Cryptic phylogeographic diversifications provide unique models to examine the role of phylogenetic divergence on the evolution of reproductive isolation, without extrinsic factors such as ecological and behavioural differentiation. Yet, to date very few comparative studies have been attempted within such radiations. Here, we characterize a new speciation continuum in a group of widespread Eurasian amphibians, the Pelobates spadefoot toads, by conducting multilocus (restriction site associated DNA sequencing and mitochondrial DNA) phylogenetic, phylogeographic and hybrid zone analyses. Within the P. syriacus complex, we discovered species‐level cryptic divergences (>5 million years ago [My]) between populations distributed in the Near‐East (hereafter P. syriacus sensu stricto [s.s.]) and southeastern Europe (hereafter P. balcanicus), each featuring deep intraspecific lineages. Altogether, we could scale hybridizability to divergence time along six different stages, spanning from sympatry without gene flow (P. fuscus and P. balcanicus, >10 My), parapatry with highly restricted hybridization (P. balcanicus and P. syriacus s.s., >5 My), narrow hybrid zones (~15 km) consistent with partial reproductive isolation (P. fuscus and P. vespertinus, ~3 My), to extensive admixture between Pleistocene and refugial lineages (≤2 My). This full spectrum empirically supports a gradual build up of reproductive barriers through time, reversible up until a threshold that we estimate at ~3 My. Hence, cryptic phylogeographic lineages may fade away or become reproductively isolated species simply depending on the time they persist in allopatry, and without definite ecomorphological divergence.

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.

SummaryIn the years 2010 and 2014, fi fty-four samples of Phoenicolacerta laevis from eight localities in Adana (n=6) and Hatay (n=48) were collected and examined for helminth parasites. New host and locality records were recorded. As a results of present study, three species of Digenea, Sonsinotrema tacapense, Prosthodendrium chilostomum, Brachylaima sp. (metacercaria); two species of Cestoda, Oochoristica tuberculata and Mesocestoides sp. and four species of Nematoda, Skrjabinodon medinae, Spauligodon sp., Thubunaea sp. and a larva of the Ascaridiidae Ascarididae gen. sp. were reported for lizard samples. We document new host records for all of helminth species reported here. Sonsionotrema tacapense (Digenea), and Thubunaea sp. (Nematoda) are recorded for the fi rst time from Turkey. There are, to our knowledge, no reports of helminths for P. laevis in Turkey and also from its range.

Genetic diversity is not always congruent with phenotypic heterogeneity, resulting in cryptic species complexes which cause a great struggle for scientists trying to define ‘species’ and describe relationships among taxa. Anatololacerta is a lizard genus distributed in southern and western Anatolia and some neighboring Aegean islands. Three morphospecies were recognized in Anatololacerta but a recent molecular study revealed the presence of cryptic diversity within the genus which led to the raise of a subspecies to species level. Currently the genus includes the species A. anatolica, A. danfordi, A. budaki and A. pelasgiana. Using a comprehensive sampling concerning both the number of specimens (218 specimens) and the genetic markers (3 nuclear and 3 mitochondrial), we performed phylogenetic analyses including tree reconstruction, species delimitation and divergence times estimation. The results revealed the occurrence of one more cryptic lineage which should be regarded as a separate species for which the name A. ibrahimi stat. nov. has priority. The existence of five well differentiated species with parapatric distributions in Anatololacerta is strongly supported. There is also evidence of recent and rapid radiation of the genus which probably causes phylogenetic relationships between these species to remain largely unresolved. At last, we proceeded to some nomenclatorial changes: The current name A. budaki was synonymized with A. pelasgiana because specimens of the type-locality of A. budaki are assigned genetically to A. pelasgiana. The genetic lineage including specimens currently assigned to A. budaki was named A. finikensis stat. nov., raising the subspecies A. b. finikensis to species level.

Arnold et al. (2007) conducted comprehensive molecular and morphological analysis on the subfamily Lacertinae and described 7 new genera. Four species (Lacerta laevis, L. kulzeri, L. cyanisparsa, and L. troodica) formerly considered as part of the genus Lacerta were elevated to a distinct genus by Arnold et al. (2007) as Phoenicolacerta. The first report of the occurrence of P. laevis in Turkey was from the Taurus Mountains (Werner, 1899). Later on, the occurrence of the species from other localities in Turkey was confirmed by Venzmer (1918, 1922), Bird (1936), Bodenheimer (1944), and Mertens (1952). Budak (1976) examined the morphology of P. laevis populations of Anatolia and concluded that they belonged to the nominal subspecies. Budak and Göçmen (1995) compared individuals from the Beşparmak Mountains in Cyprus with populations from Anatolia based on morphological characters and stated that the Anatolian populations could be distinguished from Cypriot ones in having small gular scales with higher numbers, subocular band extending below the temporal band, and an orange-red-colored site being present in the lower part of this region. Bischoff and Franzen (1993) and Bischoff and Schmidtler (1999) supported that P. laevis from Mersin differed in color patterns from P. laevis from Hatay. Tosunoğlu et al. (2001)