ECIMMEE Project: The Genomic Basis of Microbial Adaptation to New and Changing Environments
Although evolutionary biology is a historical science, it provides a powerful means of looking forward as well—offering predictions on issues ranging from the spread of human disease to adaptation of species to global climate change. Increased atmospheric carbon and global warming are having profound impacts on the world’s oceans. Changing precipitation patterns and melting polar ice caps are freshening large regions of the ocean, resulting in changes in water stratification, convection, and nutrient availability. Although these changes are predicted to have important impacts on the phytoplankton communities in these areas, relatively few data are available to predict how phytoplankton—which produce 40% of the earth’s oxygen and form the base of marine food webs—will respond to a rapidly changing ocean. Laboratory experiments have shown that microbial eukaryotes can adapt quickly to environmental change in vitro, but it’s not always clear how these results extrapolate to natural systems. This project leverages a natural evolutionary experiment, the colonization of low-salinity habitats in the Baltic Sea by an ancestrally marine diatom, Skeletonema marinoi, to determine the mechanisms and rate of adaptation to environmental stress across ecological and evolutionary timescales. Comparative and population genomic data, together with experimental transcriptomic data, will be combined to determine the tempo and mode of environmental adaptation of S. marinoi populations spanning the North–Baltic Sea salinity cline. Data from a related species, Skeletonema potamos, which has independently adapted to freshwaters, will show whether there is more than one adaptive solution to managing salinity stress, providing general insights into the adaptive potential of phytoplankton to a rapidly changing ocean.
Andrew Alverson is an evolutionary biologist whose research combines phylogenetic, experimental, and evolutionary genomic approaches to identify the ecological and genomic factors driving the diversification of diatoms. He received his B.S. in Biology from Grand Valley State University in 1997, an M.S. from Iowa State University in 2000, and a Ph.D. from The University of Texas at Austin in 2006. For his Ph.D. research, Andrew studied the patterns and consequences of marine–freshwater transitions by diatoms, a diverse lineage of microalgae that produce some 20% of the earth’s oxygen. From there he went on to Indiana University where he worked on the evolution of mitochondrial genome size in flowering plants with funding from a NIH NRSA Postdoctoral Fellowship. Andrew became an Assistant Professor in the Department of Biological Sciences at the University of Arkansas in 2011.