What aspect does disruptive selection enhance within the population?

Disruptive selection enhances variation within a population by favoring individuals at both extremes of a phenotypic range while selecting against the average or intermediate variants. This type of selection occurs when environmental conditions favor extreme phenotypes, resulting in two or more contrasting phenotypic forms within the same population.

For instance, in a habitat with two distinct resources that only extreme phenotypes can efficiently exploit, individuals with intermediate traits may not survive as well, leading to a rise in the frequency of the extreme traits. Over time, this can lead to a more diverse set of phenotypes within the population, laying the groundwork for potential speciation as extreme phenotypes become increasingly adapted to their respective niches.

Disruptive selection contrasts with stabilizing selection, which reduces variation by favoring average phenotypes, and directional selection, which favors one extreme phenotype. Thus, while disruptive selection creates diversity, other forms of selection tend to standardize traits within a population.