Daniel Jablonski

Slow worm, Anguis fragilis (Reptilia: Anguidae) as a species complex: Genetic structure reveals deep divergences

Phylogenetic relationships of the Western Palearctic legless lizard genus Anguis were inferred based on a fragment of mitochondrial DNA and two nuclear protein-coding loci, C-mos and PRLR. A. cephallonica from the Peloponnese was confirmed as a valid species. It is the sister taxon to a clade comprising all other evolutionary lineages, which were shown to represent three distinct species: (1) A. fragilis sensu stricto occurring in Western and Central Europe, the north-western Balkans, with possibly isolated populations in the eastern Balkans, and presumably also in western Scandinavia and Italy; (2) A. colchica distributed from the eastern Czech Republic and the Baltic region eastward to northern Iran, presumably also in eastern Scandinavia, and the north-eastern Balkans; (3) A. graeca restricted to the southern Balkans, and partially sympatric with A. cephallonica. According to the more variable mitochondrial marker, A. graeca appears to be the sister species to A. colchica, and these taxa together form a sister clade to A. fragilis, whereas the less variable nuclear markers show A. colchica to be closer to A. fragilis. The C-mos gene has not provided substantial variation within this species complex, while the PRLR gene, which was used for the first time in phylogeographic study in a reptile, distinguished all species successfully. Intra-specific differentiation of A. colchica is discussed, and subspecific status of the Caucasian and Caspian populations is proposed. The uncovered genetic differences should be taken into account in all future biogeographical, morphological and ecological studies, as well as in conservation.

Mitochondrial phylogeography, contact zones and taxonomy of grass snakes (Natrix natrix, N. megalocephala)

Grass snakes (Natrix natrix) represent one of the most widely distributed snake species of the Palaearctic region, ranging from the North African Maghreb region and the Iberian Peninsula through most of Europe and western Asia eastward to the region of Lake Baikal in Central Asia. Within N. natrix, up to 14 distinct subspecies are regarded as valid. In addition, some authors recognize big‐headed grass snakes from western Transcaucasia as a distinct species, N. megalocephala. Based on phylogenetic analyses of a 1984‐bp‐long alignment of mtDNA sequences (ND4+tRNAs, cyt b) of 410 grass snakes, a nearly range‐wide phylogeography is presented for both species. Within N. natrix, 16 terminal mitochondrial clades were identified, most of which conflict with morphologically defined subspecies. These 16 clades correspond to three more inclusive clades from (i) the Iberian Peninsula plus North Africa, (ii) East Europe and Asia and (iii) West Europe including Corso‐Sardinia, the Apennine Peninsula and Sicily. Hypotheses regarding glacial refugia and postglacial range expansions are presented. Refugia were most likely located in each of the southern European peninsulas, Corso‐Sardinia, North Africa, Anatolia and the neighbouring Near and Middle East, where the greatest extant genetic diversity occurs. Multiple distinct microrefugia are inferred for continental Italy plus Sicily, the Balkan Peninsula, Anatolia and the Near and Middle East. Holocene range expansions led to the colonization of more northerly regions and the formation of secondary contact zones. Western Europe was invaded from a refuge within southern France, while Central Europe was reached by two distinct range expansions from the Balkan Peninsula. In Central Europe, there are two contact zones of three distinct mitochondrial clades, and one of these contact zones was theretofore completely unknown. Another contact zone is hypothesized for Eastern Europe, which was colonized, like north‐western Asia, from the Caucasus region. Further contact zones were identified for southern Italy, the Balkans and Transcaucasia. In agreement with previous studies using morphological characters and allozymes, there is no evidence for the distinctiveness of N. megalocephala. Therefore, N. megalocephala is synonymized with N. natrix.

Contrasting evolutionary histories of the legless lizards slow worms (Anguis) shaped by the topography of the Balkan Peninsula

BackgroundGenetic architecture of a species is a result of historical changes in population size and extent of distribution related to climatic and environmental factors and contemporary processes of dispersal and gene flow. Population-size and range contractions, expansions and shifts have a substantial effect on genetic diversity and intraspecific divergence, which is further shaped by gene-flow limiting barriers. The Balkans, as one of the most important sources of European biodiversity, is a region where many temperate species persisted during the Pleistocene glaciations and where high topographic heterogeneity offers suitable conditions for local adaptations of populations. In this study, we investigated the phylogeographical patterns and demographic histories of four species of semifossorial slow-worm lizards (genus Anguis) present in the Balkan Peninsula, and tested the relationship between genetic diversity and topographic heterogeneity of the inhabited ranges.ResultsWe inferred phylogenetic relationships, compared genetic structure and historical demography of slow worms using nucleotide sequence variation of mitochondrial DNA. Four Anguis species with mostly parapatric distributions occur in the Balkan Peninsula. They show different levels of genetic diversity. A signature of population growth was detected in all four species but with various courses in particular populations. We found a strong correlation between genetic diversity of slow-worm populations and topographic ruggedness of the ranges (mountain systems) they inhabit. Areas with more rugged terrain harbour higher genetic diversity.ConclusionsPhylogeographical pattern of the genus Anguis in the Balkans is concordant with the refugia-within-refugia model previously proposed for both several other taxa in the region and other main European Peninsulas. While slow-worm populations from the southern refugia mostly have restricted distributions and have not dispersed much from their refugial areas, populations from the extra-Mediterranean refugia in northern parts of the Balkans have colonized vast areas of eastern, central, and western Europe. Besides climatic historical events, the heterogeneous topography of the Balkans has also played an important role in shaping genetic diversity of slow worms.

