Single hybrid population but multiple parental individuals at the origin of parthenogenetic rock lizards Darevskia sapphirina and D. bendimahiensis Schmidtler, & Eiselt Darevsky (1994) endemic to the area of Lake Van in East Turkey.

Among vertebrates, obligate parthenogenesis is only found in Squamata, where it always has a hybrid origin and a few lizard genera contain most of the known hybridogenous parthenogenetic taxa. Parthenogenesis thus seems to be pre-conditioned at the genus level, but it is not clear how often the encounter between two parental sexually reproducing species can result in the parthenogenetic offspring, nor whether the success of such hybridization event requires certain conditions or the specific time frame. To address this question, we studied the rock lizards of genus Darevskia, where a pair of parental species, D. valentini and D. raddei, as well as their parthenogenetic daughter species D. bendimahiensis and D. sapphirina, are found in close proximity NE of the Lake Van in East Anatolia. Using ddRAD-seq genotyping on 19 parental and 18 hybrid individuals, we found that (i) all parthenogenetic individuals from both D. bendimahiensis and D. sapphirina have a monophyletic origin tracing back to a single initial hybrid population, but their current genetic variation is geographically structured; (ii) unlike the most probable paternal ancestor, the genetically closest extant population of the maternal ancestor is not the geographically nearest one; and (iii) in the parthenogens, about 1% of loci carry multiple haplotypes, frequently differentiated by multiple substitutions. This pattern, in addition to biases in the relative frequency of haplotypes of maternal and paternal origin, does not appear compatible with a scenario of the entire parthenogenic clonal population having descended from a single pair of parental individuals. Instead, the data suggest that multiple parental individual ancestries still persist in the parthenogenetic gene pool. This supports the notion that although hybridization leading to parthenogenesis is generally rare at the level of species, it may be more common at the individual/population level once the right conditions are met.

Hidden Diversity in a Narrow Valley: Description of New Endemic Palearctic Rock Lizard Darevskia (Squamata: Lacertidae) Species from Northeastern Turkey.

Darevskia is a particularly species-rich radiation of Palearctic rock lizards from the Caucasus region. Thanks to intense systematic and taxonomic research, the knowledge of species-level diversity within this genus has increased over the last quarter century. Here, we described a new species, Darevskia salihae sp. nov. from northeastern Turkey. The new taxon is differentiated from other nearby taxon by the low number of dorsal scales in the middle of the body, the shorter body length, and the absence of blue dots both on the lateral region above the forelimbs and on the margin of the ventral plates. In addition to their morphological differences, the new taxon is phylogenetically different from close groups. It is located in a separate subclade from the rudis-valentini-portschinskii subclade. This distinction is supported by both a high bootstrap value (100) and a high posterior probability value (1.00). These two subclades are separated from each other by a genetic distance of almost 4%. This separation is supported not only genetically and morphologically, but also geographically. Since the habitat of the new taxon is limited to a high mountain and a narrow valley, it does not provide an opportunity for a different Darevskia species to shelter because it creates geographical isolation. However, Darevskia parvula that live closest to the habitat of the new taxon live only at the habitat boundaries and do not enter areas where the new taxon is found. Therefore, it might be possible that while it was separated from the rudis-valentini-portschinskii group during the evolutionary transformation, it remained as a refuge and relict in a narrow area as a result of the collapse of the valleys and the partial uplift of the Kaçkar Mountains.

Thermal biology of two sympatric Lacertid lizards (Lacerta diplochondrodes and Parvilacerta parva) from Western Anatolia.

Sympatric lizard species present convenient models for studying differentiation in thermal behavior and the role of morphological differences in their thermal biology. Here we studied the thermal biology of two sympatric lizard species which occur sympatrically in the Phrygian Valley of Western Anatolia. These two species differ in body size, with Lacerta diplochondrodes being larger than Parvilacerta parva. The surface body temperatures of the individuals belonging to both species were recorded when active in the field. Additionally, several environmental parameters including solar radiation, substrate temperature, air temperature and wind speed were monitored to investigate the relative effects of these abiotic parameters on the thermal biology of the two species. The surface body temperature and temperature excess (difference between body and substrate temperature) of the two species, while being relatively close to each other, showed seasonal differences. Solar radiation, substrate temperature and air temperature were the main factors influencing their thermal biology. Additionally, although body size did not have a direct effect on body temperature or temperature excess, the interaction between body size and solar radiation on temperature excess was significant. In conclusion, our study partially supports the conservation of body temperature of related lizard species.

A molecular phylogenetic investigation of tick species in Eastern and Southeastern Anatolia.

