Question

which of these can result in a population looking more similar over time and can be described as selection against both extremes of a trait?
disruptive selection
directional selection
species selection
stabilizing selection

Explanation:

To solve this, we analyze each option:

• Disruptive selection: Favors both extremes of a trait, increasing variation. Eliminate this.
• Directional selection: Favors one extreme of a trait, shifting the population toward that extreme. Eliminate this.
• Species selection: Acts on species, not individual traits within a population. Eliminate this.
• Stabilizing selection: Selects against extreme phenotypes, favoring intermediate ones. This makes the population more similar over time as extremes are reduced.

Answer:

stabilizing selection