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Conspicuous body colours and colour polymorphism have been hypothesized to increase rates of speciation. Conspicuous colours are evolutionary labile, and often involved in intraspecific sexual signalling and thus may provide a raw material from which reproductive isolation can easily evolve, while polymorphism could favour rapid evolution of new lineages through morphic speciation. Here, we investigated the influence of the presence/absence of conspicuous colourations, and of colour polymorphism on the speciation of Lacertids. We used several state-dependent diversification models, and showed that, regardless of the methods, conspicuous colourations and colour polymorphism were not related to species speciation. While the lack of correlation between conspicuous colourations and speciation rates is in line with most of the literature testing this hypothesis, the results for colour polymorphism contradict previous studies, and question the generality of the morphic speciation hypothesis.

Aim: Discontinuity in the distribution of genetic diversity (often based on mtDNA) is usually interpreted as evidence for phylogeographic breaks, underlying vicariant units. However, a misleading signal of phylogeographic break can arise in the absence of barrier to gene flow, under mechanisms of isolation by distance (IBD). How and under which conditions phylogeographic breaks can be reliably differentiated from populations evolving under IBD remain unclear. Here, we use multi-locus sequence data from a widely distributed lizard species to address these questions in an empirical setting. Location: Morocco. Taxon: Spiny-footed lizard (Acanthodactylus erythrurus), Squamata: Lacertidae. Methods: Using 325 samples from 40 localities, we identified genetic discontinuities within A. erythrurus based on a mitochondrial fragment and nine nuclear markers independently. Using the nuclear markers, we then applied linear regression models to investigate whether genetic divergence could be explained by geographical distances alone, or barriers to gene flow (real phylogeographic breaks). Results: A. erythrurus is characterized by an important mitochondrial diversity, with 11 strongly supported phylogeographic lineages with a crown age of 6 Mya. Nuclear markers, however, yielded weak phylogenetic support for these lineages. Using clustering methods based on genotypes at nine nuclear loci, we identified phylogeographic clusters that were partly discordant with the mtDNA lineages. Tests of IBD delimited at least four groups of populations separated by barriers to gene flow, but unambiguous separation of vicariance from IBD remained challenging in several cases. Main conclusions: The genetic diversity of A. erythrurus originates from a mix of IBD and vicariance, which were difficult to distinguish, and resulted in similar levels of mitochondrial differentiation. These results highlight that phylogeographic breaks inferred from mitochondrial data should be further investigated using multi-locus data and explicit testing to rule out alternative processes generating discontinuities in mitochondrial diversity, including IBD. We identified four groups of populations within A. erythrurus, separated by barriers to gene flow, but even using nine independent nuclear makers the power of our approach was limited, and further investigation using genome-wide data will be required to resolve the phylogeographic history of this species.

Male homosexual orientation remains a Darwinian paradox, as there is no consensus on its evolutionary (ultimate) determinants. One intriguing feature of homosexual men is their higher male birth rank compared to heterosexual men. This can be explained by two non-exclusive mechanisms: an antagonistic effect (AE), implying that more fertile women have a higher chance of having a homosexual son and to produce children with a higher mean birth rank, or a fraternal birth effect (FBOE), where each additional older brother increases the chances for a male embryo to develop a homosexual orientation due to an immunoreactivity process. However, there is no consensus on whether both FBOE and AE are present in human populations, or if only one of these mechanisms is at play with its effect mimicking the signature of the other mechanism. An additional sororal birth order effect (SBOE) has also recently been proposed. To clarify this situation, we developed theoretical and statistical tools to study FBOE and AE independently or in combination, taking into account all known sampling biases. These tools were applied on new individual data, and on various available published data (two individual datasets, and all relevant aggregated data). Support for FBOE was apparent in aggregated data, with the FBOE increasing linearly with fertility. The FBOE was also supported in two individual datasets. An SBOE is generated when sampling in presence of FBOE, suggesting that controlling for FBOE is required to avoid artefactual SBOE. AE was not supported in individual datasets, including the analysis of the extended maternal family. The evolutionary implications of these findings are discussed.

