Which of the following statements about the biogeographical aspects of diversity is not correct? a) the patterns of continental drift are important considerations in the study of the past and present distributions of species. b) the magnitude of photosynthesis is the factor that accounts for the major variations in species diversity over large areas of earth. c) species richness on an island reaches an equilibrium point when immigration equals extinction. d) a species may be limited to a particular range because it never dispersed beyond that range, or it dispersed but failed to survive in other locations. e) island equilibrium theory applies to the relatively short period of time when colonization is the important process determining species composition; over a longer time, actual speciation affects the composition.