And software is an emergent property of transistors? Math must be an emergent property of paper, then.
If the brain is just processing things in complete chaos an animal would be completely useless, but with a part/thread dedicated to processing inputs and checking memory I think it is very obvious this function of consciousness would emerge through natural evolution.
Actually another comment points out something interesting, when we get black-out drunk we are basically in this zombie-state. We can talk and hit our head and physically our brain still reacts, but it was like we aren't actually there and our body is just on autopilot mode.