Define gene flow and explain how it affects genetic differences among populations.

Define gene flow and explain how it affects genetic differences among populations.

• A. Gene flow is the creation of new alleles by mutation.
• B. Gene flow is the random change in allele frequencies due to sampling error.
• C. Gene flow is the transfer of alleles between populations via migration; it tends to reduce differences between populations and increase variation within populations.
• D. Gene flow is the selection of advantageous alleles in a population.

Answer: (C)

Gene flow is the transfer of alleles between populations through migration of individuals or their gametes. When members move and breed in a new population, they bring new alleles that shift the allele frequencies there, and they take some of the original population’s alleles with them. This movement tends to make the two populations more genetically similar, reducing differences between them over time. At the same time, introducing these new alleles increases genetic variation within each population, especially if the migrants bring alleles that were rare or absent locally. In short, gene flow homogenizes populations while boosting diversity inside populations, which is why many populations that exchange migrants stay more alike genetically than isolated ones.

Gene flow is the transfer of alleles between populations through migration of individuals or their gametes. When members move and breed in a new population, they bring new alleles that shift the allele frequencies there, and they take some of the original population’s alleles with them. This movement tends to make the two populations more genetically similar, reducing differences between them over time. At the same time, introducing these new alleles increases genetic variation within each population, especially if the migrants bring alleles that were rare or absent locally. In short, gene flow homogenizes populations while boosting diversity inside populations, which is why many populations that exchange migrants stay more alike genetically than isolated ones.