The human story will never fail to enchant us, whether it’s looking at where we’ve come from or where we may be going. Leaving the world of hypotheticals to the side for now, a brand new study – headed by the Max Planck Institute for the Science of Human History (MPISHH) – has shed some new light on our possible migration to what is now Scandinavia.
Analyzing human genome records belonging to 38 long-dead northern Europeans, the international team were able to trace the migration of those living to the east into the peninsula. As it turns out, there wasn’t just one migratory event, but two separate ones.
In case you were wondering, genomes aren’t exactly equipped with GPS data. In isolation, one person’s genetic material doesn’t tell you much about where they came from and where they went. Instead, geneticists look at a range of samples from across the region and compare those that have significant differences in their genetic code.
These differences, or genetic markers, can be quickly sequenced and compared using today’s marvelous technology. These markers can then be traced back to a common ancestor, like the genetic equivalent of triangulating on a map. Using this information, we can trace the flow of genes across continents, and thus migration.
This new study looked at the genomes of hunter-gatherers living between 12,000 and 7,000 years ago, the first Neolithic (“new stone age”) farmers in southern Sweden living 6,000 to 5,300 years ago, and the metallurgists (metal makers) of the Eastern Baltic, who lived and breathed 1,300 to 500 years before the present day.
Back in the Mesolithic (“middle stone age”), there were two hunter-gatherer populations: Those stretching from what is now Spain and Portugal to Hungary, and those stalking northwestern Russia. Despite the close proximity of the two populations in what is now Lithuania, there appears to be no significant genetic exchange between the two.
At some point, however, both made their way to Scandinavia, where the gene pools merged. So how did they both get there?
Using these genetic markers, it was revealed that there were two migratory routes into Scandinavia. Writing in Nature Communications, the team explain that a north-eastern route along the frigid coast provided a path for the Eastern population; the Westerners made their way up from a “land-bridge that connected Denmark and southern Sweden at the time.”
Thus, the Scandinavian hunter-gatherers were born.
Interestingly enough, these hunter-gatherers didn’t invent the farming that soon thrived in the region. It appears that this was brought to Scandinavia from a population of Central European agricultural maestros, whose genes can be traced back to what is now Turkey.
Plenty has been written on the passage of humanity into Scandinavia and its surroundings before, whether that be through genetics research or archaeological and historical research. One 2013 study used the spread of a type of blade-forging technique across the region to approximate when exactly those in what is now Russia made their way through Finland into Scandinavia proper – no offense, Helsinkians.
Another study released this January in PLOS Biology, which also looks at the genetic changes across the region, came to a rather similar conclusion. Shortly after the last glacial maximum, it does appear that there were two migration routes into Scandinavia: one up from Denmark into Sweden, and one along the newly ice-free Atlantic coast in the northeast.
“Yes, we were aware of [the PLOS Biology] study, and it is quite satisfying to see that they came to the same conclusion with different data,” lead author of the Nature Communications paper, MPISHH archaeogeneticist Dr Alissa Mittnik, told IFLScience.
“It also supports theories based on the distribution of cultural assemblages put forward by archaeologists a while ago, so science seemed to work out brilliantly in this case!”