They don't get any dodge bonuses as a result of their barbarian levels. If they keep taking ranks of the tumble skill however, every 5 full ranks of that skill give +1 dodge ac bonus. The Monks' version is different and totally tied to their level, though monk ac can stack with tumble bonus.
Barbarians are about the combat opposite of a monk, and don't gaint wisdom bonuses to AC at all. They do have Damage Reduction based on level, which is the ability to ignore some damage instead of dodging it.