Dairy products would not have made up a substantial portion of a regions diet until lactose tolerance had emerged. Lactose intolerance extends to all dairy prod

Dairy products would not have made up a substantial portion of a regions diet until lactose tolerance had emerged. Lactose intolerance extends to all dairy products, not just milk. And again, you need lactating animals to produce consistent dairy products. Animals do not naturally lactate unless they're feeding their young. And animals also do not naturally produce the freakish amount of milk that we're able to extract now a days from millennia of artificial selection and, in the US at least, using a lifelong cocktail of all sorts of different drugs. To be clear, I do agree with you that in certain uncommon scenarios lactose tolerance could provide a tangible, though not enormous, advantage. And that's the problem. A different shaped beak for a bird entails a never-ending constant, and enormous, advantage. Lactose tolerance is something that's pretty irrelevant by comparison, yet it would become ubiquitous.