Scandinavian Origins | DNA | Stone Age Scandinavia
Tracking the migration of humans isn’t easy , but genetics is helping us uncover new information at breathtaking speed. We know that our species originated in Africa and likely reached Europe from the southeast no later than 42,000 years ago. During the last ice age some 33,000-20,000 years ago, when a permanent ice sheet covered northern and parts of central Europe, modern humans in southwest Europe were isolated from groups further to the east. When the ice sheet retreated, some of these hunter gatherers eventually colonized Scandinavia from the south about 11,700 years ago, making it one of the last areas of Europe to be inhabited. But exactly who these individuals were and how they got there has remained a puzzle for researchers. Now we have sequenced the genomes of seven hunter gatherers, dated to be 9,500-6,000 years old, to find out. One of the reasons the origins of the first Scandinavians is so enigmatic is a major shift in stone tool technology that appeared soon after they got there. This new technology seemed to have had an origin in eastern Europe and it has been an open question how it reached Scandinavia? Our interdisciplinary research team combined genetic and archaeological data with reconstructions of the ice sheets to investigate the earliest people of the Scandinavian peninsula. We extracted DNA for sequencing from bones and teeth of the seven individuals from the Norwegian Atlantic coast and the Baltic islands of Gotland and Stora Karlsö. We then compared the genomic data with the genetic variation of contemporary hunter gatherers from other parts of Europe. To our surprise, hunter gatherers from the Norwegian Atlantic coast were genetically more similar to contemporaneous populations from east of the Baltic Sea, while hunter gatherers from what is Sweden today were genetically more similar to those from central and western Europe. One could say that – in Scandinavia at that time – the geographic west was the genetic east and vice versa. This contradiction between genetics and geography can only be explained by two main migrations into Scandinavia. It would have started with an initial pulse from the south – modern day Denmark and Germany – that took place just after 11,700 years ago. Then there would have been an additional migration from the northeast, following the Atlantic coast in northern Finland and Norway becoming free of ice.