Reconstructing Native American population history

Department of Genetics, Harvard Medical School, Boston, Massachusetts 02115, USA.
Nature (Impact Factor: 42.35). 07/2012; 488(7411):370-4. DOI: 10.1038/nature11258
Source: PubMed

ABSTRACT The peopling of the Americas has been the subject of extensive genetic, archaeological and linguistic research; however, central questions remain unresolved. One contentious issue is whether the settlement occurred by means of a single migration or multiple streams of migration from Siberia. The pattern of dispersals within the Americas is also poorly understood. To address these questions at a higher resolution than was previously possible, we assembled data from 52 Native American and 17 Siberian groups genotyped at 364,470 single nucleotide polymorphisms. Here we show that Native Americans descend from at least three streams of Asian gene flow. Most descend entirely from a single ancestral population that we call 'First American'. However, speakers of Eskimo-Aleut languages from the Arctic inherit almost half their ancestry from a second stream of Asian gene flow, and the Na-Dene-speaking Chipewyan from Canada inherit roughly one-tenth of their ancestry from a third stream. We show that the initial peopling followed a southward expansion facilitated by the coast, with sequential population splits and little gene flow after divergence, especially in South America. A major exception is in Chibchan speakers on both sides of the Panama isthmus, who have ancestry from both North and South America.

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Available from: Tábita Hünemeier, Jul 28, 2015
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    • "Moreover, it is well recognized that native, Mestizos, or Hispanics in America are underrepresented in pharmacogenetic studies even more evidently than African Americans (Cavallari and P. MA, 2013). And although endeavors are currently ongoing, a complete characterization of the genetic diversity among diverse ethnic groups still encompasses a titanic task (Reich et al., 2012). Mexico is home of at least 60 different native groups, representing 7% of the country's over 100 million population, and of Mestizos which are known to be genetically different among the 30 states, with an Amerindian admixture ranging from 30 to 70%. "
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    Gene 01/2015; 558(2). DOI:10.1016/j.gene.2014.12.068 · 2.08 Impact Factor
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    • "Ignoring anomalous evidence, not testing it objectively, rather retesting current dogma, lacks balance. American X2a does not of course 'prove' the specifics of the SH, but does oblige geneticists looking at other parts of the genome, to test available hypotheses to explain the substantial presence of pre-Columbian West Eurasian genetic signatures found in Native American populations , rather than assuming they all arrived from Beringia (e.g., Reich et al. 2012). The key genetic questions and predictions arising from the SH are: (1) is there non-cultural evidence for a Palaeolithic migration from the western Old World across the Atlantic to the Americas; (2) if so, from where and (3) when? "
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    ABSTRACT: The Solutrean hypothesis for the origin of the Clovis archaeological culture contends that people came from south-western Europe to North America during the Last Glacial Maximum. This hypothesis has received numerous critiques, but little objective testing, either of cultural or genetic evidence. We contest the assertion that there is NO genetic evidence to support this hypothesis, and detail the published evidence, consistent with a pre-Columbian western Eurasian origin for some founding genetic markers, specifically mtDNA X2a, and some autosomal influence, found in ancient and modern Native American populations. The possibility that the inferred pre-Columbian western autosomal influence came more directly than through Siberia is not even considered in such studies. The mtDNA X2a evidence is more consistent with the Atlantic route and dates suggested by the Solutrean hypothesis and is more parsimonious than the assumption of a single Beringian entry, that assumes retrograde extinction of X in East Eurasia.
    World Archaeology 10/2014; 46(5). DOI:10.1080/00438243.2014.966273
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    • "6), is dynamic in that it allows for bidirectional introgression on a site-by-site basis, setting the donor population at each site as that which has the higher frequency of the derived allele. These f estimators are distinct from the F 2 , F 3 , and F 4 statistics of Reich et al. (2009) (2012) and Patterson et al. (2012), which all test for correlated allele frequencies associated with introgression (much like the D statistic). However, Patterson's (2012) F 4 -ratio is conceptually very similar to the f estimators discussed here, in that it estimates the proportional contribution of a donor population. "
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