I love you, Dr Zaius

For some reason, 1968 was a standout year for science fiction. It saw the release of 2001: A Space Odyssey and Barbarella (granted, one of these things is not like the other), and it also gave the world a third sci-fi classic: the amazing, entertaining and profound Planet of the Apes, whose glory could not be sullied by inferior sequels.

A bit of sullying was done by Tim Burton's widely disliked 2001 remake, but even that film raked in mountains of cash; and thus it was that 20th Century Fox held on to the franchise rights and eventually put into production a prequel variously titled Caesar, Caesar: Rise of the Apes and Rise of the Apes before being released as Rise of the Planet of the Apes.

That clunky final title proves that Hollywood executives firmly believe that you, gentle reader, are too thick to comprehend precisely which apes they might be talking about; and so we're all on the same page, Sean O'Neal will now explain:

'Not just any apes, mind, but specifically, those apes with the planet - the one from those movies - whose planet will now rise, metaphorically speaking, to replace that earlier, non-ape planet. Of course, none of this would have been necessary had Tony Danza and Danny DeVito not stolen Going Ape! all those years ago.'

The opening sequence prefigures what makes Rise of the Planet of the Apes special. A chimpanzee group is wandering the African jungle, and before we know it they're ambushed by humans; several apes are caught in nets and dragged off. This could be a standard scene, but it's notable for how totally subjectivity is reversed: the chimpanzees are subjects, persons, while the humans are faceless goons; and the visual quotes director Rupert Wyatt lifts from the famous scene of apes on horseback chasing human hunter-gatherers in Planet of the Apes underline the constant dialogue between the prequel and the original.

The captured chimpanzees end up at the labs of the horribly named Gen-Sys corporation, where scientist Will Rodman (James Franco) has just developed a new type of genetic therapy. ALZ-112, which repairs and improves brain function, may prove the longed-for and - hopes Will's boss, Jacobs (David Oyelowo) - lucrative cure for Alzheimer's. Of course, chimpanzees being imprisoned and studied by humans is a neat reversal of the situation Charlton Heston found himself in in the original, but I think 'constant dialogue' above summed it up pretty well.

The study's most promising test subject, a chimpanzee called Bright Eyes (Terry Notary), breaks free, attacks several handlers and, among much destruction, is gunned down by security guards just as Will is presenting his findings to the Board. Obviously, this disaster means no-one will ever fund Will's project again, and the chimpanzee handler, Franklin (Tyler Labine), is told to put down all the apes; but when Franklin discovers that Bright Eyes had given birth just prior to seemingly running amok, he can't bring himself to kill the infant, and Will agrees to take it home.

Not a chimpanzee.

Within a couple of years, the chimpanzee, now named Caesar (Andy Serkis), has grown to maturity. Caesar, having benefited from the gene therapy his mother received while he was still in the womb, exhibits signs of extraordinary intelligence, including sophisticated sign language and a fully developed sense of self. Meanwhile (there's a lot of 'meanwhile' after the first act), Will has been successfully treating his father (John Lithgow) with ALZ-112, stemming the progress of his Alzheimer's, but after a few years antibodies have started developing. Will manages to persuade Jacobs to fund the development of another, better drug.

Meanwhile, Caesar attacks Will's neighbour (Joey Roche) and is confined to a primate shelter run by the pragmatic John Landon (Brian Cox) and his sadistic jerk son Dodge (Draco Malfoy). After having a tough time at first and becoming disillusioned with Will, Caesar eventually escapes, discovers the new ALZ-113 and takes it back to enhance the intelligence of his fellow apes. Who rise.

In truth, the human characters in this film exist for two purposes only: to set the plot in motion, and to react with shock/sympathy/speciesist arrogance to the apes' actions. (It's fitting that the non-human primates are listed first in the credits.) The lead isn't Franco, and it certainly isn't Freida Pinto, whose character is entirely superfluous to the film but exists because she's just so pretty. No, our hero - anti-hero, perhaps, but the film doesn't really make that case - is Caesar, and after the latter two Lord of the Rings films and Peter Jackson's King Kong, everyone knows that if you want your humanoid computer-generated characters portrayed right, you get Andy Serkis.

Serkis gives the best performance in the film, an earnest and subtle portrayal of a person who comes to realise that he has the power to liberate his kind and change the world. He's part Moses, part Che Guevara, and totally awesome. The other actors portraying apes come close, though, creating wonderfully rounded characters like the aggressive alpha male Rocket (Terry Notary again), solitary gorilla Buck (Richard Ridings), Methuselah Koba (Chris Gordon) and gentle orangutan Maurice (Karin Konoval). The last of these is my favourite character in the film, not only because I adore orangutans but also because his name is a shout-out to Maurice Evans, the hero who portrayed the greatest character in the history of cinema: Dr Zaius of the original film.

The best, most humane decision they ever made was not to use a single real ape in filming: every one of them is an actor's motion-capture work rendered in CGI, and it's quite beautiful, including the truly insane amounts of fur they had to create. I've resigned myself to the fact that on a large scale, CGI will never look as real as practical effects, which are real: compare the orcs (latex and make-up) to Gollum (CGI) in the Lord of the Rings films to see the difference. But CGI allows the creation of almost-real-looking things you could never do with old-school effects - and, as in this case, it helps avoid a great deal of unnecessary suffering caused by enslaving our fellow primates to perform for our amusement.

The dialogue Rise of the Planet of the Apes conducts with the original shows, though, how much our perception of great apes has changed in forty-odd years. In one of the film's key lines, Landon tells Will that '[t]hey're not people, you know'. The 1968 film argued that actually, they kind of were people, and how would you like it if someone locked you in a cage and studied you? (The analogy to racial slavery was unmistakeable.) The prequel, by contrast, sets out the apes' irreconcilable strangeness. Where the original's actors portrayed their apes as furry people, in 2011 they're all animal, aggressively physical, dextrous climbers, moving on all fours. (Caesar, of course, mostly walks on his hind legs, marking him as the leader.)

We're less certain of the similarities between us and our closest living relatives now, much more aware that we were and still are projecting aspects of ourselves onto great apes. (We did that even before we knew we have a common ancestor: see the medieval and early modern characterisation of the monkey as a clownish caricature of human beings.) In Rise of the Planet of the Apes, they're fascinating but often strange and violent. Wyatt films them to remind us that, pace decades of juvenile chimpanzees being cute on TV, an adult male of the species can grow 1.7m tall, has the strength of several people, and is prone to solving problems by violence.

It is, I should mention, a gorgeous film. Cinematographer Andrew Lesnie (of the Lord of the Rings films, King Kong, and I Am Legend, proving again the producers knew to get the best people for this project) uses colour to accentuate the apes' personhood at the expense of the literally paler human characters, while Wyatt's direction is brisk and fleet, stylish but not showy, and filled with references to killer animal films from King Kong to The Birds without ever being obnoxiously post-modern. While parts of the film are silly and overblown, certain concessions have to be made to the twenty-first-century blockbuster. Otherwise it's delightfully old-fashioned, entertaining and thoughtful.