[Tas]

interesting thing about lactose intolerance. It's actually normal for mammals to become lactose intolerant in adulthood; most mammals stop producing the enzyme necessary to process lactose (called lactase) as soon as they stop drinking their mother's milk. However, some human populations developed a genetic trait that causes lactase to continue to be produced throughout adulthood, specifically those populations that harvested milk from farm animals.

some populations that never harvested milk, particularly in Asia, are almost entirely lactose intolerant.