The rise of the Andes: A driver of diversification in Brachistosternus (Scorpiones: Bothriuridae)?

CECCARELLI, M.F.; OJANGUREN-AFFILASTRO, A. A.; RAMÍREZ, M.J.; OCHOA, J.A.; MATTONI, C. I.; PRENDINI, L.

Guarujá

Congreso; Evolution 2015; 2015

Society for the Study of Evolution (SSE), Society of Systematic Biologists (SSB), y American Society of Naturalists (ASN)

Aim. One of the planet?s most imposing geomorphological features, the Andes, played an important role in the evolution of South America?s flora and fauna. The bothriurid scorpion genus Brachistosternus Pocock, 1893 comprises more than 40 species with high diversity and endemism in the Andes. We investigate the biogeographical history of this genus using molecular phylogenetics and dating, to determine the role of Andean uplift on the distribution and diversification of its species.Location. South America.Methods. A dated phylogeny and species tree were obtained for 54 putative species based on five gene loci. Based on the species tree, ancestral range and biogeographical event estimations were conducted in BioGeoBEARS. Furthermore, diversification rates and rate shifts were calculated using the R package ?laser? and the program BAMM. Areas with high phylogenetic diversity and evolutionary distinctiveness for Brachistosternus were identified using the R package ?picante?.Results. Brachistosternus diversified at a steady rate during the main Andean uplift, while the central Andean and western slope/Pacific coastal biogeographical provinces played an important role as ancestral areas. Coastal areas of central Chile and southern Peru exhibit high levels of phylogenetic diversity in Brachistosternus, suggesting that these areas experienced a relatively long period of ecological stability, while the Andes continued to rise.Main conclusions. The findings from our study suggest that as Andean uplift created new habitats and climate regimes, favouring speciation in genera such as Brachistosternus, the coastal areas to the west continued to harbour older lineages while accommodating more recently diverged ones from the nearby Andes.