"We’ve taken a different approach to the origin of the mythology. It was apes being brought into domestic households and being enslaved, but we’ve taken a different approach, which is a more scientific approach with how the apes have evolved. I actually find that more plausible. To speculate on a period of time, we’d be talking about generations and generations of how a chimpanzee could actually evolve into a humanoid creature, which could cause a revolution. I think there needs to be some sort of scientific reasoning behind that, and that’s what we’ve gone for."
January 1, 1970
https://en.wikiquote.org/wiki/Rise_of_the_Planet_of_the_Apes