Evolutionarily Stable Strategy (ESS)

An Evolutionarily Stable Strategy (ESS) is a concept from <a href="/article/game-theory">game theory</a> and evolutionary biology that describes a strategy within a population that, once adopted, cannot be outcompeted or replaced by any alternative strategy. It's a strategy so successful that <a href="/article/natural-selection">natural selection</a> alone is enough to keep it dominant, even if new "mutant" strategies appear.