What does the Hardy-Weinberg principle illustrate regarding allele frequencies?

The Hardy-Weinberg principle illustrates that allele frequencies in a population remain constant from generation to generation under specific conditions, which include the absence of evolutionary forces such as mutation, migration, genetic drift, non-random mating, and natural selection. This principle serves as a foundational concept in population genetics, providing a model against which real populations can be compared to determine if they are evolving.

Under idealized conditions, if a population is not influenced by these forces, the allele and genotype frequencies will stabilize, allowing predictions about the genetic makeup of the population over time. This stability is essential for understanding mechanisms of evolution since deviations from Hardy-Weinberg equilibrium suggest that some form of evolutionary process is at work.

Therefore, the principle helps researchers determine the genetic structure of a population and assess the influences of various factors that might lead to changes in allele frequencies.