Phylogenetic Relationships among Palearctic and Nearctic Whitefish (Coregonus sp.) Populations as Revealed by Mitochondrial DNA Variation

We recently documented the existence of two highly distinct mitochondrial DNA (mtDNA) phylogenetic groups of Coregonus sp. in Beringia in the absence of geographic separation. To test whether this resulted from secondary intergradation of two groups that evolved in allopatry in Eurasia and Beringia, mtDNA restriction-fragment-length polymorphisms of 210 whitefish representing 22 populations from Europe and Siberia were compared with mtDNA variation observed among 581 fish from North America. Results confirmed that Beringia represents a zone of secondary contact among endemic whitefish and a group of Eurasian origin. All Beringian populations clustered much more closely to Eurasian populations than other North American ones. We also compared mtDNA variation among Palearctic populations with that observed in North America. European populations clustered into two major mtDNA groups that exhibited a strong geographic pattern of distribution, independent of the morphological variation observed among populations: one dominated all the more northern populations and extended to Alaska–Yukon; the second largely dominated samples from central alpine lakes, and was absent from Beringia. These results suggest that central alpine lakes and northern Europe were postglacially recolonized by two genetically distinct white-fish groups that most likely evolved in allopatry followed by limited intergradation.

A re-evaluation of the taxonomic status of the Moldavian steppe viper based on immunological investigations, with a discussion of the hypothesis of secondary intergradation between Vipera ursinii rakosiensis and Vipera (ursinii) renardi

The taxonomic level and phylogenetic relationship of the Moldavian steppe viper was investigated using blood serum electrophoresis, immunological comparisons of blood serum albumin and morphological comparisons. The traditional hypothesis that the Moldavian steppe viper is a secondary intergradation between Vipera (ursinii) renardi and V. ursinii rakosiensis could not be verified. Although morphologically similar (but not identical) to these two taxa, it has a closer immunological distance to the Balkan mountain subspecies, V. u. macrops and V. u. graeca. Specific antisera against serum albumins of V. u. graeca, V. u. ursinii (wettsteini) and V. u. eriwanensis were available, and the three vipers to be tested: rakosiensis, renardi and the Moldavian steppe viper branch off from different stems: rakosiensis seems close to ursinii, V. (u.) renardi appears fairly close to eriwanensis, both of which share a common stem with the rakosiensis-ursinii lineage. The Moldavian steppe viper shows high distance to both ursinii and eriwanensis, but low distance to graeca. The electrophoretic pattern show great differences from all other geographic forms tested (seven). We conclude that the Moldavian steppe viper represents a separate subspecies: Vipera ursinii moldavica ssp.n.