Evolutionary Rescue Race

Species facing climate change don't just move house or acclimatize on the fly — many rely on natural selection reshaping a heritable trait, generation after generation, to keep pace with a moving climatic target. This simulator models that race directly: a population's heat-tolerance trait sits somewhere along an axis, a fitness curve rewards individuals near the current climate optimum, and each generation the optimum creeps forward while the population's mean trait shifts in response, weighted by heritability. Push the warming rate too far ahead of what heritability and selection strength can deliver and the adaptive lag grows, mean fitness collapses, and the population spirals toward extinction — a live demonstration of evolutionary rescue versus extinction debt.