Evrim Yazgin
Cosmos science journalist
A new genetic study has mapped out the 11,000-year history of the close relationship between humans and sheep.
The earliest sheep-herding practices were discovered Aşıklı Höyük in central Turkey, detailed in a 2014 study. It showed that these ancient people of the northwestern part of the “Fertile Crescent” had penned wild sheep in about 9000 to 8200 BCE.
Since then, humans have kept domesticated sheep across continents for their protein-rich milk, meat and wool which can be turned into warm, water-resistant fabrics.
The new study, published in the journal Science, revealed the analysis of ancient DNA from 118 bones which span 12,000 years and come from places as disparate as Mongolia and Ireland.
Among the bones are those found at Aşıklı Höyük.
The research showed that the earliest European sheep populations, about 8,000 years ago, were subject to deliberate selection by farmers for coat colour. The team found evidence that the main gene being selected for is known as “KIT” and is responsible for white coat colour.
Along with similar genetic evidence found in goats, this is the earliest sign of humans moulding the biology of other animals. It also suggests that the ancient herders were interested in beautiful and unusual traits in the creatures.
By about 8,000 years ago, domestic sheep genomes in Europe had diversified from the earliest domestic sheep, as had those in Iran and Central Asia.
But this separation didn’t last as sheep were moved from the east to the west around 7,000 years ago. This coincided with the spread of human cultural influences out of the early cities of Mesopotamia.
Another westward wave of domestic sheep followed about 5,000 years ago as farmers from the Eurasian steppes moved into Europe. These pastoralists included the first horse riders.
“One of our most striking discoveries was a major prehistoric sheep migration from the Eurasian steppes into Europe during the Bronze Age,” says first author of the study Kevin Daly, from the University College Dublin (UCD) in Ireland. “This parallels what we know about human migrations during the same period, suggesting that when people moved, they brought their flocks with them.”
Their arrival into Europe also profoundly changed the genetic makeup of Europe’s inhabitants and saw the evolution of the Indo-European language group which is the ancestral form of the languages spoken across the continent today.
It is possible, according to the new study, that this massive migration was fuelled at least in part by sheep herding and exploitation of products throughout the animals’ lifetime such as milk and cheese.
