Search results
Results from the WOW.Com Content Network
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 ]
These can be caused by genetic drift or by mutation, and they will tend to slow down the process of evolution by natural selection. [2] This is most easily seen by considering the case of disequilibria caused by mutation: Consider a population of individuals whose genome has only two genes, a and b.
Dots indicate samples from each generation that are transferred to the next generation. In this population of 20, there is a shift from an allele frequency of 50% for the blue allele to 100% for the blue allele in just 5 generations. Based on File:Random_sampling_genetic_drift.gif
The drift-barrier hypothesis is an evolutionary hypothesis formulated by Michael Lynch in 2010. [1] It suggests that the perfection of the performance of a trait, in a specific environment, by natural selection will hit a hypothetical barrier.
Evolution is the change in the heritable characteristics of biological populations over successive generations. [1] [2] It occurs when evolutionary processes such as natural selection and genetic drift act on genetic variation, resulting in certain characteristics becoming more or less common within a population over successive generations. [3]
Genetic variation is the difference in DNA among individuals [1] or the differences between populations among the same species. [2] The multiple sources of genetic variation include mutation and genetic recombination. [3] Mutations are the ultimate sources of genetic variation, but other mechanisms, such as genetic drift, contribute to it, as ...
In the absence of selection, mutation, genetic drift, or other forces, allele frequencies p and q are constant between generations, so equilibrium is reached. The principle is named after G. H. Hardy and Wilhelm Weinberg, who first demonstrated it mathematically.
Molecular drive is a term coined by Gabriel Dover in 1982 to describe evolutionary processes that change the genetic composition of a population through DNA turnover mechanisms. [ 1 ] [ 2 ] [ 3 ] Molecular drive operates independently of natural selection and genetic drift .