New chromosome races of the common shrew Sorex araneus from Eastern Siberia

Two new chromosome races of the common shrew Sorex araneus Linnaeus, 1758 h ave been discovered in Eastern Siberia (Strelka and Ilga). This finding hel ps to clarify the geographical limits of other previously-described chromos ome races (Tomsk and Baikal) in the same region and to elucidate the chromo some evolution of Siberian common shrews. The diversity of chromosome races in this area can be explained by stepwise accumulation of Robertsonian fus ions and whole-arm reciprocal translocations from a Baikal-like ancestral r ace.