Extended Data Fig. 8: ADMIXTURE analysis.

a, b, Results are shown for the HumanOrigins (a) and Illumina (b) SNP-array datasets. The number of source populations in ADMIXTURE is 14 and 11 for the 2 datasets, respectively. One hundred iterations were calculated for each value of K from 5–20 (in which K is the number of ancestral populations), and the optimal K values were selected based on 10-fold cross-validation. Contributions from hypothetical ancestral populations are colour-coded, and meta-populations used in this study are indicated above the plot (abbreviations as before). Chipewyan or Northern Athabaskan and Tlingit individuals with European admixture are plotted in separate bars, as are ancient individuals: Clovis, Northern Athabaskans, Aleuts, Chukotkan Neo-Eskimos (Ekven and Uelen sites), Saqqaq and Late Dorset Palaeo-Eskimos, and a genetically heterogeneous Ust’-Belaya Angara Siberian population (Ust’-Belaya WSIB, an individual I7760 who has a West Siberian genetic profile according to PCA and this ADMIXTURE analysis; Ust’-Belaya, the remaining eight individuals from the Ust’-Belaya Angara site who have a distinct genetic profile according to our PCA analysis). Outliers, including individuals admixed with Europeans and East Asians, were not removed from Na-Dene-speaking populations in the Illumina dataset (b) to preserve their maximal diversity. Outliers were removed for the purpose of other analyses that rely on pre-defined populations (for example, qpAdm and f₄-statistics).