Anyway, let’s just say we’re dealing with a separate species which evolved on an Earthlike world independently of/isolated from humankind. There’s no logical reason why such elves should come solely in the colors we see in 99% of fantasy, which are either really pale white or really dark black (e.g., the drow/trow). Neither extreme makes sense, except in a fairly small environmental niche — and the niches used often are nonsensical too, like Forgotten Realms’ take on the drow; they’re an underground species. Nearly every underground species on our planet lacks melanin because there’s no need for UV protection; so why are these drow black?While I think it could be argued that some stories take place in a limited geographical area, making it not completely unreasonable that there would be a certain uniformity of appearance in the locals, many stories are much broader in scope. And it seems to me that it's just good world building to consider the evolution of your aliens, whether they are elves that coexist with humans or are natives of a distant planet.
Elves are usually written as intelligent, adaptable beings. There’s no reason for them to be confined to a single geographic location once they develop seafaring skills or whatever. So theoretically they could spread as far and wide as humans have, and theoretically they’d have to cope with the same environmental changes. They wouldn’t necessarily cope in the same way (e.g., humans develop deeper chests at higher altitudes; maybe high-altitude elves would develop “air-enriching” magic) but I would expect to see some regional variation among them, unless they had magical teleportation devices and could bop around the globe to keep the gene pool uniform.
Read her entire column for discussion of some of the elves in fiction that do show some variation.
Tags:elves, evolution, biology