The extinction and speciation of hominins and the appearance of innovative behavior in East Africa during the time period between 3 and 2 million years ago is the focus of the our proposed research. Australopithecus afarensis shows morphological change at the Hadar site in the Afar of Ethiopia immediately before the species disappears from the fossil record (~3 Ma). This is followed by a hiatus in sedimentation in much of the region, preceding deposits that contain stone artifacts at 2.6 Ma at Gona. The Afar Ledi-Geraru (ALG) area, east and northeast of Hadar, preserves sediments of the Hadar Formation (~3.8-2.9 Ma), the Busidima Formation (~2.7-0.15 Ma) and, most importantly, includes sediments that fill the age gap between them. Detailed paleontological, archeological, and geological investigations will provide clues to the ecological context surrounding not only the morphological change in A. afarensis, but identify climatic or other conditions may have contributed to its disappearance and the appearance of technological innovation. Three factors make this an excellent place to acquire ecological information: 1) the presence of rarely preserved sediments spanning this important time-period, 2) evidence from the spatial distribution of mammals and other indicators of climate change in different depositional environments over well-defined time-periods, and 3) significant prior paleontological, archeological, and geological research that provides an established framework. These conditions will enable us to answer the following questions: What were the environmental conditions during the change and last appearance of A. afarensis in the greater Hadar region? What was the spatial distribution of habitat types, taxa, and environments during the period of 3.0-2.3 Ma in the northern Awash region? Were tectonic and/or global drivers major controls on spatial and temporal variation? Is the onset of flaked stone technology in the northern Awash (for which we have intriguing evidence) subsequent to or associated with climate or habitat change?
|Effective start/end date||4/15/12 → 3/31/15|
- National Science Foundation (NSF): $200,024.00