Town Mouse, Country Mouse: adaptation and adaptability in Mus domesticus (M. musculus domesticus)

• Published in: Mammal Review
• Main Author: BERRY, R. J.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 1981
• Subjects: Faroe Islands
• Online Access: http://dx.doi.org/10.1111/j.1365-2907.1981.tb00001.x; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fj.1365-2907.1981.tb00001.x; https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1365-2907.1981.tb00001.x

Abstract The generally accepted idea that the house mouse is a single, world‐wide species which owes its success largely to commensalism with man is wrong. There are at least five European and two Asian species lumped together under the name Mus musculus , plus another fourteen Asian species in the same genus. The house mouse of western Europe is the one that has been introduced to the Americas and Australasia, as well as being domesticated in the laboratory and ‘fancy’ strains; it is properly described as Mus domesticus. A complication of this particular species is the existence of chromosomal races involving the fusion of pairs of chromosomes, apparently at random. These races seem to be reproductively isolated from normal (2n = 40) mice. They have been described in southern Europe and northern Britain. Genetical studies of wild‐living mice have shown the operation of powerful natural selection, contrary to earlier assumptions that most of the polymorphic variation in the species (especially that revealed by electrophoresis) was neutral. The effects of such selection are reduced (but not eliminated) by the deme structure of established mouse populations; this social structure is much less rigid than some laboratory experiments have suggested, because of opportunism by individual mice in replacing dead or debilitated animals, and filling new niches as these become available. Virtually every mouse population is unique, since a population tends to be founded by a small group of animals drawn from a genetically variable ancestral population. This differentiation has allowed laboratory workers to develop inbred strains with characteristic properties; it has also resulted in over 130 sub‐species being described from wild caught animals. A substantial proportion of these latter have probably arisen by instant sub‐speciation through the founder effect. This is well illustrated by the mice of the Faroe islands, which are often quoted as standard examples of extremely rapid evolution. The adaptive properties of the ...