Genomic evidence for the Pleistocene and recent population history of Native Americans

• Published in: Frontiers in Plant Science
• Main Authors: Raghavan, M, Steinrucken, M, Harris, K, Schiffels, S, Rasmussen, S, DeGiorgio, M, Zollikofer, C P E, Ponce de León, M S, Willerslev, E
• Format: Article in Journal/Newspaper
• Language: English
• Published: American Association for the Advancement of Science 2015
• Subjects: Department of Evolutionary Anthropology; 300 Social sciences; sociology & anthropology; Bering Land Bridge; Beringia; Siberia
• Online Access: https://www.zora.uzh.ch/id/eprint/120402/; https://www.zora.uzh.ch/id/eprint/120402/1/aab3884.full.pdf; https://doi.org/10.5167/uzh-120402; https://doi.org/10.1126/science.aab3884

INTRODUCTION: The consensus view on the peopling of the Americas is that ancestors of modern Native Americans entered the Americas from Siberia via the Bering Land Bridge and that this occurred at least ~14.6 thousand years ago (ka). However, the number and timing of migrations into the Americas remain controversial, with conflicting interpretations based on anatomical and genetic evidence. RATIONALE: In this study, we address four major unresolved issues regarding the Pleistocene and recent population history of Native Americans: (i) the timing of their divergence from their ancestral group, (ii) the number of migrations into the Americas, (iii) whether there was ~15,000 years of isolation of ancestral Native Americans in Beringia (Beringian Incubation Model), and (iv) whether there was post-Pleistocene survival of relict populations in the Americas related to Australo-Melanesians, as suggested by apparent differences in cranial morphologies between some early (“Paleoamerican”) remains and those of more recent Native Americans. We generated 31 high-coverage modern genomes from the Americas, Siberia, and Oceania; 23 ancient genomic sequences from the Americas dating between ~0.2 and 6 ka; and SNP chip genotype data from 79 present-day individuals belonging to 28 populations from the Americas and Siberia. The above data sets were analyzed together with published modern and ancient genomic data from worldwide populations, after masking some present-day Native Americans for recent European admixture. RESULTS: Using three different methods, we determined the divergence time for all Native Americans (Athabascans and Amerindians) from their Siberian ancestors to be ~20 ka, and no earlier than ~23 ka. Furthermore, we dated the divergence between Athabascans (northern Native American branch, together with northern North American Amerindians) and southern North Americans and South and Central Americans (southern Native American branch) to be ~13 ka. Similar divergence times from East Asian populations and a divergence ...