March 15, 2019

MIXED-UP, MUDDLED-UP, SHOOK-UP WORLD: Surprising DNA found in ancient people from southern Europe.

Beginning in the Bronze Age, the genetic makeup of the area changed dramatically. Starting in about 2,500 B.C., genes associated with people from the steppes near the Black and Caspian seas, in what is now Russia, can be detected in the Iberin gene pool. And from about 2,500 B.C. much of the population’s DNA was replaced with that of steppe people.

The “Steppe Hypothesis” holds that this group spread east into Asia and west into Europe at around the same time—and the current study shows that they made it to Iberia, too. Though 60 percent of the region’s total DNA remained the same, the Y chromosomes of the inhabitants were almost entirely replaced by 2,000 B.C. That suggests a massive influx of men from the steppes, since Y chromosomes are carried only by men.

“It looks like the influence was very male dominated,” says Miguel Vilar, a genetic anthropologist who serves as senior program officer for the National Geographic Society.

Who were these men—and did they come in peace? Vilar, who was not involved with the study, speculates that the steppe men may have come on horses bearing bronze weapons, hence ushering in the Bronze Age to the area. He compares the migration to the one the indigenous peoples of North and South America faced when the first Europeans landed in the 1490s.

“It shows that you could have a migration all the way across the whole continent (of Europe) and still have a heavy influence on this far extreme,” he says.

I wonder if this influx might help explain the mysterious origins of the Basque language.