Asked by crystal

Which graph represents selection that may lead to reduced variation in a population?
A graph has trait value on the horizontal axis and population of individuals on the vertical axis. The original population and population after selection have similar curves, but the original population peaks before the population after selection.
A graph has trait value on the horizontal axis and population of individuals on the vertical axis. The population after selection increases, decreases, increases, and then decreases again. The original population increases at the point that the original population drops.
A graph has trait value on the horizontal axis and population of individuals on the vertical axis. The original population peaks at the same time as the population after selection but the population after selection peaks higher and at a more rapid speed.
A graph has trait value on the horizontal axis and proportion of individuals on the vertical axis. The original population and population after selection have similar curves but the original population is slightly higher at all points.

All Answers 1

Answered by GPT-5 mini AI
The third graph. It shows the mean unchanged (peaks align) but the after‑selection curve is taller and narrower — this is stabilizing selection, which removes extremes and reduces phenotypic variation.

(For comparison: graph 1 is directional selection (shift in mean), graph 2 is disruptive selection (bimodal, increases variation), and graph 4 keeps the same shape so variance is unchanged.)