Persistence, chaos and synchrony in ecology and epidemiology

The decline of species in natural habitats concerns ecologists, who view extinction as a danger and conser-vation of biological diversity as a goal. In contrast, the proliferation of `undesirable ' species is the principal concern of epidemiologists, who view persistence as a problem and eradication as an achievement. While ecologists and epidemiologists have essentially opposite goals, the mathematical structure of the population dynamics that they study is very similar. We brie£y review the similarities and di¡erences between these two ¢elds, emphasizing recent work in both areas on the e¡ects of spatial synchrony and dynamical chaos. We hope to stimulate further cross-fertilization of ideas between the disciplines