Evolutionarily persistent and evolutionarily stable strategies in plant pathosystems

Summary Using gene-for-gene relationships as a basis for comparison, I show that Robinson's (1979, 1980) concept of an evolutionarily stable strategy, or ESS for short, is very different from the original definition of Maynard Smith & Price (1973) and, in fact, contradicts it in a number of important respects. The notion of an evolutionarily persistent strategy, or EPS for short, is introduced to clarify these differences and to reduce the potential for confusion in the future. The EPS concept is developed in terms of Holling's (1973) concept of resilience and Van Valen's (1976) notion of expansive energy. The combination of an ESS (sensu Maynard Smith & Price, 1973) and an EPS is offered as an alternative to Robinson's (1979, 1980) ESS concept. Robinson's recommendations for a holistic approach to plant pathosystem management are supported.