BRAINCAKEHardy Weinberg Equilibrium
The Hardy-Weinberg principle (proposed in 1908 by G. H. Hardy and Wilhelm Weinberg) states that in a large, randomly mating population, the allele frequencies and genotype frequencies stay constant from one generation to the next, provided no evolutionary forces act on the population. A population in this state is in Hardy-Weinberg equilibrium.
This may seem surprising: you might expect a dominant allele to become more common over time. It does not. Inheritance itself does not change allele frequencies, because meiosis and fertilisation only reshuffle the alleles already in the gene pool. A recessive allele is not lost; it is carried unchanged in heterozygotes.
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Key terms in this lesson
- allele frequency
- The proportion of all the alleles of a gene in a population that are a particular allele.
More in Gene Pools
- Population Genetics
- Allele Frequency
- Hardy Weinberg Equation
- Conditions of the Hardy Weinberg Equilibrium
- Mutations
- Non-Random Mating
- Different Sized Populations
- Isolation
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