Neanderthals are not our ancestors, but older and very close relatives. We have common ancestors, but in Africa there was no known interbreeding (because there was no Neanderthals) AFAIK. However the physical differences are significant enough, so I don't see how it is more racist than, say, making a distinction between a husky and a golden retriever. They are close relatives and can interbreed, but they're distinctively different breeds, aren't they? Racism is only in the part where we always like to presume to be the smartest ones...