Ancient apes were less advanced than modern apes, just as ancient humans were less advanced than modern ones.
And let me add the other bit that goes in here, crash, only so it gets said explicitly: back amongst those ancient apes and ancient (pre-?)humans was a little band of critters that were both at the same time. They couldn't make their own vitamin C, and they didn't have an operative urate oxidase. They likely had no noticeable tails. And some of their descendants now are being rapidly exterminated in West Africa by another line of their descendants, us.
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