The Zambia Rift Valley research project: Exploring human evolution at the crossroads of Africa

Abstract

Key evolutionary events in hominin evolution occurred between 3.5 and 2.4 Ma, including the origins of flaked tool technology and the first appearance of the genera Homo and Paranthropus. This period remains poorly understood, however, because deposits of this age are rarely exposed across Africa. The Luangwa River Valley of eastern Zambia is part of the southernmost extension of the East African Rift System; a fossil femur from South Luangwa, identified as Theropithecus cf. darti, hints at the presence of fossiliferous beds of this age in the Luangwa Valley. Additionally, Middle Pleistocene fossils and Early and Middle Stone Age artifacts have also been recovered in sediments adjacent to the Luangwa River. Fossils from these deposits could contribute data on the diversification of hominins and mammals that occurred during the Plio-Pleistocene. The Luangwa River also supports a rich modern mammalian community that represents a critical analogue for reconstructing hominin paleoenvironments. However, no systematic ecological characterizations of living or past mammalian communities of the Luangwa River Valley have been completed. The newly initiated Zambia Rift Valley Research Project (ZRVRP) will analyze the ecology of modern and fossil Luangwa River mammalian and human communities using dental microwear, enamel and collagen isotopic composition, the distribution of bones, fossils, and vegetation on the landscape, and archaeological materials. Patterns of paleoenvironmental change, climatic seasonality, and hominin landscape use over time will provide important comparative context for other Plio-Pleistocene sites. Here, we describe the goals, methods, and community engagement of the ZRVRP, and some challenges involved in launching new paleoanthropological field research.