Life the sequel

摘要

Poor, pitiful evolution. Sure, over the aeons it has managed to compile a noteworthy list of accomplishments—beetles, butterflies, birds of paradise and Beethoven, to name a few. But when David Liu contemplates the primitive building blocks it has to work with—proteins constructed from just 20 amino acids and DNA stitched together from an alphabet of four measly chemical letters—he can't help but lament what might have been. "There are millions of compounds it could play with and what does it settle on? Chemicals that are rather uninteresting," jokes the Harvard University biochemist. "Imagine what it could do with some real tools."