I would like to address the curious question of race. The issue has been contentious and badly abused by the promoters of tribalism to the point that few want to even address the issue for fear of been gratuitously attacked for their trouble. Perhaps we can openly discuss a related issue or two without a descent into barbarism.
My first observation is that it exists at all. What I mean is that this is not a characteristic of wild populations of any species able to share genes. It is a characteristic of domestication and selective breeding.
What this means is that the onset of agriculture around ten thousand years ago included selective breeding to develop a set of community characteristics. Once established, expanding populations over time subsumed the remnant wild populations. So we have the Black Bantu of Africa, the Bronze Indians of the Americas and the Verangian Scandinavians of Europe to name only a few of the more extreme examples.
Certainly agriculture brought domestication and the inherent prospect of selective breeding. Also, to be fair, it does not take very many generations to make all this happen. More importantly, it appears to be the norm everywhere. The question is how did this occur?
The answer is fairly simple. With larger domesticated communities, the chosen headman was himself the beneficiary of a beauty contest and he selected and maintained many mates during his period of control. Thus a tribal consensus over what constituted beauty drove reproduction success. Hundreds of generations would create a dominant strain that would be accepted as the archetype of tribal beauty and it would breed true.
Perhaps then there is something visceral to racial conflict. It is a clear badge of tribal separation that is easily recognized and understood.
Today, we have entered a world in which intermarriage is becoming common place and we are seeing many hybrids emerge. However we are still selecting for beauty, so I do not think that we are ever likely to have the human family revert to the original palette of human characteristics. We may actually see an expansion of types easily recognized for individual beauty.
Also the technology is emerging that allows the parent to make the aesthetic choices.
How about zebra stripes?