Genetic Analysis of Birnirk Inuit from the Alaskan North Slope

Archaeological evidence indicates that Birnirk peoples (AD 650 ??? 1300) are the proposed genetic ancestors of the Thule Inuit (AD 950 ??? 1400) and are potentially an intermediary population between the Thule Inuit and earlier Old Bering Sea people (AD 1 ??? 1000). We sequenced the first hypervariable region of the mitochondrial DNA of 22 clearly associated Birnirk individuals from the Pi??niq (Birnirk), Kugok, Kugusugaruk, and Nunavak sites on the North Slope of Alaska. Haplotypes A2a, A2a1, A2a3, A2b1, and D4b1a2a1a were identified in this population, demonstrating an expansion of Birnirk maternal genetic diversity. Maternal lineages from these individuals were evaluated with other past and contemporary Inuit populations from the Chukotka Peninsula to eastern Greenland. Our findings confirm Birnirk Inuit as probable maternal ancestors to Thule Inuit and may be among the first peoples possessing these lineages to have moved into the western North American Arctic from the Bering Strait region.