Final answer:
Stabilizing and disruptive selection differ in their effect on the phenotypic distribution. Stabilizing selection narrows the range of variation, while disruptive selection results in two overlapping phenotypes. Stabilizing selection can favor overdominance, while disruptive selection can favor underdominance.
Step-by-step explanation:
Stabilizing selection occurs when phenotypes at both extremes of the phenotypic distribution are selected against, narrowing the range of variation.
An example is human birth weight, where very large or very small babies are less likely to survive.
Disruptive selection, on the other hand, occurs when phenotypes in the middle of the range are selected against, resulting in two overlapping phenotypes at each end of the distribution.
Sexual dimorphism in humans is an example of disruptive selection.