The East African Middle and Late Stone Age eras, beginning 300 thousand years ago (ka), span an important period in the evolution of modern human behavior. Fossil, genetic and archaeological evidence show that anatomically modern humans and many of the characteristic "modern" behaviors that are used to define them appeared first in Africa. A significant dimension of the transition to modern behavior is the evolution of planning capacities, with more frequent communication about current environments and resource exploitation opportunities facilitating strategic planning of stone (lithic) tool-using activities with task-specific toolkits comprised of specialized, effective tools. Enhanced technological planning and long distance intergroup cooperative social networks, which apparently intensified after 100 ka, may have been crucial for the dispersal of modern humans from Africa and contributed to factors leading to the extinction of Neanderthals and other hominin species within and outside Africa.
This dissertation research by doctoral student Philip Slater (University of Illinois at Urbana-Champaign), under the mentorship of Dr. Stanley Ambrose, tests the hypothesis that later Middle and Late Stone Age (~100 ka) lithic technological organization reflects greater levels of planning, compared to the earlier Middle Stone Age (100-300 ka). Testing of this hypothesis is accomplished through analyses of stone tools from three archaeological sites in Kenya, including artifact type classification, size and shape measurements, combined with identification of microscopic traces of stone tool functions using Scanning Electron Microscopy.
Results from this project will promote understanding of how humans make strategic decisions regarding planning of technology based on information acquired through social networks. The research has broad implications for understanding the adaptive significance of cooperation and information sharing, including contributions toward development of policies for mitigating risk in increasingly uncertain future environments impacted by global social, political, and climatic change. In addition, the research will support Kenya's national scientific initiatives by advancing the education and training of University of Nairobi student volunteers, museum staff, and local residents in archaeological field methods, artifact curation, and technological analysis, as well as through promoting understanding of paleoanthropology.
