Collaborative Research: An Examination of Behavioral and Biological Change in an Extended Chronological Context

University Of Wisconsin-Milwaukee, Milwaukee WI

Investigators

Abstract

Drs. Jackson Njau of the Indiana University, Bloomington and Lindsay McHenry of University of Wisconsin-Milwaukee, along with colleagues from the US, Europe, and Tanzania, seek to understand the relationships between Earth system history and human ("hominin") evolution by investigating the environmental contexts in which early ancestors of humans evolved. Previous researchers have postulated that climate-driven environmental changes on the African continent strongly influenced such evolution over the last several million years. Whether (and how) humans and other species adapt to changing climate is a scientific subject that has captivated public interest. Archaeology is well placed to link climate and environmental history to hominin records by integrating paleoenvironmental datasets archived in the sediments of ancient lakes near paleoanthropological sites. In addition to generating new scientific data, this project will open new interdisciplinary research frontiers across the earth sciences and anthropology that will impact the scientific debates on human origins research. The team will investigate how and when climate and environmental forces influenced adaptation during the critical times of human evolution. Do changes in morphology, innovation, sociality, and behavioral traits reflect changes in the local ecology, such as habitat, food, predation pressure, and the availability of resources on the landscape? These questions will be addressed by linking the detailed paleoclimatic record recovered from drilled sediment cores to excavated archeological sites. Four recently acquired cores from the ancient lake at Olduvai Gorge, Tanzania, covering over 2 million years of sedimentation, will be compared to key nearby archeological layers that document records of evolving hominin species and changes in stone tool technologies. Lake sediments archive climate history through time, therefore providing an unprecedented paleoclimatic record of the paleoanthropological material from the prehistoric Olduvai lake basin. These paleoenvironmental data will inform models of hominin land use behaviors and elucidate how climatic change drove hominin adaptations in morphology and cultural behaviors that allowed them to better adapt to variable environmental conditions. Using the composition of volcanic ash layers and detailed examination of the sedimentary units preserved in both cores and outcrops, the team will examine whether times of significant environmental change (as determined in the cores) correspond to times of significant cultural or biological change (in the outcrops and excavations). This project will provide research opportunities and training to a diverse group of American and Tanzanian scholars, provide educational outreach opportunities, and foster international collaboration and understanding.