Corrected entry: The purpose of the four astronauts leaving Earth was to find a new planet and repopulate it - with just one woman? The next generation would consist of siblings and half-siblings marrying each other.
Corrected entry: After the three astronauts woke up, they notice that they have large beards due to the time they spend in suspended animation. However, their hair hasn't grown an inch.
Corrected entry: An essential plot device is that the talking human doll proves humans were productive and creative before the ascent and takeover of the apes. This is absurd. We are shown repeatedly that the apes' entire society is based heavily upon the previous human one - this is a sneaky buildup to the end scene when we find out exactly why that is! So, in human society we have talking mice, ducks, rabbits, pigs, cats, dogs, snakes, elephants, fish, crabs: name the species, we have given them the ability to speak, walk upright, drive cars, in fact to adopt every human characteristic there is. Surely the logical assumption upon finding the talking human doll is that an ape toymaker created a talking human for the same reason humans created talking apes?