On the origin of humans in Zarthuga
Humans are the result of elven breeding. Their great-grandparents may have an Archelf amongst them, but most humans are further removed. They might be the child of two half-elves, or one half-elf, and a parent of a different race. Or two human parents. Humans started popping up around year 500, and are therefore a “newer” race than other of the common races.