The proposed study focuses on genome-wide adaptation to an extreme environment, the aridity of desert ecosystems, across three rodent lineages. Understanding the evolutionary history of traits that allow organisms to adapt to their environments has long been a central goal of evolutionary biology. The project will contribute to recent medical, agricultural, and academic research that has been uncovering the genes responsible for complex adaptive traits and determining the effect mutations in these genes have on mice and other mammals, including humans. An especially important question is what is the extent of the "genetic toolbox": how many evolutionarily viable solutions are there to a common evolutionary problem, like thriving in an extreme environment? This project potentially will further our understanding of convergence at the molecular level and the repeatability of evolution. In addition, the investigators will engage in research with undergraduates from underrepresented groups and provide public and K12 outreach on this project.
Ultra-efficient kidneys are often associated with desert rodents who drink little to no free water. This study explores the genetic basis of three independent evolutionary origins of this trait. Transcriptomes will be sequenced for three pairs of species, one desert adapted and one temperate adapted, and sequence and expression data will be compared to answer: 1) is there convergence at the amino acid level in desert taxa not seen in the temperate taxa? 2) Are the same genes under selection in some or all of desert taxa? 3) Are there convergent gene expression patterns in the desert taxa not seen in the temperate taxa? The results from this research will provide essential insight into the way organisms adapt to their environment and how genomes evolve.
