HardyWeinbergegyensúly

The Hardy-Weinberg principle, also known as the Hardy-Weinberg law or equilibrium, is a fundamental concept in population genetics. It describes a hypothetical situation where allele and genotype frequencies in a population remain constant from generation to generation. This state of equilibrium is achieved under a set of specific conditions, meaning that no evolution is occurring with respect to the gene locus in question.

The conditions necessary for Hardy-Weinberg equilibrium are: no mutation, random mating, no gene flow, no genetic drift, and no natural selection. If any of these conditions are violated, allele or genotype frequencies will change, indicating that evolution is taking place.

The principle is mathematically expressed through two equations. The first, p + q = 1, relates the frequencies of two alleles (p for the dominant allele and q for the recessive allele) within a population. The second equation, p^2 + 2pq + q^2 = 1, describes the expected genotype frequencies in the next generation, where p^2 represents the frequency of homozygous dominant individuals, 2pq represents the frequency of heterozygous individuals, and q^2 represents the frequency of homozygous recessive individuals.

While real populations rarely meet all the strict conditions for Hardy-Weinberg equilibrium, the principle serves as a crucial null hypothesis. By comparing observed genotype frequencies to those predicted by the Hardy-Weinberg equations, scientists can identify when and how evolutionary forces are acting on a population. This allows for the study and understanding of evolutionary mechanisms like mutation, gene flow, genetic drift, non-random mating, and natural selection.