define the hardy-weinberg principle?

The Hardy?Weinberg principle (also known by a variety of names: HWP, Hardy?Weinberg equilibrium, Hardy?Weinberg Theorem, HWE, or Hardy?Weinberg law) states that both allele frequencies and genotype frequencies in a population remain constant?that is, they are in equilibrium?from generation to generation unless specific disturbing influences are introduced.
Those disturbing influences include non-random mating, mutations, selection, limited population size, overlapping generations, random genetic drift, gene flow and meiotic drive.