Question

How does a founder effect or a population bottleneck amplify the effect of genetic drift?

Short answer

A founder effect and a population bottleneck magnify the influence of genetic drift by creating a smaller gene pool. Their reduced size makes populations more susceptible to changes in gene frequencies due to random chance, potentially leading to significant genetic differences over time.

Step-by-step solution

Understand The Concepts

Genetic drift refers to random fluctuations in the frequencies of alleles (gene variants) in a population due to chance. These changes can lead to large differences in gene frequencies over time, particularly in small populations. The founder effect occurs when a few individuals from a larger population establish a new population. Due to its small size, this new population is likely to have different gene frequencies from the original population. A population bottleneck is an event that drastically reduces the size of a population, thereby greatly reducing genetic variation.

Elaborate on Founder Effect and Genetic Drift

The founder effect amplifies the effect of genetic drift because a few individuals establish a new population, meaning that the gene pool contains only a small fraction of the total genetic variation present in the original population. As a result, genetic drift can more easily fix or eliminate alleles, leading to a shift in gene frequencies and potentially substantial genetic differences.

Elaborate on Population Bottleneck and Genetic Drift

A population bottleneck also amplifies the effects of genetic drift. When a population's size is drastically reduced, the survivors constitute a random genetic sample of the original population. Large gene frequency changes can occur, and alleles may be lost, also due to drift engaging more effectively with the smaller gene pool, which can lead to significant genetic changes.