https://en.wikipedia.org/wiki/Lactase_persistence
And I’m not sure what you thought I said, but I’m not arguing that milk consumption is great. Well, not in the post you responded to; I do think milk is pretty amazing. All I was saying is that it is an example of humans evolving adaptations to their diets.
But on the topic of milk consumption: there may be drawbacks, but the gene for lactase persistence is one of the fastest spreading genes in recent history. Consuming milk was an utter (there’s a pun to be made here, but I will exercise restraint) game changer for Northern Europeans. Even today, milk is an amazing source of well-balanced nutrition. It’s cheap, easy to consume, and pretty tasty at room temperature.
If it doesn’t cause explosive things to happen to your intestines, that is.