Environmental factors influence cross-talk between a heat shock protein and an oxidative stress protein modification in the lizard Gallotia galloti.

Better understanding how organisms respond to their abiotic environment, especially at the biochemical level, is critical in predicting population trajectories under climate change. In this study, we measured constitutive stress biomarkers and protein post-translational modifications associated with oxidative stress in Gallotia galloti, an insular lizard species inhabiting highly heterogeneous environments on Tenerife. Tenerife is a small volcanic island in a relatively isolated archipelago off the West coast of Africa. We found that expression of GRP94, a molecular chaperone protein, and levels of protein carbonylation, a marker of cellular stress, change across different environments, depending on solar radiation-related variables and topology. Here, we report in a wild animal population, cross-talk between the baseline levels of the heat shock protein-like GRP94 and oxidative damage (protein carbonylation), which are influenced by a range of available temperatures, quantified through modelled operative temperature. This suggests a dynamic trade-off between cellular homeostasis and oxidative damage in lizards adapted to this thermally and topologically heterogeneous environment.

Does heat tolerance actually predict animals' geographic thermal limits?

The "climate extremes hypothesis" is a major assumption of geographic studies of heat tolerance and climatic vulnerability. However, this assumption remains vastly untested across taxa, and multiple factors may contribute to uncoupling heat tolerance estimates and geographic limits. Our dataset includes 1000 entries of heat tolerance data and maximum temperatures for each species' known geographic limits (hereafter, Tmax). We gathered this information across major animal taxa, including marine fish, terrestrial arthropods, amphibians, non-avian reptiles, birds, and mammals. We first tested if heat tolerance constrains the Tmax of sites where species could be observed. Secondly, we tested if the strength of such restrictions depends on how high Tmax is relative to heat tolerance. Thirdly, we correlated the different estimates of Tmax among them and across species. Restrictions are strong for amphibians, arthropods, and birds but often weak or inconsistent for reptiles and mammals. Marine fish describe a non-linear relationship that contrasts with terrestrial groups. Traditional heat tolerance measures in thermal vulnerability studies, like panting temperatures and the upper set point of preferred temperatures, do not predict Tmax or are inversely correlated to it, respectively. Heat tolerance restricts the geographic warm edges more strongly for species that reach sites with higher Tmax for their heat tolerance. These emerging patterns underline the importance of reliable species' heat tolerance indexes to identify their thermal vulnerability at their warm range edges. Besides, the tight correlations of Tmax estimates across on-land microhabitats support a view of multiple types of thermal challenges simultaneously shaping ranges' warm edges for on-land species. The heterogeneous correlation of Tmax estimates in the ocean supports the view that fish thermoregulation is generally limited, too. We propose new hypotheses to understand thermal restrictions on animal distribution.

Lizard host abundances and climatic factors explain phylogenetic diversity and prevalence of blood parasites on an oceanic island.

Host abundance might favour the maintenance of a high phylogenetic diversity of some parasites via rapid transmission rates. Blood parasites of insular lizards represent a good model to test this hypothesis because these parasites can be particularly prevalent in islands and host lizards highly abundant. We applied deep amplicon sequencing and analysed environmental predictors of blood parasite prevalence and phylogenetic diversity in the endemic lizard Gallotia galloti across 24 localities on Tenerife, an island in the Canary archipelago that has experienced increasing warming and drought in recent years. Parasite prevalence assessed by microscopy was over 94%, and a higher proportion of infected lizards was found in warmer and drier locations. A total of 33 different 18s rRNA parasite haplotypes were identified, and the phylogenetic analyses indicated that they belong to two genera of Adeleorina (Apicomplexa: Coccidia), with Karyolysus as the dominant genus. The most important predictor of between-locality variation in parasite phylogenetic diversity was the abundance of lizard hosts. We conclude that a combination of climatic and host demographic factors associated with an insular syndrome may be favouring a rapid transmission of blood parasites among lizards on Tenerife, which may favour the maintenance of a high phylogenetic diversity of parasites.

Melanistic coloration does not influence thermoregulation in the crepuscular gecko Eublepharis macularius.

