Final answer:
Gene flow is the population genetic term that describes the process of organisms migrating, mating, and reproducing in a new area. It increases genetic variation within a population and among populations.
Step-by-step explanation:
The population genetic term that describes the process of organisms migrating from an area, mating with indigenous individuals, and reproducing in a new area is gene flow. Gene flow occurs when there is a movement of alleles (genetic material) between populations due to migration of individuals or gametes. This process increases genetic variation within a population and also contributes to genetic variation among populations.