Final answer:
Stabilizing selection favors the middle phenotype and selects against extreme phenotypes by narrowing the range of variation. An example is human birth weight, where babies that are very large or very small are less likely to survive.
Step-by-step explanation:
Stabilizing selection is the selection that favors the middle phenotype and selects against the extreme phenotypes. This type of selection occurs when phenotypes at both extremes of the phenotypic distribution are selected against, resulting in a narrowing of the range of phenotypic variation. An example of stabilizing selection is human birth weight, where babies that are very large or very small are less likely to survive, keeping birth weight within a relatively narrow range.