Well the way it works in Shadowrun, there are only a small handful of dragons each holding reign over certain parts of the world. But they take on human form through the power of a glamour. The lore goes that magic comes and goes like every millennium, so there was this event known as the Awakening Of The Sixth World (the sixth time magic came to existence). So you'd have human parents giving birth to the likes of elves and dwarves and the like just as native american tribes were actually able to manipulate and summon creatures from the spirit realm (Shaman, that's an actual class in the game.)
The lore itself, is almost as vast as DnD or Warhammer, but with more of an emphasis on Sci-FI cyberpunk than entire races warring with eachother. I don't know evrything about Shadowrun just what I've seen on Splattercats's let's plays ( he's also into Warhammer) But yeah, it's a series worth checking out if your interested.