AHRC OOC-DTP students Gonzalo Linares-Matás (Oxford) and James Clark (Cambridge) have recently co-authored a paper in the Journal of Human Evolution, examining the role that seasonality may have had on the survival strategies of ancient human species (known as hominins) in East Africa. Today, these latitudes are usually characterised by the alternation of wet and dry seasons, with almost all yearly rainfall occurring in the former, and this produces important changes to the diets (and behaviour) of both nonhuman primates and modern human hunter-gatherer groups. The paper first reviews some of these changes—specifically for roots and tubers, freshwater resources and animal tissue—to make predictions for the dietary behaviour of hominins in the study period.
Gonzalo and James then focus on two key case study sites—Kanjera South, Kenya, and FLK-Zinj, Tanzania—from the Oldowan, the oldest period of consistent stone tool use in human evolution (2.6-1.5 million years ago). They argue that the abundance of young bovids at Kanjera South is consistent with repeated occupation over time during the early wet season, while the frequency of local and water-dependent bovids at FLK-Zinj may indicate a dry season occupation. This latter attribution is consistent with previous studies of the feeding signatures recorded in the teeth of bovids at the site. Furthermore, they use this distinction in season of occupation to illustrate a number of behavioural changes throughout the year by Oldowan hominins, including differences in the demographics of hunted animals, the intensity of carcass processing, and the importance of plant resources. In particular, they suggest the greater predictability of plant resource patches in the wet season may have allowed greater planning of resource consumption throughout the landscape, and therefore resulted in greater levels of mobility. This may have led to greater transport of stone for tool production, and a corresponding increase in reduction intensity in order to maximise the returns on this investment.
The paper is available to view at: https://doi.org/10.1016/j.jhevol.2021.103070
