Genetic Drift

What Is Genetic Drift?

• Genetic Drift is the change in allele frequencies in a population due to a chance event (such as a car killing insects on the road)

• Genetic Drift is random but natural selection is not random

• The Bottleneck Effect is an effect which can happen through Genetic Drift

  • Imagine a bottle and fill it with candy, then shake the bottle so some of the candy comes out. The candy that comes out represents the “survivors” and the candy that didn’t are the dead ones. However, the candy that came out does not represents the whole bottle or the genetic frequency of what came out of the genetic drift.

• The Founder Effect is another effect

  • Imagine seeds fall onto an island that is good for their ideal growth but they do not represents the original place they came from

• A big population is much better in terms of genetic drifting because it does not cause a bigger impact on their population compared to a smaller one