Artificial selection versus natural selection. New facial muscles emerging without design or intent is quite different from two separate groups of people trying

Artificial selection versus natural selection. New facial muscles emerging without design or intent is quite different from two separate groups of people trying to see how big/small they can breed a dog to be. Selective breeding works incredibly fast on evolutionary timescales. You can get a selected population to no overlap with the parent population on your variable of interest in seven generations quite easily.