Abstract
A central concept in genetics, the population is defined as a set of inter-fertile individuals evolving in time and space. Theory predicts that its size, structure and isolation from other populations affect its genetic diversity. At the end of the 20thcentury , the development of molecular biology made it possible to measure levels of variation in the human genome. These measurements were used to construct a simple genealogy of major human populations, supporting an African origin for Homo sapiens. With the massive sequencing of modern and ancient genomes, however, it's becoming clear that populations are not static, isolated entities. Our species forms a dynamic metapopulation, with periods of genetic isolation interrupted by massive waves of migration. On every continent, the populations we associate with major socio-cultural groupings are descended from the interbreeding of groups with origins as varied as they are unexpected. These discoveries lead us to a better understanding of our identity as a species, and question the joint evolution of cultures and the peoples who are their repositories.
