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Genetic drift

2:16

Genetic Drift | Founder Effect and Bottleneck Effect Explained

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Genetic Drift: Founder Effect vs. Bottleneck

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Founder Effect, Bottle Necking, and Genetic Drift

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Natural Selection vs Genetic Drift - Amoeba Sisters #Shorts

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Genetic drift

Genetic drift is the change in the frequency of an existing gene variant (allele) in a population due to random sampling of organisms. The alleles in the offspring are a sample of those in the parents, and chance has a role in determining whether a given individual survives and reproduces. A population's allele frequency is the fraction of the copies of one gene that share a particular form. Genetic drift may cause gene variants to disappear completely and thereby reduce genetic variation or cause initially rare alleles to become much more frequent or even fixed. The effects of genetic drift are strongest in small, isolated populations and can lead to significantly changed allele frequencies in a relatively short period of time in such populations.
    • Analogy with marbles in a jar 

    • Probability and allele frequency 

    • Mathematical models 

    • Drift and fixation 

    • Versus natural selection 

    • Population bottleneck 

    • History 

    • Bibliography