Humans have been a homogeneous species since the disappearance of Neanderthals. This means that despite our geographic dispersion through prehistory, we did not break apart into other species. It was only relatively recently that we were reunited by a shrinking globalized world that allowed us to mate with each other after millennia of migration away from Africa. Fortunately, there was no cataclysm strong enough to separate these isolated populations long enough for new species to develop. Since the last Ice Age, the races of the world have been conglomerating back into one as each society becomes integrated into the modern global framework.
But that doesn't mean a classic population purge will never happen. A cataclysm could wipe out all our technology and everything we've built, leaving isolated communities of humans who would evolve certain traits from selective pressure by nature. This is what happened to the dinosaurs 65 million years ago, after an asteroid impact rendered them extinct. Today there are countless species of birds- the evolutionary offspring of dinosaurs- with such varieties of appearance and function that one has to wonder what the future offspring species of human would look like if such an event occurred.
It is my intuition that the traits these new species carry will mysteriously echo the fantastic anthropogenic creatures of our fiction and mythologies. To put it bluntly, these are traits belonging to fairies, elves, dwarves, gnomes, etc. There is no reason for me to doubt that any of these mythological human imprints could eventually become reality in our offspring species. And that once the dust of the cataclysm clears and they are all brought together again, as today's birds are, there could be a global melting pot of current mythological beings becoming reality in the deep future. We are unique in that we have the ability to imagine such a deep future in our collective mythology, brought by transformations unseen in fantasy, as we call their homes other worlds when it could actually be a forecasting of our own. When reading an epic fantasy like Lord of the Rings, we are possibly witnessing derivations of our future world through all the stories we have shared, whether they be orally transmitted, written down, or projected on the screen.
There's no telling what the most accurate blueprint of human progeny is based on current mythology. Likely only several of the myriad imagined humanoid species will take shape, or just one. But that single species could blossom into an array of stunningly diverse species through a single body plan, as the birds seem to have done. If humans ever grow wings, you can be sure the cataclysm that forced it will subside to reveal a fertile breeding ground for that body plan to flourish, while in the interim, various body plans will compete with each other to win out as nature's favorite. Perhaps as birds eventually won out over dinosaurian body plans, a small, winged one will prevail in our post cataclysmic world. Perhaps the deep future of our evolutionary branch will be entirely populated by fairies.
