CHROMOSOME RACES OF THE COMMON SHREW SOREX-ARANEUS IN POLAND - A MODEL OF KARYOTYPE EVOLUTION

Five distinct chromosome races of the common shrew Sorex araneus Linnaeus, 1758 including different metacentrics with monobrachial homology have been found in Poland. Their karyotypes include polymorphic arm combinations, and chromosomal forms differing in numbers of acrocentrics can be distinguished among them. The relationship between Polish and other European races of the common shrew has been examined by phylogenetic analysis using parsimony. Five phylogenetic groups of the common shrew, two of them consist only of one race, can be recognized in Europe. The Polish races belong to two groups: the West European and East European phylogenetic groups. A model of chromosomal evolution in the common shrew consisting of two components, an allopatric one and a parapatric or stasipatric one, has been proposed. This model is based on the distribution of different races and different metacentrics in karyotypes of shrews in Poland and in central Europe.