What is Hardy -Weinberg principle?

Explanation

The Hardy-Weinberg principle states the allele frequencies in a population are stable and is constant form generation to generation. If population is large and there is random mating among members of the population. i.e. gene pool is constant. This is called genetic equilibrium or Hardy-Weinberg equilibrium. It can be expressed by following equation:
`p^(2) _ 2 pq + q^(2) = 1 `
Where, p and q are frequencies of different alleles. Any fluctuation in genetic equilibrium leads to evolution.