Side steps: the erratic pattern of hominin postcranial change through time.

The hominin fossil record reveals brain-size expansion, canine reduction, premolar metaconid development, and numerous other craniodental features that become more human-like through time. In general, the postcranial skeleton also gets more human-like through time, but in some respects it does not. This is particularly apparent in the overall morphology of one of the most frequently preserved elements, the distal humerus.

Evolutionary reversals of limb proportions in early hominids? Evidence from KNM-ER 3735 (Homo habilis).

Upper-to-lower limb proportions of Homo habilis are often said to be more ape-like than those of its reputed ancestor, Australopithecus afarensis. Such proportions would either imply multiple evolutionary reversals or parallel development of a relatively short upper limb in A. afarensis and later Homo.

Fossil hominin ulnae and the forelimb of Paranthropus.

The discovery of Pan in the Middle Pleistocene deposits of the Kapthurin Formation of the Tugen Hills (McBrearty and Jablonski: Nature 437 (2005) 105-108) inspires new interest in the search for other chimpanzee fossils in the East African Rift Valley. Craniodental evidence of an eastward excursion of chimpanzee populations in the Plio-Pleistocene goes undetected in other hominin sites, but one enigmatic postcranial fossil, the Olduvai Hominid 36 ulna, has many chimp-like features. Analyses by Aiello et al.

Hallucial convergence in early hominids.

There is a richly documented fossil record of the evolutionary transition from ape-sized brains that are less that one-third the size of modern humans through a series of intermediate-sized brains up to the modern range. The first report on the discovery of the foot of the Stw 573 skeleton emphasized the apparent transitional nature of its great toe [Clarke, R.J.

Body proportions of Homo habilis reviewed.

The ratio of fore- to hindlimb size plays an important role in our understanding of human evolution. Although Homo habilis was relatively modern craniodentally, its body proportions are commonly believed to have been more apelike than in the earlier Australopithecus afarensis. The evidence for this, however, rests, on two fragmentary skeletons, OH 62 and KNM-ER 3735.