Michael Cera is a geek poet and he knows it. He’s the stealthily saucy secret sauce - a cunning mixture of naivete, vulnerability, and nerdiness - that made Superbad, Nick and Norah’s Infinite Playlist, Juno, Arrested Development and the online Clark and Michael shorts that much better, healing the wounds of 90-pound weaklings and cubicle-bound bookish waifs with his empathetic portraits of brainy goofballs with love in their hearts and stars in their eyes.

With Year One, the Canadian export has found his match - and foil - in Jack Black, whose characters tend toward the brash and crass more often than not. Black’s the id to Cera’s super ego - he’ll say anything and do anything while Cera will reserve judgement and neurotically cower, sunken-chested, in the rear. And together, the comedic duo lift Year One out of the caveman doltishness it so easily could have become mired in and into something genuinely fun, a post-Superbad, testicle-joke-riddled, twentysomething equivalent of The Flintstones.

Sunnier and sweeter than Life of Brian, or for that matter, the Bible, Year One pins its narrative arc on two likable Neanderthals, Zed (Black) and Oh (Cera), essentially contemporary dudes in fur pelts and as different as they come: Zed is reckless, buffoonish and knowledge-hungry, particularly after eating from the tree of forbidden fruit, and Oh is dreamy, awkward and brainy, better at inventing the first water bottle than picking up the ladies. The two bond over their love of the ladies, but after meddling with the taboo apples, they’re exiled from their semi-Edenic village and take it on the road. Of course, these backward cavemen find civilization less than civilized: along the way the pair stumble over Cain (comedian David Cross) and Abel (Paul Rudd), Abraham (Hank Azaria) and Isaac (Christopher Mintz-Plasse from Superbad), and Sodom (though not Gomorrah, but then Sodom offers more opportunities to poke fun at sodomy).

Year One isn’t perfect: Despite dreaming up some genuinely laugh-out-loud one-liners, co-writer and director Harold Ramis (Ghostbusters) noticeably fumbles at a few crucial moments, cutting from the action and then never bothering to pick up the thread, particularly when Cera’s Oh is in danger of being throttled by a snake, ripped apart by a cougar, or menaced by a hairy-chested high priest (Oliver Platt). It’s as if he can’t bear to see Cera’s sweet meat in jeopardy and averts his lens discreetly.

But then again, you don’t go to Year One for the Cohen Brothers’ labyrinthian plotting and bitter laughs or Judd Apatow’s incisive yet loving jabs at men and their vanities. Instead you go for the good-natured, lite bromance - and thankfully Ramis doesn’t stint on the jokes, as corny as they might get: “I want you to enter the holy of holies,” offers the Princess, to which Zed delivers the silliest and funniest rejoinder, “That is quite a coincidence - because I want you to sit on the pole-y of pole-ys.” The success of Year One rests on its cast and their crack comic timing, and on that level, it could be in the running for the funniest buddy movie of the year. With the history of Martin and Lewis, Crosby and Hope, and Belushi and Aykroyd on their side, Black and Cera just might be at year one of a beautiful partnership.