Race is not a scientific term. Its a societal separation term. There's only one human species, the homosapiens and we're all related. This is science and doesn't fit perhaps all the views from the Nazi side or the rest of the world's side, it's just science.
For example some people are taller, and some of us a browner. Why? No reason. We just happened to be born with those genes and they happen to express strongly at the right time.
All this just means that we should stop all the inter fighting and go back to the Carl Sagan interpretation of the pale blue do. Everyone you will ever know, all the knowledge of everything you love and hate is all contained there in that tiny insignificant place. Wars and hate serve no one's purposes. We should extinguish those things at the bud. Teach your kids to not hate and to not create war. If you are an engineer or scientists, don't give your knowledge and talent to big evil companies or countries.