NJClaw
OoOoOoOoOoh
Genetics don't exist in D&D. If in a world with plenty of ways to be come literally omniscient nobody has ever discovered it, it either doesn't exist or is completely irrelevant.That is cultural inclination, not a genetic one.
I don't understand why you're acting like the only ways to explain something in a D&D setting are those that we can apply to the real world. IRL we try to justify everything with genetic or cultural influences, but you have to acknowledge that there are many substantial differences between the Forgotten Realms (which is this edition's standard generic setting) and the real world, otherwise this discussion is going nowhere. Many different gods of conflicting pantheons and evil high powers walk around the planet interacting with their followers, while you also have parallel worlds where the concepts of "law", "chaos", "good", and "evil" are tangible things. In this context, necessarily the cultural and practical aspects of races interact in ways we can't simply explain with chemical elements.