Why Can Humans Still Drink Milk as Adults?

Why can some adults drink milk when most grown mammals cannot? This episode follows that question from a cup of coffee back to the early herders who started milking. For most of human history milk was baby food, and there were no tame herds. Then, in the Near East, herders began keeping cattle, sheep, and goats alive for their milk. Pottery, ancient bones, and DNA show that dairying spread with farming across Europe, southwest Asia, and into Africa while adult bodies still shut the milk enzyme off. A much later genetic change kept that enzyme switched on in some people. The video then asks what spread that change so hard in some places and not others. The facts are checked, and the sources are in the pinned comment. Can you finish a glass of milk without thinking about it, or do you avoid it? Leave a comment.