Dictionary > Hardy-Weinberg law

Hardy-Weinberg law

A principle stating that both allele and genotype frequencies in a randomly-mating population remain constant – and remain in this equilibrium across generations — unless a disturbing influence is introduced.
For instance, a population containing the genotypes AA, aa and Aa, the frequency of AA will always be p2, aa will be q2, and Aa will be 2pq at equilibrium, where the p is the frequency of A and q is the frequency of a.
Deviation from Hardy-Weinberg principle indicates evolution of species. Examples of disturbing influences include non-random mating, mutations, selection, limited population size, random genetic drift and gene flow.
Word origin: named after G. H. Hardy and Wilhelm Weinberg.

You will also like...

Pink Lotus plant on a pond
Freshwater Lentic Communities & Animals

This tutorial looks at some of the communities in freshwater lentic habitats. For instance, symbiosis occurs in a commun..

"Cronopio dentiacutus", a prehistoric mammal (an illustration)
Mammalian Ancestors

Mammals are a diverse group of organisms, where most of them develop their offspring within the uterus of the mother. Ov..


Muscle cells are specialized to generate force and movement. Learn about the different types of muscle tissues in this t..

Pollution in Freshwater Ecosystems
Pollution in Freshwater Ecosystems

There are many environmental factors that arise due to the usage of water in one way or another and for every action tha..

Direct and indirect physiologic effects of growth hormone
Animal Growth Hormones

Hormones are produced in the endocrine glands of animals. The pituitary gland and hypothalamus are the most impor..

Pikas are an indicator species for climate change
Indicator Species and Endangered Species

Certain species are capable of expressing characteristics indicative of the state of the ecosystem they occupy. They are..