Class 12 Zoology simulations · Evolution

Hardy–Weinberg equilibrium and selection

Start with allele frequencies p and q. Without disturbance they stay constant; add selection against aa and watch q fall.

Open the simulation

What to notice

Allele frequencies change only when a disturbing factor (selection, drift, gene flow, mutation) acts.

Key relation

p² + 2pq + q² = 1 ; with selection against aa: q′ = q(1 − sq)/(1 − sq²)

Try this

Set s = 0. Do the frequencies change over generations?

What you can change

• Initial frequency p (allele A): 0.05 to 0.95
• Selection against aa (s): 0 to 1
• Generations: 0 to 100

More in Evolution

• Genetic drift in small populations
• Natural selection on a trait

See all Class 12 Zoology simulations or every Physica simulation.