In the beginning, there was a cosmic explosion at a singularity, with the later development of life from the random division of single-cell organisms. Or six days of creation, a man, a rib, a woman and a garden with an apple tree. Or a Galactic Confederacy ruler bringing billions of people to earth in space ships before detonating hydrogen bombs in the planet's volcanoes.

It all depends on who you ask or what you read, really.

Writer-director Harold Ramis, seemingly doubting Wikipedia's accuracy, has turned to more reliable, if not funnier, sources for 'Year One': an illustrated children's book of Bible stories, Monty Python's 'Life Of Brian', Ringo Starr's unfortunate 'Caveman' film, and Mel Brooks' 'History of the World Part 1' and '2000 Year Old Man' skit.

So two hunter-gatherer slackers banished from their village encounter the great Old Testament comedy double-acts (Adam and Eve, Cain and Abel, Abraham and Isaac, Sodom and Gomorrah).

But the laughs get lost somewhere out in the desert, long before their journey of self-discovery, effeminate high priests, circumcision, hot oil massages, eunuchs, virgin sacrifices and the holy of holies comes to an end.

With an emphasis on punchlines and visual gags rather than the primitive storyline, not even the A-list cast can prevent the humour going the way of the dinosaurs.

Producer Judd Apatow clearly called in favours but then simply has the succession of comic veterans (Oliver Platt, Hank Azaria, David Cross) and hot-right-now funnymen (Paul Rudd, Bill Hader, Christopher Mintz-Plasse) all do the same thing: overact in robes.

The two leads don't even do that. Jack Black plays a loud, opinionated buffoon — in other words, himself — while Michael Cera acts like an apologetic, uncomfortable geek — yes, in other words, himself.

Their performances are tired and familiar. But then again — somewhat appropriately — so is 'Year One'.