Populations evolve, not individuals.
Let's take a look at the Brightstorm video, Evolution of Populations.
Natural selection can take one of three paths:
- Directional selection - favors phenotypes at one extreme
- Stabilizing selection - favors the intermediate phenotype
- Disruptive selection - favors both extreme phenotypes
To make sure you're understanding these three types of selection, watch the Teacher's Pet video, Types of Natural Selection.