They may be small, but the information mice can convey about the movements of humans throughout history is mighty, according to a Cornell researcher.
Jeremy Searle, professor of ecology and evolutionary biology, explores the global distribution of small mammals and has found that house mice (Mus musculus) are ideal biomarkers of human settlement as well.
Where people go, so do mice, often stowing away in carts of hay or on ships. Despite a natural range of just 100 meters (109 yards) and an evolutionary base near Pakistan, the house mouse has managed to colonize every continent, which makes it a useful tool for researchers like Searle.
In a paper published March 19 in the online journal BioMed Central Evolutionary Biology, Searle and co-author Eleanor Jones of the University of York and Uppsala University, showed how mice hitched a ride with the Vikings and set up colonies in areas where the Norwegians settled, such as the British Isles, Faroe Islands, Iceland and Greenland.
Previous research conducted by Searle at the University of York supported the theory that Australian mice originated in the British Isles and probably came over with convicts shipped there to colonize the continent in the late 18th and 19th centuries.
He came to the conclusion by using evolutionary techniques to analyze mitochondrial DNA, comparing modern-day mouse populations from Australia with those from their likely regional source in Western Europe.