Milk may have been the fuel that enabled a major human migration

Drinking milk from domesticated animals was likely one of the catalysts that allowed the massive expansion of ancient people living in parts of what is now Ukraine, Russia and Kazakhstan — an area known as the Pontic Caspian Steppe — to the far reaches of Scandinavia to the west and Mongolia to the east.

The people who lived there, known as the Yamnaya, were nomadic pastoralists who lived and travelled with large herds of animals, and started migrating outward about 5,000 years ago.

The steppe region they traveled through isn't very hospitable to humans because this wide open grassland area, that stretches throughout Eurasia, is arid, often cold, didn't have a lot of resources. 

Nicole Boivin, a Canadian archeologist and director of the Department of Archeology at Max Planck Institute for the Science of Human History in Jena, Germany, said she and her colleagues deduced from evidence in ancient dental tartar that the Yamnaya started drinking animal milk right around when this massive expansion of people occurred.

Boivin and her colleagues used the fact that proteins in the tartar build up can reveal a person's diet. They studied the skeletons of 56 people who lived around the Pontic Caspian Steppe from about 5,300 to about 4,500 years ago.

In an interview with Quirks & Quarks host Bob McDonald, Boivin said that the cattle, sheep, goats and even horses the Yamnaya milked would have been like refrigerators they could travel with.

Since it would likely would have been very difficult to milk wild horses, Boivin said that the fact they found direct evidence the Yamnaya were consuming milk products from horses is evidence that horses were domesticated by this point in time.

Produced and written by Sonya Buyting. Click on the link at the top of the page to hear the interview with Prof. Nicole Boivin.