DUBLIN, Ireland, Oct. 22 (UPI) -- New DNA analysis confirms that as ancient human populations developed new technologies during their transition from hunting and gathering to agriculture, genomes adapted. But strangely, tolerance for lactose didn't arrive for more than 5,000 years after the development agriculture and the domestication of animals, and 4,000 years after cheese-making culture arrived in Central Europe.
"Our findings show progression towards lighter skin pigmentation as hunter and gatherers and non-local farmers intermarried, but surprisingly no presence of increased lactose persistence or tolerance to lactose," study author Ron Pinhasi, an archaeology professor at the University College Dublin, explained in a press release.
"This means that these ancient Europeans would have had domesticated animals like cows, goats and sheep, but they would not yet have genetically developed a tolerance for drinking large quantities of milk from mammals."
Most of the rest of the world is lactose intolerant. And now, scientists know it took ancient Europeans much longer than previously thought to develop their digestive tolerance for the sugars in mammalian milk. It's likely these early European populations stuck to cheese and yogurt, the processing of which breaks down the stomach-churning lactose.
Pinhasi and his research partners were able to extra DNA from the skulls of 13 specimens collected from archaeological sites on the Great Hungarian Plain. The skull samples dated from 5,700 BCE to 800 BCE, or from the Early Neolithic period through the Iron Age.
In addition to detailing the evolution of lactose tolerance, the researcher's genome analysis also confirmed population movements and technological advancements were strongly correlated. Shifts in tools and technology from stone to various types of metal working were consistent with influxes of new genetic materials.
"Our results also imply that the great changes in prehistoric technology including the adoption of farming, followed by the first use of the hard metals, bronze and then iron, were each associated with the substantial influx of new people," Pinhasi said. "We can no longer believe these fundamental innovations were simply absorbed by existing populations in a sort of cultural osmosis."
The study was published this week in the journal Nature Communications.