Gene Pool

DNA Molecule. Getty/Pasieka

A gene pool is a collection of all available genes in a population that are able to be passed down from parents to offspring. The more diversity there is in a population of a species, the larger the gene pool. The gene pool determines with phenotypes are visible in the population at any given time.

How Gene Pools Change

The gene pool can change in an area due to the migration of individuals into or out of a population.

If individuals that have certain traits are the only ones in the population and the emigrate to a different population, the gene pool shrinks and those traits are no longer available to be passed down to offspring. If individuals that have different traits immigrates into a population, they increase the gene pool and a new type of diversity can be seen within the population in that area as they interbreed with the others who already live there.​

The size of the gene pool directly affects the evolutionary trajectory of that population. The theory of evolution states that natural selection acts on a population to favor the desirable traits for that environment while simultaneously weeding out the unfavorable characteristics. As natural selection works on a population, the gene pool changes. The favorable adaptations become more plentiful and the less desirable traits become fewer or even disappear from the gene pool completely.

Populations with larger gene pools are more likely to survive as the environment changes than those with smaller gene pools. Larger populations with more diversity will tend to have at least some desirable characteristics within the population as the environment changes and requires new adaptations.

A smaller and more homogeneous gene pool puts the population at risk for extinction if there are few or no individuals have the genes for the traits necessary to survive the change.

Examples of Gene Pools

For example, in bacteria populations, individuals that are antibiotic resistant are more likely to survive any sort of medical intervention and will live long enough to reproduce. Therefore, the gene pool has now changed to include only bacteria that are antibiotic resistant.

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Scoville, Heather. "Gene Pool." ThoughtCo, Apr. 16, 2017, Scoville, Heather. (2017, April 16). Gene Pool. Retrieved from Scoville, Heather. "Gene Pool." ThoughtCo. (accessed February 24, 2018).