Journal ArticleDOI
Evidence that humans evolved from a knuckle-walking ancestor
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TLDR
Evidence is presented that fossils attributed to Australopithecus anamensis and A. afarensis retain specialized wrist morphology associated with knuckle-walking, which removes key morphological evidence for a Pan–Gorilla clade and suggests that bipedal hominids evolved from a knuckles-walking ancestor that was already partly terrestrial.Abstract:
Bipedalism has traditionally been regarded as the fundamental adaptation that sets hominids apart from other primates. Fossil evidence demonstrates that by 4.1 million years ago1, and perhaps earlier2, hominids exhibited adaptations to bipedal walking. At present, however, the fossil record offers little information about the origin of bipedalism, and despite nearly a century of research on existing fossils and comparative anatomy, there is still no consensus concerning the mode of locomotion that preceded bipedalism3,4,5,6,7,8,9,10. Here we present evidence that fossils attributed to Australopithecus anamensis (KNM-ER 20419)11 and A. afarensis (AL 288-1)12 retain specialized wrist morphology associated with knuckle-walking. This distal radial morphology differs from that of later hominids and non-knuckle-walking anthropoid primates, suggesting that knuckle-walking is a derived feature of the African ape and human clade. This removes key morphological evidence for a Pan–Gorilla clade, and suggests that bipedal hominids evolved from a knuckle-walking ancestor that was already partly terrestrial.read more
Citations
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Comparative analysis of
TL;DR: This paper critically analyzes the deployment issues of best three proposals considering trade-off between security functions and performance overhead and concludes that none of them is deployable in practical scenario.
Journal ArticleDOI
Paleolithic Technology and Human Evolution
TL;DR: This work has shown that stone tool technology, robust australopithecines, and the genus Homo appeared almost simultaneously 2.5 million years ago, and once this adaptive threshold was crossed, technological evolution was accompanied by increased brain size, population size, and geographical range.
Journal ArticleDOI
A juvenile early hominin skeleton from Dikika, Ethiopia
Zeresenay Alemseged,Fred Spoor,William H. Kimbel,René Bobe,Denis Geraads,Denné Reed,Jonathan G. Wynn,Jonathan G. Wynn +7 more
TL;DR: The foot and other evidence from the lower limb provide clear evidence for bipedal locomotion, but the gorilla-like scapula and long and curved manual phalanges raise new questions about the importance of arboreal behaviour in the A. afarensis locomotor repertoire.
Journal ArticleDOI
Hominin life history: reconstruction and evolution
Shannen L. Robson,Bernard Wood +1 more
TL;DR: It is found that body mass is the best predictor of great ape life history events, while the body sizes, brain sizes, and dental development of Homo heidelbergensis and Homo neanderthalensis are consistent with a modern human life history but samples are too small to be certain that they have life histories within the modern human range.
Journal ArticleDOI
Chimpanzee locomotor energetics and the origin of human bipedalism
TL;DR: Variation in cost between bipedal and quadrupedal walking, as well as between chimpanzees and humans, is well explained by biomechanical differences in anatomy and gait, with the decreased cost of human walking attributable to the authors' more extended hip and a longer hindlimb.
References
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Journal ArticleDOI
The Origin of Man
TL;DR: Evidence provided by the fossil record, primate behavior, and demographic analysis shows that the traditional view that early human evolution was a direct consequence of brain expansion and material culture is incorrect, and that the unique sexual and reproductive behavior of man may be the sine qua non of human origin.
Journal ArticleDOI
The locomotor anatomy of Australopithecus afarensis.
Jack T. Stern,Randall L. Susman +1 more
TL;DR: It is demonstrated that A. afarensis possessed anatomic characteristics that indicate a significant adaptation for movement in the trees, and it is speculated that earlier representatives of the A.Afarensis lineage will present not a combination of arboreal and bipedal traits, but rather the anatomy of a generalized ape.
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Australopithecus ramidus, a new species of early hominid from Aramis, Ethiopia
TL;DR: The antiquity and primitive morphology of A. ramidus suggests that it represents a long-sought potential root species for the Hominidae.
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New four-million-year-old hominid species from Kanapoi and Allia Bay, Kenya
TL;DR: The mosaic of primitive and derived features shows this species to be a possible ancestor to Australopithecus afarensis and suggests that Ardipithecus ramidus is a sister species to this and all later hominids.
Journal ArticleDOI
Morphology of the Pliocene partial hominid skeleton (A.L. 288-1) from the Hadar formation, Ethiopia
Donald C. Johanson,C. Owen Lovejoy,William H. Kimbel,William H. Kimbel,Tim D. White,Steven Ward,Steven Ward,Steven Ward,Michael E. Bush,Michael E. Bush,Bruce Latimer,Bruce Latimer,Yves Coppens +12 more
TL;DR: The upper part of the Pliocene Hadar Formation, central Afar, Ethiopia, has yielded a 40% complete fossil hominid skeleton (A.L. 288-1, “Lucy”).