Equilibrium theory and paleoecology



Although several paleontologists have recently attempted to apply MacArthur & Wilson's equilibrium theory to the fossil record, their efforts have not met with overwhelming success. The major difficulties have involved the use of questionable methodologies and the application of a fundamentally inappropriate theoretical base. In the first category it appears as if previous methods of data collection and their subsequent analyses must be critically reviewed in order to adequately test the equilibrium theory. Thus detailed species lists that include population numbers must be compiled for spatially restricted habitats. Sampling of local stratigraphic sections must be carried out on a centimeter by centimeter basis rather than at meter intervals. It appears most likely that the use of colonization curves, coupled with a determination of species saturation levels, will provide a rigorous, quantitative technique for the analysis of equilibrium states. It has become obvious over the past ten years that paleoecologists need to be more critical in their application of ecological theories to the fossil record and in substantiation of this claim, and contrary to earlier reports, it seems as if a valid test of the equilibrium theory in the fossil record has yet to be made.