What does stabilizing selection entail?

Stabilizing selection is a form of natural selection that actively favors intermediate phenotypes, which are those traits that fall near the average within a population. This process reduces the occurrence of extreme phenotypes, thereby leading to a decrease in variation for that specific trait. For example, in a population of birds, if the average wing size is favored for flight efficiency, birds with either very large or very small wings may be less successful in surviving and reproducing, leading to more individuals with wing sizes closer to the average.

This type of selection plays a crucial role in maintaining the status quo in a population, ensuring that advantageous traits—those that offer the best balance of survival and reproduction—are preserved over generations. In essence, stabilizing selection contributes to the consistency of traits within a population by filtering out extremes, thereby enhancing the likelihood that individuals carry characteristics that are best suited for their specific environment.