Which of the following is NOT a condition for Hardy-Weinberg Equilibrium (HWE)?

Hardy-Weinberg Equilibrium (HWE) is a fundamental concept in population genetics that describes the conditions under which allele and genotype frequencies remain constant from one generation to the next in a population. For a population to be in HWE, it must meet specific conditions.

One of those conditions is that there must be no natural selection acting on the population. Natural selection, which favors certain alleles over others, can alter allele frequencies over time, thereby leading the population away from equilibrium. Therefore, the presence of natural selection directly violates one of the core assumptions of HWE, making it NOT a condition for achieving equilibrium.

In contrast, an infinite population size is essential to preventing genetic drift, which could lead to changes in allele frequencies. No mutation is required to maintain allele frequencies, as mutations introduce new alleles and genotypes but do not affect the equilibrium status if they happen at a rate that does not impact allele frequency significantly. Random mating ensures that all individuals have an equal chance of mating and producing offspring, which minimizes deviations from expected genotype frequencies under HWE.

Understanding these established conditions provides insight into the dynamics of evolutionary processes and helps to identify when populations are not behaving in a stable genetic manner.