When environmental conditions are unpredictable, expressing alternative phenotypes spreads the risk of failure, a mixed strategy called bet-hedging. In the southern part of its range, the Parsley Frog Pelodytes punctatus breeds both in autumn and in spring. Our aim was to study the breeding phenology and reproductive success associated with the use of those two seasonal niches to understand how this breeding strategy can be maintained. Field surveys revealed that breeding phenology was typically bimodal with a higher breeding effort in autumn. More importantly, in spring, the survival rate of offspring was severely reduced by the presence of autumn tadpoles, indicating a clear priority effect. However, the autumn cohort often failed to survive over winter, in which case spring cohorts were often successful. Based on those results, we constructed a model in which females can allocate a variable portion of eggs to each season and added a priority effect. We conclude that the existence of the two breeding seasons may indeed constitute a bet-hedging strategy.

Aim: Deserts represent dynamic ecosystems that support communities of endemic and specialised species. We analysed the role of present and past climatic conditions in shaping the distribution of the widespread Bunopus geckos in the Arabian and south‐west Asian deserts. We studied their phylogeographic and demographic history to test whether the Bunopus geckos colonised Arabia from Asia or, vice versa, Asia from Arabia and to identify migration corridors that have historically enabled the dispersal of Bunopus geckos. Location: The Middle East, especially the Arabian Peninsula. Taxon: Genus Bunopus (Squamata; Gekkonidae). Methods: We generated sequence data for four genes and performed maximum likelihood, Bayesian inference and time‐calibrated phylogenetic analyses and ancestral area reconstruction to infer the phylogenetic and biogeographic history of the genus. We modelled the species' distribution and projected it to several past time periods spanning from mid‐Pliocene to the present. We analysed contemporary landscape connectivity across the peninsula to identify dispersal corridors that enable migration and promote gene flow among Bunopus populations in Arabia. Results: Bunopus is formed by deeply divergent lineages that correspond to up to eight candidate species. The genus originated in southwest Asia and dispersed to Arabia in the late Miocene. The Arabian populations were stable through most of their history in terms of size and distribution extent. Major corridors for contemporary Bunopus dispersal stretch along the eastern Arabian coasts from where they cross through the peninsula to the northern Red Sea coasts. Main Conclusions: The evolutionary history of Bunopus was substantially influenced by paleoenvironmental conditions. The generalist habits and ground‐dwelling lifestyle enabled the geckos to colonise most of the arid regions of southwest Asia, with Arabia being colonised from the Iranian Plateau in the late Miocene. The distribution extent of Bunopus responded to the past climatic and habitat oscillations; the range was fragmented during moist climatic phases, and it expanded in times of increased aridity. The genus requires taxonomic revision to formally assess its diversity. Based on the results obtained in this study, Crossobamon orientalis is reassigned to Bunopus. [ABSTRACT FROM AUTHOR]

MtDNA barcoding is regularly applied to determine the provenance of invasive species. Variation in spatial genetic structuring across a species' range, typically high within glacial refugia and low in postglacially colonized areas, influences the precision of this approach. The palmate newt (Lissotriton helveticus) has been introduced north of its native range inside the Netherlands. We conduct mtDNA barcoding to try and retrace the origin of the introduced localities. A large increase in sample size, particularly focusing on temperate Europe, emphasizes that the palmate newt shows practically no genetic variation outside the Iberian Peninsula glacial refugium. While we find a haplotype previously only known from the Iberian Peninsula inside the native range in Belgium, the haplotype present in the introduced Dutch populations occurs widely throughout the native range north of the Iberian Peninsula. Although mtDNA barcoding can be a powerful tool in invasion biology, the palmate newt case exposes its limitations. [ABSTRACT FROM AUTHOR]

The Pelophylax genus comprises two main hybridogenetic systems resulting from hybridization between Pelophylax ridibundus and other species: the P. lessonae-esculentus (LE) system and the P. perezi-grafi (PG) system, whose distribution ranges lie partly (LE) or entirely (PG) outside the natural distribution of P. ridibundus. The introductions and subsequent expansions of P. ridibundus in many areas naturally inhabited by these hybridogenetic systems have led to their decrease or local extinction. One of the major impediments to efficient population surveys and conservation measures for these systems is the difficulties of reliable species identification due to their similar morphology and poorly documented vocalizations, especially for the PG system. Our aim in this work was to design a reliable method of acoustic identification to distinguish the taxa composing the hybridogenetic systems from P. ridibundus and to assess the possibility of separating the PG and LE systems by their vocalizations. Our acoustic identification methods proved highly accurate to separate the PG and LE systems from P. ridibundus but only a fraction of the PG and LE calls can be identified. [ABSTRACT FROM AUTHOR]

