What are the consequences of genetic drift?
The consequences of genetic drift are numerous. It leads to random changes in allele frequencies. Drift causes fixation of alleles through the loss of alleles or genotypes. Drift can lead to the fixation or loss of entire genotypes in clonal (asexual) organisms. Drift leads to an increase in homozygosity for diploid organisms and causes an increase in the inbreeding coefficient. Drift increases the amount of genetic differentiation among populations if no gene flow occurs among them.
Genetic drift also has two significant longer-term evolutionary consequences. Genetic drift can facilitate speciation (creation of a new species) by allowing the accumulation of non-adaptive mutations that can facilitate population subdivision. Drift also facilitates the movement of a population from a lower fitness plateau to a higher fitness plateau according to the shifting balance theory of Sewall Wright.
The amount of population subdivision is expected to increase because of the random losses of alleles that occur in different populations. In addition, random changes in allele frequencies are expected to occur in different populations, and these random changes tend to make populations become differentiated. Finally, small effective population sizes increase the likelihood that mating events will occur between close relatives, leading to an increase in inbreeding and subsequent loss of heterozygosity.
The consequences of genetic drift are numerous. It leads to random changes in allele frequencies. Drift causes fixation of alleles through the loss of alleles or genotypes. Drift can lead to the fixation or loss of entire genotypes in clonal (asexual) organisms. Drift leads to an increase in homozygosity for diploid organisms and causes an increase in the inbreeding coefficient. Drift increases the amount of genetic differentiation among populations if no gene flow occurs among them.
Genetic drift also has two significant longer-term evolutionary consequences. Genetic drift can facilitate speciation (creation of a new species) by allowing the accumulation of non-adaptive mutations that can facilitate population subdivision. Drift also facilitates the movement of a population from a lower fitness plateau to a higher fitness plateau according to the shifting balance theory of Sewall Wright.
The amount of population subdivision is expected to increase because of the random losses of alleles that occur in different populations. In addition, random changes in allele frequencies are expected to occur in different populations, and these random changes tend to make populations become differentiated. Finally, small effective population sizes increase the likelihood that mating events will occur between close relatives, leading to an increase in inbreeding and subsequent loss of heterozygosity.
