AP BIOLOGY

Detailed explanation-1: -Natural selection on polygenic traits can affect the distributions of phenotypes in three ways: directional selection, stabilizing selection, or disruptive selection.

Detailed explanation-2: -The essence of Darwin’s theory is that natural selection will occur if three conditions are met. These conditions, highlighted in bold above, are a struggle for existence, variation and inheritance.

Detailed explanation-3: -Natural Selection and Polygenic Traits Three ways that natural selection can affect the phenotype of polygenic traits includes stabilizing selection, directional selection, and disruptive selection. Stabilizing selection occurs when phenotypes at both extremes of the phenotypic distribution are selected against.