The Null Model: Five Forces Held at Zero

You'll learnwhy Hardy-Weinberg is a null model and what its five conditions each switch off.

Tip every copy of one gene into a single pool and the whole population becomes two numbers. Two equations count them, one for copies and one for individuals, and confusing the two is where every mark goes. Eleven short steps; press Next for each one.

AP BIOLOGY · 11 STEPS · 6 QUICK CHECKS · p + q = 1 COUNTS ALLELES · p² + 2pq + q² = 1 COUNTS GENOTYPES · DEVIATION = A CONDITION BROKE · v5

a pool of copies · a square of individuals · and the gap between

Before you start

What you're looking at

Every copy of one gene in a population, tipped into a single pool and lettered A or a.

The question

What do those allele frequencies do when nothing at all is acting on the population?

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