What is the term for when a small group of individuals establishes a new population, potentially with different allele frequencies?

The concept being addressed is known as the founder effect, which occurs when a small group of individuals breaks away from a larger population to establish a new population. Because this new population is formed by only a subset of the original group's genetic makeup, the allele frequencies in the new population can differ significantly from those of the source population. This can lead to reduced genetic variation and can influence the evolutionary trajectory of the new population.

The founder effect highlights the importance of sampling, as the genetic make-up of the few individuals establishing a new population can lead to unique adaptations or traits that may not be present in the larger original group. This phenomenon is crucial in understanding how populations evolve and can have significant implications for conservation biology and the management of species that are founded by a limited number of individuals.