A law that states that under random mating in a population the proportions with particular genetic characteristics remain constant over the generations. Suppose that a large population contains individuals with gene pairs AA, Aa, and aa, and that individuals mate with randomly chosen partners. Their offspring receive one gene from each parent. If, from each gene pair, the gene is chosen at random, then the Hardy–Weinberg law, first published independently by Hardy and by Wilhelm Weinberg, both in 1908, states that the proportions of the three types of gene pair will remain constant. The population is in equilibrium.