“The distinctiveness that we have so assiduously ascribed to ourselves as humans is, in reality, an accident of history. Imagine, for instance, how much more distinct we could have claimed our species to be had all the great apes become extinct before we began pondering our position in the world of nature. If vervet monkeys were our closet relatives, humans would indeed appear to stand separate. Equally, if the species of hominid that links us to our common ancestor with the African apes had not become extinct, the gap between us and chimpanzees would be closed all the way. Gradations between human and ape would be present at every step, and our revered distinctiveness would vanish. It is simply a contingent fact of history that certain species did become extinct during the past five million years, leaving us to compare ourselves with the African apes as our closest living relatives. And it is a sobering fact of current history that the comparison between humans and apes may soon become virtually artificial, as each species of ape faces extinction in its natural populations. If this happens, it means we will lose the opportunity to learn about ourselves from our nearest living relatives, just at the time that we have indeed recognized them as our relatives. It also means that we will have frittered away our one remaining chance to allow our sibling species to live the way of life for which they, and we, co-evolved across the millennia.”