Correct answer: Founder Effect
The founder effect is the effect that occurs when the newly isolated population is founded by a small number of individuals having a limited genetic variation as compared to the larger population from which they migrated.
It occurs when there is low genetic variation due to the reduction in the size of a mating population. It happens when there is decreased genetic diversity that occurs as a result of small colonies of individuals from the original population that remain inaccessible to other colonies.
