stabilizing, directional, disruptive??

Question

what does it mean? im studying biology but dont get it.

thanks!

Answer 1

These are three different trends in natural selection.

1. Stabilizing selection means that the environment favors the average individuals. The extremes (too big, too small, too dark, too light, too slow, ...) are more likely to be eaten or die in other ways and the average ones are more likely to survive.

2. Directional selection means that the environment favors one extreme over the average or the other extreme (ex: dark ones survive while average or light ones do not).

3. Disruptive selection means that both extremes are more likely to survive than the average individuals.