“Our analysis suggests that this is the same population living in this part of the world over time, so we have genetic continuity from 10,000 years ago to the present,” said University of Illinois anthropology professor Ripan Malhi, who led the study with University of Chicago postdoctoral researcher John Lindo; Penn State University biology professor Michael DeGiorgio; Rosita Worl, the director of the Sealaska Heritage Institute in Juneau, Alaska; and University of Oklahoma anthropology professor Brian M. Kemp.
The findings, reported in the Proceedings of the National Academy of Sciences, also suggest that these early American peoples had a complex population history, the researchers report.
The new work comes on the heels of earlier studies of ancient Americans that focused on mitochondrial DNA, which occurs outside the nucleus of cells and is passed only from mothers to their offspring.
“Mitochondrial DNA just traces the maternal line — your mother’s mother’s lineage — so, you’re missing information about all of these other ancestors,” said Lindo, the first author on the paper. “We wanted to analyze the nuclear genome so we could get a better assessment of the population history of this region.”
The team looked at genomic data from Shuká Káa (Tlingit for “Man Before Us”), an ancient individual whose remains — found in a cave in southeastern Alaska — date to about 10,300 years ago. They also analyzed the genomes of three more individuals from the nearby coast of British Columbia whose remains date to between 6,075 and 1,750 years ago.