Chance events that cause allele frequencies to change result in genetic drift. Genetic drift becomes very important when the population size decreases. One type of genetic drift is the bottleneck effect. Explain how the bottleneck effect changes the population size and leads
to changes in allele frequencies and evolution.

The bottleneck effect is an extreme example of genetic drift that happens when the size of a population is severely reduced.

Explanation:

lizards have adapted to life in the desert. some desert lizards have toes with spiny scales to them run across the sand without sinking. some use the sand to hide from predators, or to search for small animals that they prey upon.