I had an idea, what if the classical fantasy races, like elves, orc, goblins, dwarves, etc, were all humans who were abducted by aliens and transplanted on other worlds? Their inhuman features, like pointed ears, unusual skin and hair colors, height, reproductive traits, etc, would thus be a result of a combination of evolutionary factors from their new environments, as well as deliberate alterations. It would certainly explain why they keep showing up in myths and popular culture if they visit once in a while to keep tabs on us. But what kind of environments would their traits best suit them to? How far from the human baseline could they go and still have kids with Earth humans?