I will disagree with your views, scientifically we are same race and our genetic differences are insignificant. Our ancestors originated in Africa. Indeed today most nation's are a hotpot of multi-culture, language, colors, food etc.

All these difference you talk about came from our tribal nationalistic mentality. Indeed the reason USA and many other countries succeeded is due to openness to embrace diversity.

Single human race does not mean everyone is same, I am not sure if you heard "Unity in diversity". All the boundaries we talk about today hopefully do not extend to space.