I’ve long had the idea of writing a science fiction story in which several different human species coexist on Earth in modern times. For example, Neanderthals, Denisovans, and Cro-Magnons. They would differ physically and have completely different cultures, political systems, and ways of life. In this setting, the different branches of humanity would try to build relationships with one another while sharing the same world.
My question is: are there already books like this? The idea feels so obvious that someone must have explored it before.
by Xartym