Understanding the local tick species composition is crucial for overcoming the diseases they transmit. A comprehensive survey integrating molecular identification was conducted in the eastern and southeastern parts of Turkey, where tick surveys have previously been neglected. A total of 596 specimens belonging to four tick genera were collected from 27 localities in Turkey during the summers of 2019 and 2020. Seventy-seven representative individuals were chosen for molecular analysis. Nine distinct species, Rhipicephalus bursa, Rhipicephalus turanicus, Rhipicephalus rossicus, Hyalomma asiaticum, Hyalomma excavatum, Hyalomma marginatum, Hyalomma aegyptium, Haemaphysalis sulcata, and Dermacentor marginatus were identified. The presence of R. rossicus was demonstrated for the first time in Turkey. Two lineages of R. turanicus were identified, and representatives of both lineages were recorded. Our Hyalomma phylogenetic tree was consistent with previous findings from Turkey; however, new sympatric areas for Hy. marginatum and Hy. excavatum and Hy. marginatum and Hy. asiaticum were recorded. Two haplotypes (Haemaphysalis sp. and Dermacentor sp.) could not be identified using morphological and molecular methods. In addition to making a valuable contribution to the molecular database of ticks in the Middle East, this study will also stimulate comparative studies on the genetic structure, ecology, and vector competence of different populations of these species in Turkey as well as in other parts of the world.

Genotypic similarities among the parthenogenetic Darevskia rock lizards with different hybrid origins.

BACKGROUND: The majority of parthenogenetic vertebrates derive from hybridization between sexually reproducing species, but the exact number of hybridization events ancestral to currently extant clonal lineages is difficult to determine. Usually, we do not know whether the parental species are able to contribute their genes to the parthenogenetic vertebrate lineages after the initial hybridization. In this paper, we address the hypothesis, whether some genotypes of seven phenotypically distinct parthenogenetic rock lizards (genus Darevskia) could have resulted from back-crosses of parthenogens with their presumed parental species. We also tried to identify, as precise as possible, the ancestral populations of all seven parthenogens. RESULTS: We analysed partial mtDNA sequences and microsatellite genotypes of all seven parthenogens and their presumed ansectral species, sampled across the entire geographic range of parthenogenesis in this group. Our results confirm the previous designation of the parental species, but further specify the maternal populations that are likely ancestral to different parthenogenetic lineages. Contrary to the expectation of independent hybrid origins of the unisexual taxa, we found that genotypes at multiple loci were shared frequently between different parthenogenetic species. The highest proportions of shared genotypes were detected between (i) D. sapphirina and D. bendimahiensis and (ii) D. dahli and D. armeniaca, and less often between other parthenogens. In case (ii), genotypes at the remaining loci were notably distinct. CONCLUSIONS: We suggest that both observations (i-ii) can be explained by two parthenogenetic forms tracing their origin to a single initial hybridization event. In case (ii), however, occasional gene exchange between the unisexual and the parental bisexual species could have taken place after the onset of parthenogenetic reproduction. Indeed, backcrossed polyploid hybrids are relatively frequent in Darevskia, although no direct evidence of recent gene flow has been previously documented. Our results further suggest that parthenogens are losing heterozygosity as a result of allelic conversion, hence their fitness is expected to decline over time as genetic diversity declines. Backcrosses with the parental species could be a rescue mechanism which might prevent this decline, and therefore increase the persistance of unisexual forms.

The relation between melanism and thermal biology in a colour polymorphic bush cricket, Isophya rizeensis.

According to the thermal melanism hypothesis, darker coloured melanic individuals heat up faster and to higher temperatures than lighter coloured individuals due to lower skin reflectance. Consequently, it is assumed that darker melanic types may be advantageous compared to light coloured types in colder regions. As temperature gradually decreases with elevation and latitude the degree of melanism is expected to increase along these gradients in ectothermic species. Isophya rizeensis, a colour polymorphic bush cricket species endemic to Northeastern Turkey is an interesting case since the degree of melanism decreases with elevation, contrary to the thermal melanism hypothesis. In order to investigate the relation between colouration and thermal biology of this species, body temperatures (Tb) of crickets from different colour morphs, environmental temperatures (Ta), solar radiation and vegetation height were measured to test the relation between these variables and thermoregulation. Field results showed that solar radiation was the most effective factor on temperature excess (Tex), the difference between body and ambient temperature. Additionally, Tex values showed negative correlation with vegetation height. Although Tex values did not differ significantly between colour morphs, paired experiments under sunlight showed that darker morphs heated up faster and attained higher body temperatures than light morphs. We conclude that, since higher Tex values at alpine short swards might also increase the risk of facing deleterious temperatures at high elevations, protection against overheating might be one of the factors responsible for this polymorphism.