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The cicada species, Hyalessa fuscata and H. maculaticollis(Hemiptera: Cicadidae), share numerous morphological characters, and their status as distinct species remains controversial. We reconstructed a phylogeny based on two new mitogenomes of H. fuscata from Korea and H. maculaticollis from Japan, in combination with GenBank sequences of H. maculaticollis from China and Japan, and other closely related cicada species. Maximum likelihood and Bayesian inference phylogenies showed that H. fuscata from Korea is more closely related to H. maculaticollis from China than either is to H. maculaticollis from Japan. The time-calibrated Bayesian evolutionary analysis by sampling trees (BEAST) phylogeny indicated that the mainland and insular forms diverged approximately 1.7-2.6 million years ago. This coincides with the formation of the East China Sea land bridge between East Asia and the Japanese archipelago, which would provide a dispersal corridor for Hyalessa from the mainland via the Korean peninsula southeastward to Japan. East Asian H. fuscata is a geographic variant that may be considered synonymous with H. maculaticollis.
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Hemípteros , Teorema de Bayes , Filogenia , República da Coreia , Hemípteros/genética , AnimaisRESUMO
The phylogeography of the Kaloula genus in East Asia is still poorly understood. One of the difficulties is the absence of fossils to corroborate molecular dating estimates. Here, we examined the mitochondrial structure of Kaloula spp. in East Asia and focused on the impact of glaciations on the northernmost species: Kaloula borealis. We determined the phylogenetic relationships, molecular dating, and genetic connectivity assessments within the genus from 1211 bp of concatenated mitochondrial 12S and 16S. The relaxed clock analyses reveal the emergence of Kaloula spp. common ancestor in East and Southeast Asia between the Eocene and Oligocene, c. 38.47 Ma (24.69-53.65). The genetic diversification of lineages then increased on the East Asian Mainland during the Lower Miocene, c. 20.10 (8.73-30.65), most likely originating from the vicariance and radiation triggered by the orogeny of the Qinghai-Tibetan Plateau. Later, the dispersal towards the North East Asian Mainland during the Upper Miocene drove the population diversification of K. borealis c. 9.01 Ma (3.66-15.29). Finally, the central mainland population became isolated following orogenesis events and diverged into K. rugifera during the Pliocene, c. 3.06 Ma (0.02-10.90). The combination of population genetic and barrier analyses revealed a significant genetic isolation between populations of Kaloula spp. matching with the massive Qinling-Daba Mountain chain located in south-central China. Finally, we highlight a young divergence within the Eastern Mainland population of K. borealis, possibly attributed to refugia in south eastern China from which populations later expanded.
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Anuros , Refúgio de Vida Selvagem , Animais , Anuros/genética , Fósseis , Filogenia , FilogeografiaRESUMO
Taxa with vast distribution ranges often display unresolved phylogeographic structures and unclear taxonomic boundaries resulting in hidden diversity. This hypothesis-driven study reveals the evolutionary history of Bufonidae, covering the phylogeographic patterns found in Holarctic bufonids from the West Gondwana to the phylogenetic taxonomy of Asiatic true toads in the Eastern Palearctic. We used an integrative approach relying on fossilized birth-death calibrations, population dynamics, gene-flow, species distribution, and species delimitation modeling to resolve the biogeography of the clade and highlight cryptic lineages. We verified the near-simultaneous Miocene radiations within Western and Eastern Palearctic Bufo, c. 14.49-10.00 Mya, temporally matching with the maximum dust outflows in Central Asian deserts. Contrary to earlier studies, we demonstrated that the combined impacts of long dispersal and ice-age refugia equally contributed to the current genetic structure of Bufo in East Asia. Our findings reveal a climate-driven adaptation in septentrional Eastern Asian Bufo, explaining its range shifts toward northern latitudes. We resolve species boundaries within the Eastern Palearctic Bufo, and redefine the taxonomic and conservation units of the northeastern species: B. sachalinensis and its subspecies.
