Genetic Drift: Genetic drift is a mechanism of evolution characterized by random fluctuations in the frequency of a particular version of a gene (allele) in a population. Though it primarily affects small, isolated populations, the effects of genetic drift can be strong, sometimes causing traits to become overwhelmingly frequent or to disappear from a population.

Types of Genetic Drift

• Bottleneck Effect: In the bottleneck effect, the population size severely decreases due to competition, predators, or diseases. The frequency of certain alleles in a population changes because the organisms that carry them are eliminated. The others increase in number because they are the only alleles left.
• Founder Effect: In the founder effect, a new population is founded in a new location due to physical or geographical barriers. The new population formed does not interact and mate with the original population. As a result, the allelic frequencies of the new population will be different from the original population.

Examples of Genetic Drift

Let us take the example of children with tigers and brown eyes. The brown eye is found most compared to tiger-eyed children; this makes brown eyes a dominant allele. However, due to instability in tiger-eyed children, they might be endangered as their next generation might not remain with tiger eyes.

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By Team Learning Mantras