Which statement best describes the implication of a violation of Hardy-Weinberg equilibrium?

Which statement best describes the implication of a violation of Hardy-Weinberg equilibrium?

• A. It indicates evolution is occurring.
• B. It indicates the population is at equilibrium.
• C. It has no effect on allele frequencies.
• D. It only affects phenotype frequencies.

Answer: (A)

Violating Hardy-Weinberg equilibrium means evolutionary forces are acting in the population, causing allele frequencies to change across generations. When the balance that keeps allele frequencies constant is disrupted—by factors like natural selection, genetic drift, migration, mutation, or nonrandom mating—allele frequencies no longer stay the same, so evolution is occurring. This is why the most fitting implication is that evolution is taking place. It’s not indicating equilibrium, and the change involves allele frequencies (not only phenotypes) because phenotype frequencies depend on which alleles are present and how they’re inherited.

Violating Hardy-Weinberg equilibrium means evolutionary forces are acting in the population, causing allele frequencies to change across generations. When the balance that keeps allele frequencies constant is disrupted—by factors like natural selection, genetic drift, migration, mutation, or nonrandom mating—allele frequencies no longer stay the same, so evolution is occurring. This is why the most fitting implication is that evolution is taking place. It’s not indicating equilibrium, and the change involves allele frequencies (not only phenotypes) because phenotype frequencies depend on which alleles are present and how they’re inherited.