Geographic structure of human genetic variation: medical and evolutionary implications

Abstract

The geographic structure of human populations can be summarized by two numbers: 85 and 15, and two keywords: Continuous Genetic Change (CGC), and outliers . Eighty‐five and fifteen percent of the global variation represent, on the average, the genetic differences within and between populations, respectively. CGC characterizes most of the differences between groups at different geographic scales; and outlier populations, or genetic isolates, generated by different types of barriers to gene flow, punctuate with peaks the clinal landscape. The presence of this patterning, probably consistent across the genome with some exceptions, has several biomedical and evolutionary implications. However, its origin and evolution is only partially understood, and the geographic distribution of genetic variation at selectively important genes is still poorly investigated. Major efforts in these directions, as well as in the study of potential population outliers, will be of great importance to better define and predict the implications and future evolution of our geographic structure.

Genetic variation in Northern Thailand Hill Tribes: origins and relationships with social structure and linguistic differences

“…In a restricted geographic area, the levels of divergence can reach the values observed in world wide analyses [18]. Most of tribes, with an exception related to a specific habit of children adoptions, preserve traces of genetic similarity with the populations living in the areas (in different countries) where the geographic origin of these groups has been suggested.…”