To the first statement, I dunno. I would have to look into it. "The fact that their jaws changed because their diet change is not evolution, their diet changed so their jaws changed. The same exact thing can happen to birds--not to their offspring but to the bird itself. If a bird is used to eating soft foods, its beak will tend to be short and thin, but during a drought, soft foods tend to die first, therefore, if the bird likes to live, it must find something else to eat. Suppose it finds nuts, but the nuts are too hard for the beak to easily break and eat. What would happen to the beak? Same thing that would happen to your arms if you lifted weights." All I can say is what?! A birds beak does not grow or shrink like a muscle from use. It would be like your teeth. They do not grow from more use or eating hard things at all. If there is a drought and soft things die leaving only nuts, the beak does not change so it can eat them. If it cant, the bird will starve and die. The more successful ones (i.e. ones that can eat nuts) will pass on their genes to their offspring. So in the next generation more of the population will have beaks that can eat nuts. AKA Natural selection