Historical sources say that Ingolf Arnarson was the first Norse settler in Iceland, arriving in the 870s, but this may not be true.
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Scandinavian people may have lived in Iceland nearly 70 years earlier than historians thought, and their arrival may not have been the environmental disaster it is often portrayed as.
Historical evidence suggests that people first settled in Iceland in the 870s. This early migration is often portrayed as an environmental disaster caused by Viking raids or Scandinavian settlers how are they cleared the island's forests for fuel, building materials and fields. Forests now cover only 2 percent countries.
It is difficult to find hard evidence as to when the first settlers arrived. Archaeologists have unearthed an ancient wooden longhouse near the Stödvarfjörður fjord in eastern Iceland, dating back to around 874 AD, under which lies old longhouse, probably a summer village, built in the 800s rather than a permanent home, but this discovery has not yet been reported in a scientific paper.
Now, Eske Willerslev from the University of Copenhagen, Denmark, and colleagues examined environmental DNA (eDNA) extracted from two sediment cores drilled from Lake Tjornin in central Reykjavik, one of Iceland's earliest and longest-lasting settlements, to see what species were present there when. By studying layers of volcanic ash and using radiocarbon dating and plutonium isotope analysis, the researchers created a timeline spanning from about 200 AD to the present day, consistent with known historical events.
One of the key markers they used is known as the Landnam tephra layer, ash and fragments left over from a volcanic eruption in around 877 AD. Most evidence of human activity in Iceland lies above this layer, so it was formed after the eruption.
“The marks under the tephra are like a smoking gun, indicating earlier human activity,” says Chris Callow from the University of Birmingham, UK, who was not involved in the study.
Willerslev and his colleagues suggest that humans arrived almost 70 years before this point: around 810 AD. That's because at this point they saw an increase in a compound known as levoglucosan, an indicator of biomass burning, as well as an increase in viruses associated with wastewater.
“If it was 850 I wouldn't be so surprised, but 810 is early for Viking expansion in the North Atlantic,” says Callow. “Overall, this is a good confirmation of what we might have suspected, but calling the date as early as 810 is still highly controversial.”
Piecing together this comprehensive environmental history of the region is phenomenal, but the evidence this early is not conclusive, he says. Catherine Kathleen at Jacksonville State University in Alabama. “For wastewater biomarkers, there is a small jump around 800 and then nothing until 1900. Where are all the human indicators in wastewater biomarkers and the time period in between?” she says. And while burning biomass can indicate the presence of people, fires can also be caused by natural sources such as lightning, she adds.
Willerslev and his colleagues, who declined to speak with New scientistalso found that the arrival of settlers coincided with an increase in local biodiversity. DNA records suggest that they brought with them grazing livestock, raised hay fields, and practiced small-scale cultivation of barley for brewing.
Contrary to conventional wisdom about rapid deforestation, eDNA from pollen showed that birch and willow trees were growing during the period of settlement. For example, the number of birch pollen grains increased fivefold between 900 and 1200 AD, which researchers believe may have been due to deliberate management keeping livestock away from the trees so that settlers continued to have easy access to the wood for timber and fuel.
“This is the nail in the coffin of that old story about how the Vikings got to Iceland and then all of a sudden, 'Oh no, the environment is destroyed,'” Kathleen says.
Appreciable numbers of sheep, cattle, pigs and horses do not appear until several decades after initial settlement, which Willerslev and colleagues believe is because it would take about 20 years to establish herds large enough to be detected in eDNA records.
Callow suggests an alternative reason: perhaps the first people did not take many animals with them because they only came during the summer season to search walrus ivory. “They could kill a few walruses and then go home,” he says.
eDNA suggests that pronounced loss of biodiversity, including birch and willow trees, only occurred after 1200. Willerslev and his colleagues suggest that this was not due to the presence of settlers, but to the cooling of the climate associated with Little Ice Age – a period of colder conditions from about 1250 to 1860. – plus volcanic eruptions and storm surges.
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