Europeans Only Started Digesting Dairy 4,000 Years Ago
They can enjoy that cheese thanks to ancient nomadic herders
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Europe is home to many of the world’s finest cheeses, but new research shows that the European's taste for dairy is much more recent than scientists once thought. According to a recent study published in the journal Nature, Europeans only started being able digest cow’s milk about 4,000 years ago thanks to a group of nomadic herders hailing from Russia’s Great Steppes.
"Everyone assumed it came to Europe with the first farmers, but you actually had a 4,500-year period when European farmers could not actually drink milk." University of Adelaide researcher and study co-author Bastien Llamas tells Anna Salleh for ABC News Australia.
Most mammals lose the ability to digest milk after their infancy, and for millennia Europeans were the same way. For a long time researchers believed that the genetic mutation that allows adult humans to process milk was introduced to Europeans by Anatolian farmers from modern-day Turkey, who started raising cattle around 6,500 B.C., Wyatt Marshall reports for Munchies. But according to Llamas, they should be thanking Russian herders instead.
The study examined DNA from the remains of 230 Eurasians who lived between 6,500 and 300 B.C. Llamas and his colleagues discovered that the mutation that lets Europeans keep producing an enzyme called lactase throughout their adult lives was introduced right at the time that the Russian herders arrived in Europe, Salleh reports.
“Suddenly 4,000 years ago, there’s a revolution when the Steppe herders brought the enzymes they needed,” Llamas tells Salleh.
While the nomadic origins of European cheese lovers was a surprise, the study didn’t stop there. Llamas and his colleagues also discovered that the same herders are the reason why Northern Europeans tend to be so tall, while the Anatolian farmers were responsible for the shorter stature of many Mediterraneans. The Anatolians also introduced the genes for light skin color into the modern European gene pool, Salleh reports.
"All of those 230 individuals were screened across their genomes for more than a million variable sites. That means we have a very accurate picture of what's going on in their genomes,” Llamas tells Salleh. "For once we can have the same power for genomic analysis in ancient populations as we have in modern populations."
The study also found evidence that linked resistance to diseases like tuberculosis and leprosy to the rise of agriculture. While early humans lived a solitary, hunter-gatherer life, the steady source of food from farming led to larger, more densely-populated villages that aided the spread of disease. As a result, people had to evolve ways to fight off these diseases, Marshall reports.
"Whether you like it or not, generation after generation, this constant pressure on the environment will shape humans genetically," Llamas tells Salleh.