>Are they speaking and using sign language because they lost
>the ability to communicate with each other through other
>means? Is that a thing? Do sign language apes do that irl?
>Also it seems to me that it's pretty good being a talking ape,
>why would human beings evolve from that to a point where they
>can't smash cars, scale buildings and use their feet?

they hinted that Caesars intelligence & accelerated evolution (by way of drugs) was common among the other lab monkeys
just not to the same degree
maybe i'm misremembering though