Explain the various factors which are known to affect Hardy-Weinberg equilibrium.

Explanation

Various factors affecting Hardy-Weinberg equilibrium are- (i) Gene migration or gene flow, (ii) Genetic drift, (iii). Mutation, (iv) Genetic recombination, (v) Natural selection.
(i) Gene migration or gene flow. It is the transfer of genes between populations that differ genetically from one another but can interbreed. When migration of a section of population to another place and population occurs, gene frequencies change in the original as well as in the new population. New genes are added to the new population and these are lost from the old population.
(ii) Genetic drift. It is the change in the gene frequency which is purely as a matter of chance. The smaller populations have greater chances for genetic drifts.
(iii) Mutation. The pre-existing advantageous mutations when selected, result in observation of new phenotypes.
(iv) Genetic recombination. The exchange of genetic material provides new combination of genes, especially in large population with large gene pool. Thus, new combination of old genes produces new combination of characters in organisms and adds to genetic variability.
(v) Natural selection. It is the process in which heritable variations enabling better survival to reproduce and leave greater number of progeny.
Thus, the occurrence of variations due to mutation or recombination during gametogenesis or due to gene, flow or genetic drift results in changed frequency of genes and alleles in future generation.