What is the definition of gene flow?

Gene flow refers to the transfer of genetic material between populations. This process occurs when individuals from one population migrate to another and breed, introducing new alleles and increasing genetic diversity within the receiving population. Gene flow can have significant evolutionary implications, as it can help to reduce differences between populations and allow for adaptive traits to spread more widely.

For example, if a population of plants is located on one side of a mountain and another population is on the opposite side, if pollinators travel between these areas and carry pollen from one population to the other, gene flow occurs. This exchange helps maintain genetic variation and can influence the evolutionary trajectory of both populations.

The other choices define different biological concepts. The change in allele frequencies within a single population relates to genetic drift or natural selection. Random mutation involves changes in the DNA sequence that can create new alleles, while natural selection is the process through which certain traits become more or less common based on their survival advantages. Gene flow specifically pertains to the exchange of genetic material and is distinct from these other processes.