The Hardy-Weinberg principle determine that evolution will not occur by demonstrating how allele and genotype frequencies remain stable when undisturbed by intervening forces of nature. They came to understand that evolution will not take place if the following conditions are met at the same time:
1. no mutations occur at DNA level
2. natural selection is not occurring
3. the population is sufficiently large
4. all members of the population breed
5. all mating is totally random
6. all individuals produces the same number of offspring
7. no migration in or out of the population happens