This project examines the Pleistocene-Holocene Transition (PHT), during which the first peoples of North America were dispersing across the continent and adapting not only to novel environments, but also to a rapidly changing climate as the Ice Age ended. Anthropologists’ understanding of this time period is limited by a paucity of archaeological sites. The principal investigator, in collaboration with Tribal descendant partners, studies a mortuary site using a range of biological and biogeochemical methods to advance knowledge about PHT residents of North America, including colonization of the Americas, the lifeways of the earliest Indigenous occupants, and human adaptation to rapid climatic shifts. The project supports undergraduate and graduate student training, research collaborations and community engagement with the Muwekema Ohlone Indian Tribe, and public science education activities. <br/><br/>The project focuses on an archaeological site that dates to 12,000-9,000 years ago and was used by the ancestors of the Muwekma Ohlone Indian Tribe of the San Francisco Bay Area as a burial ground for their relatives. This is among the oldest known mortuary sites in North America and contains a large number of Indigenous ancestors (n=41). The project is a collaborative effort with the Muwekma Ohlone Indian Tribe to improve collective understanding of their ancestors’ lifeways and the adaptive strategies employed by North America’s first peoples. Specifically, the project seeks to reconstruct mobility, kinship systems, diet, parental investment strategies, and associated fertility by employing proteomic sex-estimation, stable isotope analysis (carbon and nitrogen) of dentinal serial sections of first and third molars, and strontium analysis of tooth enamel. The research outcomes include the generation of osteobiographies that allow ancestors’ life stories and Tribal history to be told.<br/><br/>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.