Somewhere on Earth, close to 4 billion years ago, a set of molecular reactions flipped a switch and became life. Scientists try to imagine this animating event by simplifying the processes that characterize living things. ...... Shapiro, however, thinks this so-called "RNA world" is still too complex to be the origin of life. Information-carrying molecules like RNA are sequences of molecular "bits." The primordial soup would be full of things that would terminate these sequences before they grew long enough to be useful, Shapiro says. ........ The researchers propose in this month's issue of Molecular Biology and Evolution that this...