Human mtDNA and Y-chromosome variation is correlated with matrilocal versus patrilocal residence.

Genetic differences among human populations are usually larger for the Y chromosome than for mtDNA. One possible explanation is the higher rate of female versus male migration due to the widespread phenomenon of patrilocality, in which the woman moves to her mate's residence after marriage. To test this hypothesis, we compare mtDNA and Y-chromosome variation in three matrilocal (in which the man moves to his mate's residence after marriage) and three patrilocal groups among the hill tribes of northern Thailand. Genetic diversity in these groups shows a striking correlation with residence pattern, supporting the role of sex-specific migration in influencing human genetic variation.