Darwinian Logic: The Latest on Chimp and Human DNA

Protein-coding regions of DNA in chimps and humans are remarkably similar -- 98%, by many estimates -- and this similarity has been used as evidence that the two species are descended from a common ancestor. Yet chimps and humans are very different anatomically and behaviorally, and even thirty years ago some biologists were speculating that those differences might be due to non-protein-coding regions, which make up about 98% of chimp and human DNA. (In other words, the 98...