what are the five assumptions of the hardy weinberg equilibrium?

The Hardy?Weinberg principle (also known as the Hardy-Weinberg equilibrium) states that both allele and genotype frequencies in a population remain constant?that is, they are in equilibrium?from generation to generation. This assumes that, within a given population:

1. Mating is random
2. No mutations are arising
3. No gene flow
4. No natural selection
5. Population size is infinitely large

Evolution is defined as the change in allelic frequencies over time. (Change in allelic frequencies over time = change in the frequency of traits over time.) If a population remains in equilibrium, trait frequencies does not change. However, if a population violates one of the 5 assumptions mandatory for equilibrium, trait frequencies will begin to alter. (E.g. If natural selection is present, beneficial traits will become more frequent over time.)

Thus, the violation of one of these assumption results in evolution.

Note: It is important to understand that outside the lab, one or more of these "disturbing influences" are always in effect. That is, Hardy?Weinberg equilibrium is impossible in nature. Genetic equilibrium is an ideal state that provides a baseline against which to measure change (evolution).

1. random mating
2. no gene flow
3. no mutations,
4. natural selection stopped  
5. small population size

If it is violated .. da hardy-weinberg principle wouldnt work !!