Humans are primates, and our closest relatives are the other African apes - chimpanzees closest of all. With the mapping of the human genome, and that of the chimp, a direct comparison of the differences between the two, letter by letter along the billions of As, Gs, Cs, and Ts of the DNA code, has led to the widely vaunted claim that we differ from chimps by a mere 1.6% of our genetic code. A mere hair"s breadth genetically! To a rather older tradition of anthropomorphizing chimps, trying to get them to speak, dressing them up for "tea parties", was added the stamp of genetic confirmation. It also began an international race to find that handful of genes that make up the difference - the genes that make us uniquely human. But what does that 1.6% really mean? And should it really lead us to consider extending limited human rights to chimps, as some have suggested? Are we, after all, just chimps with a few genetic tweaks? Is our language and our technology just an extension of the...