Western Palearctic
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Within the Palearctic ecozone we have worked mainly in Central and Eastern Europe, Mediterranean region, Middle East, and North Africa. We have studied phylogeographic patterns, species diversifications, molecular taxonomy, or phenotype variation in various amphibian and reptile taxa, in the first place tree frogs (Hyla), slow-worm lizards (Anguis), and geckos (Hemidactylus).
Our research is commonly conducted in cooperation with colleagues from the Department of Zoology of the Natural History Museum, National Museum in Prague (Jiří Moravec, Jiří Šmíd), and Department of Zoology at the Comenius University in Bratislava, Slovakia (David Jandzík, Peter Mikulíček, Daniel Jablonski). Some (important ;-)) projects were carried out during my doctoral studies at the Institute of Animal Physiology and Genetics, Liběchov, Czech Academy of Sciences (under supervision of Petr Kotlík).
Research highlights
Slow worm as a species complex
Semifossorial legless lizards from the genus Anguis, slow worm, had been understood as representing only two species till the end of the first decade of the 21st century – A. fragilis and A. cephallonica. Using phylogeographical approach we showed that A. fragilis represents more species, a species complex. Using genetic markers we distinguished as separate species the western populations (A. fragilis sensu stricto), eastern populations (A. colchica), and the species name A. graeca was applied for the southern Balkan populations. These findings were published in 2010 here. Later, an ancient lineage of slow worms was detected in the Italian Peninsula, named A. veronensis, and introduced together with a thorough morphological analysis in 2013 (see here). We hypothesize that the Tertiary Alpine orogeny with subsequent vicariance might have played a role in differentiation of this species. The current genetic variability was later shaped in multiple glacial refugia, with the first splitting event separating populations from the region of the Dolomite Mountains, thus, highlighting their biogeographical importance.
In 2016, we published an article studying distribution and genetic structure of mitochondrial lineages in the Balkans. Phylogeographic pattern is concordant with the refugia-within-refugia model. 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. We further found a strong correlation between genetic diversity of slow-worm populations and topographic ruggedness of the mountain systems they inhabit. Areas with more rugged terrain harbour higher genetic diversity.
We continue our research on the phylogeography and population genetics of slow worms with special interests in the situation in the Balkans and Central Europe. Our further aims are mainly to characterize still widely unknown distribution ranges, to detect contact zones of the parapatric species, and to test for the signature of introgressive hybridization using genomic data.
Tree frogs
The Western Palearctic tree frogs (Hyla) are distributed from the Northwest Africa and Canary Islands, across Europe including the main Mediterranean Islands to the Iranian Highlands and south-western Arabian Peninsula. We have studied tree frogs from around the Western Palearctic range with special emphasis on the populations from the eastern Mediterranean and Middle East.
Morphological evolution
First studies were using morphological approach and compared populations of the Middle Eastern tree frog, H. savignyi, and eastern populations of what was H. arborea at that time. The analyses showed that the body shape is more similar in areas of similar climatic conditions, even when different species are compared, than in areas of different climate, even within the same species. Thus, in tree frogs the external morphology is more affected by environmental/climatic conditions than by genotype.
Middle Eastern tree frogs
Similarly, when we evaluated the colour pattern of the eastern Mediterranean tree frogs (H. savignyi) we found out that tree frogs from Cyprus are more frequently spotted than the mainland populations, however, as we tested later they are not differentiated genetically as they form the same haplogroup with the southern Turkish population. Within this phylogeographic study we detected distribution, evolutionary relationships and demographic history of several lineages of tree frog distributed within the Middle East and Caucasus. In addition, we also described a new species, H. felixarabica. Using bioacoustics tools we also identified H. orientalis for the first time in Iran.
Arabian Tree Frog (Hyla felixarabica) was described as a new species in 2010, and is known from two disjunct populations, from the south-western Arabian Peninsula and southern Levant (Jordan, southern Syria, and extreme north-eastern Israel).
Illustration of a Cypriote specimen of H. savignyi published by Boulenger (1898: The Tailless Batrachians of Europe. Part II. Ray Sociandy, London, Plate XV, Figure 3).
Widespread introgression in the European short-call tree frogs
Finally, so far, we also studied the speciation history of the European short-call tree frogs, i.e. a group of the Western Palearctic tree frogs morphologically cryptic but genetically differentiated and characterized by short temporal parameters of the advertisement call (H. arborea, H. orientalis and H. molleri from across Europe to western Asia, two putative taxa within H. intermedia from the Italian Peninsula and Sicily, and H. sarda from Sardinia and Corsica). We inferred genealogical histories and species limits showing that gene introgression played an important role in the evolutionary history of the short-call tree frogs. A mitochondrial capture upon secondary contact appears to explain the close mtDNA relationship between the geographically remote Iberian H. molleri and H. orientalis from around the Black Sea.
