Answer to Question #192874 in Evolution for Jude Ofori

Question

Discuss the role of Gene Flow in evolution

Answer 1

Gene flow is the physical movement of alleles into and out of a population, by way of immigration and emigration. It tends to counter the effects of mutation, natural selection, and genetic drift.

When an individual migrates from one population to another, it carries genes that are representative of its own ancestral population into the recipient population. If it successfully establishes itself and breeds it will transmit those genes between the populations. The transfer of genes is called gene flow. If the two populations originally had different gene frequencies and if selection is not operating, migration (or, to be exact, gene flow) alone will rapidly cause the gene frequencies of the different populations to converge.

Migration will generally unify gene frequencies among populations rapidly in evolutionary time. In the absence of selection, migration is a strong force for equalizing the gene frequencies of populations within a species. Provided that the migration rate is greater than 0, gene frequencies will eventually equalize. Even if only one successful migrant moves into a population per generation, gene flow inevitably draws that population’s gene frequency to the species’ average. Gene flow acts, in a sense, to bind the species together.

Gene flow is a microevolutionary process that counters the diversifying effects of mutations, natural selection, and genetic drift in a population.