What is the founder effect?

The founder effect refers to a phenomenon in genetics where a small group from a larger population establishes a new population in a different location, often resulting in a limited gene pool. This can lead to reduced genetic diversity as the new population is formed from just a few individuals who carry only a subset of the genetic variation present in the original population.

In the case of the founder effect, the genetic traits of the initial members of this smaller population will dominate in subsequent generations, which can result in certain alleles being overrepresented or even completely absent from the new population. This can have significant implications for the population's evolution, potentially leading to rapid differentiation from the original group due to genetic drift.

The other options describe different genetic concepts. A significant population decrease leading to allele loss pertains to the bottleneck effect, where a drastic reduction in population size decreases genetic diversity. A genetic trait spread across a large population describes gene flow or the general spread of traits through a population over time. Finally, merging multiple founder populations into a large one does not accurately capture the essence of the founder effect, which focuses on the establishment of a new population from a small number of individuals.