Arid Hemidactylus geckos, Mediterranean thin-toed geckos (Mediodactylus) & Middle Eastern Mesalina lizards
Hemidactylus is a speciose gecko genus with more than 130 species, circumtropical (and subtropical) almost worldwide distribution, and is formed by several main clades. The Arid clade is represented by more than 50 species occurring in arid habitats of the north-eastern Africa, Horn of Africa, Arabian Peninsula and western Asia. This includes also the single circum-Mediterranean species, and the only European species, H. turcicus. We initially focused on populations from the Mediterranean, Syrian Desert and Arabia with the aim to find out the phylogenetic position of H. t. lavadeserticus. Based on the molecular data and morphology, we not only elevated H. t. lavadeserticus to a full species but more importantly discovered a new species distributed in Jordan and southern Syria, which we named H. dawudazraqi. We also suggested the existence of a possible new taxon in north-eastern Israel, and highlighted an overlooked extremely high diversity in the Arabian Peninsula, including a presence of an unnamed form in Sinai.
Hemidactylus turcicus 
This study was a stepping stone for a series of subsequent studies (performed in the course of the PhD study of Jiří Šmíd), which detailed the taxonomy and biogeography of the Arabian, Near Eastern, and north-east African populations and brought descriptions of further four species (H. adensis, H. mandebensis, H. ulii from Yemen, and H. awashensis from Ethiopia), and a revalidation of one species (H. granosus from Sinai, and Saudi Arabia).
The molecular data allowed an inference of the evolutionary and biogeographical history of the Arid clade. Two basal divergences correspond with the break-ups of the Arabian and African landmasses and subsequent separation of the Socotra Archipelago from the Arabian mainland, respectively. Formation of the Red Sea led to isolation and subsequent radiation in the Arabian Peninsula, which was followed by multiple independent expansions: to present-day Iran, two colonizations to NE Africa, two to Socotra, and two to the Near East. Our study also highlighted the role of Arabia and the Horn of Africa as an important Hemidactylus diversity hotspot.
Diversity and taxonomy of the Mediodactylus kotschyi complex
Mediterranean thin-toed geckos are small geckos native to southeastern Europe, Asia Minor and the Levant. These geckos display great morphological variation with a high number of recognized subspecies. It has been suggested that they constitute a species complex but the only species was recognized before our study. Using multilocus sequence data, the phylogenetic relationships were inferred among populations from a substantial part of the distribution range. Diversification within the Mediodactylus kotschyi complex began approximately 15 million years ago in the Middle Miocene. Species delimitation analysis supported a hypothesis of five species within the complex, and we proposed the following names: M. kotschyi (mainland Balkans, most of Aegean islands, Italy), M. orientalis (Levant, Cyprus, southern Anatolia, and south-eastern Aegean islands), M. danilewskii (Black Sea region and south-western Anatolia), M. bartoni (Crete), and M. oertzeni (southern Dodecanese Islands). Two of these species (M. bartoni, M. orientalis) were originally described in 1930s by a Czech herpetologist, Otakar Štěpánek! Common names and a tentative subspecies nomenclature were also proposed in the supplementary material of our study.
Mediodactylus orientalis lycaonicus, Konya, Turkey
The research was led by Nikos Poulakakis.
Diversification and taxonomy of Mesalina brevirostris
Mesalina are small lacertid lizards occurring in the Saharo-Sindian deserts from North Africa to the east of the Iranian plateau. We aimed at resolving the phylogeny and taxonomy of the M. brevirostris species complex distributed from the Middle East to the Arabian/Persian Gulf region and Pakistan. The results of the genetic analyses support the presence of four clearly delimited species that diverged approximately between the middle Pliocene and the Pliocene/Pleistocene boundary. Species distribution models showed that most of the species have rather divergent environmental niches. The species-level taxonomy was revised in accordance to the lines of evidence as follows: M. brevirostris s. str. was redefined, M. bernoullii was resurrected from the synonymy; M. microlepis was elevated from the subspecies status; and M. saudiarabica was described (by Moravec, Šmíd, Schmitz, Shobrak, Wilms) as a new species from Saudi Arabia.
Mesalina microlepis from northern Lebanon.
This research was led by Jiří Šmíd & Jiří Moravec.
