Founder Effect

∞ generated and posted on 2016.09.06 ∞

Single round of bottlenecking that occurs when a new population is established, especially a relatively small population that has been derived from a relatively large population.

The founding of a new population generally involves either a geographical shift in the location of organisms or the erection of a geographical barrier between the new population and its parental population.

In any case, the reproductive isolation that has been imposed on the new population is a key component of the founder effect as too is a small size of the new population.

Genetic bottlenecking, in the more traditional sense of ongoing small population sizes, can follow the founder effect but is distinct from the founder effect. In all cases, the typical consequence is that of genetic drift, meaning that there is a tendency for beneficial alleles to be lost from populations as well as a potential for simply a shift in the genetic endowment of a population such that on a whole it becomes dissimilar to the parental population.