Here's how it works:
* Extreme phenotypes are selected against: Individuals with traits at either end of the spectrum are less likely to survive and reproduce.
* Intermediate phenotypes are favored: Individuals with traits closer to the average are more likely to survive and reproduce.
Example:
Imagine a population of birds where beak size varies. Birds with very small beaks struggle to crack open seeds, and birds with very large beaks struggle to maneuver in dense foliage. Birds with medium-sized beaks are the most successful at both tasks and therefore have the highest survival and reproduction rates. Over time, stabilizing selection will lead to a population with predominantly medium-sized beaks.
Other types of natural selection:
* Directional selection: Favors one extreme phenotype.
* Disruptive selection: Favors both extreme phenotypes, while selecting against the intermediate phenotype.
