Question

Short answer question.

Give an example of disrruptive selection

Answer 1

1. In this selection, nature selects extreme phenotypes and eliminate intermediates.

2. This results in the formation of two peaks in the distribution of traits.

3. This kind of selection is rare.

4. It ensures the effect on the entire gene pool of a population, considering all mating types or systems.

e.g. Disruptive selection was observed in the different beak sizes of African seed cracker finches. The birds have different sizes of the beak and they feed on seeds. The available seeds were of two kinds i.e., small and large-sized seeds. Large beak sized birds feed on large seeds while small beak sized birds feed on small seeds and their number was increased. Intermediate beak sized birds were unable to feed on either type of seeds so their population decreased gradually and then were eliminated by natural selection.