My latest Dissection column for Wired.com takes on the old tug-of-war between Nature and Artifice. As I write in my new book Microcosm: E. coli and the New Science of Life, scientists began to manufacture strange versions of the microbe in the early 1970s. In 1974, for example, scientists engineered E. coli carrying DNA from a frog. The difference between such “unnatural” bacteria and “natural” ones may seem obvious, but today the dividing line is surprisingly tricky to draw, and will only get trickier. In my new column, I describe the first systematic attempt to do so. Check it out.