Final answer:
The Hardy-Weinberg theorem, independently shown by Godfrey Hardy and Wilhelm Weinberg, states that allele frequencies do not change in a population if certain conditions are met. This principle helps to understand the dynamics of genetic variation and serves as a model for comparing real population changes.
Step-by-step explanation:
The Hardy-Weinberg theorem, independently shown by Godfrey Hardy and Wilhelm Weinberg, is a principle of population genetics that states that allele frequencies do not change in a population if certain conditions are met. This equilibrium is achieved when there is no selection, mutation, migration, genetic drift, or non-random mating in a population. The principle is useful as a model to compare real population changes and understand the dynamics of genetic variation.