The founder effect

Suppose a boat travelled from one island to another. In the process, several lizards were transferred from the first island to the other. The lizards breed and settle down to form a new lizard population on their new island. This is called the founder effect. The small number of founding lizards formed the genetic base on which the whole population was built. This genetic base is significantly smaller than that of the original lizard population on the first island.

Therefore, the genetic diversity of the new population is lower than that of the original population.

Genetic bottlenecks

The only difference between the founder effect and genetic bottlenecks is the way in which the new genetic pool is formed. In the founder effect the new pool is formed when a few individuals from a population become geographically isolated, while in genetic bottlenecks the new gene pool is formed when only a few individuals from a population survive a mass disaster, or are the only ones to breed.

The effect is the same: the genetic variation of the new population is decreased compared to…