Search

TheMediterranean Basin has experienced extensive change in geology and climate over the past sixmillion years. Yet, the relative importance of key geological events for the distribution and genetic structure of the Mediterranean fauna remains poorly understood. Here, we use population genomic and phylogenomic analyses to establish the evolutionary history and genetic structure of common wall lizards (Podarcis muralis). This species is particularly informative because, in contrast to other Mediterranean lizards, it is widespread across the Iberian, Italian, and Balkan Peninsulas, and in extra-Mediterranean regions. We found strong support for six major lineages within P. muralis, which were largely discordant with the phylogenetic relationship of mitochondrial DNA. The most recent common ancestor of extant P. muralis was likely distributed in the Italian Peninsula, and experienced an “Out-of-Italy” expansion following the Messinian salinity crisis (similar to 5 Mya), resulting in the differentiation into the extant lineages on the Iberian, Italian, and Balkan Peninsulas. Introgression analysis revealed that both inter- and intraspecific gene flows have been pervasive throughout the evolutionary history of P. muralis. For example, the Southern Italy lineage has a hybrid origin, formed through admixture between the Central Italy lineage and an ancient lineage that was the sister to all other P. muralis. More recent genetic differentiation is associated with the onset of the Quaternary glaciations, which influenced population dynamics and genetic diversity of contemporary lineages. These results demonstrate the pervasive role of Mediterranean geology and climate for the evolutionary history and population genetic structure of extant species.

International audience; Abstract The Mediterranean Basin has experienced extensive change in geology and climate over the past six million years. Yet, the relative importance of key geological events for the distribution and genetic structure of the Mediterranean fauna remains poorly understood. Here, we use population genomic and phylogenomic analyses to establish the evolutionary history and genetic structure of common wall lizards (Podarcis muralis). This species is particularly informative because, in contrast to other Mediterranean lizards, it is widespread across the Iberian, Italian, and Balkan peninsulas, and in extra-Mediterranean regions. We found strong support for six major lineages within P. muralis, which were largely discordant with the phylogenetic relationship of mitochondrial DNA. The most recent common ancestor of extant P. muralis was likely distributed in the Italian Peninsula, and experienced an “Out-of-Italy” expansion following the Messinian salinity crisis (∼5 Mya), resulting in the differentiation into the extant lineages on the Iberian, Italian and Balkan peninsulas. Introgression analysis revealed that both inter- and intraspecific gene flows have been pervasive throughout the evolutionary history of P. muralis. For example, the Southern Italy lineage has a hybrid origin, formed through admixture between the Central Italy lineage and an ancient lineage that was the sister to all other P. muralis. More recent genetic differentiation is associated with the onset of the Quaternary glaciations, which influenced population dynamics and genetic diversity of contemporary lineages. These results demonstrate the pervasive role of Mediterranean geology and climate for the evolutionary history and population genetic structure of extant species.

International audience

According to animal signalling theory, various mechanisms can maintain signal honesty in the face of deception. Conventional signals are usually cheap to produce but socially imposed costs, often taking the form of aggression from conspecifics, can enforce their honesty. While our understanding of signal evolution and honesty has much improved for some pigment-based colour signals, the mechanisms maintaining the honesty of structural colour signals, such as ultraviolet (UV), remain elusive. Here, we used the common lizardZootoca viviparato test whether or not the honesty of UV signals displayed on male throats is under social control. To do so, we staged dyadic agonistic interactions between non-manipulated focal males and opponents of either larger or smaller body size, and with either control or manipulated UV signals so as to create small cheaters with UV-enhanced throats, large cheaters with UV-reduced throats, and their respective controls. Focusing on control interactions, we first confirmed that male UV coloration and bite force were good predictors of contest outcomes in this species. Furthermore, in support of a conventional signal hypothesis, focal males were more aggressive towards large cheaters and became more submissive when these large cheaters retaliated, and were less submissive against small cheaters. However, that focal males were not more aggressive towards small cheaters contradicts our initial predictions. Overall, we provide some evidence suggesting that socially imposed costs may enforce the honesty of UV signals in common lizards.

Habitat destruction has resulted in the fragmented distribution of numerous terrestrial species, which poses a challenge for conservationists. Furthermore, species management can be further compounded by life history constraints such as low dispersal, hindering the ability of species to recolonize areas they formerly occupied. For these species, a thorough understanding of the local threats and factors that limit their distribution is crucial for effective management. We used occupancy models to examine which factors at landscape and habitat scales (i.e. land uses, fire history, and vegetation structure) explain the presence of terrestrial tortoises within the range of the westernmost isolated population of the endangered Testudo hermanni hermanni in the Albera Range (NE of the Iberian Peninsula). We randomly surveyed 25 sites (75% of the area known with presence of tortoises) of natural woodlands with 5 to 8 replicates per site in spring 2012-2014. From a sampling effort of 148 hours, we only detected 52 tortoises in 12 of 25 transects. These low numbers are evidence of low population densities. Sites with presence of tortoises were spatially aggregated although the species was absent from apparently adequate sites on the edges of its distribution range. Current and historic land-use primarily explained the presence of tortoises. Besides, wildfires and reduction of habitat complexity also participate to explain the distribution of Hermann’s tortoises. We also discuss some aspects of the conservation of Testudo hermanni in relation to our results.

Badiane, Arnaud, Garcia-Porta, Joan, Červenka, Jan, Kratochvíl, Lukáš, Sindaco, Roberto, Robinson, Michael D., Morales, Hernan, Mazuch, Tomáš, Price, Thomas, Amat, Fèlix, Shobrak, Mohammed Y., Wilms, Thomas, Simó-Riudalbas, Marc, Ahmadzadeh, Faraham, Papenfuss, Theodore J., Cluchier, Alexandre, Viglione, Julien, Carranza, Salvador (2014): Phylogenetic relationships of Semaphore geckos (Squamata: Sphaerodactylidae: Pristurus) with an assessment of the taxonomy of Pristurus rupestris. Zootaxa 3835 (1): 33-58, DOI: http://dx.doi.org/10.11646/zootaxa.3835.1.2