A migration that long went unnoticed could change the history of the languages spoken by hundreds of millions of people.
English, German, Dutch and the Scandinavian languages belong to the same family: the Germanic languages. They evolved over the centuries, eventually becoming very different in some cases. But their history began long before the earliest texts that allow us to identify them. To look further back, researchers examined traces left behind in... bones.
Language families in Europe; Germanic languages appear in red.
CC BY-SA 3.0 · Wikimedia
These traces are fragments of DNA, the material that transmits inherited traits from one generation to the next. An international team, led in particular by the universities of Copenhagen and Leiden, studied the genetic data of more than 4,500 bodies. Among them, 712 genomes were analyzed for the first time.
Comparing these data makes it possible to identify related populations and track their movements. When a new group arrives in a region, part of its genetic heritage may appear in subsequent generations. These changes therefore provide clues about migrations, even when no written account mentions them.
It was precisely in Scandinavia that a surprise emerged. About 4,000 years ago, populations from the Baltic Sea region are thought to have arrived in what is now Sweden. Their presence had previously escaped the major reconstructions of local history. Within a few centuries, their genetic heritage had spread across a large part of the region.
This period could correspond to an important stage in the arrival of the earliest Germanic languages.
The research also covers the Celtic languages, whose present-day descendants include Breton, Welsh and Irish. Another genetic analysis links their possible spread to movements from central Europe toward the west. However, several waves of migration remain possible, and their linguistic role cannot be proven by DNA alone.
The next step is to compare more burials from regions that have still been little studied. This will allow researchers to refine the dates and routes of the migrations, then compare these findings with the oldest known traces of languages.