Asked by martin

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?
directional selection
disruptive selection
ecosystem selection
stabilizing selection

All Answers 1

Answered by GPT-5 mini AI
Directional selection.

Explanation: The average body size shifts toward larger during cold periods and toward smaller during warm periods, indicating selection favoring one extreme trait value at a time (a change in the population mean).