Hidden diversity in the Podarcis tauricus (Sauria, Lacertidae) species subgroup in the light of multilocus phylogeny and species delimitation

The monophyletic species subgroup of Podarcis tauricus is distributed in the western and southern parts of the Balkans, and includes four species with unresolved and unstudied inter- and intra-specific phylogenetic relationships. Using sequence data from two mitochondrial and three nuclear genes and applying several phylogenetic methods and species delimitation approaches to an extensive dataset, we have reconstructed the phylogeny of the Podarcis wall lizards in the Balkans, and re-investigated the taxonomic status of the P. tauricus species subgroup. Multilocus analyses revealed that the aforementioned subgroup consists of five major clades, with P. melisellensis as its most basal taxon. Monophyly of P. tauricus sensu stricto is not supported, with one of the subspecies (P. t. ionicus) displaying great genetic diversity (hidden diversity or cryptic species). It comprises five, geographically distinct, subclades with genetic distances on the species level. Species delimitation approaches revealed nine species within the P. tauricus species subgroup (P. melisellensis, P. gaigeae, P. milensis, and six in the P. tauricus complex), underlining the necessity of taxonomic re-evaluation. We thus synonymize some previously recognized subspecies in this subgroup, elevate P. t. tauricus and P. g. gaigeae to the species level and suggest a distinct Albanian-Greek clade, provisionally named as the P. ionicus species complex. The latter clade comprises five unconfirmed candidate species that call for comprehensive studies in the future.

Distribution and diversity of reptiles in Albania: a novel database from a Mediterranean hotspot

Although Albania has a rich reptile fauna, efforts to reveal its diversity have so far been limited. To fill this gap, we collected available published and unpublished (museum collections, online sources) records of reptile occurrences and conducted several expeditions to search for reptiles in areas with few or no previous records. Our georeferenced database contains 3731 records of 40 species from between 1918 and 2015. Based on this comprehensive dataset, we prepared distribution maps for each reptile species of the country. Applying spatial statistics, we revealed that overall sampling effort was clustered, with hotspots associated with easily accessible areas and natural heritage sites. The maximum number of species per cell was 26 with an average of seven. Cells harbouring large reptile diversity were located along the Adriatic and Ionian coasts, on the western slopes of south Albanian mountains, i.e. in areas generally considered as Balkans biodiversity hotspots or potential historical refugia. We found that species presence and diversity is strongly influenced by landscape features. Diversity of land cover, altitudinal variation, temperature and precipitation variation explained the observed pattern in our models. Our study presents the largest database of reptile occurrences to date and is the first to analyse reptile diversity patterns in Albania. The database and the diversity patterns can provide a basis for future macroecological studies and conservation planning.

Nuclear markers support the mitochondrial phylogeny of Vipera ursinii–renardi complex (Squamata: Viperidae) and species status for the Greek meadow viper

Meadow vipers (Vipera ursinii-renardi complex) are small-bodied snakes that live in either lowland grasslands or montane subalpine-alpine meadows spanning a distribution from France to western China. This complex has previously been the focus of several taxonomic studies which were based mainly on morphological, allozyme or immunological characters and did not clearly resolve the relationships between the various taxa. Recent mitochondrial DNA analyses found unexpected relationships within the complex which had taxonomical consequences for the detected lineages. The most surprising was the basal phylogenetic position of Vipera ursinii graeca, a taxon described almost 30 years ago from the mountains of Greece. We present here new analyses of three nuclear markers (BDNF, NT3, PRLR; a first for studies of meadow and steppe vipers) as well as analyses of newly obtained mitochondrial DNA sequences (CYT B, ND4).Our Bayesian analyses of nuclear sequences are concordant with previous studies of mitochondrial DNA, in that the phylogenetic position of the graeca clade is a clearly distinguished and distinct lineage separated from all other taxa in the complex. These phylogenetic results are also supported by a distinct morphology, ecology and isolated distribution of this unique taxon. Based on several data sets and an integrative species concept we recommend to elevate this taxon to species level: Vipera graeca Nilson & Andrén, 1988 stat. nov.

