Why Can Some Adults Drink Milk?

Every mammal on Earth stops digesting milk after weaning. So do most humans. If you can drink a glass of milk as an adult, you carry a genetic change that most of your ancestors never had. This video traces that change from the wild aurochs and the first dairy farmers, to 7,000-year-old cheese strainers, to a man frozen in the Alps and a Bronze Age battlefield where almost nobody could drink milk. Then it asks the real question: why did the milk gene spread so fast? The answer involves famine, disease, and one of the strongest signals of natural selection ever found in human DNA. Subscribe for more videos exploring the hidden systems behind everyday life. 🔔 New videos every week 0:00 Most adults can't digest milk 0:32 The switch every mammal has 1:18 What happens when adults drink milk 1:42 The "intolerance" problem 1:58 A map that isn't random 2:22 One letter out of three billion 3:00 The first dairy farmers 3:53 Cheese was a workaround 4:42 The man in the ice 5:06 A Bronze Age battlefield 5:36 The fastest change in your genome 6:00 The calcium theory 6:21 Famine, disease and survival 7:34 Evolution solved it more than once 8:06 Mongolia's ancient workaround 8:36 How milk became "normal" 9:29 It's a sliding scale 9:54 The chain behind your milk carton 10:23 Nothing wrong with you #TheQuietMachine #Evolution #Biology