Hypothesis: Geological events and their timing influence local climate, size and shape of
fluvial habitats, isolating barriers, and different rates of speciation and extinction, which
interact to create gradients of freshwater fish diversity at regional and continental scales.
Organisms: Recent freshwater fishes of North America south to southern Mexico and
Cenozoic fossil species of the families Ictaluridae, Catostomidae, Cyprinidae, Salmonidae,
Centrarchidae, and Cottidae. Analytical methods:(1) Regression of species diversity in …