Doctoral Dissertation Research: Examining Changes in Ecology and Bifacial Flake Reduction Patterns during the Pleistocene-Holocene Transition
Human response to environmental change is as relevant today as it was 10,000 years ago. We can choose to adapt our technology, change our subsistence practices, migrate to new locations, or seek other alternatives to environmental shifts. This study examines the relationship between ecological fluctuations and human groups in Alaska during the Pleistocene-Holocene Transition and the Younger Dryas cooling event. Researchers look specifically at how humans adapted their technology to stresses created by abrupt environmental change. Using three-dimensional imagery of stone tools from previously excavated museum collections we attempt to address questions related to ecological changes and human technological responses to those changes by examining three artifact complexes present in Alaska after initial colonization of the New World. This research is significant as the methodological approaches used in this project for paleoenvironmental reconstruction and three-dimensional imagery of technology have the potential to be tailored to address specific questions relevant to different areas of the world and for different time periods, allowing us to better understand the complex relationship between humans and a changing environment. This research focuses on ecological responses to the onset of the Younger Dryas climatic perturbation ~12,800 cal yr BP as an enabling factor in technological change seen in the Arctic and subarctic of Alaska. Understanding how ecological fluctuations affected the cultural groups of Alaska during the Pleistocene-Holocene Transition can provide insight into the shifts seen in the lithic technological organization and the relationships between the people who produced the Nenana, Denali microblade, and Northern Paleoindian artifact complexes. The first step is to reconstruct the ecological shifts during this time period and the distributions between plant biome boundaries. By identifying the most predictive variable(s) for modern boundaries between shrub and herb tundra communities correlations defined by discriminant function analysis can be used to examine where these boundaries were located during the Pleistocene-Holocene Transition. This will lay the foundation for the second part of the Co-PIs’ research, which is to examine the relationship between the culture groups of the Nenana, Denali, and Northern Paleoindian artifact complexes located in Eastern Beringia at the onset of the Younger Dryas. Under the assumption that flintknapping strategies and knowledge are socially transmitted, this project will apply new analyses from three-dimensional imagery of bifacial tools to empirically ascertain the relationships between early culture groups from the flake scar patterning on bifaces. These data will be used to determine whether changes in technology seen in the archaeological record are the result of in situ adaptation, or immigration of new peoples due to ecological changes at the onset of the Younger Dryas. While three-dimensional imagery holds the potential for a number of analyses, this study focuses on flake scars resulting from the final stages of bifacial production. This analysis has the potential to help archaeologists examining lithic technologies understand the relationships among different human cultures not only in Alaska but also across the New and Old World.