ABSTRACT
Populations that have been isolated from one another will accumulate linguistic differences relatively rapidly, and perhaps even speak different, mutually unintelligible, languages. Neighboring populations frequently exchange individuals that contribute to an ongoing process of bidirectional gene flow between them. Disease prevalences are often different between ancestral populations. Human populations often harbor their own populations of pathogens to which they have previously developed resistance. The release of these pathogens into previously unexposed populations could result in a substantial increase in the incidence and severity of infectious disease. The simplest scenario occurs when no alleles are shared between the ancestral populations. High-resolution genomewide genotype data are available for many populations throughout the world and a number of approaches have been developed to simultaneously assess population structure and admixture from such data. Admixture mapping can also be applied to cases involving more than several ancestral populations.
