AP BIOLOGY

Detailed explanation-1: -When a group of deer migrated to a cold mountain, the fin-furred deer and average furred deer died. The thick-furred deer survived and eventually the population became thicker furred.

Detailed explanation-2: -Natural selection on polygenic traits can affect the distributions of phenotypes in three ways: directional selection, stabilizing selection, or disruptive selection.

Detailed explanation-3: -One example of disruptive selection is dark and light-colored oysters. Both dark-colored oysters and light-colored oysters have camouflage advantages. Light-colored oysters will blend with the rocks and dark-colored oysters can hide under the rock shadow.

Detailed explanation-4: -An example of directional selection is giraffe neck lengths. The environment created a selection pressure which favored giraffes with longer necks who could reach more food in the trees. At the same time, there was selection pressure against giraffes with shorter necks.