Major corridors of the Silk Road in Central Asia were already home to high-mountain herders more than 4,000 years ago, experts say.
Ancient pastoral herders living in the mountains helped form cultural and biological links across the region thousands of years before the Silk Road started.
Scientists made the discovery by looking at ancient proteins and DNA recovered from tiny pieces of animal bone.
The silk road is a complex system of trade routes linking East and West Eurasia through its arid continental interior.
It derives its name from the lucrative trade in silk that occurred across continents from at around 200BC.
However, in many of the most important channels of the Silk Road itself, including Kyrgyzstan’s Alay Valley, very little is known about early people who lived there in the time preceding the Silk Road era.
Archaeologists at the Max Planck Institute and the Russian Academy of Sciences found people were moving domestic animals such as cattle, sheep, and goat across the high mountain corridors as long as 4,000 years ago.
Researchers identified a series of never-before-seen habitation sites along the mountain margins that form Kyrgzstan’s southern border with Tajikistan.
Test excavations and surveys at these sites produced archaeological animal bones that shed light on how people used the Alay region in the past, according to the study published in Plos One.
When researchers analysed the bones that had been recovered they were so small and badly broken that they could no longer decipher their size and shape.
This meant they were unable to identify which species they originally belonged to.
‘We were crushed,’ said lead researchers Dr. Svetlana Shnaider from the Max Planck Institute.
‘To get so close to understanding the early economy of one of the most important channels of the Silk Road -and come up empty-handed – was incredibly disheartening.’
However, researchers then applied a technique known as Zooarchaeology by Mass Spectrometry, or ZooMS.
This method uses laser-based, mass spectrometry to identify the peptide building blocks that make up collagen inside the bone itself.
Peptides differ across animal taxa, and produce unique ‘fingerprints’.
These fingerprints can be used to identify otherwise unrecognisable pieces of bone.
With this technique, researchers discovered that people living in the Alay Valley began herding sheep, goat, and cattle by at least 4300 years ago.
Combining their work with ancient DNA research at France’s University of Toulouse, they also found that in later centuries, as Silk Road trade flourished across the region.
They say that transport animals like domestic horses and Bactrian camel became increasingly significant in Alay.
This research is especially exciting because of the range of possibilities it points to for archaeological research across the high mountains of Inner Asia.
‘This study shows us that biomolecular methods like ZooMS and ancient DNA can take the fragmented piles of bone that have been almost worthless to archaeologists’, said lead researcher Dr. William Taylor from the the Max Planck Institute.
He says it opens up a ‘whole new world of insights into the human story across Central Asia.’