Plug-in hybrid cars aren't as efficient as they could be. While starting in a pure electric mode is good for relatively short trips, it actually hurts your fuel economy if you have to switch to the gas engine. Science may have a solution, though, and it's taking its cue from nature. University of California, Riverside researchers have developed evolutionary algorithms that learn to combine electric and gas power for maximum fuel economy. The approach mimics natural energy-saving processes to invoke the electric motor throughout the trip, and adapts based on your driving conditions -- it should help whether you're stuck in downtown traffic or cruising effortlessly on the highway.