ABSTRACT
Chapter 17 outlines the history of thought leading to equilibrium theory in community ecology, the idea that communities self-regulate through the action of competition, later expanded to other interactions. Attempts to make the outcomes of competition predictable led to the formation of Lotka-Volterra equations and a quantifiable niche. Niche is defined in comparison to habitat, and the changing definition of niche is followed over time. The contributions of Hutchinson, MacArthur, and Wilson to niche theory are reviewed. The main ideas behind the Island Biogeography Theory are explained. The contributions of Diamond and Simberloff in testing the equilibrium hypothesis of the Island Biogeography Theory are outlined. By debating the equilibrium theory, how to do science, and how to configure reserves, the Diamond-Simberloff debate led to a paradigm shift in how ecologists think about communities. Current thinking has benefited from the neutral theory in realizing that competition may be an important operator within small patches, but overall, chance, predation, parasitism, cooperation, and environmental factors are thought to play much greater roles in explaining why ecological communities are the way they are than previously thought.
