Diversity and Evolution of Flowering Plants of the Caatinga Domain

We announce the release of Reconstruct Ancestral State in Phylogenies (RASP), a user-friendly software package for inferring historical biogeography through reconstructing ancestral geographic distributions on phylogenetic trees. RASP utilizes the widely used Statistical-Dispersal Vicariance Analysis (S-DIVA), the Dispersal-Extinction-Cladogenesis (DEC) model (Lagrange), a Statistical DEC model (S-DEC) and BayArea. It provides a graphical user interface (GUI) to specify a phylogenetic tree or set of trees and geographic distribution constraints, draws pie charts on the nodes of a phylogenetic tree to indicate levels of uncertainty, and generates high-quality exportable graphical results. RASP can run on both Windows and Mac OS X platforms. All documentation and source code for RASP is freely available at http://mnh.scu.edu.cn/soft/blog/RASP.

The evolution of grasses using C4 photosynthesis and their sudden rise to ecological dominance 3 to 8 million years ago is among the most dramatic examples of biome assembly in the geological record. A growing body of work suggests that the patterns and drivers of C4 grassland expansion were considerably more complex than originally assumed. Previous research has benefited substantially from dialog between geologists and ecologists, but current research must now integrate fully with phylogenetics. A synthesis of grass evolutionary biology with grassland ecosystem science will further our knowledge of the evolution of traits that promote dominance in grassland systems and will provide a new context in which to evaluate the relative importance of C4 photosynthesis in transforming ecosystems across large regions of Earth.