The Hardy-Weinberg Law of Genetic Equilibrium
In 1908 G. Hardy and W. Weinberg independently proposed that the frequency of alleles and genotypes in a population will remain constant from generation to generation if the population is stable and in genetic equilibrium. Five conditions are required in order for a population to remain at Hardy-Weinberg equilibrium:

1.	A large breeding population
2.	Random mating
3.	No change in allelic frequency due to mutation
4.	No immigration or emigration
5.	No natural selection

Let's look more closely to see how each factor functions to maintain genetic equilibrium and how the opposite condition can bring about a change in the gene pool.