Question

Which of the following represents a condition opposite to that of what is necessary for the Hardy-Weinberg equilibrium to be maintained?

• A. Population size should be small
• B. Absence of mutation in the population
• C. Absence of migration in the population
• D. Absence of natural selection

Answer 1

The correct option is A Population size should be small

According to the Hardy-Weinberg principle, the allelic frequencies in a population are constant and remain stable from generation to generation provided the population satisfies certain criteria.
The criteria includes:
I. Very large population size
II. No mutation
III. No gene migration or gene flow
IV. No natural selection

(I) The genetic equilibrium is easier to be maintained in a large population.

(II) Mutation refers to a change in the genetic material of an organism. This results in change in allele frequency and does not allow it to remain constant. This brings about variation among organisms which forms the basis of evolution.

(III) If individuals migrate from one population to another, the alleles that they possess also are transferred. This is called gene migration or gene flow. This will certainly disturb the allele frequencies in the population.

(IV) Natural selection is a mode of evolution in which organisms who are better adapted to their environmental conditions survive. The rest of those who couldn’t cope with the changing environments will perish. If natural selection is operating in the population, it certainly disturbs the genetic equilibrium of that population.
If any of the criteria mentioned above are not met by a population, it won’t be in Hardy-Weinberg equilibrium.

Therefore, to maintain Hardy-Weinberg equilibrium in a population, the size of the population should be large. Hence, small population size represents a condition opposite to that of what is necessary for the Hardy-Weinberg equilibrium to be maintained.