6560 Impact of Climate Change on Hominins: Late Miocene to Middle Pleistocene

Friday, February 17, 2012: 1:30 PM
Ballroom A (VCC West Building)
Bernard Wood , George Washington University, Washington, DC
The first unambiguous hominins occur approximately four million years ago. Prior to that, despite one 4.4 Ma impressively complete associated skeleton (ARA-VP-6/500 from Aramis in the Middle Awash), the fossil record is still poor. It is not at all clear that any of the possible early hominin taxa really do belong to the hominin clade. The earliest known fossil evidence of true hominins comes from sites in East Africa and recently published dating evidence suggests that the earliest known evidence of hominins in southern Africa may be as late as c.2.5-2.0 Ma. Between 2.5 and 2.0 Ma the hominin fossil record seems to resolve into two trends: one towards even larger chewing teeth with thick enamel and one in which postcanine tooth size diminishes, brain size increases, and in which obligate bipedalism becomes established. This presentation will draw on recent research to explore whether the timing of any of these ‘events’ can be pinned down with sufficient accuracy and precision to allow them to be linked with global and regional changes in climate. It will also consider whether any of these ‘events’ within the hominin clade coincide with speciation events or adaptive shifts captured in the fossil records of other groups of large mammals