Doctoral Dissertation Research: Factors Which Lead to Faunal Extinction

This doctoral dissertation research project addresses questions about megafaunal extinction at the end of the last ice age using new data on one species. The project models the extinction timing in two regions using new radiocarbon dates on bone collagen. Using radiocarbon dates and associated stable isotope values, this research also addresses changes to the animal’s diet leading up to extinction. This allows the research to assess how differences in bone collagen prep techniques affect radiocarbon and stable isotope models. The outcome of this research has implications for the use of molecular data modelling in the archaeological record, helping archaeologists and other users of radiocarbon dating better assess the results of radiocarbon dating. This provide a higher reliability estimation of Pleistocene extinction date that can be compared to human and environmental events in the past while providing an assessment of radiocarbon modelling. These results will be relevant to the megafaunal extinction debate and to radiocarbon dating, the most used absolute dating technique in archaeology. The research’s specific questions are ‘when did this Pleistocene species go extinct in North America?’ ‘Do we have evidence of environmental change before extinction?’ and ‘How does our extinction estimate change based on the quality of the data input into the model?’ Using the highest standard of collagen purification, the project generates much needed radiocarbon dates on this Pleistocene species and model extinction timing using this new data. The model generated using this high standard of data is compared to models using lower quality standards of data to assess the importance of bone collagen preparation technique. Conclusions about the role of humans in Pleistocene extinction is assessed based on the temporal overlap between them and evidence for the contribution of environmental change. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.