In their attempts to pin down the meaning of “life,” scientists and philosophers have offered dozens of definitions. Lately, researchers more or less agree that, for something to be alive, it has to be able to reproduce and evolve by natural selection. While these attempts might be getting us incrementally closer to understanding what life on Earth is, and what life elsewhere could be, none has proven particularly helpful in deciphering how life arose. So far, the most fruitful approach has invo...