Long ago, I saw this as a child back in the Sixties when it was shown on television. Decades later, with the internet available to track it down, I finally got a knock-off DVD of it. Now I am excited to see it has been given the final glory- bluray!
This is one of those excellent plane-crash in remote areas genre of films from the Fifties and Sixties. The cast is terrific, the location is gloriously desolate, and then there's those baboons. My favorite character is Whitman's who devolves into a primal man, willingly abandoning civilization. There seems to be a backstory to him, but that is left as a mystery.
And now an observation after viewing this fine film 40 years later. And this is a spoiler, so don't read further if you haven't seen it. When O'Brian has his final battle, I had always assumed the worst. But, as he did kill the leader, what if the others are not attacking him, but gathering to recognize the new baboon king? This would complete his devolution. Just a comforting thought opposed to the horror of what probably happened.