Why are you so sure? Are you scientist that specializes in this area? If not, how do you know? From scientists? How do you know what they think? Let's imagine for a second that you are a scientist and you think that there is some validity to this idea. Would you announce this thought in public? To become a racist in the eyes of this public? If you plan a research in this area, which evidences would you look for - for and against this idea? What would you prefer - to receive a grant or to become a target for witch-hunt?

So the honest answer to the question "is there any scientific validity to the idea of different human races" should be: We don't know because unbiased research in this area is politically impossible.