Aghascrebagh Ogham Stone in Northern Ireland shows much-worn inscriptions.Credit: Radharc Images/Alamy
More than one billion people worldwide speak Germanic languages such as English, German and Dutch, whereas Celtic languages — including Welsh, Irish and Gaelic — are spoken by only two or three million people, mostly in northern Europe.
A pair of studies analysing more than 4,700 ancient human genomes has now identified the possible origins of Celtic1 and Germanic2 languages and found migrations that might have dispersed their speakers around Europe — partly explaining their distribution today. The papers were published in Nature on 4 November.
Linguistic and archaeological studies have indicated that Celtic languages were widespread across Europe about 2,500 years ago, reaching into present-day Italy, Spain and France. Speakers of early Germanic languages might have been limited to a pocket of northern Germany, Scandinavia and the Baltic Sea coast some 3,000 years ago.
“We wanted to kind of see how this change occurs. How does the range swap through time?” says Hugh McColl, a population geneticist at the University of Copenhagen and a co-author of both studies.
How one language family took over the world: ancient DNA traces its spread
Linguists have previously proposed that migrations played some part in the dispersal of Germanic and Celtic languages. But Guus Kroonen, a historical linguist at Leiden University in the Netherlands and a co-author of both studies, says that there are other ways for languages to spread. “You can easily adopt a new language without changing your genes.”
‘Enigmatic’ population
McColl, Kroonen and their colleagues looked for signs of migration through shifts in the ancestry of ancient population groups. To do so, they used newly sequenced genomes from more than 700 people, alongside published data from some 4,000 ancient humans.
The researchers identified an enigmatic population that migrated to Sweden around 4,000 years ago, possibly from Baltic regions. They found that the presence of this ancestry in Scandinavia and its spread throughout Europe was consistent with previous linguistic theories and archaeological evidence. “It’s a good tracer dye for the spread of Germanic languages,” says Kroonen.
For instance, the ancestry was present in southern Scandinavia and northern Germany around 3,000 years ago, when linguistic evidence points to exchanges with other language groups in this region. After some 1,000 years, the population moved into central, southern and western Europe, including the British Isles, which also chimes with linguists’ ideas and historical evidence about the spread of these languages, such as the first appearance of Germanic language inscriptions, called runes, around 2,000 years ago. The ancestry was present in Anglo-Saxon individuals in Britain, who spoke a Germanic precursor to Old English.
The study on the spread of Germanic languages also turned up a surprising ‘back-migration’ of people from present-day Germany into Scandinavia, which coincided with the emergence of Old Norse — the predecessor of modern Scandinavian languages — and with the Vikings’ influence on the region.
The Rök Stone, which bears the longest runic carving on stone with more than 700 characters, is thought to have been erected by Vikings in present-day Östergötland, Sweden.Credit: JEPPE GUSTAFSSON/TT News Agency/AFP via Getty
In many cases, the expansion of Germanic languages occurred in regions where Celtic languages were dominant.
Linguists debate both where Celtic languages emerged and how they became so widespread, says McColl, with some favouring an Atlantic origin overlapping with the current range of Celtic speakers in the British Isles. Other models put Celtic origins farther east, in Europe.
