Evolution and Island biogeography in the continental tropics: Reconstructing timing and patterns of diversification in endemic Neotropical cloud forest bess beetles (Passalidae: Proculini)

Tropical cloud forests have a naturally patchy distribution, typically occurring in montane areas geographically isolated from other such areas. While continental, they are thought to function evolutionarily much like oceanic islands. For example, similar to oceanic islands, the floras and faunas of tropical cloud forests are typically species rich, and have many local endemics. However, very little is known about the historical, biogeographical, and evolutionary processes underlying these patterns, particularly among insects. To gain further insight into these processes, we are reconstructing relationships and timing and patterns of diversification in an endemic radiation of Neotropical bess beetles (Passalidae: Proculini). Specifically, we are using nuclear DNA sequence data to reconstruct the phylogenetic relationships of proculine genera and the evolutionary histories of the montane distributed – and often highly endemic – taxa within these genera. While our focus is on Mesoamerica, we are sampling broadly, including genera and species that occur elsewhere in the New World (Nearctic and South America). Proculini have been widely studied in the Neotropics, are abundant in collections, and are otherwise well-suited for such an investigation.  This research will ultimately provide a phylogenetic framework for testing hypotheses relating to the geographic origins and evolutionary history of the tribe Proculini in Mesoamerica, including temporal and geographical patterns of diversification of supra-specific taxa, e.g., vicariance vs. dispersal, and Pleistocene or Pliocene origins vs. much deeper ones. Further, these data and analyses will help resolve taxonomic problems in Proculini and should clarify the taxonomic, geographical and temporal origins of the tribe.