How does gene flow function in population variation?

Gene flow introduces new alleles into a population, increasing genetic diversity and reducing genetic differentiation.

Gene flow, also known as migration, occurs when individuals move between populations and bring their genes with them. This can happen through physical migration or through the movement of gametes, such as pollen or sperm. When new alleles are introduced into a population, they can increase genetic diversity and reduce genetic differentiation between populations.

Gene flow can have both positive and negative effects on population variation. On the one hand, it can increase genetic diversity, which can provide a greater range of traits for natural selection to act upon. This can lead to the evolution of new species and the adaptation of populations to changing environments. On the other hand, gene flow can also introduce harmful alleles into a population, which can reduce fitness and increase the risk of extinction.

The extent to which gene flow affects population variation depends on a number of factors, including the rate of migration, the size of the populations involved, and the degree of genetic differentiation between them. In some cases, gene flow may be restricted by physical barriers, such as mountains or oceans, which can limit the movement of individuals between populations. In other cases, gene flow may be facilitated by human activities, such as the introduction of non-native species or the movement of domesticated animals.