I agree with Matt. Replace beer with "Disney Land" and water with "Safeway" and I think you'll get the same obvious conclusion. Dopamine levels increased when a person was told they would go to Disney Land even though they didn't....but did not increase when told they were going to Safeway.
How does one know that it is a mutation versus genetic adaptation ie., the genetic code is already present? It is impossible to tell unless 2 separate species arise. It is like saying that the reason that Americans are typically bigger and taller today is either by evolution or better nutrition ei., adaptation. In the case of the Andean people, if moved to a lower elevation, they would simply revert back to normal lung capacity. I wouldn't call this a mutation or evolution. It's not like they evolved and then evolved back, their bodies adapted. It's just like blind cave salamanders when raised in non-cave conditions became normal salamanders.
Evolved greater lung capacity. LOL. That's only adaptation/variation. They didn't become a separate specie. So far every human is capable of reproducing with every other human, just like every variety of dog. Plus, if I feed my cat milk after it was weened is it also evolving into a lactose tolerant animal?
Codes call out the number of urinals and toilets you need for a building, which is why they didn't go with just 3. It looks like they don't have codes to spacing them out though!