Researchers Reconstruct 4,000 Years of Europe's Genetic History

Using DNA from skeletons in Germany representing 4,000 years of prehistory, researchers have pieced together the most detailed genetic history of today's Europeans.

Extracted from bone and teeth samples from 364 skeletons, the samples of mitochondrial DNA unveiled significant population shifts triggered by waves of prehistoric migration.

The study, published in the journal Science, included 10 times more samples than any other DNA study.

"This is the largest and most detailed genetic time series of Europe yet created, allowing us to establish a complete genetic chronology," joint-lead author Wolfgang Haak of the Australian Center for Ancient DNA (ACAD) said in a statement. "Focusing on this small but highly important geographic region meant we could generate a gapless record, and directly observe genetic changes in 'real-time' from 7,500 to 3,500 years ago, from the earliest farmers to the early Bronze Age."

From this detailed record, the scientists found migrations not only from the oft-cited path through the Near East, but from Western and Eastern Europe, too.

"Our study shows that a simple mix of indigenous hunter-gatherers and the incoming Near Eastern farmers cannot explain the modern-day diversity alone," said joint-lead author Guido Brandt, a PhD candidate at the University of Mainz. "The genetic results are much more complex than that. Instead, we found that two particular cultures at the brink of the Bronze Age 4,200 years ago had a marked role in the formation of Central Europe's genetic makeup."

According to Kurl Alt, also from the University of Altz, these genetic changes are echoed in the archaeological record.

"It is fascinating to see genetic changes when certain cultures expanded vastly, clearly revealing interactions across very large distances," Alt said.

The results further highlight the effects of changing societal climates on a region's genetic makeup.

"There was a period of stasis after farming became established and suitable areas were settled, and then sudden turnovers during less stable times or when economic factors changed, such as the increasing importance of metal ores and secondary farming products," ACAD Director Alan Cooper said. "While the genetic signal of the first farming populations becomes increasingly diluted over time, we see the original hunter-gatherers make a surprising comeback."

Such a complex and diverse story could never have been told without the research, Haak argues.

"None of the dynamic changes we observed could have been inferred from modern-day genetic data alone," he said, "highlighting the potential power of combining ancient DNA studies with archaeology to reconstruct human evolutionary history."