Organisms and Species as Complex Adaptive Systems: Linking the Biology of Populations with the Physics of Ecosystems

Summary

Historical constraints of paradigms, approaches, training, and methodology currently prevent the conceptual unification of ecology. They inhibit communication and collaboration between the biologists who study the structure and dynamics of populations and communities and the earth scientists, physicists, chemists, and biologists who study the distribution and fluxes of energy and materials in ecosystems. To link the attributes of individual organisms and species with the biogeochemical processes that occur in their environments requires an integration of biology and the physical sciences.

To make these linkages, I suggest that individuals and species be considered a special class of complex adaptive systems (CASs) with some uniquely biological attributes. This view encourages a focus on the physical relationships of the biological CAS: on developing an energetic/thermodynamic currency that can be used to characterize population growth and fitness in terms of basic physical processes; on characterizing the niche in terms of the environmental requirements of the CAS for survival and reproduction; and on understanding the impacts of species on ecosystems in terms of work performed in meeting these requirements.