Question

Which of the below statements is NOT a legitimate mechanism by which natural selection can

maintain genetic variation in a population.

1. Overdominance. When there is heterozygote advantage, as long as a population starts

with two alleles (i.e., is not fixed for one or the other allele) both alleles will be maintained

at a stable equilibrium.

2. Fluctuating selection. Temporally or spatially varying selective regimes that favor

different genotypes can preserve genetic variation. The maintenance of variation by this

mechanism requires a fairly narrow set of conditions.

3. Frequency-dependent selection. If the rare genotype has a fitness advantage and the

common genotype a selective disadvantage, then genetic variation will be maintained in

the population.

4. All three are viable mechanisms by which natural selection can maintain variation

Answer 1

Answer:

All these options are viable mechanisms that help in maintaining genetic variation.

Explanation:

Natural selection maintains genetic variation by selecting fit organisms. In many cases ,heterozygotes have fitness advantage which allows both the alleles to continue in population.For example: sickle called heterozygotes are resistant to malaria.

Mutation and recombination also allows recessive and rare alleles to have more fitness and prevent them from elimination.

Varying regimes for natural selection also helps in maintaining genetic variation because different areas and their population have different conditions and environment and hence different selection criteria.