Collaborative Research: Rates of lineage, phenotypic, and genomic diversification in replicated radiations of murine rodents

University Of Montana, Missoula MT

Investigators

Abstract

Much of the diversity of life has arisen through the process of adaptive radiation. Adaptive radiation occurs when a group rapidly diversifies into many species to fill a variety of ecological roles. While adaptive radiation is a common theme in the evolution of life, many of its features are poorly understood. This project seeks to better understand how adaptive radiation proceeds. The project will examine the rate of diversification in genes, morphology and species diversity over the evolutionary history of a group of rodents containing more than 600 species. The study will determine how changes in genes, morphology and species are correlated as the species diversified. Importantly, the group under study contains the common lab mouse and rat, two species that serve as scientific models in medical and basic research. This study will place these model organisms in an evolutionary context that will allow scientists to better understand how their genes and other characteristics have evolved. Such understanding provides new insight into genes and characteristics of medical significance. Scientific meetings organized by the researchers will bring together scientists who study mice and rats from different perspectives, including molecular biology and medicine, to share insight and generate new research questions. In addition to the broader impacts on basic science and medicine, public outreach and education events at participating natural history museums will use the results of this research to teach principles of evolutionary biology to K-12 students and improve public understanding of science. This project integrates comparative genomics with quantitative morphology in a rigorous phylogenetic framework to illuminate the dynamics of diversification in lineages, phenotypes, and genes across the most species-rich adaptive radiation in mammals. The exceptional species and ecomorphological diversity in rats and mice (subfamily Murinae, 634 living species) arose over the last 14 million years through replicate adaptive radiations, primarily in the distinct biogeographic units of Indo-Australia. This research will expand on the genomic resources from the leading mammalian model organisms to encompass the diversity of murine rodents by sequencing whole exomes from a large, phylogenetically dispersed set of species. In addition, the project will generate high-resolution, 3D morphometric models of cranial and post-cranial skeletons from the same species. The project will combine these distinct data layers to: estimate a species-level phylogeny of the Murinae; identify and date biogeographic and ecological transitions; estimate diversification rate shifts across the phylogeny; estimate rates of phenotypic and molecular evolution relative to transitions (biogeographic and ecological) and shifts in lineage diversification rate; test for correlations between the tempos of phenotypic and molecular evolution; and, quantify morphological and molecular convergence. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.