I want to stress again that if you believe that the world is 6000 years old obviously evolution could never have happened..
The point is also that there are never large scale changes and it is pretty accepted that the evolution of species happens when a population of animals is isolated from its original population…. As far as dogs the argument is that given enough time they would change to another species. It is an accepted fact that the Shi Tzu’s ancestors were wolves as recently as a couple thousand years ago, what a 100 million years (or more) of changes could do is unfathomable, you don’t see Shi Tzus reverting back to wolves either so i’m not sure were you’r going with your “reverting back to the mean” statement either.