Question

How does the process of Natural Selection affect Hardy-Weinberg equilibrium? Explain with the help of graphs.

Hint:

Natural selection causes changes in allele frequencies over time by favoring individuals with advantageous traits. This disrupts Hardy-Weinberg equilibrium and leads to evolution in a population.

Answer 1

The Hardy-Weinberg equilibrium is a theoretical concept in population genetics that describes the genetic variation in a population at equilibrium, assuming no evolutionary influences. The equilibrium occurs when allele frequencies remain constant from generation to generation. The five conditions required for Hardy-Weinberg equilibrium are: 
1. No mutation.
2. No natural selection.
3. Random mating.
4. Large population size.
5. No gene flow (migration).

Effect of Natural Selection on Hardy-Weinberg equilibrium: 
Natural selection is one of the key evolutionary forces that can disrupt Hardy-Weinberg equilibrium. It acts on individuals in a population by favoring those with advantageous traits, which leads to changes in allele frequencies over time. This is not in accordance with the assumption of no natural selection in Hardy-Weinberg equilibrium.
In a population where natural selection is acting:
- Alleles that provide a survival advantage increase in frequency over time.
- Alleles that reduce fitness decrease in frequency.
- This results in a change in genotype and allele frequencies, which causes the population to evolve, thereby deviating from Hardy-Weinberg equilibrium.