Biogeography of biodiversity hotspots

– Comparative Biogeography of Lepidoptera in Wallacea
Wallacea is a biodiversity hotspot located between the Oriental and Australian regions that has been central to the development of evolutionary theory. Nonetheless, this zone is poorly known from biogeographical and molecular evolutionary perspectives. This project represents the first comparative molecular phylogenetic and biogeographic analysis of organisms co-occurring in the region: three widespread butterfly genera, Charaxes, Cethosia and Delias, each with numerous species with restricted distribution useful for biogeographical analysis. Phylogenetic divergences in each group appear consistent with morphological diversification and support ancient speciation events in Wallacea. So far we have reported on well-supported phylogenies for each group (see publication list) and are currently preparing a biogeographic redefinition of Wallacea based on the comparative dataset and inferred geological evolution of a palaeo micro-continent. Patterns and processes depicted in this study provide a useful framework for illuminating future studies on evolution and conservation of Wallacea’s historically isolated biodiversity. Team members and collaborators: C Muller and L Beheregaray (Macquarie and Flinders); N Wahlberg (University of Turku, Finland).

– Biogeography of Elasmobranchs from the Gulf of California, a Marine Hotspot
This project aims to understand historical and ecological factors that have influenced biogeographic history in co-distributed elasmobranchs from the Gulf of California (Mexico), a marine biodiversity hotspot. The fascinating Gulf of California (also known as the Sea of Cortez) ranks amongst the five most productive and biodiverse marine ecosystems in the world, and supports significant fisheries and tourism activities that are key to the national economy. Our study groups include sharks and rays of Rhinobatos, Squatina, Mustelus and Rhizoprionodon. The project makes use of both nuclear and mtDNA data to assess phylogenetic relationships, phylogeography and seascape genetics in co-distributed samples. Team members and collaborators: J Sandoval-Castillo and L Beheregaray (Flinders), Oscar Sosa-Nishizaki (Center of Scientific Research of Ensenada, Mexico).

– Biogeography of Cerrado Herpetofauna – Origins, Evolution and conservation
The Cerrado (central Brazil) is one of the 34 global biodiversity hotspots for conservation. It is a savanna-like landscape with a complex and diverse vegetation structure that originally covered around 2 million km². Much of the Cerrado is poorly sampled and only a few biogeographic and phylogeographic studies were conducted in the region. We are investigating biogeographic history of four co-distributed lizard species from the Cerrado using a combination of nuclear and mitochondrial DNA sequences. The species to be included are Gymnodactylus amarali (Phyllodactylidae), Micrablepharus atticolus (Gymnophtalmidae), Tropidurus itambere (Tropiduridae) and Anolis chrysolepis (Polychrotidae). Team members: Fabricius Domingos and Luciano Beheregaray (Flinders) and Guarino Colli (University of Brasília, Brazil).

– Biogeography of Amazonian Fishes
The Amazon Basin is the hottest in the world in fish diversity. We are sudying evolution and biogeography of co-distributed Amazonian fishes sampled over the last ten years along the basin’s four major rivers (Amazonas, Negro, Tapajos and Madeira). We have produced several papers that pioneered the combination of population genomics with large-scale phylogeographic datasets to understand evolution in Amazonia. We have reported on an extensive number of cryptic species in Amazonian fishes and on speciation events caused by Andean neotectonics or divergent natural selection. Team members and collaborators: L Beheregaray, G Cooke, M Sistrom, M Piggott and S Corrigan (Macquarie), N Chao (UFAM, Brazil), G Caccone (Yale).

– Biogeography of Galapagos Giant Tortoises
The Galapagos Islands contain some of the world’s most remarkable biological radiations and offer an exceptional natural laboratory to study evolution. These isolated islands have provided opportunities for rapid colonization and speciation and have a geological record that can be used to estimate the chronology of biogeographic and evolutionary events. This project (based at Yale at headed by Gisella Caccone and Jeff Powell), uses a combination of molecular, morphological and field-based approaches to understand the evolutionary history and inform the conservation management of the iconic radiation of Galapagos giant tortoises. Key findings include the effects of a prehistoric volcanic eruption in population demography and evolution, a biogeographic reconstruction of a complex adaptive radiation associated with oceanography and volcanism, the implications of island colonization and diversification for conservation of endangered species and the rediscovery of extinct species using genetic data from extant and extinct populations. Team members include: G Caccone and J Powell (Yale), L Beheregaray (Flinders), C Ciofi (Univ of Florence), M Russello (UBC), N Poulakakis (Univ of Crete), J Gibbs (Univ of New York at Syracuse).