A species-based theory of insular zoogeography

1 I present an alternative to the equilibrium theory of island biogeography , one which is based on the premise that many of the more general patterns in insular community structure result from, not despite, nonrandom variatio n among species. 2 For the sake of simplicity, the model is limited to patterns and processe s operating over scales of ecological space and time: evolution is not incl uded in the current version of the model. 3 The model assumes, as did MacArthur and Wilson's model, that insular comm unity structure is dynamic in ecological time, but the model does not assum e a balance, or equilibrium, of immigration and extinction. 4 The model presented here is hierarchical, phenomenological (it requires l ittle parameterization beyond that which is directly derived from distribut ional data), graphical, and it includes potential feedback processes (inclu ding interspecific interactions). 5 The model offers an alternative explanation for a variety of patterns ran ging from distributions of individual species, species-area and species-iso lation relationships, to patterns of assembly of insular communities. The m odel also generates some new predictions and identifies some potentially im portant areas for future studies.