Occurs in small populations. Has a bigger impact on smaller gene pools.
Genetic Drift
Some genes become more or less common as individuals that carry them produce more offspring as a result of change rather than an actual adaptive advantage.
Alleles in Genetic Drift
Alleles can become fixed or lost by genetic drift, decreasing genetic diversity.
Founder Effect
Occurs when small number of individuals establish a new population. The gene pool will reflect genotypes of found individuals.
Founder Effect
Is not representative of the original populations genetic diversity. The individuals are reproductively isolated from the original population.
Genetic variation in Founder Effect
Genetic variation is reduced, but otherwise rare genes may be common simply because they were carried by 'founders'.
Bottleneck Effect
When a population becomes very small and then expands. The new gene pool will reflect the genotypes of individuals at the bottleneck. (This is important consideration for endangered species).
Small Populations
Smaller populations have less genetic variation to counteract natural selection pressures.
Small Populations
Smaller populations means a higher chance of inbreeding which means less genetic diversity.
