Human genetic diversity (immunoglobulin GM allotypes), linguistic data, and migrations of Amerindian tribes.

GM haplotype frequencies were examined in 49 Amerindian tribes (from North, Central, and South America) to investigate the congruence of genetic variation with that observed in language and geography. We used two approaches: (1) the mobile site method, which allows a two-dimensional representation of genetic variation where the distances between reference points (i.e., the locations of the populations in the geographic map after displacements) are close to the genetic distances, and (2) a multivariate analysis (factorial correspondence analysis), which permits a visual interpretation of the geographic distribution of GM haplotypes on a map, completed by a cluster analysis. The results show a strong gradient from the Bering Strait to South America. The Eskimo and Na-Dene are genetically different from all other Amerindians, reflecting their more recent migrations. The orientation of most trajectories of the tribes from Central and South America can be interpreted as earlier migrations along the Pacific and Atlantic coasts. We conclude that geographic and linguistic factors played a part in the genetic diversity of Amerindian tribes.