LifeEurope
Adults begin to tolerate milk
A gene spreads faster than almost any other in human history
See it on the timeline →In depth
The gene reached nearly eighty per cent in northern Europe within a few thousand years, extremely fast in evolutionary terms. Recent work suggests the advantage lay less in nutrition during normal years than in survival during famine and disease, when milk might be all that remained. Equivalent variants arose independently among herders in East Africa and Arabia.
For children
All mammals stop tolerating milk once grown — humans included, originally. But in some a small change arose that let them drink milk for life. Wherever there were cattle, it spread with great speed.
Connects to
Part of Terra Saga — the story of Earth on a timeline. terrasaga.org