Which process refers to the movement of alleles between populations?

The movement of alleles between populations is referred to as gene flow. This process occurs when individuals from one population migrate to another and breed, introducing new genetic material into the gene pool of the receiving population. Gene flow can increase genetic diversity within a population and can help maintain genetic similarity between populations that may otherwise diverge due to isolation.

In contrast, genetic drift involves random changes in allele frequencies in a population, particularly in small populations, and does not specifically refer to the movement of alleles between populations. Natural selection is the process where certain traits become more or less common in a population based on their impact on survival and reproduction, and it does not inherently involve the movement of alleles. Mutation refers to changes in the DNA sequence that can introduce new alleles to a population, but it does not involve the movement of alleles between distinct populations. Thus, gene flow is the most accurate term for the movement of alleles between populations.