Hardy-Weinberg Law | Animal Husbandry & Veterinary Science Optional for UPSC PDF Download

Hardy-Weinberg Law

• The Hardy-Weinberg law, formulated by G.H. Hardy and W. Weinberg in 1908, is a fundamental principle in population genetics.
• This law states that in a population, allele frequencies tend to reach an equilibrium over generations when certain conditions are met.
• For instance, if two alleles exist in equal proportions in a large population, and there is no selective advantage for either allele nor any mutations occurring differentially, the alleles will maintain their proportions over time.
• The frequencies of alleles can be calculated from a representative sample of the population, enabling predictions about genetic makeup.
• In a population, the frequencies of different genes and alleles can vary, but under the Hardy-Weinberg equilibrium, these frequencies remain constant from generation to generation.
• The law establishes a relationship between gene frequencies and genotype frequencies, showing how genetic variation is maintained in populations.

Genetic Equilibrium

• Genetic equilibrium occurs when the frequencies of alleles and genotypes in a population remain constant from one generation to the next.
• This equilibrium is maintained under conditions of random mating, absence of selection, mutation, or migration.
• The Hardy-Weinberg law assumes an infinitely large population to avoid the effects of genetic drift, which can cause fluctuations in gene frequencies in small populations.
• A predictable relationship exists between the frequencies of heterozygotes and homozygotes in a population following the Hardy-Weinberg equilibrium.
• Heterozygote frequency is calculated as twice the square root of the product of the frequencies of the homozygotes.