Body coloration in ectotherms serves multiple biological functions, including avoiding predators, communicating with conspecific individuals, and involvement in thermoregulation. As ectotherms rely on environmental sources of heat to regulate their internal body temperature, stable melanistic body coloration or color change can be used to increase or decrease heat absorption and heat exchange with the environment. While melanistic coloration for thermoregulation functions to increase solar radiation absorption and consequently heating in many diurnal ectotherms, research on crepuscular and nocturnal ectotherms is lacking. Since crepuscular and nocturnal ectotherms generally absorb heat from the substrate, in these organisms melanistic coloration may have other primary functions beside thermoregulation. As such, in this work we hypothesized that the proportion of dorsal melanistic body coloration would not influence heating and cooling rates in the crepuscular gecko, Eublepharis macularius, and that changes in environmental temperature would not trigger color changes in this species. Temperature measurements of the geckos and of the environment were taken using infrared thermography and temperature loggers. Color data were obtained using objective photography and a newly developed custom software package. We found that body temperature reflected substrate temperatures, and that the proportion of melanistic coloration has no influence on heating or cooling rates or on color changes. These findings support that melanistic coloration in E. macularius may not be used for thermoregulation and strengthen the hypothesis that in animals active in low light conditions, melanistic coloration may be used instead for camouflage or other functions.

Time changes everything: a multispecies analyses of temporal patterns in evaporative water loss.

Increasing trends in environmental temperatures and changes in the hydrological cycle caused by climate change are affecting organisms around the world. Water balance is an important feature of organisms as warmer and drier environments increase water vapour pressure deficit and cutaneous water loss. The aim of our study was to understand the hourly kinetics of losses under water-restricted conditions. In general, these kinetics are thought to be negligible, and values from water loss studies have often been summed or averaged for population and species comparisons. We compiled a cross-species data set of instantaneous water loss (EWLi) of lizards in which weight was recorded every hour for 12 h (a period considered ecologically relevant for lizards) under standardized conditions with minimal disturbance. We statistically tested whether the duration of the experiment affected the values and found that the duration affected 83% of the data sets. In most cases, water loss was significantly higher during the first hour. This is likely a result of increased activity due to acclimation to the experimental conditions. However, as the experiment progressed, other temporal patterns of EWLi occurred that were not consistent between species. In addition, the average value and the first and last values of EWLi changed significantly for most species as the experiment progressed. These results suggest that the hourly kinetics of water loss should not be ignored, while experimental procedures in which EWL is recorded continuously rather than only at the beginning and end of the experiment should be used to find finer temporal variations.

Parthenogenesis in Darevskia lizards: A rare outcome of common hybridization, not a common outcome of rare hybridization.

Hybridization is a common evolutionary process with multiple possible outcomes. In vertebrates, interspecific hybridization has repeatedly generated parthenogenetic hybrid species. However, it is unknown whether the generation of parthenogenetic hybrids is a rare outcome of frequent hybridization between sexual species within a genus or the typical outcome of rare hybridization events. Darevskia is a genus of rock lizards with both hybrid parthenogenetic and sexual species. Using capture sequencing, we estimate phylogenetic relationships and gene flow among the sexual species, to determine how introgressive hybridization relates to the origins of parthenogenetic hybrids. We find evidence for widespread hybridization with gene flow, both between recently diverged species and deep branches. Surprisingly, we find no signal of gene flow between parental species of the parthenogenetic hybrids, suggesting that the parental pairs were either reproductively or geographically isolated early in their divergence. The generation of parthenogenetic hybrids in Darevskia is, then, a rare outcome of the total occurrence of hybridization within the genus, but the typical outcome when specific species pairs hybridize. Our results question the conventional view that parthenogenetic lineages are generated by hybridization in a window of divergence. Instead, they suggest that some lineages possess specific properties that underpin successful parthenogenetic reproduction.

Shared haemogregarine infections in competing lacertids.

In parasite­host interactions host species may differ in their ability to fight parasitic infections, while other ecological interactions, including competition, may differentially alter their physiological state, making them even more susceptible to parasites. In this study, we analyse the haemogregarine blood parasites infecting two competing lizard species, Iberolacerta horvathi and Podarcis muralis, and explore host­parasite relationships under different host competition scenarios. Both species were infected with haemogregarine parasites belonging to the genus Karyolysus. Using the 18S rRNA gene, six new Karyolysus haplotypes were identified clustering with other Central and Eastern European samples, and widely shared between both lizard hosts. Haemogregarine infections were detected at all sampled sites with over 50% of individuals parasitized. Overall, I. horvathi was more frequently and also more intensely parasitized than P. muralis, with higher infection rates observed in syntopy. Males of both species tended to be more frequently infected and showed a higher infection intensity than conspecific females. The results suggest that parasitisation by haemogregarines may be relevant in the dynamics of the competitive relationship between these lizard species. More studies, including immunological response analysis, and the identification of the vectors are needed to better understand host­parasite relationships and competition.

