Ancient DNA sheds light on hidden European migrations of the first millennium AD

A study led by the Francis Crick Institute, using a more precise method of analyzing ancestry using ancient DNA, has revealed that there was a wave of human migration across Europe in the first millennium AD.

Researchers can piece together how people moved around the world by looking at changes in DNA, but if groups of people throughout history are genetically very similar, this It will be very difficult.

In a study published today in Nature, researchers report a new data analysis method called Twigstats. This allows researchers to more accurately measure differences between genetically similar groups, revealing previously unknown details of migration in Europe.

They include more than 1,500 European genomes (a person’s complete DNA set) of people who lived primarily during the first millennium of the Common Era (1 to 1000 AD), including the Iron Age, the fall of the Roman Empire, and early B.C. This new method was applied. The Medieval “Immigrant Age” and the Viking Age.

Germanic-speaking people moved south in the early Iron Age

The Romans, whose empire was flourishing at the beginning of the first millennium, wrote about conflicts with Germanic groups outside the empire’s borders.

Using new methods, scientists have uncovered waves of these groups that migrated south from northern Germany or Scandinavia at the beginning of the first millennium, adding genetic evidence to the historical record.

This ancestry is found in people in southern Germany, Italy, Poland, Slovakia, and southern England, and one person in southern Europe has 100% Scandinavian ancestry.

The research team showed that many of these populations eventually intermingled with existing populations. The two main zones of migration and exchange reflect the three main lineages of Germanic languages, one remaining in Scandinavia, one extinct, and one in modern Germanic and English languages. formed the basis.

Looking for Roman gladiators?

In York, England between the 2nd and 4th centuries, 25% of individuals’ ancestors, who may have been Roman soldiers or slave gladiators, were from early Iron Age Scandinavia. This highlights the presence of people with Scandinavian ancestry in Britain, predating the Anglo-Saxon and Viking Ages, which began in the 5th century.

Germanic-speaking people migrated north to Scandinavia before the Viking Age

The researchers then used this method to uncover a further wave of northward migration into Scandinavia at the end of the Iron Age (300-800 AD) and just before the Viking Age. They showed that many Viking Age people in southern Scandinavia had ancestry from central Europe.

Biomolecular analysis of another type of tooth reveals that people with ancestors from central Europe buried on the Swedish island of Oland grew locally, suggesting that this influx of people northward was not a one-off. A change in ancestry that suggests continuity.

There is archaeological evidence of repeated conflicts in Scandinavia at this time, and researchers speculate that this unrest may have played a role in encouraging people to move, but More archaeological, genetic, and environmental data are needed to clarify the reason. In and out of Scandinavia.

Viking expands from Scandinavia

Historically, the Viking Age (approximately 800-1050 AD) is associated with Scandinavian peoples raiding and settling throughout Europe.

Research shows that many people outside Scandinavia during this period had a mix of local and Scandinavian ancestry, corroborating the historical record.

For example, the researchers found Viking Age individuals with ancestry in modern-day Sweden in the east (present-day Ukraine and Russia), and individuals in Britain with ancestry in modern-day Denmark.

At a Viking Age mass grave in Britain, the remains of men who died violent deaths show genetic links to Scandinavia, suggesting they may have been executed as part of a Viking raiding party. Suggested.

Adding genetic evidence to historical accounts

Lead author Leo Speidel, a former postdoctoral fellow at Crick University and UCL, and now a group leader at RIKEN in Japan, said: “We already have reliable statistical tools to compare genetics.” However, robust analysis of more detailed scale population changes, such as migration, as revealed in this paper, has so far been largely obscured.

“Thanks to Twigstats, we can now see things that were previously invisible, in this case migrations across Europe that began in northern Europe during the Iron Age and returned to Scandinavia before the Viking Age. ‘s new method can be applied to other regions as well.” We hope to study populations around the world and uncover more missing pieces of the puzzle. ”

“The goal was a data analysis method that would provide a sharper lens into detailed genetic history. We now need to expand our record of ancient whole-genome sequences, because the questions we would have asked before are now within reach.”

Peter Heather, Professor of Medieval History at King’s College London and co-author of the study, said: “Historical sources show that migration led to a major reshaping of the human landscape in western Eurasia in the second half of the first millennium. “It shows that he played some role.” AD first created the contours of a politically and culturally recognizable Europe, but the nature, scale, and even trajectory of the movement have always been hotly debated. It’s an exciting possibility that these important questions will finally be answered. ”