The Hardy-Weinberg equilibrium law is an important way to check whether natural selection or other evolutionary factors are influencing a particular population. Through the Hardy-Weinberg equation, we can determine the genetic configuration of a population that is not evolving. From this analysis, we can compare the data with the actual information of the population and thus understand whether or not there is evolution.
According to Hardy and Weinberg, a population that is not evolving has, from generation to generation, constant frequency of alleles and genotypes. In those cases, where only recombination is observed according to Mendel's laws, we say that the population is in Hardy-Weinberg equilibrium.
A population is in Hardy-Weinberg equilibrium when its genotypic and allelic frequencies remain constant. For the equilibrium to occur, the analyzed population must obey some premises. The essential conditions for a population to remain in Hardy-Weinberg equilibrium are:
- Lack of natural selection
- No mutations
- No gene flow
- Large population
- Same number of males and females in population
- All couples should be fertile and have the same number of puppies.
- Occurrence of random intersections.