Temperature variation is one of the best‐known and studied factor constraining life history along the altitudinal gradients.
Ectotherms such as insects are sensitive to temperature across all life ...stages, resulting in a wide range of adaptations in populations and species living at different elevations. In butterflies, the egg stage is particularly sensitive to temperature variation as eggs cannot move and deploy behavioural responses to overheating.
Using a gradient polymerase chain reaction thermocycler to finely control temperature treatments, we tested for differences in egg heat tolerance between five closely related Coenonympha (Nymphalidae: Satyrinae) species living at different elevations.
We found strong differences in egg heat tolerance ranges between lowland species (C. arcania (Linnaeus) and C. pamphilus (Linnaeus)) and two high elevation alpine species (C. gardetta (Prunner) and C. cephalidarwiniana Verity). Surprisingly, the third alpine species (C. darwiniana Staudinger) showed a heat tolerance range closer to that of the lowland species than that of alpine species.
The sensitivity of eggs to overheating matched the temperature regimes recorded in the microhabitats utilised for oviposition and may explain the oviposition site selection of females observed in the wild.
The narrower egg heat tolerance of some of alpine species may partly explain the position of their lower elevational limit but also raises concern about the fate of these species in the face of current climate change.
Our results highlight the need to study all life stages, as well as microclimate choice for oviposition, to understand species distribution and the threats to their persistence.
Coenonympha species replace each other along the elevational gradient despite their similar phenotypes, phenology and host plants.
Estimated egg heat tolerance ranges strongly differed between lowland and alpine Coenonympha species but not between populations of the same species from different elevations.
Species‐specific egg heat tolerance range could partly explain elevation range differences as higher thermal maxima occur in lower elevations and could also influence egg laying microhabitat choice.
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.
The description of Vipera walser from the Northern Italian Alps as a new species (Ghielmi et al., 2016, Journal of Zoological Systematics and Evolutionary Research, 54, 161) was one of the most ...unexpected surprises of European herpetology in the 21st century. In mitochondrial (mt) DNA, it is closely related to a group of vipers only present in the Caucasus region and Northeastern Anatolia. However, its morphology is similar to the V. berus populations that inhabit nearby mountains in the Swiss‐Italian Alps, which raises questions on its relationships and status. We thus sequenced five nuclear (nu) genes to determine the position of V. walser relative to V. berus and to the Caucasian/Northeastern Anatolian vipers in nuDNA. We also reanalyzed five previously sequenced mtDNA fragments. NuDNA markers recovered V. walser as closely related to Italian populations of V. berus and not to the Caucasian/Anatolian species, thus contradicting the mtDNA phylogeny. We checked that each of the five mtDNA fragments independently amplified by Ghielmi et al. (2016, Journal of Zoological Systematics and Evolutionary Research, 54, 161) produced individual gene trees compatible with the concatenated mtDNA phylogeny, thus excluding the hypothesis that NUMTs sequencing generated the mtDNA relationships reported by Ghielmi et al. (2016, Journal of Zoological Systematics and Evolutionary Research, 54, 161). Given the low level of nuclear differentiation between V. walser and the Italian population of V. berus, we argue that ancient admixture between V. berus and the ancestral population of V. walser is the most likely explanation for this case of cyto‐nuclear discordance and we discuss the consequences of these results on the systematic status of V. walser.
Résumé
La description de Vipera walser comme une nouvelle espèce des Alpes italiennes du Nord (Ghielmi et al., 2016, Journal of Zoological Systematics and Evolutionary Research, 54, 161) a été l'une des surprises les plus inattendues de l'herpétologie européenne au 21e siècle. Son ADN mitochondrial est étroitement apparenté à celui d’un groupe de vipères uniquement présent autour du Caucase et de l'Anatolie orientale. Cependant, sa morphologie est similaire aux populations de V. berus qui vivent dans la même région des Alpes italiennes, ce qui soulève des questions sur ses relations de parenté et son statut systématique. Nous avons donc séquencé cinq gènes nucléaires pour déterminer la position de V. walser par rapport à V. berus et aux vipères du Caucase/Anatolie orientale pour l'ADN nucléaire. Nous avons également réanalysé les cinq fragments d'ADN mitochondrial précédemment séquencés. Les marqueurs nucléaires ont identifié V. walser comme étroitement apparenté à la population italienne de V. berus et non aux espèces caucasiennes/anatoliennes orientales, contredisant ainsi la phylogénie de l'ADN mitochondrial. Nous avons vérifié que chacun des cinq fragments d'ADN mitochondrial amplifiés indépendamment par Ghielmi et al. (2016, Journal of Zoological Systematics and Evolutionary Research, 54, 161) ont produit des arbres de gènes individuels compatibles avec la phylogénie mitochondriale concaténée, excluant ainsi l'hypothèse selon laquelle le séquençage de NUMTs a généré les relations mitochondriales identifiées par Ghielmi et al. (2016, Journal of Zoological Systematics and Evolutionary Research, 54, 161). Compte tenu du faible niveau de différenciation nucléaire entre V. walser et la population italienne de V. berus, nous pensons qu’une introgression ancienne entre V. berus et la population ancestrale de V. walser est l'explication la plus probable de cette discordance cyto‐nucléaire; nous discutons en conclusion des conséquences de ces résultats sur le statut systématique de V. walser.