Translation and validation of the “personal evaluation of transitions in treatment (PETIT)” scale for people with schizophrenia.

To adapt the ‘Personal Evaluation of Transitions in Treatment (PETIT)’ scale into Spanish and analyse its psychometric properties on schizophrenic population.

No genomic repercussions of assortative pairing in a colour polymorphic lizard.

Long-term maintenance of colour polymorphisms often depends on the interplay of multiple selective forces. In the common wall lizard (Podarcis muralis), up to three pure and two mosaic ventral colour morphs co-exist across most of its range. Available evidence suggests that colour morphs in this species are maintained through the interaction between sexual and environment-dependent selection. In particular, colour-assortative pairing has been recorded, suggesting some degree of assortative mating. Here, we combined reduced-representation sequencing (ddRADseq) and fine-scale distribution data to explore the effects of assortative pairing on the common wall lizard. Overall, our results do not support any population structure (FST  = 0 and K = 1) nor a significant effect of colour morph or geographic location on genomic differentiation. Therefore, we argue that assortative pairing may not fully translate into assortative mating and genomic differentiation between colour morphs and discuss possible explanations. Nonetheless, we find potential support for an elevated population size and/or source-sink dynamics and debate the potential contribution of other forms of selection to the maintenance of colour polymorphisms in lacertids.

Traducción y validación de la escala personal evaluation of transitions in treatment (PETIT)” para población conesquizofrenia / Translation and validation of the “personal evaluation of transitions in treatment (petit)” scale for schizophrenic population

Objetivo. Adaptar al español la escala Personal Evaluation of Transitions in Treatment (PETIT) y analizar sus propiedades psicométricas en población con esquizofrenia. Metodología. Participaron 223 pacientes en tratamiento ambulatorio con diagnóstico de esquizofrenia según criterios DSM-5. Se utilizaron como gold estándar la variable cumplimiento terapéutico, DAI10 y SMAQ y se analizaron las propiedades psicométricas de la escala en tres momentos (basal, al mes y 6 meses). Resultados. La validez de apariencia (lógica) de la escala es muy elevada. En el análisis factorial exploratorio identificamos que sería necesario eliminar el ítem-7. La fiabilidad de la escala es alta con un alfa-Cronbach de 0,91 demostrando buena consistencia interna. El análisis factorial confirmatorio tras eliminar el ítem-7 obtiene 5 componentes que explican el 57,76% de la varianza. El contenido de la escala es válido para discriminar pacientes con diferente adherencia, respuesta al tratamiento y calidad de vida. El punto de corte de la escala PETIT en español se establece en 24 puntos para ambos sexos; presentando una buena sensibilidad al cambio, y una fuerza de concordancia muy buena para los tres momentos evaluados. Conclusiones. La escala PETIT tras eliminar el ítem7 y utilizando 24 como punto de corte permite detectar cambios en la adherencia al tratamiento, su respuesta y las modificaciones resultantes en la calidad de vida de los pacientes. Su uso como único instrumento que mide todo lo anterior lo hace recomendable en la práctica clínica ya que esta precisa de métodos de evaluación sencillos que no consuman grandes esfuerzos o tiempo.(AU)

Aims. To adapt the ‘Personal Evaluation of Transitions in Treatment (PETIT)’ scale into Spanish and analyse its psychometric properties on schizophrenic population. Method. 223 patients in outpatient treatment diagnosed with schizophrenia according to DSM-5 criteria participated in the study. A defined variable ‘therapeutic compliance’, DAI10 and SMAQ were used as a gold standard and the psychometric properties of the scale were analysed at three time points (baseline, 1 month and 6 months). Results. The scale has very high face (or logical) validity. Exploratory factor analysis showed it would be necessary to eliminate item 7. The reliability of the scale is high (Cronbach’s alpha = 0.91), demonstrating good internal consistency. After eliminating item 7, confirmatory factor analysis obtained 5 components that explained 57,76% of the variance. The content of the scale is valid for discriminating between patients of different treatment adherence, response and quality of life. The cut-off point of the ‘PETIT’ scale in Spanish is set at 24 points for both sexes, with good sensibility to change and very good concordance force over the three time points evaluated. Conclusions. After eliminating item 7 and using ‘24’ as cut-off point, the ‘PETIT’ scale was able to detect changes in both adherence and response to treatment as well as the resulting modifications to the quality of life of patients. Its use as a single instrument to measure all of the above makes it advisable for use in clinical practice, as the evaluationmethods it requires are relatively simple and quick to perform.(AU)

Population Genomics of Wall Lizards Reflects the Dynamic History of the Mediterranean Basin.

