Assclown

Description of how genetic variation and genetic drift affects extinction of various species.

http://highered.mheducation.com/sites/9834092339/student_view0/chapter20/simulation_of_genetic_drift.html

http://anthro.palomar.edu/synthetic/synth_5.htm

Genetic drift has many factors that can be linked to the extinction of a species. Genetic drift is a change in allele frequency which can rise or fall over time. Genetic drift lowers genetic variation every generation. The strength genetic drift depends on the size of population. Therefore the lower the population size, the less genetic variation there will be compared to the previous generation. This being said, species that have a lower genetic variation have a high risk of being wiped out by disease because they won’t be able to adapt. Environmental changes such as global warming can also affect those species with low genetic variation. Within a small population, some alleles will eventually be wiped out by genetic drift. The recessive alleles that are less common, eventually cease to exist putting a species at risk.

Random forces lead to genetic drift

Sometimes, there can be random fluctuations in the numbers of alleles in a population. These changes in relative allele frequency, called genetic drift, can either increase or decrease by chance over time.

Typically, genetic drift occurs in small populations, where infrequently-occurring alleles face a greater chance of being lost. Once it begins, genetic drift will continue until the involved allele is either lost by a population or is the only allele present at a particular gene locus within a population. Both possibilities decrease the genetic diversity of a population.

Genetic drift is common after a population experiences a population bottleneck. A population bottleneck arises when a significant number of individuals in a population die or are otherwise prevented from breeding, resulting in a drastic decrease in the size of the population. Genetic...