Natural Selection: Allele Frequency Drift

Natural selection needs three ingredients: heritable variation, differential survival, and differential reproduction. This simulation gives a population a single visible trait (coat tone), lets an environment set a camouflage target, and removes and replaces individuals each tick according to how well their trait fits that target. Adjust selection pressure, mutation rate and the environment itself — or trigger a sudden "industrial event" — to watch the population's mean trait and allele frequency shift generation by generation, exactly as Darwinian selection predicts.