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Department of Geosciences
An international team of researchers led by UA professor of geosciences Andrew Cohen has received a $4.78 million grant to expand its study of the connections between past climate and human evolution in Africa's Rift Valley.
The Hominin Sites and Paleolakes Drilling Project, led by Andrew S. Cohen of the University of Arizona, has been awarded $4.78 million from the National Science Foundation to continue and expand its research on human evolution and climate.
The researchers anticipate their findings will transform our understanding of how environmental and climate change affected the evolution of our ancestors and have implications for humans today.
The project takes core samples of sediment from dry lake beds near important fossil and archaeological sites of ancient hominins in Africa's Rift Valley in Kenya and Ethiopia. Hominins are the group of organisms that includes humans and our fossil near-relatives and ancestors.
"With these detailed new paleoclimate records, we will be able to reliably test the important hypotheses that anthropologists have offered concerning possible links between the evolution and extinction of various human ancestors and close relatives, and past climate and environmental change," said Cohen, director of the project and a UA professor of geosciences.
"Our team is really excited about this international partnership of geologists, anthropologists and climate scientists working on the interface of two critical topics: climate change and human evolution."
The new funding will allow Cohen and his colleagues to extract cores from additional sites and to analyze those samples. The scientists will use data from the cores to reconstruct climate changes – especially temperature and precipitation – in eastern Africa over the last 4 million years, a critical period in human evolution.
By analyzing fossil pollen, charcoal and lake organisms in the cores, the team will also be able to reconstruct the ecosystems that early humans depended on.
The new monies allow the team to expand the project by including additional researchers who can model the region's paleoclimate and environment. The modeling will be done by an international team that includes UA geosciences faculty members Jon Pelletier, Joellen Russell and Jianjun Yin. Additionally, UA geoscience faculty member Owen Davis and graduate students will be involved in the fossil pollen analysis.
The computer models will reveal the atmospheric processes underlying past environmental change in Africa and how the resources early humans relied on would have responded to those climate changes.
To obtain cores from the dry lake beds, the scientists use a drill rig that collects continuous sediment cores in 10-foot segments. The cores will penetrate up to 1,600 feet (about half a kilometer) below the earth's surface at some sites and will contain sediments up to 4 million years old.
In all, the researchers will collect more than 1.5 miles (2.4 kilometers) of cores of lake deposits. The team completed drilling at the first two sites in Kenya this summer and will collect samples at two sites in Ethiopia this fall and the final site in Kenya next summer.
The project caught the attention of Earth Images Foundation, a film production company based in Oakland, Calif. The company filmed the researchers this summer as they drilled in Kenya and collected hominin fossils near the drill sites and will continue filming the researchers in Ethiopia later this year. The 3-D film documentary of the Hominin Sites and Paleolakes Drilling Project is expected to be available for distribution to museums in 2014.
Department of Geosciences