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.

Unravelling the origin of the common wall lizards (Podarcismuralis) in south-eastern Europe using mitochondrial evidence.

The origin of the common wall lizards (Podarcismuralis) populations in south-eastern Europe (namely in Bulgaria and Romania), representing the north-eastern range border of this species, was addressed using mitochondrial DNA. We compared cytochrome b sequences from Bulgaria and Romania with those from the contiguous range in Central Europe that are available from previous studies. We recorded five main haplogroups in Bulgaria and Romania, belonging to the Central Balkan clade. However, haplogroup III was recorded in more localities than previously found. Additionally, signs of haplotype admixture were identified in several populations along the Danube River. The presence of the Southern Alps haplotype in one population from Otopeni, Bucharest (Romania) and its close phylogenetic relationships to north Italy populations suggests human-mediated introductions of this wall lizard clade in Romania. Our results confirm that P.muralis can have non-native lineages and admixture through active human-mediated transport.

An integrative analysis of the short-term effects of tail autotomy on thermoregulation and dehydration rates in wall lizards.

Maintaining body temperature is essential for the optimal performance of physiological functions. Ectotherms depend on external heat sources to thermoregulate. However, thermoregulation may be constrained by body condition and hydration state. Autotomy (i.e., the voluntary shed of a body part) evolved in various animal lineages and allowed surviving certain events (such as predator attacks), but it may affect body condition and volume/surface ratios, increase dehydration and constrain thermoregulation. In the framework of a general analysis of the evolution of autotomy, here we assessed the effects of tail loss on the thermal preferences and evaporative water loss rates (EWL) in the lizard Podarcis bocagei, integrating the thermal and hydric factors. We did not observe shifts in the thermal preferences of experimentally autotomized lizards when compared to the controls, which contradicted the hypothesis that they would raise preferred temperature to increase metabolic rates and accelerate regeneration. Evaporative water loss rates were also similar for tailed and tailless individuals, suggesting negligible increase of water loss through the injury and no specific ecophysiological responses after autotomy. Therefore, the changes observed in autotomized lizards in the field are to be considered primarily behavioural, rather than physiological, and thermoregulation could be secondarily affected by behavioural compensations for an increased predation risk after autotomy. Functional studies are necessary to understand how lizards' interaction with the environment is altered after autotomy, and further studies including different dehydration levels would be useful to fully understand the effect of water shortage on lizards' performance after caudal autotomy.

Pleistocene climate fluctuations as the major driver of genetic diversity and distribution patterns of the Caspian green lizard, Lacerta strigata Eichwald, 1831.

Green lizards of the genus Lacerta have served as excellent models for studying the impact of Pleistocene climatic oscillations on genetic structures. The Caspian green lizard, Lacerta strigata, occupies various habitats across the Caucasus and the South Caspian Sea, with the Hyrcanian Forests and north of the Alborz Mountains forming the core of the range. This study aimed to re-examine the phylogenetic relationships of L. strigata with other congeneric members and to assess the genetic structure and historical demography of the species. Furthermore, Species Distribution Models (SDMs) were performed to infer the species' potential habitat suitability and were then projected on climate scenarios reflecting current and past (6 ky and 21 ky before present) conditions. A total of 39 individuals collected from most of the distribution range, together with additional lacertid species sequences from the GenBank database, were examined using mtDNA (Cyt b and 12S ribosomal RNA) and nuclear (C-mos and ß-fibrinogen) sequence data. Based on the phylogenetic analyses, L. strigata was found to be a sister taxon to all other members of the genus. The species included two main clades (regional western and eastern) that diverged in a period between the Early and Middle Pleistocene. Based on the BBM and S-Diva analyses, both dispersal and vicariance events explained the phylogeographic structure of the species in the Hyrcanian Forests. The historical demographic analyses using Bayesian skyline plots showed a mild increase in the effective population size from about 120 Kya for the western regional clade. According to phylogeographic structures and SDMs evidence, as in other species within the region, it appears that the south of the Caspian Sea (Hyrcanian Forests), and the Alborz Mountains acted as multiple refugia during cold periods and promoted expansion outwards amid the warm periods. Overall, the results provided evidence that the genetic structure of the species has been influenced by the Pleistocene climatic fluctuations.

