Same Beetles, Three Answers

You'll learnhow directional, stabilizing, and disruptive selection each reshape a trait's distribution.

Sixty beetles, one bark at a time, and a curve that answers everything. The same population meets three different environments, and the mean and the spread do three different things: one moves, one narrows, one splits into two peaks around an average nobody has. Eleven short steps; press Next for each one.

AP BIOLOGY · 11 STEPS · 6 QUICK CHECKS · DIRECTIONAL MOVES THE MEAN · STABILIZING SHRINKS THE SPREAD · DISRUPTIVE SPLITS THE CURVE · v6

one population · three barks · read the mode from the curve

Before you start

What you're looking at

Sixty beetles as discs along a shade axis from pale to nearly black, with a curve above showing how common each shade is.

The question

What does each mode of selection do to the shape of that distribution?

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