Morphometric variation of the common shrew Sorex araneus in Poland, in relation to karyotype

Morphometric differentiation among six chromosome races of the common shrew Sorer araneus Linnaeus, 1758 in Poland was examined by the use of 26 orthogonal mandibular measurements in 388 specimens. The discriminant function analysis (DFA) performed on 21 morphological variables led to a correct classification in 59.3% of cases. Comparison of morphological and chromosomal distances showed that there is no significant agreement; the two matrices were apparently discordant (cophenetic correlation coefficient, r(coph) = 0.216, p > 0.05). Multiple regression analysis revealed that 9.9% of the total morphological variance could be explained by eight geoclimatic variables. The DFA of residuals, remaining after regression of the morphological variables by the geoclimatic ones, let to correct assignment of only 26.3% specimens. Our research revealed that karyotypic divergence plays no important part in differentiating mandibular morphology in chromosome races of S. araneus, and morphological differences cannot be treated as a by-product of chromosomal speciation.