Status of the largest extant population of the critically endangered Aeolian lizard Podarcis raffonei (Capo Grosso, Vulcano island).

The Aeolian wall lizard Podarcis raffonei is an island endemic that survives only on three tiny islets, and on the Capo Grosso peninsula of the Vulcano island, thus is among the European vertebrates with the smallest range and one of the most threatened by extinction. This species is declining due to competition and hybridization with the non-native lizard Podarcis siculus, but a regular monitoring program is lacking. Here we assessed the size and status of the Capo Grosso population of P. raffonei on Vulcano. In September 2015 we captured 30 individuals showing the typical brown phenotype of P. raffonei, while one single male showed a green phenotype, apparently intermediate between P. raffonei and the non-native Podarcis siculus. In May 2017, only 47% of 131 individuals showed the typical brown phenotype (P. raffonei-like) and 53% showed the green phenotype (P. siculus-like). Based on N-mixture models and removal sampling the estimated size of the Capo Grosso population was of 800-1300 individuals in 2017, being similar to 2015; available data suggest that the total range of the species could be as small as 2 ha. The frequency of individuals with the typical P. raffonei phenotype dramatically dropped between two samplings with a parallel increase of individuals displaying the green phenotype. Observation on outdoor captive-bred individuals demonstrates plasticity for colouration in P. raffonei individuals from Capo Grosso, with several individuals showing the typical brown pattern in September 2017 and a green pattern in March 2021. Non-exclusive hypotheses, including hybridization with P. siculus and plasticity in colour pattern of P. raffonei, are discussed to explain the phenotypic shifts of the P. raffonei population of Capo Grosso. While genomic evidence is required to reach conclusions and investigate eventual hybridization, it is urgent to undertake a programme for the monitoring and management of this lizard.

Fluctuating asymmetry as biomarker of pesticides exposure in the Italian wall lizards (Podarcis siculus).

The extensive use of pesticides in agricultural environments produces drastic effects on wildlife, hence the need for less invasive indicators of environmental stress to monitoring the impact of agriculture treatments on biological systems. Fluctuating asymmetry (FA), as measure of developmental instability, has recently been proposed as reliable biomarker of populations stress due to environmental disturbance. We investigate femoral pores (FP) and dorsal head shape (HS) traits in populations of the Italian wall lizard inhabiting agricultural environments to examine whether different pesticide exposures (conventional, organic and control) can cause distinctive degree of FA. High-resolution photographs of FP and HS were taken in the field with a digital camera. The number of FP were counted twice on both sides and HS was analysed using geometric morphometrics with 25 landmarks and 12 semilandmarks. Individuals under conventional management showed higher levels of FA compared to control ones, and females exhibited higher FA levels than males for the FP. However, no significant difference was found for the HS trait. Our study provided evidence that FA may have a real potential as biomarker of population stress in wall lizards, highlighting the importance in the choice of the experimental design and the traits adopted for estimating DI.

Ecophysiology of a lacertid community in the high Moroccan mountains suggests conservation guidelines.

Lizard species may differ in their ecophysiology due to adaptation, plasticity and/or phylogeny. In restrictive environments, ecophysiological differences of species living in sympatry are expected to reveal long-term evolutionary responses to the abiotic environment while competitive interactions should be limited. These influences can be disentangled by combining field monitoring with experimental tests. Here, three lacertid lizard species, Atlantolacerta andreanskyi, Scelarcis perspicillata and Podarcis vaucheri sharing high mountain habitats in Oukaimeden (High Atlas, Morocco), were studied. In the field, spatiotemporal variation of the thermal and hydric environment used by the lizards was monitored using data-loggers. In the lab, thermal and hydric ecophysiology was estimated through assessments of preferred temperatures (Tp) and water loss (WL) rates. Species differed in microhabitat use and, hence, in their exposure to variations in temperature and humidity. However, they only differed in their WL (A. andreanskyi > S. perspicillata > P. vaucheri) while their Tp were similar. Such partial differences of species in in the fundamental niche, likely derived from their long-term independent phylogenetic trajectories, can be used to predict their responses to climate and habitat shifts in this and other parts of their respective ranges. Results also confirm previous suggestions that, together with thermal physiology, hydric physiology plays a prominent role in the organisation of lizard communities in the temperate region.

