Experimental Evolution and Next Generation Sequencing Illuminate the Evolutionary Trajectories of Microbes

Abstract

The advent of next generation sequencing technology has opened new avenues of research in microbes. In particular, the prices meltdown has made it possible sequencing hundreds of microbial genomes at once and at a reasonable cost. This advance in technology has increased our ability to test hypotheses at many levels, of which chief is the population level. Importantly, experiments ongoing for decades in which microbes have been evolving under different experimental regimes and evolutionary scenarios can be now taken to a next level of complexity. Mutation accumulation experiments coupled with genome sequencing reveals the many evolutionary trajectories of microbes under different environments, providing thereby an unprecedented power to explicitly testing fundamental hypotheses that remained hitherto in the realm of theory. Results and conclusions in this field illuminate the underlying selective forces determining the fixation of mutations and the contribution of fundamental mechanisms, such as epistasis, molecular chaperones, and gene duplication, in shaping the molecular spectrum of mutations.