Simon A. Levin, Director

James S. McDonnell Distinguished University Professor in Ecology and Evolutionary Biology, Princeton University

My research interests have been in complexity, and in understanding how macroscopic patterns and processes are maintained at the level of ecosystems and the biosphere, in terms of ecological, behavioral, and evolutionary mechanisms that operate primarily at the level of the organisms. In recent years, I have turned my attention to the parallels between ecological systems and financial and economic systems, particularly with regard to what makes them vulnerable to collapse, and to the evolution and development of structure and organization. Of particular interest to me are discounting, intergenerational and intragenerational equity, cooperation and social norms. I have been especially interested in the management of public goods and common-pool resources. Much of my ecological research is concerned with the evolution of diversification, the mechanisms sustaining biological diversity in natural systems, and the implications for ecosystem structure and functioning. The work integrates empirical studies and mathematical modeling, with emphasis upon how to extrapolate across scales of space, time, and organizational complexity. The essential mathematical challenge is the development of macroscopic descriptions for the collective behavior of large and heterogeneous ensembles that are subject to continual evolutionary modification. Specific attention is directed to the evolution and ecology of collective behavior, from the movements of flocks of birds and schools of fish to human decision-making. Current ecological systems of study include plant communities, as well as marine open-ocean and intertidal systems. In related work, I have been interested in the dynamics of infectious diseases, and in particular in the self-organization of strain structure in influenza A, and in the dynamics of antibiotic resistance. In addition, I have been involved in issues of sustainable development, with emphasis on the linkages between environmental and socio-economic systems. My book, Fragile Dominion: Complexity and the Commons, is an introduction to my view of the issues underlying the dynamics and management of ecological systems, with broad analogies to socioeconomic systems.