Fig. 4. Diversification within the Americas.

SNP chip genotype data-based outgroup f₃ statistics (47) of the form f₃(X, Ancient; Yoruba) were used to estimate the shared ancestry between ancient samples from the Americas and a large panel of worldwide present-day populations (X), including Athabascan and Amerindian groups from North America (table S3), some of which were masked for non-Native ancestry prior to the analysis (28). The outgroup f₃ statistics are depicted as heat maps with the sampling location of the ancient sample marked by the dotted lines, and corresponding ranked plots with error bars are shown in fig. S14. BP refers to time before present. We find the Anzick-1 sample to share most ancestry with the ‘southern’ branch of Native Americans when using multiple northern Native Americans sequenced in this study, consistent with (5). The seven Holocene aged samples share most ancestry with Native Americans, with a general tendency to be genetically closer to present-day Native American populations from the same geographical region.