Final answer:
The Hardy-Weinberg principle is a null hypothesis that focuses on genetic equilibrium, stating that allele and genotype frequencies stay constant in the absence of evolutionary forces.
Step-by-step explanation:
The Hardy-Weinberg principle provides a null hypothesis about genetic equilibrium. This principle, formulated by Godfrey Hardy and Wilhelm Weinberg, states that allele and genotype frequencies in a population will remain constant from generation to generation in the absence of evolutionary forces. These forces include natural selection, mutation, genetic drift, and migration (gene flow). In reality, no natural population is completely free from these forces; thus, the Hardy-Weinberg principle serves as a benchmark to determine whether a population is evolving. If allele or genotype frequencies do not conform to those predicted by the Hardy-Weinberg equation, it can be inferred that evolutionary forces are at play within the population.