Award Holder: Robert Patalano
University: University of Calgary
Title of Research: Water Availability and Human Dietary Behaviour at Olduvai Gorge, Tanzania
Research Aims and Methods
The principle goal of Water Availability and Human Dietary Behaviour at Olduvai Gorge, Tanzania is to investigate the effective human response to fluctuating climates, habitat choice, and diet, by answering questions on how evolutionary outcomes correspond in time and space with particular types of environmental events. The emphasis is on a 34,000-year period (1.698 to 1.664 million years ago – Ma), a timeframe including a key transition in stone tool technology from the Oldowan to the Acheulean, and the widespread distribution of the genus Homo. To do so, plant lipid biomarkers (normal (n-) alkanes and acids) preserved in terrestrial sediments are systematically sampled and processed from the Olduvai Gorge Bed II FLK-West site, and quantified using gas chromatography to assess changes in water availability, temperature, and vegetation through carbon and hydrogen isotope measurements.
Assessing hydrogen and carbon isotopes of n- alkanes and acids will act as a coupled proxy record for paleohydrology and paleovegetation. By utilizing multiple proxies such as plant biomarkers and stable isotopes, this project will help to understand human evolution in response to such things as water accessibility, precipitation/aridity, and the relative abundance of C3 and C4 plants.
Encountered Difficulties
As much as Olduvai is one of the primary localities for studying human evolution and stone tool technologies, working in Tanzania (and East Africa), often has many logistical obstacles to overcome. One such issue encountered this field season involved a delay in obtaining COSTECH (Tanzanian Commission for Science and Technology) research permits. An error on the initial permit granted to the Stone Tools, Diet, and Sociality (SDS) project omitted the Bed III/IV Juma’s Korongo (JK) site, an Olduvai locale SDS planned to excavate in 2017. Due to this error, a new application had to be fast-tracked through COSTECH with the assistance of the University of Dar es Salaam to include JK on the updated research permit. This process delayed the start of fieldwork at Olduvai by roughly one week. Fortunately, our research group was able to adapt and continue our field season around the delay. We still conducted geological surveys and archaeological test trenches to help understand the JK site and plan for future excavations.
Contribution to Biological Anthropology
Preliminary results from measured carbon isotope ratios provide new perspectives on the environmental context of the FLK-West site, the location of the oldest known Acheulean at Olduvai Gorge. Our isotope data show that C4 plants were not a substantial component of the landscape 1.698 to 1.664 Ma. In addition, recovered phytolith data show that an arboreal assemblage dominated the sequence, never representing less than 90% of the total phytolith abundance. Both the isotopes and phytoliths suggest that C3 plants were abundant at FLK-W, while C4 grasses did not comprise a significant portion of the paleovegetation. However, isotope data does show changes through time. While the lower archaeological levels suggest cooler temperatures and wetter conditions, there is an overall warming/drying trend through time; similar to environmental reconstructions conducted elsewhere in East Africa for this time-period. Our data imply that the environmental context of Olduvai’s earliest Acheulean was that of a riverine forest surrounded by ecotones, which experienced warming/drying climate over time, but not an expansion of C4 grasses. Additional samples and biomarkers are undergoing analyses, and will further our understanding of the climatic context of the FLK-W site and surrounding landscape, and the earliest Acheulean at Olduvai Gorge.
With much appreciation, I would like to thank the Royal Anthropological Institute of Great Britain and Ireland and the Ruggles-Gates Fund for Biological Anthropology for their generous support of my 2017 summer fieldwork. Additional financial assistance was available through the Stone Tools, Diet, and Sociality at the Dawn of Humanity project and the Social Sciences and Humanities Research Council of Canada. Thank you.
