On Friday, as the E. coli outbreak gained horrific speed in Germany, Newsweek asked me to write about how this epidemic came to be. Scientists still have a lot to figure out about it, but some things are clear–in particular, that the bacteria have great scope for evolution into new deadly strains, thanks in part to the shuttling of viruses between them. (In my book Microcosm, I explain how this is true not just for E. coli, but for much of life.) My piece appears in the new issue of Newsweek, which you can read online here. (One late-breaking piece of news that didn’t make it in, by the way, is the finding yesterday that the new outbreak appears