The distributions of the six species constituting the smooth newt species complex ( Lissotriton vulgaris sensu lato and L. montandoni ) – an addition to the New Atlas of Amphibians and Reptiles of Europe

The ‘smooth newt’, the taxon traditionally referred to as Lissotriton vulgaris , consists of multiple morphologically distinct taxa. Given the uncertainty concerning the validity and rank of these taxa, L. vulgaris sensu lato has often been treated as a single, polytypic species. A recent study, driven by genetic data, proposed to recognize five species, L. graecus , L. kosswigi , L. lantzi , L. schmidtleri and a more restricted L. vulgaris . The Carpathian newt L. montandoni was confirmed to be a closely related sister species. We propose to refer to this collective of six Lissotriton species as the smooth newt or Lissotriton vulgaris species complex. Guided by comprehensive genomic data from throughout the range of the smooth newt species complex we 1) delineate the distribution ranges, 2) provide a distribution database, and 3) produce distribution maps according to the format of the New Atlas of Amphibians and Reptiles of Europe, for the six constituent species. This allows us to 4) highlight regions where more research is needed to determine the position of contact zones.

Pleistocene extinctions and recent expansions in an anguid lizard of the genus Pseudopus

Climatic changes during the Pleistocene played an instrumental role in the shaping recent distribution and diversity of the Western Palearctic biota. Range oscillations often lead to allopatric differentiation followed by the establishment of secondary contact zones. As a result, many species are composed of complex networks of phylogenetic lineages with different histories. Pseudopus apodus is the only surviving member of an ancient genus of Western Palearctic anguid lizards (Anguidae) distributed from the Balkans through Anatolia and Caucasus to central Asia. Here, we used mitochondrial and nuclear DNA sequences to reconstruct the evolutionary history of the species in phylogeographic and demographic frameworks. Our analyses revealed three main phylogenetic lineages that diverged during or shortly before the Pleistocene. Two of them more or less correspond to the known subspecies, and their low genetic variability suggests relatively recent dispersal and colonization of vast parts of the range. The third, southern, lineage is more geographically restricted and diversified than the other two. This pattern shows that the Quaternary climatic oscillations presumably caused repeated large‐scale population extinctions of the species, depleting most of its diversity. Only a few refugia located in Anatolia, Levant, and Transcaucasia served as sources for subsequent recolonization to the areas of the recent distribution. This is in contrast to many other Western Palearctic reptiles that survived unfavorable climatic conditions in numerous local refugia and sanctuaries, which resulted in more complex phylogenetic structure.

Two new species of Cricetidae for the fauna of Albania

Abstract Albania represents an important area in Europe where zoological research brings interesting findings, even in a well-studied group such as small mammals. During field research in the central-south part of the country (Tomorr Mountains; Hellenides range) trapping of small terrestrial mammals was carried out. Using ten traps per night/locality, two specimens of family Cricetidae and one of family Muridae were trapped. The first two individuals were genetically and morphologically examined and identified as Chionomys nivalis (Martins, 1842) and Microtus subterraneus (de Selys-Longchamps, 1836). They represent unique mitochondrial haplotypes and the first records of these species in Albania. The third species, Apodemus sylvaticus (L., 1758), represents the first record of the species in this region and the highest recorded occurrence for the country.

Resolving complex phylogeographic patterns in the Balkan Peninsula using closely related wall-lizard species as a model system

The Balkan Peninsula constitutes a biodiversity hotspot with high levels of species richness and endemism. The complex geological history of the Balkans in conjunction with the climate evolution are hypothesized as the main drivers generating this biodiversity. We investigated the phylogeography, historical demography, and population structure of closely related wall-lizard species from the Balkan Peninsula and southeastern Europe to better understand diversification processes of species with limited dispersal ability, from Late Miocene to the Holocene. We used several analytical methods integrating genome-wide SNPs (ddRADseq), microsatellites, mitochondrial and nuclear DNA data, as well as species distribution modelling. Phylogenomic analysis resulted in a completely resolved species level phylogeny, population level analyses confirmed the existence of at least two cryptic evolutionary lineages and extensive within species genetic structuring. Divergence time estimations indicated that the Messinian Salinity Crisis played a key role in shaping patterns of species divergence, whereas intraspecific genetic structuring was mainly driven by Pliocene tectonic events and Quaternary climatic oscillations. The present work highlights the effectiveness of utilizing multiple methods and data types coupled with extensive geographic sampling to uncover the evolutionary processes that shaped the species over space and time.