Historical relationships among Neotropical endemic areas based on Sepedonea (Diptera: Sciomyzidae) phylogenetic and distribution data

The present study used the previously defined relationships among the snail-killing species of Sepedonea as the starting point for a cladistic biogeography analysis of endemic areas in the Neotropical region. The goal of the study was to use two different data sets to test the possible monophyly of two important biomes in the region: the Amazon and the Atlantic Forest. The possible historical significance of the arid biomes was also investigated. The study used Brooks Parsimony Analysis (Primary BPA). The area groups were based on previous biogeographical classifications of the Neotropial region. The analyses showed Amazonia to be non-monophyletic whereas the Atlantic forest was found to be a natural unit. The importance of including dry areas in the analyses, was highlighted by Sepedonea individuals that probably inhabit enclaves of humid forest present in the area. In general, the results indicate incongruence with the prior pattern of area relationships. In fact, one single history of the current distribution of organisms in the region is unlikely. This situation has been supported by several studies proposing incongruent hypotheses of historical relationships between endemic areas of the region.