Reconstruction of the postglacial colonization of Sorex araneus into northern Scandinavia based on karyotype studies, and the subdivision of the Abisko race into three

Fredga K.

P. 085-096

To clarify the number, distribution and origin of chromosome races of common shrews in northern Scandinavia, 117 specimens were karyotyped from 12 new localities, six in Sweden and six in Norway. Including previous investigations, altogether 257 specimens from 26 localities in northern Fennoscandia have been analysed. Inspection of this complete dataset shows that the Abisko chromosome race, which occupies a wide range in northern Scandinavia, should be subdivided into three races: Abisko (Ai) in the north, Ammarnдs (Am) in the centre, and Hattsjц (Ha) in the south. The characteristics of these races and their distributions are described. The colonization of small mammals into northern Scandinavia is closely associated with the history of deglaciation. Most likely, common shrews of the Abisko race were the first to spread westwards along the northern coast of Norway. Later, when the ice and water had disappeared from northern Sweden, a new and wider immigration route from the east was opened for shrews of the Ammarnдs race. Another possibility is that northern Sweden and Norway were colonized from the west by shrews which had survived the last glaciation on the isle of Andцya in northwest Norway. The Hattsjц race, located between the Ammarnдs and Sidensjц races, may be regarded as a hybrid race.DOI: 10.15298/rusjtheriol.6.1.12

• Andersen B.G. & Borns H.W., Jr. 1997. The Ice Age World. An Introduction to Quaternary History and Research with Emphasis on North America and Northern Europe During the Last 2.5 Million Years. Oslo: Scandinavian University Press.
• Andersson A.-C. 2004. Postglacial Population History of the Common Shrew (Sorex araneus) in Fennoscandia. Molecular Studies of Recolonisation, Sex-Biased Gene Flow and the Formation of Chromosome Races. Dissertation 986. Uppsala: Acta Universitatis Upsaliensis.
• Andersson A.-C., Alström-Rapaport C. & Fredga K. 2005. Lack of mitochondrial DNA divergence between chromosome races of the common shrew, Sorex araneus, in Sweden. Implications for interpreting chromosomal evolution and colonization history // Molecular Ecology. Vol.14. P.2703-2716.
• Andersson A.-C., Narain Y., Tegelström H. & Fredga K. 2004. No apparent reduction of gene flow in a hybrid zone between the West and North European karyotypic groups of the common shrew, Sorex araneus // Molecular Ecology. Vol.13. P.1205-1215.
• Björck S. & Svensson N-O. 2002. [Development of the Baltic Sea and the Skagerrak/Kattegat] // Fredén C. (ed.). Geology: National Atlas of Sweden. 3rd edition. Stockholm [in Swedish].
• Brunhoff C., Yoccoz N.G., Ims R.A. & Jaarola M. 2006. Glacial survival or late glacial colonization? Phylogeography of the root vole (Microtus oeconomus) in north-west Norway // Journal of Biogeography. Vol.33. P.2136-2144.
• Fredga K. 1987. Chromosome preparations in the field from mammals long after death // Stain Technology. Vol.62. P.167-171.
• Fredga K. 1996. The chromosome races of Sorex araneus in Scandinavia // Hereditas. Vol.125. P.123-135.
• Fredga K. 2003. Chromosome races of Sorex araneus in Norway. Description of two new races // Mammalia. Vol.67. P.179-185.
• Fredga K. & Narain Y. 2000. The complex hybrid zone between the Abisko and Sidensjö chromosome races of Sorex araneus in Sweden // Biological Journal of the Linnean Society. Vol.70. P.285-307.
• Fredga K. & Nawrin J. 1977. Karyotype variability in Sorex araneus (Insectivora, Mammalia) // Chromosomes Today. Vol.6. P.153-161.
• Frykman I., Simonsen V. & Bengtsson B.O. 1983. Genetic differentiation in Sorex. I. Electrophoretic analysis of the karyotypic races of Sorex araneus in Sweden // Hereditas. Vol.99. P.279-292.
• Halkka L., Söderlund V., Skarén U. & Heikkilä J. 1987. Chromosomal polymorphism and racial evolution of Sorex araneus L. in Finland // Hereditas. Vol.106. P.257-275.
• Halkka L., Kaikusalo A. & Vakula N. 1994. Revision of Sorex araneus L. chromosome nomenclature, and race N new to Finland // Annales Zoologici Fennici. Vol.31. P.283-288.
• Hausser J., Fedyk S., Fredga K., Searle J.B., Volobouev V., Wójcik J.M. & Zima J. 1994. Definition and nomenclature of the chromosome races of S. araneus // Folia Zoologica. Vol.43. Suppl.1. P.1-9.
• Jaarola M., Tegelström H. & Fredga K. 1999. Colonization history in Fennoscandian rodents // Biological Journal of the Linnean Society. Vol.68. P.113-127.
• Lundqvist J. 2002. [The deglaciation] // Fredén C. (ed.). Geology: National Atlas of Sweden. 3rd edition. Stockholm [in Swedish].
• Möller J.J., Danielsen T.K. & Fjalstad A. 1992. Late Weichselian glacial maximum on Andöya, North Norway // Boreas. Vol.21. P.1-13.
• Narain Y. & Fredga K. 1998. Spermatogenesis in common shrews, Sorex araneus, from a hybrid zone with extensive Robertsonian polymorphism // Cytogenetics and Cell Genetics. Vol.80. P.158-164.
• Searle J.B., Fedyk S., Fredga K., Hausser J. & Volobouev V.T. 1991. Nomenclature for the chromosomes of the common shrew (Sorex araneus) // Mémoires de la Société Vaudoise des Sciences Naturelles. Vol.19. P.13-22.
• Vorren T. O., Vorren K.-D., Alm T., Gulliksen S. & Lövlie R. 1988. The last deglaciation (20,000 to 11,000 B.P.) on Andöya, northern Norway // Boreas. Vol.17. P.41-77.
• Wang H. C. & Fedoroff S. 1972. Banding in human chromosomes treated with trypsin // Nature New Biology. Vol.235. P.52-53.
• Zima J., Fedyk S., Fredga K., Hausser J., Mishta A., Searle J.B., Volobouev V.T. & Wójcik J.M. 1996. The list of the chromosome races of the common shrew (Sorex araneus) // Hereditas. Vol.125. P.97-107.