Vipera walser appears as embedded in the diversity of Vipera berus in a neighbor‐joining population tree based on mean inter‐populations pairwise distances using concatenated sequences of five independent nuclear genes (3457 bp in total). Despite based on a very small portion of the genome, this result is supported by all analyses of concatenated or gene‐by‐gene alignments and conflicts with the highly divergent mitochondrial DNA of this species.
Abstract
We report the discovery of a population of the exotic North African Water Frog Pelophylax saharicus around the Etang de Berre, on the Mediterranean coast of France, about 25 km north-west of ...Marseille. The animals had been originally identified as P. perezi or P. kl. grafi by a combination of acoustic and morphological characters and their true identity was not revealed until three samples from one locality were included in a large-scale genomic work dedicated to the genus Pelophylax. Mitochondrial barcoding of the samples from other areas around Etang de Berre did not detect any native P. perezi or P. kl. grafi and confirmed that P. saharicus has spread to several localities, does reproduce and has been present since 2011 at least. We suggest that dedicated field work is needed as soon as possible to (i) map the extant of P. saharicus’s distribution around the Etang de Berre, (ii) establish if populations of the native P. perezi – kl. grafi system still persist around the Etang de Berre or not and (iii) check if P. saharicus has spread to neighboring areas or not. Depending on the answers to these three questions, local conservationists will need to evaluate the feasibility and relevance of any action to control the spread of this new invasive species and attempt to eradicate it.
The evolution of migration routes in birds remains poorly understood as changes in migration strategies are rarely observed on contemporary timescales.1–3 The Richard’s Pipit Anthus richardi, a ...migratory songbird breeding in Siberian grasslands and wintering in Southeast Asia, has only recently become a regular autumn and winter visitor to western Europe. Here, we examine whether this change in occurrence merely reflects an increase in the number of vagrants, that is, “lost” individuals that likely do not manage to return to their breeding grounds, or represents a new migratory strategy.4–6 We show that Richard’s Pipits in southwestern Europe are true migrants: the same marked individuals return to southern France in subsequent winters and geo-localization tracking revealed that they originate from the western edge of the known breeding range. They make an astonishing 6,000 km journey from Central Asia across Eurasia, a very unusual longitudinal westward route among Siberian migratory birds.7,8 Climatic niche modeling using citizen-science bird data suggests that the winter niche suitability has increased in southwestern Europe, which may have led to increased winter survival and eventual successful return journey and reproduction of individuals that initially reached Europe as autumn vagrants. This illustrates that vagrancy may have an underestimated role in the emergence of new migratory routes and adaptation to global change in migratory birds.9,10 Whatever the underlying drivers and mechanisms, it constitutes one of the few documented contemporary changes in migration route, and the first longitudinal shift, in a long-distance migratory bird.
Display omitted
•Richard’s Pipit normally breeds in Siberia and winters in southern Asia•The species has recently increased in Europe from occasional to regular visitor•Birds undertake a rare westward seasonal migration across Eurasia to southern Europe•Vagrancy and climate change likely promoted the establishment of this migration route
Richard’s Pipit is an Asian migratory passerine that normally winters in Southeast Asia. Dufour et al. find that the species is now a regular migrant to Europe. Vagrancy probably allowed the colonization of this new wintering area, helped by an increase of wintering niche suitability due to climate change.
We present the first chromosome-level genome assembly and annotation of the pearly heath Coenonympha arcania, generated with a PacBio HiFi sequencing approach and complemented with Hi-C data. We ...additionally compare synteny, gene, and repeat content between C. arcania and other Lepidopteran genomes. This reference genome will enable future population genomics studies with Coenonympha butterflies, a species-rich genus that encompasses some of the most highly endangered butterfly taxa in Europe.
The Buff-bellied Pipit Anthus rubescens comprises two allopatric subspecies groups: A. r. rubescens and A. r. alticola in North America and A. r. japonicus in north-east Asia. Despite their great ...morphological resemblance in breeding plumage, most individuals can be assigned to one or the other subspecies group in non-breeding plumage. Allopatric distributions, morphological differentiation and previously reported molecular divergence suggested the need for additional taxonomic study to assess the rank of these two populations. To resolve the taxonomy of the Buff-bellied Pipit species complex we analysed i) two mitochondrial DNA (mtDNA) loci and ii) nine bioacoustic parameters across 69 sound recordings (338 flight calls) recovered from public databases using principal component analysis and Euclidean distance measures. By comparing our mtDNA and call divergence measures with similar values measured between long-recognised species pairs of the genus, we show that the level of mitochondrial and acoustic divergence between the two Buff-bellied Pipit subspecies groups is typical of species-level divergence in the genus Anthus. Therefore, we recommend splitting the Buff-bellied Pipit species complex into two species: Anthus rubescens (American Pipit) and Anthus japonicus (Siberian Pipit). Our results also suggest that the Water Pipit A. spinoletta deserves taxonomic reassessment as its lineages are highly divergent in acoustics and mtDNA, while mtDNA relationships suggest paraphyly relative to the Rock Pipit A. petrosus. Our work highlights the crucial importance of integrative approaches in taxonomy and the usefulness of bioacoustics in studying cryptic diversity.
Abstract
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 2n = 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.
