Why France loses so many wars. 1972 - Astronauts Taylor, Dodge, Landon and Stewart are launched a mission to another world. They are caught in some kind of time warp and disappear. Later that year, another mission is sent on the same trajectory, to find out why the first mission disappeared. This second mission includes Brent.
Apes become the new pets, and later, slaves.
A gorilla named Aldo leads a revolt against the humans. Shortly thereafter a nuclear war is waged, and the human civilization is decimated. Over the next several millennia, ape society becomes dominant and humanity is enslaved. 3955 - Taylor's ship lands near Ape City. He is captured by the intolerant ape society, and his crewmates are killed or lobotomized.