Incorporating rules for responding into evolutionary games.

Discusses evolutionary game theory relative to the process of natural selection. Standard assumption that two players choose a single action; Approach of the authors which suggests a series of interactions with the final outcome negotiated; Variations in quality; Analysis of negotiation given in the context of a pair of animals feeding their young; Authors' contention that there should be a fundamental remodelling in evolutionary game theory. INSET: Evolutionary stability.