Evidence from Tarentola mauritanica (Gekkota: Phyllodactylidae) helps validate thermography as a tool to infer internal body temperatures of lizards.

Infrared (IR) thermal imaging has become an increasingly popular tool to measure body temperature of animals. The high-resolution data it provides with short lag and minimum disturbance makes it an appealing tool when studying reptile thermal ecology. However, due to the common phenomenon of regional heterothermy and surface-to-core temperature gradients, it is essential to select the appropriate body part to measure and provide calibrations to accurately infer internal body temperatures. This work follows from a previous study on lacertid lizards to assess the reliability of thermography-measured body temperatures, from several body locations, as a proxy for internal body temperature in lizards. This study focuses on the Moorish gecko, Tarentola mauritanica, due to its distant phylogenetic relationship and its different ecology and morphology from the previously tested species. A total of 60 adult geckos of both sexes and of a range of sizes were tested in thermal gradients and subjected to a sequence of randomly assorted treatments of heating and cooling. The temperatures of the animals were periodically measured with a thermal camera at six different body parts and, immediately after, the cloacal temperature was then measured with a thermocouple probe. Body parts' temperatures, obtained thermographically, were regressed against cloacal temperature using OLS regression and the pairwise correlations were tested using Spearman coefficients. Relationships among all body parts and between all body parts and the cloaca were strong in all cases (R2 > 0.87, Spearman Correlation > 0.95). The observed pattern was very similar to those previously obtained from lacertid lizards. Ultimately, the eye proved to provide the best overall proxy for internal temperature, when accounting for both the slope and intercept of the regression. Hence, this study provides further support for the establishment of the eye as the standard location to infer internal body temperatures of lizards through thermography.

New Insights into Bite Performance: Morphological Trade-Offs Underlying the Duration and Magnitude of Bite Force.

Biting performance is important for feeding, territory defense, and mating in many animals. While maximal bite force is a well-studied trait, other aspects of biting and their variation depending on behavior are rarely considered. Here, we took an innovative approach, where (1) we quantified a novel trait, bite duration in lizards; (2) we examined variation across setups that simulate feeding and antagonistic behavior; and (3) we used F-matrix statistics to investigate how different functional components are optimized for ecological and social demands with respect to individual morphology. Our results did not show differences between the sexes in bite duration, but bite performance varied across experimental setups in males, suggesting a higher functional flexibility in this sex. The investigation of form-function associations revealed that trade-offs, facilitations, and one-to-one relationships are simultaneously involved in the morphological optimization of bite force and duration. Put together, our integrated analysis of two different components of bite performance-force and duration-demonstrates their importance for males in both ecological and social tasks. Our findings also suggest the existence of trade-offs in the morphological optimization of functional components, possibly due to physiological constraints on muscle composition, insertion, and orientation.

Infection of parthenogenetic lizards by blood parasites does not support the "Red Queen hypothesis" but reveals the costs of sex.

Sexual organisms should be better suited than asexual ones in a context of continuous evolution in response to opposite organisms in changing environments ("Red Queen" hypothesis of sex). However, sex also carries costs associated with the maintenance of males and mating (sex cost hypothesis). Here, both non-mutually excluding hypotheses are tested by analysing the infestation by haemogregarines of mixed communities of Darevskia rock lizards composed of parthenogens generated by hybridisation and their bisexual relatives. Prevalence and intensity were recorded from 339 adult lizards belonging to six species from five syntopic localities and analysed using Generalized Mixed-Models (GLMM). Both infestation parameters depended on host-size (like due to longer exposure with age), sex and, for intensity, species. Once accounting for locality and species, males were more parasitized than conspecific females with bisexual species, but no signal of reproductive mode itself on parasitization was recovered. Essentially, male-male interactions increased haemogregarine intensity while females either sexual or asexual had similar reproductive costs when in the same conditions. These findings deviate from the predictions from "Red Queen" dynamics while asymmetric gender costs are here confirmed. Thus, increased parasitization pressure on males adds to other costs, such as higher social interactions and lower fecundity, to explain why parthenogenetic lizards apparently prevail in the short-term evolutionary scale. How this is translated in the long-term requires further phylogenetic analysis.