15 September (WNN) — The hard dental plaque coating the ancient teeth of Bronze Age shepherds suggests that the rise of dairy and milk drinking coincided with a wave of migration in the Pontic-Caspian steppe.
For thousands of years, Eurasia has hosted human movement and admixture, with recent surveys revealing genetic links between Scandinavia and Siberia.
Now, research published Wednesday in the journal Nature suggests that some of the region’s earliest herders were drinking milk as they moved east.
“We were really blown away when the data came in,” senior author Nicole Boivin told WNN in an email.
Boivin, professor of archeology at Max Planck, said, “We did not expect such a large change in milk consumption during the time of large-scale human migration. But once we had our data, the correlation was so strong that we overlooked it. can not do.” Institute of Science of Human History in Germany.
After carefully removing samples of tartar, or dental calculi, the researchers used sophisticated molecular analysis techniques to identify ancient proteins trapped in the hard layers.
The analysis showed that 90% of individuals before the Bronze Age were not drinking milk. However, by the early Bronze Age, 94% of the people living and visiting Eurasia were milk drinkers.
Past genetic and archaeological surveys suggest that the Yamnaya people, a group of herders from the western steppe, began expanding into the Pontic-Caspian steppe around 3000 BC.
Researchers found evidence that Yamnaya shepherds were migrating vast distances from western Russia to Mongolia. Previous studies have also shown that some of these people were drinking milk.
“I had the idea that it was the use of milk, a renewable resource of both calories and hydration, that allowed these people to expand into arid plains,” lead study author Chevan Wilkin told WNN.
“The steppe is unusual because it is covered by ground forage that humans cannot eat, but animals can,” said Wilkin, a paleoproteomics expert and MPI researcher.
“Through proteins and ancient DNA, we were able to see that the western steppe people and milkweed were present on the Far Eastern steppe 5,000 years ago,” Wilkin said. “From the data we now have from this paper, we can see that these vast expansions coincided with the addition of milk to the diet of the Yamanaya people on the Pontic-Caspian steppe.”
The latest findings have implications not only for the study of human movement in Eurasia, but also for the discovery of the origins of the domestic horse – a hot topic in Eurasian archaeology.
Some researchers point to Botai, Kazakhstan, as the birthplace of the domestic horse, but recent archaeological analysis has cast doubt on such claims.
By analyzing the proportion of peptides preserved in Bronze Age tartar, the authors of the latest study were able to identify the different sources of milk being consumed by Yamnaya shepherds and their relatives.
Cows, sheep and goats provided most of their milk to early herders, but researchers found evidence that the Yamnaya people were also drinking horse milk.
“We also extracted protein from Botai, a site in northern Kazakhstan that has been suggested as a site for horse domestication, but we did not find any milk protein in those samples,” Wilkin said.
The discovery suggests that the earliest domestic horses originated on the Pontic-Caspian steppe.
Today, non-urban people living on the Eurasian steppe still practice mobile dairy pastoralism. Researchers suspect that milk was even more important to Bronze Age herders thousands of years ago.
“The steppe is a very harsh environment – it’s wide open, very dry, there isn’t much growth and water is limited,” Boivin said. “It’s a difficult environment for humans to live in.”
“So the milk benefited people because it meant the animals gave them high-quality fluids, a dynamic source of protein and vitamins — and they didn’t have to kill precious animals to get it,” Boivin said. .
The study’s authors said they still don’t know much about the herders who migrated to the Eurasian Steppe during the Bronze Age.
However, he hopes that additional surveys of animal remains and dental calculus will help him better understand the logistics of human expansion and the spread of dairy across the region.
Researchers are also curious to understand how these herders developed the stomach for all that dairy.
“Lactase resistance, the genetic adaptation to break down lactose in milk as adults, was not common during this time. So it is an unanswered question as to how all these people were drinking milk,” Wilkin said.
It’s possible that they were processing the milk through some sort of manual fermentation process, or that their gut microbiome had adapted and contained the bacteria that fermented the milk in the digestive tract, she said. Wilkin said.