Nobody Was Fitter. It Won Anyway.

You'll learnhow selection and drift change allele frequencies in a gene pool.

Twelve beetles dissolve into a pool of twenty-four allele copies, and from there a population is just a pair of numbers. Watch what moves those numbers when nothing at all is favoured. Eleven short steps; press Next for each one.

AP BIOLOGY · 11 STEPS · 6 QUICK CHECKS · EVOLUTION = Δ ALLELE FREQUENCY · DRIFT IS RANDOM, SELECTION IS NOT · DRIFT ∝ 1/√N · v5

a pool of allele copies · one frequency · two engines that move it

Before you start

What you're looking at

Twelve beetles on the left, and on the right the gene pool holding all twenty-four of their allele copies.

The question

What actually changes when a population evolves, once you stop counting organisms?

Step 1 / 11