Settling a decades-long debate on the origins of the mysterious ancient European “Beaker folk”, a history-making Nature study has revealed that a wave of immigration by this group replaced 90 percent of Britain's pre-existing populations about 4,500 years ago.

The distinctive, bell-shaped clay vessels that inspired the Beaker folk moniker first appeared in the archaeological record in 2750 BCE, and became a common addition to burials across western and central Europe by 2500 BCE, before disappearing around 2000 BCE. Whether the expansion of the pottery type represented a physical spread of people from a single culture, or merely a diffusion of an art form through diverse groups has always been murky.

To shed light on this puzzle, over 100 anthropologists, archaeologists, and geneticists collected and sequenced DNA from 400 skeletal remains found across Europe that were radiocarbon dated to between 4700 and 800 BCE. Of these, 226 were buried with beakers and 174 were from different populations that lived before and after the Beaker period.

Comparing the genes of these individuals to one another, sequences from previously gathered ancient DNA, and modern-day samples, the researchers identified two largely separate lineages of beaker enthusiasts. The population that lived on the Iberian Peninsula at this time was rarely closely related to the region’s pre-existing peoples and rarely intermixed with those living in central Europe. In contrast, central Europe's population appears to have originated in the Eurasian Steppe to the east, before widely dispersing westward over a period of several hundred years.

In an unexpected finding, the team discovered that ancient people buried with beakers in Britain have a good deal of Steppe-origin genetics, and are thus related to the central European Beaker people. This is not entirely surprising considering the central Europeans appeared to be keen migrators to nearby France and Germany. Yet, British Beaker people were also nearly entirely unrelated to the groups who had lived there before – including the culture that built Stonehenge – implying a sudden surge of new arrivals beginning in 2450 BCE. And DNA from individuals who lived during the ensuing 500 years proved that the migrants took over while pre-existing groups faded away.

“In the centuries after the Beaker burials the DNA shows that the earlier Britons did not just come slipping back out of the woods,” senior author Ian Armit told The Guardian. “It’s not necessarily a story of violent conquest… But we certainly now have the evidence that they were replaced – and they never came back.”

The study also revealed that Steppe-origin Beaker people were among the first British Isles inhabitants to carry genes for light skin and pale hair. Because they belonged to the dominant group in the area, these genes eventually won out as the beaker people mingled with the 10 percent of Britons who remained, many of whom were likely quite darkly pigmented.