Well I think I agreed with the fact some genes get on and off depending if we need them or not. The same with wisdoms tooth, if we need them since childhood there you got you get functioning wisdom teeth, and if we don't there you get no functioning wisdom teeth. The same with other mechanisms. If you are raise in Iceland, probably you melamine production is minimal but then if you move to the Caribbean your melamine production increase, these are genes we can turn then on or off, depending if we need them or not. Human body is a wonderful Machine.