Y-chromosome analysis reveals genetic divergence and new founding native lineages in Athapaskan- and Eskimoan-speaking populations

TLDR

The peopling of the Americas has been studied using uniparental genetics, but Y‑chromosome evidence for the predominant Eskimo‑Aleut and Na‑Dene language families in northern North America has been lacking. The study aimed to test the hypothesis that Eskimoan- and Athapaskan-speaking populations share a distinct biological origin and to clarify their migration histories. Y‑chromosomal data were collected from Inuvialuit, Gwich’in, and Tłįchǫ groups in the Northwest Territories, genotyping over 100 biallelic markers and 19 short tandem repeats to produce a high‑resolution dataset. The analysis revealed a unique SNP in Inuvialuit, confirmed that Canadian Eskimoan and Athapaskan populations are genetically distinct due to two post‑initial expansions, highlighted the distinctiveness of Tłįchǫ within Athapaskans, and showed that Y‑chromosomal diversity among first Native Americans was higher than previously thought.

Abstract

For decades, the peopling of the Americas has been explored through the analysis of uniparentally inherited genetic systems in Native American populations and the comparison of these genetic data with current linguistic groupings. In northern North America, two language families predominate: Eskimo-Aleut and Na-Dene. Although the genetic evidence from nuclear and mtDNA loci suggest that speakers of these language families share a distinct biological origin, this model has not been examined using data from paternally inherited Y chromosomes. To test this hypothesis and elucidate the migration histories of Eskimoan- and Athapaskan-speaking populations, we analyzed Y-chromosomal data from Inuvialuit, Gwich’in, and Tłįchǫ populations living in the Northwest Territories of Canada. Over 100 biallelic markers and 19 chromosome short tandem repeats (STRs) were genotyped to produce a high-resolution dataset of Y chromosomes from these groups. Among these markers is an SNP discovered in the Inuvialuit that differentiates them from other Aboriginal and Native American populations. The data suggest that Canadian Eskimoan- and Athapaskan-speaking populations are genetically distinct from one another and that the formation of these groups was the result of two population expansions that occurred after the initial movement of people into the Americas. In addition, the population history of Athapaskan speakers is complex, with the Tłįchǫ being distinct from other Athapaskan groups. The high-resolution biallelic data also make clear that Y-chromosomal diversity among the first Native Americans was greater than previously recognized.