DIMENSIONS: COLLABORATIVE RESEARCH: GENETIC, PHYLOGENETIC, AND FUNCTIONAL MICROBIAL DIVERSITY IN PERMANENTLY FROZEN AQUATIC SEDIMENTS OVER GEOLOGICAL TIME

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Permafrost (permanently frozen soil) may provide snapshots of ancient life and represent fossil archives of plant, animal and microbial communities. Microbes are of particular interest because, unlike most animals and plants, they can survive very long periods of extreme conditions. Therefore, it is possible that some microbes in permafrost are not fossils but are still alive -- essentially, living fossils. This research addresses an unresolved question of whether microbes embedded in permafrost are extinct, representing ancient terrestrial surface or marine communities preserved through time, or actively living communities that have been evolving since being buried. To determine how long microbial communities can live in permafrost, this project will study permafrost collected from the oldest known sediments of the Northern Hemisphere, which occur in Siberia. These intriguing marine and lake sediments are five thousand to three million years old and are found in stratified cliffs. This project will help scientists understand how biological communities respond to large changes in the environment, and its results will be shared with university students and high school teachers and students.This five year project will document evolution of taxonomic, genetic and functional biodiversity over time using state of the art "omic" approaches combined with single cell genomic, cultivation studies and physical-chemical characterization of permafrost sediments. One of the key challenges of this project will be the application of evolutionary models to the DNA sequence datasets to distinguish between permafrost strata containing fossil archive models versus contemporary community models. The data will elucidate evolutionary mechanisms that shape taxonomic, genetic and functional diversity, providing insight into genome evolution and microbial adaptation to low temperatures. Functional, population genetic and phylogenetic approaches will be integrated. The international nature of this project provides a platform to expand a network of collaborative permafrost research with open system data management and sharing. This project will train scientists at the undergraduate, graduate and post-doctoral levels, and engage high school teachers through molecular biology workshops. Interaction with Russian collaborators and travel to the Siberian study sites will promote international cooperation and provide training to students in how to conduct research with colleagues from different cultures.