Disturbance in the value of allele frequency in Hardy Weinberg equilibrium is directly proportional to the:

Extent of evolutionary change in a population

The correct answer is Option (2) → Extent of evolutionary change in a population 

The Hardy–Weinberg equilibrium (HWE) states that allele frequencies remain constant from generation to generation in a population if no evolutionary forces act (no mutation, no gene flow, no selection, no genetic drift, no non-random mating).

Disturbance in gene flow

• Gene flow (migration of individuals/alleles between populations) does affect allele frequency, but not always directly proportional. It’s one of the factors.

Extent of evolutionary change in a population . Correct.

• Any disturbance in allele frequency = evolutionary change. The greater the deviation in allele frequency, the greater the extent of evolution in that population.

Gene pool of a population

• Gene pool = sum of all alleles. It is the base, but deviation is not directly proportional to size of gene pool.

Retention of original gene in new population

• Not relevant to Hardy–Weinberg deviation.

 
Deviation from Hardy–Weinberg equilibrium = Evolution.