Genflusses

Genflusses (gene flow) is a process in population genetics that describes the movement of genetic material between populations due to the migration of individuals or the dispersal of gametes, such as pollen. Through these movements, alleles are introduced into new populations and removed from source populations, altering allele frequencies over time.

The primary mechanisms are the migration of individuals between populations and the transport of gametes by wind, water, or animals. Human activities can also induce gene flow, for example through translocations, farming practices, or the introduction of cultivated varieties. The rate and pattern of flow depend on distance, landscape features, species’ dispersal abilities, and ecological barriers.

Gene flow tends to homogenize genetic differences among populations by spreading alleles across groups. It can increase genetic diversity within populations by introducing new alleles, while reducing differentiation between populations. However, it can also introduce alleles that are maladaptive in the local environment or counteract local adaptation and divergent selection, thereby influencing evolutionary trajectories and potential speciation.

Common ways to study genflusses include comparing allele frequencies across populations using genetic markers (such as SNPs or microsatellites) and estimating migration rates with statistics like F-statistics or coalescent-based methods. Conceptually, the balance between gene flow, genetic drift, and natural selection shapes the genetic structure of populations.

Applications of understanding genflusses span conservation genetics, management of endangered species, control of invasive species, and the improvement of crops through introgression from related populations.