What phenomenon occurs when a new population is established by a few individuals?

The phenomenon that occurs when a new population is established by a few individuals is known as the Founder Effect. This concept describes how a small group of individuals can start a new population and carry only a limited portion of the genetic diversity present in the original larger population. Because of this reduction in genetic variation, the traits of the new population can be significantly different from those of the source population, potentially leading to increased prevalence of certain genetic traits and reduced genetic diversity.

The Founder Effect plays a crucial role in evolutionary processes, particularly in isolated environments or new habitats where a small number of colonizers are responsible for establishing a new community. This can also amplify the effects of genetic drift, as the small population size may lead to random fluctuations in allele frequencies.

Understanding the Founder Effect is key in genetics and evolutionary biology because it highlights how significant genetic differences can arise in populations due to historical events involving a small number of founders.