Hardy–Weinberg equilibrium model
The Hardy–Weinberg equilibrium model (also known as: Hardy–Weinberg principle, Hardy–Weinberg law or Hardy–Weinberg Theorem) states that both allele and genotype frequencies in a population remain constant, namely, they are in equilibrium, generation after generation unless specific disturbing influences are introduced. Among others, such disturbing influences can be mutations, random genetic drift, non-random mating, natural selection, gene flow and meiotic drive.
In 1908 G. H. Hardy in England and W. R. Weinberg in Germany demonstrated mathematically that the allelic frequencies in populations would stay constant, generation upon generation, if certain processes did not occur to cause the loss of existing genes or the acquisition of new genes. They expressed this law in the form of a mathematical formula as a reapplication of the binomial-expansion.