There is no need for transcendant purpose. Quinoa intolerance is pretty uncommon, whereas milk intolerance is the norm. Even without a lactose intolerance, there are several health issues with milk consumption, unlike quinoa consumption. That is because we've evolved for a orders of magnitude longer to eat plant material.

Yes, some northern European peoples have evolved to be more tolerant of milk. And some tibetans have evolved to live at very high altitudes. It's not a good argument to take a small exceptional population and apply that reasoning to the general case.

And this doesn't even get into all the problems with the dairy industry with regards to environmental damage and animal suffering.

But in this case with this country, that small exceptional worldwide population is overrepresented in our national population. It stands to reason that many people can infact consume lactose in the U.S. given this demographic history. The general case in the context of the U.S. population could very well refer to this population of people historically predisposed to tolerate lactase.

And on the other hand, I think there is this false logic at play with the meat/dairy industry as a whole. People assume these interconnected systems are in fact discrete. That we could do away with eating meat and suffer no consequences, in fact even see improvement in our ways of life. I am not so optimistic given how interconnected systems are. For instance, take the cow. Its not just used to derive meat. 99% of the cow is used. The pancreas is used to extract insulin and other factors. Same with the liver, and the pituitary gland. Serum is used for biomedical research applications. The hair is used for products, the hide is used. The fats are used for everything from toothpaste to flooring to crayons. Collagen and gelatin are extracted. I don't even need to go into the uses of the hide, I feel. The bones and blood are used for organic fertilizer, so I'd wager that many organic vegetarian products today actually rely on the cheap organic fertilizers produced by the meat industry versus synthetic sources. On top of that pasture land is often land that is not compatible for traditonal farming, owing to terrain mostly (e.g. Summit county in Colorado sports a lot of ranching versus farming, due to the rocky mountainous terrain being almost impossible to plow but trivial for a grazer to roam on).

Could you replace all of the parts of the cow with synthetic sources? Certainly. Would this lead to a net reduction in greenhouse gasses and other environmental externalities replacing each and every of these products with synthetic sources that hopefully aren't any more costly? That I doubt, and it worries me that headlines and other material in the media seem to ignore how all these externalizes will be resolved, assuming it will be an easy transition.

> several health issues with milk consumption, unlike quinoa consumption.

Are you claiming that most people who consume milk as a major part of their diet suffer health problems from it? Or that grain-based diets do not cause health issues?

> That is because we've evolved for a orders of magnitude longer to eat plant material.

Evolution has no telos. Evolutionary leaps into new niches are the norm, and hunting had formative impacts on the evolution of modern humans. We've also evolved for orders of magnitude longer walking on all fours (and walking erect causes health issues, such as stressing the back), but that has no bearing on what is healthy or suitable.

> It's not a good argument to take a small exceptional population and apply that reasoning to the general case.

I don't believe I did so. Northern European-origin populations are not small or insignificant, but I agree that for lactose-intolerant populations who have no tradition of using milk-based foods they are generally nutritionally unnecessary.

Dairy isn't nutritionally necessary for anyone. Perhaps it was in the past, but not now. You won't find evidence for that.

Not sure what you mean about telos. Evolution informs us about why we eat what we eat and how we might be affected by various foods, but it does not control us. We can choose what we want to eat.

> Dairy isn't nutritionally necessary for anyone. Perhaps it was in the past, but not now.

Assuming alternative sources of the same essential nutrients, I agree – no single food is nutritionally necessary or ever was. In the real world, meanwhile, dairy products are a key source of protein etc. for people in at least some regions where sufficient alternative sources are not widely affordable or available. Certainly, milk was crucial to the survival of many populations as recently as a century ago (not "aeons ago during some ancient famine").

> Evolution informs us about why we eat what we eat and how we might be affected by various foods

Evolution is an open-ended history of accidents, with much to say about what works for us (as opposed to what cannot).

> but it does not control us.

Indeed. Not only does it not control us, we cannot even conclude based on it that a novel environment or resource will not be advantageous. In the case of ungulate milk consumption, it turns out it was.

> Not sure what you mean about telos.

Evolutionary adaptations are in the nature of accidents, not guided by any purpose or implying any optimal "natural" state. Populations taking advantage of accidental fitness for new niches is a defining pattern in the evolution of life on earth, and consumption of milk by some human populations fits that pattern. Drawing conclusions about the suitability of drinking milk because "we didn't evolve to drink it" is fallacious (in contrast to, say, explaining most people's lack of lactase persistence by their ancestors' non-consumption of milk, which is sound, non-teleological reasoning).