How do gene flow and migration affect variation?

Gene flow and migration increase genetic variation by introducing new alleles into a population.

Gene flow, also known as gene migration, is a key mechanism for transferring genetic diversity among populations. It occurs when individuals from one population migrate to another and breed. This process introduces new alleles (different versions of a gene) into the population, increasing its genetic variation.

Migration is a significant factor in gene flow. When organisms move from one location to another, they carry their genetic information with them. If they breed with the local population, their genes become part of the gene pool of that population. This can lead to an increase in genetic variation, especially if the migrating individuals possess alleles that were previously rare or absent in the population.

However, it's important to note that gene flow can also decrease variation between populations. If there is a lot of gene flow between two populations, they can become more similar over time as genes are exchanged. This can lead to a reduction in genetic differences between the populations, making them more genetically homogeneous.

In addition, gene flow can have a significant impact on the evolution of species. By introducing new alleles into a population, it can lead to the development of new traits and adaptations. This can increase the population's ability to survive and reproduce in its environment, leading to evolutionary change.

In summary, gene flow and migration play a crucial role in shaping genetic variation within and between populations. They can introduce new alleles, increase genetic diversity, and drive evolutionary change. However, they can also make populations more similar and reduce genetic differences.