The population biologist John Harper (1967) wrote that ‘the theory of evolution by natural selection is an ecological theory, founded on ecological observation by perhaps the greatest of all ecologists’. More than 40 yr since this observation, it is surprising that the professional societies devoted to the study of ecology and evolution still remain largely distinct (for example, consider the S...

1 Department of Integrative Biology, Ecology, Evolutionary Biology, and Behavior Graduate Group, Michigan State University, MI 48824 2 Center for Population Biology, Department of Evolution and Ecology, University of California, Davis, CA 95616 3 Institute of Ecology and Evolution, Departments of Mathematics and Biology, University of Oregon, Eugene, OR 97403 a [email protected]; b gmcoop@ucdavi...

S. M. Ulam’s contributions to biology are surveyed. The survey covers cellular automata theory, population biology, Fermi-Pasta-Ulam results, pattern recognition, and sequence similarity.