has anyone read the book, "The 3rd Chimpanzee"? The book argues that from a biological point of view you can argue that, Bonobos, Chimpanzees, and Humans are all the same species! Now of course there are also obviously differences, but it's a fascinating idea. According to the book for example when you look at the differences in DNA, Chimpanzees are more closely related to Humans, than Gorillas are to Chimpanzees. I would highly recommend the book.