An interesting study: the history of milk consumption in Europe

Early Europeans Could Not Tolerate Milk but Drank It Anyway, Study Finds

From The NY Times, so I'm not sure about the paywall factor:
https://www.nytimes.com/2022/07/27/science/early-europeans-milk-tolerance.html

Here's another news source.

https://www.euronews.com/next/2022/07/28/lactose-intolerance-didnt-stop-ancient-...

The study was published in Nature this month.

The scientific paper is too difficult for me to read at this time on the device I have, so I'm left with questions about what appear to have been assumptions made. Mainly, what indication was there that the milk was drunk by adults? The way I see it, milk might have been stored for use in cleansing (like olive oil was before people began to consume it) or to supplement the diets of children and/or domesticated animals.

>2 aspirit: I think part of the determination that adults were drinking milk comes from the lactase mutation that made milk consumption more palatable. What would drive that mutation otherwise if adults weren't consuming milk?

>3 rocketjk: I thought that but was confused why adaptation would take a thousand years when we can see human (survivable, possibly adaptive) mutations happen so quickly in modern times. Unless... the difference is a matter of population size and favorable conditions for mutations?

That's possible.

But humans are in an exceptional demographic and ecological transient. Rapid population growth has been coupled with vast changes in cultures and ecology during the Late Pleistocene and Holocene, creating new opportunities for adaptation. The past 10,000 years have seen rapid skeletal and dental evolution in human populations and the appearance of many new genetic responses to diets and disease.

https://www.pnas.org/doi/10.1073/pnas.0707650104

I still think it's a big leap to assume that evidence of milk storage means milk was regularly drunk by adult humans. People store all sorts of things adults avoid putting in their mouths, even when starving.

>4 aspirit: Well, your point is a logical one, certainly, and I would like to see it addressed directly in one of these articles, but for me the bottom line is still the question I posed in >3 rocketjk:: "What would drive that mutation otherwise if adults weren't consuming milk?" Speed of the mutation notwithstanding, it had to have occurred for some reason, right? Sorry that I haven't read the article you linked to yet, but what is their definition, in this context, of "rapid" when they say, "The past 10,000 years have seen rapid skeletal and dental evolution in human populations and the appearance of many new genetic responses to diets and disease"?

At any rate, it's an interesting point to ponder.

Could it not be that adults just started drinking milk, but that older children who could continue drinking milk without ill effects would have an advantage in nutrition so they'd have more children some of whom could drink milk at even older ages, etc etc

Part of the argument seems to be that studies of modern humans show that adults without the persistence of the lactase gene drink as much milk as those with the gene and suffer few ill effects, and produce as many children as those with the LP gene. Under ordinary circumstances, healthy people were able to consume milk without serious consequences, and thus did not have to forego a readily available source of nutrition. The authors argue that with the increasing practice of animal husbandry in the Neolithic, infectious diseases more readily spread to humans, and those who became sick from these diseases were at a greater disadvantage if they lacked the LP gene. When sicker, they are more prone to exacerbation of symptoms, especially with diarrheal diseases, where there is a risk of dehydration and death when the lactose intolerant consumed milk. While they haven’t proved that this contributed to the proliferation of the gene, it’s an interesting argument, and one which will no doubt be subjected to further study.