Ancient DNA points to a previously unknown migration that may have brought early Germanic

The team sequenced 712 genomes for the first time and compared them with thousands already published, the University of Gothenburg said. It combined genetics, archaeology and linguistics to reconstruct migrations that helped shape languages spoken across Europe today.

Hugh McColl, an assistant professor at Copenhagen's Globe Institute, is first author. Guus Kroonen and Eske Willerslev are among the senior authors, La Brújula Verde reported.

Unknown migration into Scandinavia

Around 4,000 years ago, a second group with steppe ancestry appeared in Eastern Scandinavia, probably arriving from across the Baltic Sea, The Conversation reported. This previously unknown population spread across much of Scandinavia and ultimately matched the region where the ancestral form of Germanic is believed to have been spoken during the first millennium BC. Their ancestry persists in most later Germanic-speaking populations, the article said.

Researchers who took part said the newcomers may have introduced the precursor of Germanic some 800 years later than traditionally assumed. A University of Gothenburg statement put the shift at a thousand years for the linguistic foundations of English, German, Dutch and the Scandinavian languages. The two accounts describe the same migration but give different sizes for the shift.

The traditional account tied the earliest form of Germanic to the first steppe migrants around 4,800 years ago, The Conversation reported. The new group appeared around 4,000 years ago. The earliest runic inscriptions date from roughly the first to fourth century AD, La Brújula Verde reported.

The authors describe the newcomers as archaeologically elusive because they left few recognisable material traces. The earliest Germanic contains loanwords from Celtic to the south and Finno-Saamic languages to the east, the authors note. That suggests it was already spoken somewhere between northern Germany and the eastern Baltic by the end of the Bronze Age.

Old Norse and northern German arrivals

Around 1,600 years ago, people from what is now northern Germany moved into Denmark and southern Sweden, several centuries before the Viking Age. The migration coincides with the emergence of Old Norse, the University of Gothenburg said.

"The big surprise came around 1,600 years ago, when Old Norse emerged in Scandinavia. People from northern Germany largely replaced the local population in Denmark and southern Sweden. But they also brought with them a new religion, with Odin as the principal god, and a new material culture inspired by the Huns," said Kristian Kristiansen, professor of archaeology at the University of Gothenburg.

The newcomers were genetically closely related to the Anglo-Saxons, which may help explain shared artistic traditions and closely related languages, the statement said. Kristiansen said many Danish and Swedish Vikings therefore shared common roots with the Anglo-Saxons.

Norway remained largely unaffected by that migration but still took part in the linguistic changes that gave rise to Old Norse, The Conversation reported. This suggests linguistic changes spread through cultural contact between closely related Scandinavian communities, it said.

Celtic origins

The companion paper used the same approach to examine whether Celtic began on Europe's Atlantic coast or farther east in central Europe, a debate lasting more than a century. The DNA points to a movement from central Europe around 3,000 years ago, westwards into France, Britain, Ireland and the Iberian Peninsula, according to the Gothenburg statement. Celtic languages were spoken across much of Europe 2,500 years ago.

According to the researchers, this provides the simplest explanation for the spread of Celtic languages. The statement also quoted Johan Ling, professor of archaeology at the University of Gothenburg, saying the findings help explain the expansion of the Urnfield culture and shifts in the balance of power in Bronze Age Europe.

What DNA cannot settle

"DNA sequences do not tell us directly which language people spoke," said Eske Willerslev, senior author and professor at the Globe Institute at the University of Copenhagen.

The authors place the formation of the Germanic group somewhere between Finland and northeastern Sweden, but no genomes survive from that area and period. They also leave room for Germanic spreading through cultural contact with hardly any genetic trace, or even in the opposite direction to the migrants. In the paper's own assessment, the Baltic newcomers are the simplest vector to explain, not the only possible one.