Fierce Viking raiders spread out from Scandinavia during the late eighth to mid-10th centuries. They spread terror, destruction … and mice … wherever they went.
House mice (Mus musculus domesticus) accompanied the Norse in their longships and colonized the same lands. Genetic studies of mice in lands visited by ancient Scandinavians showed that the mice lived on in Iceland along with their Norse hosts but died out on Greenland and Newfoundland, just like the Vikings.
"Human settlement history over the last 1,000 years is reflected in the genetic sequence of mouse mitochondrial DNA. We can match the pattern of human populations to that of the house mice," said one of the scientists involved in the study, Eleanor Jones of the University of York and Uppsala University, in Sweden, in a press release.
DNA samples from nine sites in Iceland, Narsaq in Greenland and four sites near the Viking archaeological site, L'Anse aux Meadows, in Newfoundland, formed the modern set of mouse genetics. Mouse remains from the Eastern and Western settlements in Greenland and four archaeological sites in Iceland provided ancient samples of mouse DNA.
Icelandic mice still contained the genetic fingerprint of their seafaring ancestors, but mice on Greenland had been replaced by Danish mice (Mus musculus musculus), brought over by a more recent wave of European colonizers.
"If house mice arrived in Newfoundland with the Viking settlers at all, then, like the humans, their presence was also fleeting and left no genetic trace," according to the abstract of the study published in BioMedCentral Evolutionary Biology.
Image: Painting of Leif Eiriksson discovering America. Credit: Christian Krohg, Wikimedia Commons.