.
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Australopithecus boisei
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A gracile australopithecine from South Africa that was contemporaneous with Au. aethiopicus, Au. garhi, and Au. boisei and was likely ancestral to Au. robustus.
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Australopithecus africanus
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A robust australopithecine from South Africa that may have descended from Au. afarensis, was contemporaneous with Au. boisei, and had the robust cranial traits of large teeth, large face, and heavy muscle attachments.
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Australopithecus robustus
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The earliest Homo species, a possible descendant of Au. garhi and an ancestor to H. erectus;
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Homo habilis
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The earliest known tools date to about ___ mya.
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2.6
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The earliest evidence of brain expansion dates to sometime after ___ mya.
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2
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Hunting likely didn't begin until after ___ mya.
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2
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The idea that bipedalism arose in areas where the forest was becoming fragmented, a process that began toward the end of the Miocene.
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Patchy Forest Hypothesis
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The idea that bipedalism arose so that fathers could provide food and protection to mothers.
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Provisioning hypothesis
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Hominins evolved out of ____.
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Hominoids
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These represent the first recognizable ancestors of the lineage leading to humans.
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pre-australopithecines
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The earliest pre-autralopithecuine.
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Sahelanthropus tchadensis
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Humans originated in Africa during the early ___ and late ___.
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Miocene/pliocene
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The brain of Sahelanthropus tchadensis was ____.
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Primitive
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This is one of the fossils that have transformed our understanding of the earliest period of human evolution.
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Ardipithecus ramidus
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This discovery provides compelling evidence that the first hominins did not evolve in the open grasslands.
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Ardipithecus ramidus
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This species was adapted to life in the trees and to life on the ground.
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Ardipithecus ramidus
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Key features: Skull and teeth found. Tiny brain. Skull like apes' with massive browridge. Lived in forest setting.
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Sahelanthropus tchadensis
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Key features: Skull, teeth, postcranial bones found. Small brain. Perihoning. Thin enamel. Curved foot phalanges. Capable of bipedalism. Less than 1 m tall. Lived in wooded setting.
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Ardipithecus Kadabba
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Key features: Postcranial bones found. Likely bipedalism. Hand phalanx curved like apes'. Less than 1 m tall. Lived in forest setting.
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Orrorin tugenensis
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Key features: Skull, teeth, postcranial bones found. Small brain. No perihoning. Thin enamel. Curved foot phalanges. Capable of bipedalism. 120 cm tall. Lived in wooded setting.
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Ardipithecus Ramidus
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The only hominin with thin enamel.
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Ardipithecus ramidus
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Compared with other mammals, ____ didn't vary greatly.
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Australopithecines
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As a group, ___ had a small brain, small canines, large premolars, and large molars.
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Australopithecines
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The oldest australopithecine species.
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Anamensis
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One of the most significant fossils: 40% complete skeleton of an adult female Au. afarensis, found in East Africa.
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Lucy
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This was an efficient, habitual biped that spent most of its time on the ground.
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Au. afarensis
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They lived in various habitats, including forests, woodlands, and open country.
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Au. afarensis
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One of the most important characteristics of the Laetoli footprints is the ___ ___ ___.
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nondivergent big toe
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Australopithecines were highly diverse, including in their ___.
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locomotion
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The genus Australopithecus evolved into two branches, one of which became the genus ___.
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Homo
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A late australopithecine from East Africa that was contemporaneous with Au. africanus and Au. aethiopicus and was the likely ancestor to the Homo lineage.
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Australopithecus garhi
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Its teethe were larger than the earlier australopithecines'. Like Au. afarensis, beneath the nose the face had a primitive projection and a small brain.
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Au. garhi
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The first hominin with a more humanlike ratio of arm length to leg length.
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Au. garhi
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This primates features and its age, 2.5 mya, suggest that it was ancestral to Homo.
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Au. garhi
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The stone tool culture associated with H. habilis and, possibly, Au. garhi, including primitive chopper tools.
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Oldowan complex
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The oldest part of the period during which the first stone tools were created and used. beginning with the Oldowan Complex.
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Lower Paleolithic
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The first hominin culture and the earliest culture of the Lower Paleolithic.
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Oldowan complex
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Much of the record of early stone tool use is early ____.
