Racism is not a human only trait. In nature, animals breed with the same, uh, RACE in their genome. It's why you don't see a Magpie and Crow cross. You don't see red and gray Sqirrels crossing. It's a natural behavior for animals really, uh, exept for us HUMAN beings, since we're not animals (ugh). There are situations where the instinct to breed within your own, uh, race becomes subdued, a situation our 'boundaryless' society we have built. Call it immersion if you like. That's only one example I can think of. Still have other issues, territoriality is a big one. Herd or tribal security. Prejudice and bigotry are learned concepts. "Racism" is actually instinct.
I have to disagree with your biology.
You are talking about species, not race. Crows and magpies don't typically cross because they are whole different species. Humans are one of the least genetically diverse species on the planet, so we can all interbreed just fine.
