Using geochemistry to contextualize human social and technological innovation in southern Africa during the Pleistocene: evidence from the drylands and highlands
Prof. Genevieve Dewar
Tue, 12/04/2022 - 18:30 to 19:30
Western Cape
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By: Prof. Genevieve Dewar

In this talk I will discuss some results of a major research program called “Adaptations to marginal environments in the Middle Stone Age” co-directed by myself and Brian Stewart. The goal of this multidisciplinary project is to look for evidence of human adaptive plasticity in the archaeological record of southern Africa, as evidence for complex behaviour, rather than relying on the retrieval of rare material remains, such as engraved ochre.  We are using a biogeographic approach to understand how Pleistocene foragers were able to colonize inland regions with unpredictable resources, focussing on drylands and highlands like the Namaqualand and Namib Deserts and the Maloti-Drakensberg Mountains. Specifically, I will present the results using geochemistry on ostrich eggshell to identify social and technological innovations within their palaeoenvironmental contexts from Spitzkloof Rockshelter in Namaqualand and Melikane and Sehonghong Rockshelters in Lesotho. These results show that past populations developed new innovations within Africa during the Pleistocene, equipping them with the repertoire of skills that allowed for rapid dispersals through the continent and eventually ‘Out of Africa’.  

Professor Genevieve Dewar is a bioarchaeologist whose research addresses the origins and development of modern human behaviour in southern Africa. Her research program involves identifying archaeological evidence for social and technological innovations, and their palaeoenvironmental contexts.  A technological innovation that she has published on is the use of ostrich eggshell flasks to navigate African desert environments by 70 ka.  This artefact reflects our species unique behavioral flexibility within Africa, which has ultimately allowed for the rapid expansion through and ‘out of Africa’. Professor Dewar and colleagues have recently published geochemistry evidence for the development of social risk reduction strategies at least 33,000 years ago. That study used strontium isotope analysis to show that ostrich eggshell beads had travelled over 500 km up to Sehonghong Rockshelter where they were retrieved.
Professor Dewar’s research lab uses zooarchaeological methods and isotope analyses to identify human and faunal bone, teeth, and ostrich eggshell from archaeological sites, to recreate palaeoenvironmental contexts and identify hunting strategies. Professor Dewar is currently a Co-PI with Dr Brian Stewart (U of Michigan) on two large multidisciplinary archaeological excavation projects at Pleistocene rockshelters in Lesotho and South Africa: Sohonghong and Ha Soloja in the highlands of Lesotho; and Spitzkloof A and Spitzkloof B in the coastal desert of Namaqualand, South Africa. Professor Dewar is also the zooarchaeologist on the Metolong Dam project in Lesotho, run by the University of Oxford.
Professor Dewar’s research is highly collaborative as the projects she is involved in include managing and integrating data from multiple specialists in South Africa, Lesotho, UK, USA, Australia, and Germany. Her research has been funded by major government agencies in Canada (SSHRC), South Africa (NRF), the USA (NSF), as well as the Wenner-Gren Foundation and National Geographic. Professor Dewar has published over 25 papers in peer-reviewed journals including Science, Proceedings of the National Academy of Sciences of the USA, Journal of Archaeological Science, Quaternary International, The Holocene, and Radiocarbon.