October 1, 2008

Mouse Genetics Hint At Human Exploration Patterns

Scientists in the UK are studying the genes of mice with the goal of tracking human migration patterns throughout history.

York University professor Jeremy Searle and colleagues collected genetic data of house mice from more than 100 locations across the UK. One strain in particular was noted to have arrived with the Vikings.

Scientists say rodents provide a historic map of past human ventures because the small rodents often accompanied travelers when they set off in search of new places to live.

Rodents from Orkney are among those helping the scientists. It has been shown that mice from the islands have a DNA signature similar to their Scandinavian relations.

But these house mice (Mus musculus domesticus) were also found in areas around the Atlantic coast of Europe reached by the Norse explorers, said Professor Searle.

"If we look at the genetic patterning of the mice, we find they have patterning that very much relates to human history; and so we get a particular genetic type of mouse that is found in the region where the Norwegian Vikings operated," he said.

"What this suggests to us is that the Norwegian Vikings were taking these mice around and they were taking a particular genetic type; because there are all sorts of genetic types and the particular type that happened to be where the first Vikings picked them up is the one that got spread around."

A strain in Great Britain revealed genetic similarities to a type in Germany, researchers said.

It is thought that this rodent probably arrived from continental Europe with Iron Age people.

The common mouse originated in Asia and migrated to the Middle East.

"Interestingly, [the house mice] didn't migrate into Europe at the same time as agriculture, about 8,000 years ago," Professor Earle explained.

"They only migrated in about 3,000 years ago. And the reason for this is that it wasn't until the Iron Age that we got the development of large settlements in western Europe. The house mouse needs these large settlements in order to survive and out-compete the local field mouse."

Searle hopes that further investigation of mouse genes will show how Vikings explored and colonized regions of Faroe, Iceland and North America.

Image Courtesy Wikipedia


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