So @wyattsalazar, I was listening to the first part of the first episode of Book Hell and I couldn’t help but notice you guys trying to remember the name of a book that had weird human-monkey people from the future in it. As it so happens, I know exactly what you were talking about.
The book you were looking for was called Man After Man, by the British paleontologist and author Dougal Dixon. As it so happens, Man After Man is the last of three books he wrote playing with the concept of “speculative evolution.” The first (below) was After Man: A Zoology of the Future. Published in 1981, it was an overview of life all around the world 50 million years from now, long after our extinction. If memory serves, there were a whole lot of rabbit-deer and rat-wolves running around.
The second was 1988′s The New Dinosaurs: An Alternative Evolution. The premise for that was that the Cretaceous-Tertiary mass extinction of 65 million years ago never occurred, and the dinosaurs (and a whole bunch of other critters) were allowed to survive and evolve in peace to the present day. Personally, I think it’s the best book of the three, but then again I have a pro-dinosaur bias, so interpret that as you will.
Man After Man came out in 1990, and it’s something of the black sheep of the trilogy. According to Dixon, his original idea for the book was to write a sequel to After Man in which humans, using time travel to flee the dying Earth of the modern day, arrive in the new world of 50 million years hence, and proceed to rebuild civilization and muck the planet up all over again. For whatever reason the idea fell through (though it did get reused for a space-colonization story that was only ever published in Japan), and Dixon wrote Man After Man instead, despite having no real desire to do so. I don’t like the book myself, partially because I feel it it delves too deeply into stock sci-fi tropes, chief among them telepathy, for a “serious” work of biological extrapolation, but also because I find the idea of creatures who wear the faces of humans but have the minds of animals to be...deeply unsettling. Still, it did give us a few good memes.