Re:Modern city dwellers have lost about half their gut microbes
by easytiger on Thursday June 30, 2022 @07:35PM
(#31940134)
Or people who worked out they were tolerant to it, farmed it, and the high density nutrients allowed faster more reliable development of healthy children in adverse conditions. i.e. North Western Europe.
Lactose intolerance is normal, but for a few people, presumably dairy animal farmers, something happened to their genes and they became tolerant, and it was an evolutionary avantage because they had access to all that milk. But because access to farmed milk is relatively recent from an evolutionary standpoint and people can live with lactose intolerance, the trait hasn't spread to all of humanity.