New DNA Analysis of Native Americans

PLoS Genetics has a new paper (PLoS Genet 3(11): e185. doi:10.1371/journal.pgen.0030185) that examines autosomal microsatellite markers (repeating units of base pairs) from Native American DNA:

“We examined genetic diversity and population structure in the American landmass using 678 autosomal microsatellite markers genotyped in 422 individuals representing 24 Native American populations sampled from North, Central, and South America. The Native American populations have lower genetic diversity and greater differentiation than populations from other continental regions. We observe gradients both of decreasing genetic diversity as a function of geographic distance from the Bering Strait and of decreasing genetic similarity to Siberians—signals of the southward dispersal of human populations from the northwestern tip of the Americas”

From the press release, the data shows that:

“Genetic diversity, as well as genetic similarity to the Siberian groups, decreases the farther a native population is from the Bering Strait – adding to existing archaeological and genetic evidence that the ancestors of native North and South Americans came by the northwest route.”

“A unique genetic variant is widespread in Native Americans across both American continents – suggesting that the first humans in the Americas came in a single migration or multiple waves from a single source, not in waves of migrations from different sources. The variant, which is not part of a gene and has no biological function, has not been found in genetic studies of people elsewhere in the world except eastern Siberia.”

HT: Yann Klimentidis’ Blog and henry on genetics.