Major Biogeographic and Phylogenetic Patterns

Abstract This chapter summarizes the major patterns of biodiversity and biogeography in Neotropical freshwaters. It describes latitudinal and altitudinal gradients in species richness and species-area relationships and evaluates the role of barriers and corridors to the formation of the species-rich Amazon-Orinoco-Guiana Core and the highly endemic Continental Periphery. It proposes testable macroevolutionary hypotheses for the elevated species richness of the Neotropical ichthyofauna based on rates of speciation, extinction, and dispersal of taxa on the Brazilian and Guiana shields and in the Amazonian lowlands.