What is the main impact of gene flow in a population?

The main impact of gene flow in a population is that it adds genetic variation. Gene flow, also known as gene migration, occurs when individuals from one population migrate to another and breed, introducing new alleles into the gene pool. This process can enhance genetic diversity within the population, which is crucial for adaptability and evolutionary potential. Increased genetic variation can lead to improved resistance to diseases, better adaptability to changing environments, and overall population resilience.

While increased competition, prevention of population growth, and alterations in physical appearances can occur in the context of specific ecological situations, they are not direct outcomes of gene flow itself. Instead, gene flow primarily enhances the genetic diversity that can lead to a more robust and adaptable population over time.