Aim: While the evolution of seasonal migration and its association with biogeography have been the subject of numerous studies, its influence on species diversification has rarely been examined. The aim of this study is to explain the atypical latitudinal diversity gradient in shorebirds: did seasonal migration influence diversification and did the gradient evolve from higher in situ diversification or repeated transitions? Location: Global. Time Period: Palaeogene to present. Major Taxa Studied: Order Charadriiformes (shorebirds and allies). Shorebirds include the species with the longest annual migrations in birds and exhibit an inverse latitudinal diversity gradient, with more species breeding toward higher latitudes. Methods: We first assessed the temporal and geographical framework of the evolution of migration using a newly reconstructed time‐calibrated phylogeny, and using the fossil record as a complementary source of information. We then used hidden state speciation and extinction models to test whether diversification and thus the latitudinal diversity gradient has been shaped by migratory behaviour or species latitudinal distribution. Results: We found that the ancestor of Charadriiformes was likely a tropical year‐round resident and that the current clade's distribution of diversity was not shaped by dispersal events out of the tropics but rather by higher in situ diversification in temperate biomes compared to tropical biomes. Seasonal migration did not affect diversification rate in our models. However, the evolution of seasonal migration seems to be a prerequisite to breed in temperate biomes, indirectly enabling the higher diversification observed in temperate biomes. Main Conclusions: Our results bring original insights into how the migratory behaviour acted as a precursor in the diversification and biogeographical history of a large bird clade, ultimately shaping an atypical latitudinal diversity gradient. [ABSTRACT FROM AUTHOR]

Palearctic water frogs (genus Pelophylax) are an outstanding model in ecology and evolution, being widespread, speciose, either threatened or threatening to other species through biological invasions, and capable of siring hybrid offspring that escape the rules of sexual reproduction. Despite half a century of genetic research and hundreds of publications, the diversity, systematics and biogeography of Pelophylax still remain highly confusing, in no small part due to a lack of correspondence between studies. To provide a comprehensive overview, we gathered >13,000 sequences of barcoding genes from >1700 native and introduced localities and built multigene mitochondrial (~17 kb) and nuclear (~10 kb) phylogenies. We mapped all currently recognized taxa and their phylogeographic lineages (>40) to get a grasp on taxonomic issues, cyto‐nuclear discordances, the genetic makeup of hybridogenetic hybrids, and the origins of introduced populations. Competing hypotheses for the molecular calibration were evaluated through plausibility tests, implementing a new approach relying on predictions from the anuran speciation continuum. Based on our timetree, we propose a new biogeographic paradigm for the Palearctic since the Paleogene, notably by attributing a prominent role to the dynamics of the Paratethys, a vast paleo‐sea that extended over most of Europe. Furthermore, our results show that distinct marsh frog lineages from Eastern Europe, the Balkans, the Near East, and Central Asia (P. ridibundus ssp.) are naturally capable of inducing hybridogenesis with pool frogs (P. lessonae). We identified 14 alien lineages (mostly of P. ridibundus) over ~20 areas of invasions, especially in Western Europe, with genetic signatures disproportionally pointing to the Balkans and Anatolia as the regions of origins, in line with exporting records of the frog leg industry and the stocks of pet sellers. Pelophylax thus emerges as one of the most invasive amphibians worldwide, and deserves much higher conservation concern than currently given by the authorities fighting biological invasions. [ABSTRACT FROM AUTHOR]

North Africa is the most important centre of diversification for the skinks of the genus Chalcides. Morocco alone is inhabited by 16 species of which nine are endemic, while eight species are known from Algeria, none of them endemic. We add here to this diversity a taxon that was first collected by Paul Pallary in 1925, discussed by Pellegrin in 1926, and whose status has been debated by several authors since without reaching a satisfactory consensus. In 2003 and 2008, two specimens with the same habitus as Pallary's specimen were found near Missour (Morocco) and near Djelfa (Algeria), respectively. A molecular analysis based on mitochondrial and nuclear genes shows that these two recent individuals belong to an undefined lineage that is sister to Chalcides montanus, and that we describe here as a new subspecies. It shares many morphological features with the nominate subspecies, but differs most prominently in its colour pattern of five black stripes in the first third of the dorsum, ocelli on the dorsum and on the flanks that disappear roughly in the first third or half of the body, and two broad light dorsolateral bands that disappear around midbody; its genetic divergence is estimated at 4.2% in cytochrome b sequence and 0.8% in a concatenated alignment of several nuclear loci. This new taxon is presently known from three specimens and two localities in the Hauts Plateaux of eastern Morocco and Algeria. [ABSTRACT FROM AUTHOR]

