Are there rules that all living things must obey? Is death inevitable? If we rewound the tape of life and let evolution run a second time, would it end up like the original? To explore these questions, Zimmer says he wrote "an (un)natural history of E. coli." Scientists have been earning Nobel Prizes for decades by poking and prodding this microbe, and their work is coalescing into an extraordinary portrait of a living thing. Today, with engineered E. coli spewing out everything from insulin to jet fuel, the microbe is redefining the boundaries of life itself.