Maps showing possible colonization routes taken by the western house mouse Mus musculus domesticus, based on mtDNA evidence. Neolithic (starting 12,000 years ago): colonization restricted to the eastern Mediterranean close to where this subspecies first became commensal . Iron Age (starting 3,000 years ago): colonization westwards along the Mediterranean and then into north-west Europe by overland and coastal routes [3,5]. Viking Age (around 1,000 years ago): movements around the periphery of north-west Europe and colonization of Scandinavia and Madeira [2,5,7,8]. (The colonization of Scandinavia may have been earlier .) Recent history (a few hundred years ago): mice were taken substantial distances from western Europe, including to Kerguelen . The dashed line shows the location of the hybrid zone between the subspecies M. m. domesticus and M. m. musculus.
Gabriel et al. BMC Biology 2010 8:131 doi:10.1186/1741-7007-8-131