YEAR ONE — ★— Jack Black, Michael Cera; rated PG-13 (vulgarity, violence, profanity, slurs, brief sex, brief drugs, torture, brief gore, nude artwork); in general release

"Year One" — a film so simple-minded that even a caveman could have written it. Or could have directed it …

But really, what more could you expect from movie that's so reliant on the tiresome shtick of alleged funnymen Jack Black and Michael Cera?

They star as Zed and Oh, members of a tribe of primitive hunter-gatherers. The portly Zed (Black) is terrible at hunting. The painfully shy Oh (Cera) is just as inept at gathering.

But worse things befall the pair after the fast-talking Zed samples forbidden fruit from the Tree of Knowledge. They're banished from the tribe, and then the rest of the movie sees them stumbling around from one ill-conceived and painfully unfunny skit to another.

In their travels, our dopey heroes:

Encounter Cain (David Cross) and Abel (Paul Rudd).

Stop Abraham (Hank Azaria) from sacrificing his son, Isaac (Christopher Mintz-Plasse).

Wind up being enslaved in Sodom and Gomorrah, alongside their would-be lady loves, Maya (June Diane Raphael) and Eema (Juno Temple).

Predictably, Black and Cera simply offer versions of the same characters they have for several movies now.

What's really hard to believe, though, is that this film was directed by Harold Ramis, who at one point in his career gave us the original "Vacation" movie as well as "Groundhog Day."

"Year One" is rated PG-13 and features crude humor relating to bodily and sexual functions (sight gags and references), supposedly comic violence (pratfalls, brawlings, swordplay, beheadings and some violence against women), occasional strong profanity (including one use of the so-called "R-rated curse word), derogatory language and slurs (some based on sexual orientation), a brief sex scene (implied), brief drug content and references (hallucinogens), a scene of torture, brief gore, and nude statues. Running time: 97 minutes.

E-mail: jeff@desnews.com