Uncertainties on species taxonomy and distribution are major factors hampering efficient conservation planning in the current context of biodiversity erosion, even concerning widespread and abundant species in relatively well‐studied regions. Species delimitation have long been based on phylogenetic analyses of a small number of standard markers, but accurate lineage identification through this approach can be hampered by incomplete lineage sorting, introgression or isolation by distance. In that context, analyses of introgression patterns at secondary contact zones offer an interesting alternative by allowing a direct estimation of reproductive isolation, especially when using genome‐wide markers. Here, we investigated a contact zone between two genetic groups of the Spiny‐footed Lizard Acanthodactylus erythrurus (Schinz, 1833) in Morocco, whose status as separate lineages remained disputed in previous multilocus studies. Based on thousands of genome‐wide markers obtained through a RADseq approach, we confirmed that they represent distinct evolutionary lineages. Furthermore, the transition at their contact zone was very steep, with spatially restricted gene flow, highlighting levels of reproductive isolation consistent with species‐level lineages. Our study further illustrates the power of RADseq‐based studies of contact zones to understand cryptic diversity in non‐model organisms. [ABSTRACT FROM AUTHOR]

Hybrid taxa from the genus Pelophylax can propagate themselves in a modified way of sexual reproduction called hybridogenesis ensuring the formation of clonal gametes containing the genome of only one parental (host) species. Pelophylax grafi from South-Western Europe is a hybrid composed of P. ridibundus and P. perezi genomes and it lives with a host species P. perezi (P-G system). Yet it is unknown, whether non-Mendelian inheritance is fully maintained in such populations. In this study, we characterize P. perezi and P. grafi somatic karyotypes by using comparative genomic hybridization, genomic in situ hybridization, fluorescent in situ hybridization, and actinomycin D-DAPI. Here, we show the homeology of P. perezi and P. grafi somatic karyotypes to other Pelophylax taxa with 2 n = 26 and equal contribution of ridibundus and perezi chromosomes in P. grafi which supports F1 hybrid genome constitution as well as a hemiclonal genome inheritance. We show that ridibundus chromosomes have larger regions of interstitial (TTAGGG)n repeats flanking the nucleolus organizing region on chromosome no. 10 and a high quantity of AT pairs in the centromeric regions. In P. perezi , we found species-specific sequences in metaphase chromosomes and marker structures in lampbrush chromosomes. Pericentromeric RrS1 repeat sequence was present in perezi and ridibundus chromosomes, but the blocks were stronger in ridibundus. Various cytogenetic techniques applied to the P-G system provide genome discrimination between ridibundus and perezi chromosomal sets. They could be used in studies of germ-line cells to explain patterns of clonal gametogenesis in P. grafi and broaden the knowledge about reproductive strategies in hybrid animals. [ABSTRACT FROM AUTHOR]

Dispersal has major impacts on population dynamics, population genetics and evolution, and also is critical for population management and conservation. Dispersal is frequently sex‐ and age‐specific, but current knowledge is strongly taxonomically biased toward birds and mammals.Here, we provide estimates of dispersal in a threatened freshwater turtle species, the European pond turtle Emys orbicularis. Based on 15 years of capture‐mark‐recapture (CMR) monitoring and DNA samples from 194 individuals, we quantified both demographic and genetic dispersal between three sites separated by 1.5–3.5 km. We also investigated the effect of age and sex on dispersal.Direct (CMR) and indirect (genetic) approaches provided consistent results, showing that the studied sites are connected with a flow of about one to three dozen migrants per generation. Dispersal was both age‐ and sex‐biased in this species, with frequent dispersal of adult males and a strong philopatry of juveniles (of both sexes) and adult females.The network of canals and marshes allow effective dispersal to occur among the three study sites despite the relatively large distance separating them (≤3.5 km).The strong philopatry of juveniles contrasts with the frequently higher dispersal rate in young birds and mammals and shows the relevance of investigating dispersal in various taxonomic groups. Our results provide useful information for the conservation of European pond turtle populations. [ABSTRACT FROM AUTHOR]