Year One

Conceptually Year One bears fruit, but as a finished product the movie is overripe. Basically a hodgepodge of Biblical reference points (Cain and Abel as well as Abraham and Isaac are characters) mixed with stone age living conditions Year One posits that some boys from the country (Jack Black and Michael Cera) are banished from their tribe after Black eats from the tree of knowledge. It's just as well because the rest of the primitive village people are now Roman slaves. About the midpoint our bumpkin knuckleheads end their journey through Cathechism 101 and end up in the big city. That would be Sodom of Sodom and Gomorrah fame. Cue the anal rape jokes, the fart and poop jokes were used up during the first half.
Director Harold Ramis hasn't exactly been expelled from the garden but the tone and humor in Year One exists light years from his classic Groundhog Day. Despite some interesting comic cameos and enticing femmes Year One will be best appreciated by an immature teen audience. Oddly I doubt if that demo is familiar with two films from 1981, Caveman and History of the World, Part 1, second-tier comedies that lived on due to the advent of cable. You might laugh twice. it's obvious that Black and Cera are running on the fumes of everything they've done previously.