Q. 17 - Biology

Question

Explain the Hardy-Weinberg principle of equilibrium theory.

Step-by-Step Solution

Answer

Thus, in the absence of evolutionary effects, Hardy- Weinberg equilibrium exposes the constancy of gene frequency with time from generation to generation.

Hardy- Weinberg principle :

The Hardy- Weinberg equilibrium, model, theory, or rule is also known as the Hardy- Weinberg principle. In the absence of evolutionary effects, the frequencies of alleles and genotypes in a population will, on average, remain constant from generation to generation. 

Explanation :

To maintain Hardy-Weinberg equilibrium in a population, five requirements must be met.

1. There is a sizable breeding population.

2. There will be no immigration or emigration.

3. There has been no natural selection.

4. Mating at random.

5. There was no change in allelic frequency as a result of the mutation.

Hardy-Weinberg equation : 

$p^2+2pq+q^2=1$

where, 

$p^2$ is frequency for homozygous genotype AA.

$q^2$ is frequency for homozygous genotype aa.

$2pq$ is frequency for heterozygous genotype Aa.

For all alleles at the locus, the overall allele frequencies must equal$1$.

For a population in equilibrium genetically:

$p+q=1$

The sum of the frequencies of both alleles is $100\%$.