Question

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

Hint:

Hardy-Weinberg equilibrium assumes no evolutionary forces, but natural selection drives adaptation by changing allele frequencies, often visible as diverging trends in graphs.

Answer 1

Step 1: The Hardy-Weinberg equilibrium describes a population where allele and genotype frequencies remain constant over generations, assuming no evolutionary forces like natural selection, mutation, migration, or genetic drift.
Step 2: Natural selection disrupts this equilibrium by favoring certain alleles that confer a survival or reproductive advantage, changing allele frequencies over time. For example, if allele A is advantageous, its frequency increases, while the frequency of allele a decreases.
Step 3: Graphically, in Hardy-Weinberg equilibrium, allele frequencies (e.g., p for A and q for a) remain constant (straight lines over generations). Under natural selection, the frequency of the favored allele (p) increases exponentially, while the other (q) decreases, shown as diverging curves.
Thus, natural selection alters allele frequencies, disrupting Hardy-Weinberg equilibrium.