Which mechanism tends to homogenize genetic variation among populations?

Which mechanism tends to homogenize genetic variation among populations?

• A. Mutation
• B. Gene flow
• C. Natural selection
• D. Genetic drift

Answer: (B)

Gene flow is the movement of alleles between populations as individuals migrate or as pollen/gametes move between groups. This exchange mixes gene pools, so allele frequencies in different populations become more alike over time. In other words, gene flow tends to equalize genetic variation across populations, reducing differences that might have built up by isolation. Mutation introduces new alleles within a population, which can increase variation locally and, if different populations acquire different mutations, can create differences between populations. Natural selection can drive populations apart if they face different environments and favor different traits, though similar selective pressures can also align traits. Genetic drift randomizes allele frequencies and often causes divergence between small, isolated populations.

Gene flow is the movement of alleles between populations as individuals migrate or as pollen/gametes move between groups. This exchange mixes gene pools, so allele frequencies in different populations become more alike over time. In other words, gene flow tends to equalize genetic variation across populations, reducing differences that might have built up by isolation.

Mutation introduces new alleles within a population, which can increase variation locally and, if different populations acquire different mutations, can create differences between populations. Natural selection can drive populations apart if they face different environments and favor different traits, though similar selective pressures can also align traits. Genetic drift randomizes allele frequencies and often causes divergence between small, isolated populations.