SGER: Scientific Drilling for Human Origins: Exploring the Application of Drill Core Records to Understanding Hominin Evolution

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PIs propose to investigate how continental scientific drilling can be used as a tool in understanding the environmental background of human origins. This new research direction in merging earth science and paleoanthropology will involve obtaining sediment drill core samples from lake beds located on-land, close to areas of critical importance for understanding human evolution. Their efforts will be focused around critical time intervals for human origins during the last 3.5 million years. In this first phase of research, they will obtain critical site-survey and subsurface data for four key localities in Kenya and Ethiopia, essential to the success of a future drilling program, to be funded by a later proposal. They also request partial funding for a drilling workshop, to consider the technical and scientific opportunities and challenges posed by each of the sites under consideration.Prior researchers have asked the key question of why evolution of humans and their close relatives displays a pulsed pattern, with well-defined periods of extensive speciation or extinction, cultural change and geographic expansion, interspersed with long periods when relatively little change seems to occur. Is this the result of broad forcing effects of either directional environmental change (climate, etc.), the result of changes in the variability of local or regional environments, or some yet-unrecognized mechanism. These efforts have proceeded either by correlating broad-scale patterns of human evolutionary patterns with the global beat of climate variability as recorded in the continuous records of deep-sea sediment cores or, by correlating regional shifts in the fossil and archaeological record with more local patterns of environmental change, inferred from outcrop records of ancient soils, lake beds and non-hominin fossils. PIs argue for a new research direction linking the earth science and anthropology communities in addressing this central question about human origins, combining the strengths of both of the approaches above, and avoiding some of their inherent weaknesses. Their plan promotes a concerted effort to obtain drill core records from near-continuous sedimentary sequences located close to areas of critical importance for understanding hominin evolution, focused around critical time intervals for their key question above. Drill cores will provide a record that will vastly improve understanding of environmental history in the places and times where various species of our near-relatives lived. Obtaining such records from on land will provide a more detailed and resolved record than what we can currently infer from deep sea core records. Finally, because the largest number of critical events in man's evolutionary history occurred in Africa, such a drilling campaign should start in that continent. Few scientific questions can be more central to humanity than understanding where we have come from as a species, and how our environment has shaped our biological and technological evolution. Results from this proposal will pave the way for a new direction for helping researchers address these questions and will foster a new avenue for earth science/anthropology collaborations. This international drilling program has important science training opportunities for involving early-career American and African scientists in all aspects of the project. Several students will be involved in the seismic site survey exercises leading up to the workshop, and some students who are likely to join the program in post-graduate work would be able to attend the workshop. This award is co-funded by NSF's Office of International Science and Engineering.