Survival of the Systems

Since Darwin, individuals and more recently genes, have been the focus of evolutionary thinking. The idea that selection operates on nonreproducing, higher-level systems including ecosystems or societies, has met with scepticism. But researchemphasising that natural selection can be based solely on differential persistenceinvites reconsideration of their evolution. Self-perpetuating feedback cyclesinvolving biotic as well as abiotic components are critical to determining persis-tence. Evolution of autocatalytic networks of molecules is well studied, but the principles hold for any'self-perpetuating'system. Ecosystem examples includecoral reefs, rainforests, and savannahs. Societal examples include agricultural systems, dominant belief systems, and economies. Persistence-based selection of feedbacks can help us understand how ecological and societal systems surviveor fail in a changing world