Random changes in gene frequency in a population.

Random changes in gene frequency in a population.

• A. Founder effect
• B. Genetic bottleneck
• C. Genetic drift
• D. Sexual selection

Answer: (C)

Random changes in gene frequency in a population are driven by genetic drift, the random fluctuation of allele frequencies from generation to generation in small populations. Because sampling is imperfect, alleles can become more or less common by chance rather than due to natural selection. This effect is stronger when populations are small, and it can lead to fixation or loss of alleles, reducing genetic variation over time. The founder effect and genetic bottlenecks are special cases where drift is especially pronounced because the population is reduced to a small number of individuals, so random sampling greatly shapes the genetic makeup. Sexual selection, on the other hand, involves nonrandom mating and differential reproductive success based on traits, which is a form of selection rather than random drift. So the concept described is genetic drift.

Random changes in gene frequency in a population are driven by genetic drift, the random fluctuation of allele frequencies from generation to generation in small populations. Because sampling is imperfect, alleles can become more or less common by chance rather than due to natural selection. This effect is stronger when populations are small, and it can lead to fixation or loss of alleles, reducing genetic variation over time. The founder effect and genetic bottlenecks are special cases where drift is especially pronounced because the population is reduced to a small number of individuals, so random sampling greatly shapes the genetic makeup. Sexual selection, on the other hand, involves nonrandom mating and differential reproductive success based on traits, which is a form of selection rather than random drift. So the concept described is genetic drift.