Tooth plaque shows drinking milk goes back 3,000 years in Mongolia
Milk proteins preserved in tartar show that ancient Mongolians drank cow, yak and sheep milk
![yaks in Mongolia](https://i0.wp.com/www.sciencenews.org/wp-content/uploads/2019/02/021619_CG-yaks-mongolia-main.jpg?fit=860%2C460&ssl=1)
MODERN MILK Seven species of animals, including yaks (shown), are milked in Mongolia today; recent research suggests that yaks were milked in the region 3,000 years ago, too.
C. Warinner