the fossil record shows that the average size of black bears was large during cold glacial periods and got…

the fossil record shows that the average size of black bears was large during cold glacial periods and got smaller during warmer time periods. what is this an example of?\no directional selection\no disruptive selection\no ecosystem selection\no stabilizing selection

the fossil record shows that the average size of black bears was large during cold glacial periods and got smaller during warmer time periods. what is this an example of?\no directional selection\no disruptive selection\no ecosystem selection\no stabilizing selection

Answer

Brief Explanations:

Directional selection favors phenotypes at one extreme of a trait. Here, bear size changes in one - direction (larger in cold, smaller in warm) in response to environmental change. Disruptive selection favors extreme phenotypes over intermediate ones. Ecosystem selection is not a standard evolutionary term. Stabilizing selection favors intermediate phenotypes.

Answer:

A. directional selection