Understanding how diversity of life on earth grows is a fundamental goal of evolutionary biology. To address this essential question, this research will: (1) build an evolutionary tree (phylogeny) for muroid rodents (the most diverse and successful group of mammals) using DNA sequence data from 550 muroid species, (2) conduct anatomical studies of the skulls of those species using 3D imaging tools, and (3) combine the anatomical results with the phylogenetic results to determine when and where different lineages diversify, in terms of numbers of species and modifications of the skull and dentition. The results will determine which mechanisms - adaptation, colonization of new areas, or changes in inherent "evolvability" - cause diversity to increase.
This research will also have broad utility to the biomedical sciences because the muroid rodents include most of the species used in biomedical research (e.g., mouse, rat, hamster). Understanding their evolutionary history can profoundly change how we interpret those studies. The phylogeny will also serve as a road map for choosing new species for biomedical studies. In addition, the research team will train several post-doctoral researchers, graduate students, undergraduate students, and high school students in DNA sequencing, morphological analysis, and phylogenetics.
