Genetic Evidence for Ancient Population Shifts and Migrations in Central and Southern California

Описание: Genetic Evidence for Ancient Population Shifts and Migrations in Central and Southern California

Dr. Nathan Nakatsuka

California, prior to European contact, harbored more linguistic diversity than all Europe, and studies of language relationships, archaeological evidence, and traditional oral histories have led to many hypotheses about movements of people over the minimum of 13,000 years this region has been occupied. In the absence of ancient DNA, it has not been possible to test directly alternative hypotheses about the spread of groups with distinct biological ancestry. Working collaboratively with local Indigenous groups in California and Mexico, we report genome-wide data from 87 ancient Californian individuals and 40 ancient Mexican individuals ranging from 7,600 to 200 years old (BP), which we co-analyze with previously reported data. We find evidence for movement of ancestry related to ancient and present-day individuals from northwest Mexico, who would have likely spoken Uto-Aztecan languages, arriving in southern and central California from at least 5,300 BP that ultimately reached its highest level in regions where Uto-Aztecan speakers currently reside. Ancient individuals from Baja California share more alleles with the earliest (5,200 BP) central California individual than with later Indigenous Californians, potentially reflecting the first “Hokan” language associated populations in central California having a high degree of relatedness with groups like those in Baja, and subsequent mixture transforming much of their ancestry. We find that ancient California individuals harbor increased affinity to the ~12,800 year old Anzick-1 individual associated with the Clovis culture compared to ancient northwest Mexico groups, which are on a different ancient lineage. Lastly, we find that some of the ancient groups from California and northwest Mexico had very small population sizes, similar to that of ancient Patagonian groups and significantly lower than ancient groups from the Andes and the Caribbean Ceramic period.

Nathan Nakatsuka was born and raised in Honolulu, Hawaiʻi. He graduated from Kamehameha Schools Kapālama High School then attended Harvard College, earning an AB in Chemical and Physical Biology. He then attained an MPhil in Genetics from University of Cambridge on a Gates Cambridge scholarship, working at the Wellcome Trust Sanger Institute with Inês Barroso. Nathan received his MD at Harvard Medical School in the Harvard-MIT Health, Sciences, and Technology MD track and his PhD from the Systems, Synthetic, and Quantitative Biology PhD program working in the laboratory of David Reich on population genetics of South Asia and the Americas. During his PhD the majority of his work focused on studying ancient DNA to uncover the ancient history of North, Central, and South America. He currently is a postdoctoral fellow at New York Genome Center in the laboratory of Rahul Satija working on single cell analyses of neuropsychiatric traits.

Presented to the Pacific Coast Archaeological Society (PCAS) on June 8, 2023.

For additional information on the Pacific Coast Archaeological Society, see the PCAS website at www.pcas.org