What does Hardy-Weinberg equilibrium describe?

What does Hardy-Weinberg equilibrium describe?

• A. Allele frequencies always change over generations
• B. Phenotype frequencies determine genotype frequencies
• C. Genotype frequencies in a large population remain constant from generation to generation in the absence of evolutionary influences
• D. Evolution always occurs in large populations

Answer: (C)

Hardy-Weinberg equilibrium describes a population genetics scenario where, if a population is very large, mates randomly, and there are no evolutionary forces acting (no mutation, migration, natural selection, or genetic drift), allele frequencies remain constant from one generation to the next. When these conditions hold, the genotype frequencies stabilize according to p^2 for the homozygous dominant, 2pq for the heterozygotes, and q^2 for the homozygous recessive, with p and q representing the frequencies of the two alleles and p + q = 1. This setup serves as a null model for evolution: any deviation from these constant frequencies indicates that some evolutionary influence is at work.

Hardy-Weinberg equilibrium describes a population genetics scenario where, if a population is very large, mates randomly, and there are no evolutionary forces acting (no mutation, migration, natural selection, or genetic drift), allele frequencies remain constant from one generation to the next. When these conditions hold, the genotype frequencies stabilize according to p^2 for the homozygous dominant, 2pq for the heterozygotes, and q^2 for the homozygous recessive, with p and q representing the frequencies of the two alleles and p + q = 1. This setup serves as a null model for evolution: any deviation from these constant frequencies indicates that some evolutionary influence is at work.