Scientists are trying to break through the innovation bottleneck for the renewable bioproduction of fuels and chemicals. They've looked into a new approach -- harnessing the trial-and-error power of evolution to coax nature into revealing the answer. By growing bacteria over generations under specially controlled conditions in fermentation tanks, they have test-tube evolved bacteria to better ferment sugars derived from biomass ----a rich, potential renewable energy source for the production of biofuels and chemicals.