Snakes (Vipera, Zamenis, Natrix)
Endangered meadow vipers (Vipera ursinii complex)
The last two populations of the Hungarian meadow viper Vipera ursinii rakosiensis were thought to persist in the steppe fragments of Hungary until meadow vipers were discovered in central Romania (Transylvania), suggesting a possible existence of remnant populations elsewhere. We assessed the phylogenetic position of the Transylvanian vipers using mitochondrial DNA. We showed that they were closely related to the Hungarian vipers, while those from northeastern Romania (Moldavia) and Danube Delta belonged to the subspecies Vipera ursinii moldavica. Montane subspecies from Europe (Vipera ursinii ursinii and Vipera ursinii macrops) formed a sister clade to the two lowland subspecies. Vipera renardi formed a sister clade to V. ursinii, with populations from the Greater Caucasus (Vipera renardi lotievi) and Tien Shan (Vipera renardi tienshanica) as the sister group to Vipera renardi renardi, and Vipera renardi eriwanensis from the Lesser Caucasus as the most basal taxon in the species. Our results illustrated that the divergence between the lowland and montane populations occurred separately in each species and several times in V. renardi. In our publication in 2012, we demonstrated that the recently discovered Transylvanian population is the third surviving population of V. u. rakosiensis and the only known population outside of Hungary.
Vipera ursinii rakosiensis from Romanian Transylvania
Two subspecies and three lineages of a rare snake, Zamenis hohenackeri
Two morphologically differentiated subspecies with presumably allopatric distribution have traditionally been recognized in the rare Transcaucasian rat snake, Zamenis hohenackeri: Z. h. hohenackeri (Caucasus region and E Turkey, NW Iran and N Iraq) and Z. h. tauricus (S Anatolia and Levant). Both subspecies are sometimes considered just colour forms of a monotypic species. We used mitochondrial DNA to find out whether both subspecies are also genetically differentiated. We found that the species forms not two but three divergent lineages: one corresponds to the nominotypic subspecies, another comprises an individual from the region of the type locality of Z. h. tauricus in southern Anatolia and the third, with no available name and separated from the previous by the Amanos (Nur) Mountains, is distributed in the Levant (‘Southern lineage’). The pattern of divergence and distribution of the lineages correspond to other species of amphibians and reptiles, demonstrating that similar geo-climatic events presumably formed genetic variation and triggered speciation processes in this region.
This research was led by David Jandzík, Comenius University, Bratislava, Slovakia.
From left to right: Z. h. hohenackeri from Armenia (photo by R. Sindaco); Z. h. tauricus from Toroslar, S Turkey (photo by B. Göçmen); Z. h. ‘Southern lineage’ from Hatay, S Turkey (photo by B. Göçmen); and recently described (2018) Z. h. lyciensis from SW Turkey (not included in our study from 2013; photo by K. Mebert). “B” and “F” from Hofmann et al. (2018), Fig. S2.
Phylogeography, contact zones and taxonomy of Natrix natrix
Grass snakes (Natrix natrix) represent one of the most widely dist
ributed snake species of the Palaearctic region, ranging from Northwest Africa and the Iberian Peninsula through most of Europe and western Asia eastward to the region of Lake Baikal. Within N. natrix, up to 14 distinct subspecies were regarded as valid. In addition, some authors recognized big-headed grass snakes from western Transcaucasia as a distinct species, N. megalocephala. We presented a nearly range-wide phylogeography for both nominal species. Within N. natrix, 16 terminal mitochondrial clades were identified, most of which conflicted with morphologically defined subspecies. These 16 clades corresponded to three more inclusive clades from (i) the Iberian Peninsula plus Northwest Africa, (ii) East Europe and Asia and (iii) West Europe including Corso-Sardinia, the Apennine Peninsula and Sicily. In Central Europe, two contact zones of three distinct mitochondrial clades were uncovered, which was quite unexpected situation. In agreement with previous studies using morphological characters and allozymes, we found no evidence for the distinctiveness of N. megalocephala. Therefore, we synonymized N. megalocephala with N. natrix.
This research was primarily performed by Carolin Kindler and led by Uwe Fritz, Museum of Zoology, Dresden, Germany.
Natrix natrix from SE Azerbaijan
Paedomorphic newts
Facultative paedomorphosis is an environmentally induced polymorphism that is well known for many caudate species including newts. Although facultative paedomorphosis has been documented in some smooth-newt populations, records of entirely paedomorphic populations outside the Balkans are limited. We found and reported on a unique paedomorphic population of the smooth newt (Lissotriton vulgaris) in Central Bohemia, Czech Republic, and discussed potential causes of this paedomorphosis.
