Abstract
Rationality and evolution are apparently quite different, applying, respectively, to the acts of complex, well-informed individuals and to populations of what may be mindlessly simple entities. So it is remarkable that evolutionary game theory shows the theory of rational agents and that of populations of replicating strategies to be isomorphic. Danielson illustrates its main concepts—evolutionarily stable strategies and replicator dynamics—with simple models that apply to biological and social interactions; and he distinguishes biological, economic, and generalist ways of interpreting the theory. Against the background of isomorphism, he considers three ways in which evolution and rationality differ and how two-level models may combine them. He concludes with a survey of the normative significance of the unification of rationality and evolutionary game theory and some speculation about the evolution of human rationality.