Have you read "Human Devolution" by any chance?
I honestly don't recall, but wouldn't be surprised.
I DID read Pan Satyrus though.
That is about a chimp that is put into orbit. The satellite orbits 'the wrong direction' causing 'time to reverse' and devolving the chimp into a human, befor returning to earth.
The rest of the book is his quest, remembering what exalted heights he once held, to get reorbited and reevolved. It ends with him a happy chimp once again, returned to the jungle.
Are we not men? We are Devo!
Are we not men? D-E-V-O!