"Apocalypto," Mel Gibson's new thriller about the ancient Maya civilization, is exactly that: thrilling. But this entertainment comes at a price. The Maya at the time of Spanish contact are depicted as idyllic hunters and gatherers, or as genocidal murderers, and neither of these scenarios is accurate. The film represents a step backward in our understanding of the complex cultures that existed in the New World before the Spanish invasion, and it is part of a disturbing trend re-emerging in the film industry, portraying non-Western natives as evil savages. "King Kong" and "Pirates of the Caribbean: Dead Man's Chest" show...