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Genetic drift, also known as random genetic drift, allelic drift or the Wright effect, [1] is the change in the frequency of an existing gene variant in a population due to random chance. [ 2 ] Genetic drift may cause gene variants to disappear completely and thereby reduce genetic variation . [ 3 ]
The founder effect occurs when a small group of migrants—not genetically representative of the population from which they came—establish in a new area. [4] [5] In addition to founder effects, the new population is often very small, so it shows increased sensitivity to genetic drift, an increase in inbreeding, and relatively low genetic ...
This image shows how though successive generations random allele fluctuations, or genetic drift, can lead to the fixation or loss of certain alleles within a population. Similar to the bottleneck effect, the founder's effect can also cause allele fixation. The founder effect occurs when a small founding population is moved to a new area and ...
Fixation rates can easily be modeled as well to see how long it takes for a gene to become fixed with varying population sizes and generations. For example, The Biology Project Genetic Drift Simulation allows to model genetic drift and see how quickly the gene for worm color goes to fixation in terms of generations for different population sizes.
Genetic drift is a cause of allelic frequency change within populations of a species. Alleles are different variations of specific genes. They determine things like hair colour, skin tone, eye colour and blood type; in other words, all the genetic traits that vary between individuals. Genetic drift does not introduce new alleles to a population ...
Population structure commonly arises from physical separation by distance or barriers, like mountains and rivers, followed by genetic drift. Other causes include gene flow from migrations, population bottlenecks and expansions, founder effects, evolutionary pressure, random chance, and (in humans) cultural factors. Even in lieu of these factors ...
The founder effect occurs when few individuals from a larger population establish a new population and also decreases the genetic diversity, and was originally outlined by Ernst Mayr. [4] The founder effect is a unique case of genetic drift, as the smaller founding population has decreased genetic diversity that will move alleles within the ...
Whether genetic drift is a minor or major contributor to speciation is the subject of much ongoing discussion. [ 5 ] Rapid sympatric speciation can take place through polyploidy , such as by doubling of chromosome number; the result is progeny which are immediately reproductively isolated from the parent population.