Mystery Orkney Islands genetics

By Paul Robinson - 09 Sep 2013 10:11:0 GMT
Mystery Orkney Islands genetics

The common European vole is much less diverse across its range than the 5 island populations (no longer sub-species) found on the Orkneys. Go figure that out!; Field vole image; Credit: © Shutterstock

While we gave you the friendly water vole (in "The Wind in the Willows") the other day, the common vole, Microtus arvalis must have had his moment in the limelight. Many thousands of years ago, people transported this species in 3100 BC from the area now called Belgium to the islands of Orkney. The result is the Orkney vole. These animals have such numerous genetic variations that they are more diverse than the European vole population from which they originally came.

The meaning of all this is that female bank voles must have been taken across the length of the North Sea on boats with hay (bedding for domestic animals) or some other farming produce. They may have formed this "ark" of ancient diversity because they were treasured by the farmers who carried them. The endless reasons include use as pets or for religious purposes. The post-Neolithic European gene pool may have been badly affected by disease epidemics or badly affected by human land use change.

We do possess a genetic snapshot of the original vole's diversity in Europe because of the offshore islands' ability to preserve diversity in a way that "the island effect" on isolated islands does not. That is to say that the model island species normally suffer from genetic loss known as genetic bottlenecks where selection (and lack of predation or competition) causes them to become smaller, specialised and this makes island species ideal for evolutionary studies; but this novel situation seems to infer even more reasons for investigating if great variation could exist on such offshore islands, or maybe on peninsula that have suffered from isolation.

Why did Neolithic people bring these voles to Orkney and not to the rest of the British Isles. When archaeology is brought into the equation, then we must remember that these people were building ancient stone circles in Orkney at this time and elsewhere too. The long-distance travel has been mentioned in association with the circle-builders before, but the voles could help solve (or create) more problems for students of ancient history as well as the more obvious diverse evolutionary processes. We look forward to the next piece of evidence on these vole antiques.

Natália Martinková and her colleagues publish the paper and findings.