Globe-trotting mice help scientists examine the history of human migration. The mice left markers over thousands of generations. In the eighth century, the Vikings invaded Orkney, Scotland, and with them on board arrived the mice. Scientists at the University of York have found that the Scandinavian mice spread their DNA around among the indigenous rodent population.
The mice left markers that have been passed down thousands of generations, markers so clear that they allow scientists to draw maps of human population movements.
As well as finding evidence of Viking mice in the northern and western peripheries of Britain, the team also found that in much of Britain there is a type of mouse that bears genetic similarities to certain German mice. They have deduced that their ancestors probably came over from continental Europe with Iron Age settlers.
The researchers, who publish their study in Proceedings of the Royal Society, studied the DNA sequence variations of 328 house mice from 105 locations.
The scientists believe that with the mice’s help, they will be able in future to document Viking movements in more detail, looking at things such as the colonisation of different parts of Faroe, Iceland and even North America.