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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 ]
It is argued instead that the modern distribution of the obese phenotype likely comes about because of genetic drift in the genes encoding the regulation system controlling an upper limit on our body fatness. Hence the name "drifty" genes, to contrast the positively selected "thrifty genes".
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.
Neutral drift is the idea that a neutral mutation can spread throughout a population, so that eventually the original allele is lost. A neutral mutation does not bring any fitness advantage or disadvantage to its bearer. The simple case of the Moran process can describe this phenomenon.
Early observations that indicated higher than expected heterozygosity and overall variation within the protein isoforms studied, drove arguments as to the role of selection in maintaining this variation versus the existence of variation through the effects of neutral mutations arising and their random distribution due to genetic drift.
Genetic drift is the process by which allele frequencies fluctuate within populations. Natural selection and genetic drift propel evolution forward, and through evolution, alleles can become fixed. [8] [9] Processes of natural selection such as sexual, convergent, divergent, or stabilizing selection pave the way for allele fixation. One way ...
Setting aside other factors (e.g., balancing selection, and genetic drift), the equilibrium number of deleterious alleles is then determined by a balance between the deleterious mutation rate and the rate at which selection purges those mutations.
Both genetic drift and genetic draft are random evolutionary processes, i.e. they act stochastically and in a way that is not correlated with selection at the gene in question. Drift is the change in the frequency of an allele in a population due to random sampling in each generation. [9]