The significance of the Hardy-Weinberg equilibrium in population genetics is that it provides a mathematical framework to understand genetic variation in a population. This principle states that allele and genotype frequencies in a population remain constant from generation to generation in the absence of evolutionary influences, such as selection, mutation, or gene flow. By comparing real populations to Hardy-Weinberg predictions, scientists can identify evolutionary processes affecting genetic diversity. This concept is essential for studying evolutionary biology, conservation genetics, and understanding how populations respond to environmental changes.