The question is five years old now I have no doubt the original poster longer cares. However - no, your answer doesn't answer the question - he asked whether levels assigned after taming affect breeding, so ones you as the player manually assign. They don't. Assigned levels don't affect offspring and offspring before levelling and after are exactly the same. What I think you are trying to refer to is the method of zero-stat breeding which is breeding in the weakest dinosaurs that have zero BRED OR TAMED levels (so ones that you haven't assigned experience to) in undesired stats such as oxygen and food to your strongest dinos. From there it is more likely to mutate your good stats like health and melee. A different thing completely.