Languages, geography and HLA haplotypes in native American and Asian populations.

A number of studies based on linguistic, dental and genetic data have proposed that the colonization of the New World took place in three separate waves of migration from North-East Asia. Recently, other studies have suggested that only one major migration occurred. It is the aim of this study to assess these opposing migration hypotheses using molecular-typed HLA class II alleles to compare the relationships between linguistic and genetic data in contemporary Native American populations. Our results suggest that gene flow and genetic drift have been important factors in shaping the genetic landscape of Native American populations. We report significant correlations between genetic and geographical distances in Native American and East Asian populations. In contrast, a less clear-cut relationship seems to exist between genetic distances and linguistic affiliation. In particular, the close genetic relationship of the neighbouring Na-Dene Athabaskans and Amerindian Salishans suggests that geography is the more important factor. Overall, our results are most congruent with the single migration model.