Introduction

Recall that we define evolution as a change in the allele frequency of a population. There are four mechanisms of evolutionary change: natural selection, genetic drift, gene flow, and mutation pressure. Genetic drift is the random change in allele frequency. It occurs when chance events shift the allele frequency.

Learning Goals

After reading your text and completing this exercise, you should be able to:

To understand the mechanism of genetic drift.
To understand the genetic consequences of drift.
To understand the factors that determine the significance of genetic drift.