Black-bellied seedcrackers have either small beaks (better for eating soft seeds) or large beaks (better for hard seeds). there are no seeds of intermediate hardness; therefore, which kind of selection acts on beak size in seedcrackers? view available hint(s)

Disruptive selection is acting on the beak size in seedcrackers.

Explanation:

There are different types of natural selection: sexual selection, stabilizing selection, directional selection, frequency-dependent selection, and disruptive selection.

Disruptive selection occurs when selective pressure favor homozygous. In equilibrium, the two alleles might be present. If there are extreme factors in an environment, such as the seed type, that favor one or the other allele, then both alleles appear in a homozygous state.

The disruptive selection causes an increase in the two types of extreme phenotypes over the intermediate forms. Limits between one extreme and the other are frequently very sharped. Individuals belonging to one phenotype can not feed on the same seeds as individuals belonging to the other phenotype, due to the traits differences between them, competition, or predation.

Both extreme phenotypes are favored over intermediated forms.

1. is geographic distribution

2 is increasing complexity

3 is transitional forms