Question

How does the process of natural selection affect Hardy-Weinberg equilibrium ? Explain. List the other four factors that disturb the equilibrium.

Answer 1

Hardy-Weinberg's principle says that allele frequencies in a population are stable and constant from generation to generation. The gene pool remains constant. This is called genetic equilibrium. Sum total of all the allelic frequencies is 1. Individual frequencies, e.g. can be named p, q, etc. Natural selection disturbs the allelic frequencies. Through natural selection either the frequency of p increases or the frequency of q it will disturb the natural frequency. In a diploid, p and q represent the frequency of allele,A and allele a. The frequency of AA individuals in a population is simply p². This is simply stated in another ways, i.e., the probability that an allele A with a frequency of p appear on both the chromosomes of a diploid individual is the product of the probabilities.

Hence, p² + 2pq + q² =1

The factors that affect the Hardy-weinberg's equilibrium are : 

(i) Migration 

(ii) Gene flow 

(iii) Genetic drift 

(iv) Mutation 

(v) Genetic recombination