Identify which type of natural selection is described in each case below. Results in the evolution of the species:
Results in new species:
Favors traits at the two extremes:
No increase in diversity:
One extreme trait is favored:
Diversity decreases:
Diversity increases:

Results in the evolution of the species: Directional selection

Results in new species: Disruptive selection

Favors traits at the two extremes: Disruptive selection

No increase in diversity: Directional selection

One extreme trait is favored: Directional selection

Diversity decreases: Stabilizing selection

Diversity increases: Disruptive selection

Explanation:

Directional selection which is also known as positive selection is known to be a mode of natural selection. In this type of selection, an extreme phenotype is favored over other phenotypes. This makes the allele frequency to move in the direction of that phenotype and this takes place over time.

Disruptive selection (known to be diversifying selection) talks about the certain changes in the population genetics whereby extreme values of a particular trait are favored over intermediate values. This results in new species.

While Stabilizing selection is a natural selection whereby there is a stabilization of the population mean on the particular value of a non-extreme trait. Here the diversity is decreases.