So along with always eternal good, population-static-or-declining nearly biologically immortal elves he gave us a remnant of scientific racism. At least the fantasy of our genus having not undergone a vicious internal culling to rival the Ottoman fratricides has been weakened.(TLDR, Tolkien, granddaddy of fantasy, used "race" to describe what were essentially different species in his books, set it as precedent in fiction, and accidentally contributed to the idea of real-world races being similarly irreconcilably separate.)