Allozyme Variation and Systematics of European Moles of the Genus Talpa (Mammalia, Insectivora)

Abstract

Genetic variation and divergence of several populations of moles of the genus Talpa from Spain, Austria, Italy, and Greece were investigated by means of the electrophoretic analysis of 38 enzyme loci. All samples tested showed a low level of genetic variability, most loci being monomorphic. The expected mean heterozygosity per locus (He) ranged from 0 to 0.024 (0.061 in the population of T. romana from Calabria). Each of the 230 specimens tested falls within one of five distinct gene pools, differentiated from each other by from 7 to 13 diagnostic loci. No evidence of hybridization or gene flow was found among the five groups. The data confirm specific status of T. europaea, T. caeca, and T. romana (by some authors considered as a subspecies of T. europaea); they also suggest specific rank for stankovici (until now treated as a subspecies of T. romana) and for occidentalis (generally considered as a subspecies of T. caeca). Further support is provided by the analysis of two pairs of sympatric and syntopic populations, respectively of T. romana and T. caeca, and of T. romana and T. europaea. In both cases, neither hybrids nor introgressed individuals were observed. The values of Nei's genetic distance found among the mole species considered range from 0.22 (between T. europaea and T. caeca) to 0.46 (between T. occidentalis and T. stankovici). From these values, times of evolutionary divergence of 1 to 3 million years were estimated. These figures appear consistent with those from fossil records. The validity of a number of subspecific taxa is discussed on the basis of genetic data. T. europaea velessiensis from Greece was found virtually identical to the Italian populations of T. europaea; the validity of T. romana brachycrania appears also not supported by genetic data; genetic differentiation of T. r. major and T. r. adamoi from T. r. romana is low (D ≅ 0.03), as is that of T. caeca augustana from T. c. caeca. Some discrepancies found between morphological and genetic data and their consequences at the taxonomic level are discussed.