Area-relationships in the Neotropical lowlands: an hypothesis based on rawdistributions of Passerine birds

Using raw geographic distributions for Neotropical species and subspecies o f the perching birds (Order Passeriformes), we present an hypothesis of are a-relationships for twelve avian areas of endemism in the lowland Neotropic s. With 1717 characters (distributions of species and subspecies) we find a single most parsimonious tree of area-relationships. This topology does no t match area-relationships determined from phylogenetic studies of morpholo gic characters in some Neotropical birds. Analyses of data partitions repre senting major taxonomic subdivisions within Passerine birds provide many di fferent hypotheses of area-relationships. These results suggest that a sing le set of Neotropical area-relationships is not likely. In the future, we s uggest greater emphasis be placed on research to document patterns in the N eotropics, particularly phylogenetic patterns, than on speculation about wh at processes have been important for diversification.