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Pleistocene
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Early hominins most likely ate:
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insects/meat
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A late species of australopithecine from South Africa that may have descended from Au. africanus, was a contemporary of Au. robustus, and expresses anatomical features found in Australopithecus and in Homo.
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Australopithecus sediba
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This showed the first substantial increase in brain size and was the first species definitively associated with the production and use of stone tools.
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Homo habilis
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Using tools and toolmaking is an adaptation by hominins linked to:
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bipedalism
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Evidence indicating that Orrorin Tugenensis was bipedal comes mainly from which part of the skeleton?
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femur
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In an argument with your parents, they claim that the only difference between australopithecines and early Homo species is that the latter had a bigger brain. You argue that there are other differences, such as that....
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In addition to a larger brain, early Homo species have smaller faces and smaller teeth
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Ardi was adapted to life in the trees and:
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on the ground
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Beginning more than 3 mya, at least two lineages of hominin emerged, one that led to the genus Homo and one that:
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included the now extinct descendants of Au. afarensis
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____ arose around 3.5 mya and gave rise to at least two branches of hominins-- later australopithecines and the genus Homo.
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Au. afarensis
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Owen Lovejoy's provisioning hypothesis proposes that:
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monogamy and food provisioning created the necessity for bipedalism
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The foundational behavior of hominins was:
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bipedalism
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Au. garhi has be proposed as an ancestor for Homo mainly because it:
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had longer legs relative to arm length than other australopithecines
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The _______ hypothesis about hominin bipedalism states that energy-efficient walking on two legs arose so that hominins could search for food that was dispersed s a result of climatic changes at the end of the Miocene.
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patchy forest
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The Oldowan tool complex is attributed to __________, making that hominin species the first to use tools.
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Au. garhi
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Humans use their molars for:
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crushing
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Robust australopithecine species include:
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Au. aethiopicus
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The oldest australopithecine species is:
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Au. anamensis
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Au. robustus's large masticatory complex (large molars, face, and muscles) indicate an adaptation to:
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eating foods requiring heavy chewing
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Speech, advanced cognition, and complex material culture:
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do not define a hominin
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Fossils attributed to Au. garhi were found at the Bouri site, in Ethiopia, along with:
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animal bones with cutmarks
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Two types of australopithecines were using two different types of locomotion in E Africa:
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one was a climber and the other a biped
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Robust Au.'s differ from earlier Au.'s in their:
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larger faces/smaller front teeth/larger back teeth
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Humans differ from apes because
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they use spoken language
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The Laetoli footprints demonstrate that the foot of Au. afarensis was humanlike in having a:
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nondivergent big toe/double arch/ *one more, look up in book
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The best-known australopithecine, represented by hundreds of fossils and dozens of individuals found mostly at Laetoli and Hadar, is:
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Au. afarensis
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A preaustralopithecine most likely has the following characteristics:
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modified honing dentition/primitive apeline traits/small brain size
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They proposed the Patchy Forest Hypothesis.
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Rodman/McHenry
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In this classification system, Chimps and Humans are similar to siblings, instead of cousins.
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Cladistic/phylogenetic
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S. tchadensis live around ____, and was discovered in ____.
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7 mya/chad
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Apes have a higher level of ___ ___, which is reflected in their larger canines.
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male-male aggression
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Anatomies: small brain, non honing chewing. massive browridge, bipedal.
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S. tchadensis
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This was the first thing to develop in Hominins.
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Bipedalism
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Non honing chewing developed around ____.
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5.5 mya
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In this classification system, Chimps are more like Gorillas and Orangs than like Humans.
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Traditional/gradistic
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Material culture (tool making) developed about ____.
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3.5 mya
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Hunting developed around ___.
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1 mya
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Darwin's theory for why bipedalism evolved was based on ____, although it has been proved incorrect.
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Hunting
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Upright walking developed about ____.
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7 mya
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The last of the pre-astralopithcines is ____.
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Ardipithecus
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Anatomies: bipedal based on femur, tree climber based on hands, partially honing canines.
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Orrorin
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The three pre-australopithecines:
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sahelanthropus/orrorin/ardipithecus
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They lived around 6 mya in the forest, and were found in the Tugen Hills, Kenya.
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Orrorin
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