Based on the water snake example, we can see that gene flow from the mainland tends to homogenize the genetic diversity of these populations and tends to make them more similar. When gene flow occurs between populations of the same species (intraspecifically) or between populations of different species (interspecifically), it can lead to the movement of genes and alleles. Thick arrows represent natural selection over many generations, thin arrows represent gene flowįlow is a fascinating process that can have significant effects on the evolution and genetics of populations. Simplified diagram of intraspecific gene flow. This is because about 3-10 snakes are estimated to migrate to the islands per year, reintroducing the alleles for the band pattern into the islands. Despite this, a small fraction of snakes with bands are still found on these islands. On the other hand, most snakes that reside on the islands in the lake have a uniform coloration that is more advantageous along rocky shores. Most snakes on the mainland have a strong band pattern, which is advantageous for camouflage in marshes. The species is divided into several subpopulations that differ in their coloration. An example of this is the water snake, Nerodia sipedon, which inhabits the area of Lake Erie in Ohio and Ontario. This is because the introduction or reintroduction of a trait to a population through gene flow is considered a random event in population genetics. When there is a significant rate of gene flow between two populations, they can eventually share the same gene pool, which tends to homogenize the genetic makeup of populations.Ī trait or allele that is beneficial in one population may not necessarily have the same effect in the receiving population. For example, plants pollinated by birds or bats will their gametes further away than wind-pollinated plants, and animals like frogs will have a lower rate of gene flow than more mobile organisms like birds. Gene flow can vary between two populations. This can have a significant effect on the evolution and genetics of a population. It is important to note that gene flow only occurs when a gene or allele enters a receiving population's gene pool. It can occur through the migration of, or their gametes, and can be seen in both animals and plants.

Gene Flow is the movement of genes and alleles between populations.

Genetic drift gene flow