Genetic Drift and Gene Flow

Genetic drift

Random changes in the gene pool that are not influenced by fitness.

Driftworm simulation

An example showing that a random color of worm became fixed in less than 20 generations.

Founder’s effect

Occurs when a small group from a larger population starts a new population, leading to a higher prevalence of certain genetic disorders.

Founder’s Effect example

Amish immigrants in 1800s. About 300 immigrants founded the Amish population, resulting in higher rates of genetic disorders.

Bottleneck effect

A significant reduction in population size due to a random event, leading to loss of genetic variation.

Gene flow

The movement of individuals between subpopulations, introducing new variations and homogenizing gene pools.

Genetic disorders

Conditions caused by abnormalities in the genome, often more prevalent in isolated populations.

Natural disaster

An event that can lead to a bottleneck effect by randomly killing off a large portion of a population.

Homogenization

The process by which gene pools become more similar between populations due to gene flow.

Polydactylism

A genetic disorder characterized by the presence of more than five fingers on a hand.

Surviving variants

The remaining genetic variations after a population bottleneck, which may lead to increased genetic drift.

Small populations

Populations that are more susceptible to genetic drift and loss of genetic variation.