The east Asian Asiatic toad (also known by the latin name Bufo gargarizans) lives in a wide range of habitats across East Asia including forests, meadows and cultivated land. However, it remains unclear how these toads evolved and became so widespread partly because it has proved difficult for researchers to clearly define the species and what distinguishes it from other closely-related species of toads (collectively known as Bufo toads). Othman et al. combined several bioinformatics techniques to study Asiatic toads and 38 other species of bufonid toads from across the globe. This approach found that Bufo toads first emerged in eastern Asia between 14 and 10 million years ago. This coincides with a point in time when large swathes of land in central Asia turned from adequate to sustain toad populations into desert, suggesting the change in climate prompted the toads to migrate eastwards from central Asia. The Bufo toads then divided into two groups of species: one in mainland East Asia and the other in Japan. Furthermore, the study revealed there is more genetic diversity that is, more variety in the DNA of individuals in Asiatic toads than previously thought. The findings also help to define several other species of Bufo toads more clearly and describe a new toad species restricted to the Korean Peninsula, northeastern China and the Russian Primorye region: the Sakhalin toad (Bufo sachalinensis). This work demonstrates that a large-scale study of many species across the globe can be used to understand how the species evolved and more clearly distinguish one species from another. The findings of Othman et al. will be of interest to both professional and citizen scientists interested in the natural history of Asia. Furthermore, as several species of Bufo toads are in decline in the wild, they provide evidence that may aid future efforts to conserve them.
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Evolução Biológica , Bufonidae , Animais , Bufonidae/genética , Fluxo Gênico , Filogenia , FilogeografiaRESUMO
We de novo assembled the complete mitochondrial genome of the green peach aphid, Myzus persicae, using its genomic DNA isolated from the bell pepper in Korea. The circular mitogenome of M. persicae is 16,936 bp long and contains the standard 37 genes: 13 protein-coding genes, 2 ribosomal RNA genes, and 22 transfer RNA genes, as well as a single control region of 798 bp. Given the high AT ratio (84.1%) of the M. persicae mitogenome, we found, through the comparison of the Chinese M. persicae mitogenomes, that approximately 1.6% of the mitogenome is polymorphic, including 30 single nucleotide polymorphisms (SNPs), 12 insertions and deletions (INDELs), and large sequence variations in the control region. To resolve the phylogenetic position of M. persicae, we analyzed all mitochondrial protein-coding genes from 38 species within the Aphidoidea superfamily, with Adelges laricis as an outgroup. Our M. persicae sample was significantly grouped with three existing M. persicae samples, and the species belonging to the family Aphididae formed a monophyletic clade.
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We have determined the second mitochondrial genome of Myotis bombinus Thomas, 1906 in mainland of Korea. The circular mitogenome of M. bombinus is 17,035 bp long which is slightly shorter than that of the previous mitogenome of M. bombinus. It includes 13 protein-coding genes (PCGs), two ribosomal RNA genes, and 22 transfer RNAs. The base composition was AT-biased (66.1%). Fifty single nucleotide polymorphisms and 14 insertions were identified between two mitogenomes of M. bombinus. Phylogenetic trees show that both M. bominus mitogenomes are clustered in one clade.
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Completed chloroplast genome of Campanula takesimana Nakai isolated from Dokdo island in Korea is 169,719 bp long (GC ratio is 38.8%) and has four subregions: 102,381 bp of large single-copy (37.8%) and 7,750 bp of small single-copy (32.6%) regions are separated by 29,794 bp of inverted repeat (41.3%) regions including 131 genes (87 protein-coding genes, eight rRNAs, and 36 tRNAs). Phylogenetic analyses suggested that C. takesimana from Dokdo Island form a clade with C. takesimana from Ulleungdo Island and that chloroplast genomes of the two accessions are diverged.
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Determining the range, status, ecology and behaviour of species from areas where surveys and samplings are uncommon or difficult to conduct is a challenge, such as in the Democratic People's Republic of Korea (DPR Korea). Here, we used genetic samples, field surveys, call recordings, photographic identification and a literature review to estimate the presence, range and status of amphibians in the DPR Korea. From our combined results and based on the IUCN Red List categories and criteria, we were able to estimate the national threat levels for most species. Our results demonstrated the presence of 18 native species and the suspected presence of Karsenia koreana and two Onychodactylus species. We reported the first record for Rana uenoi in the vicinity of Pyongyang using molecular tools and similarly confirmed the presence of Dryophytes japonicus at the same location. Based on distribution and modelling, we can expect the contact zone between species within the Rana and Onychodactylus genera to be located along the Changbai Massif, a mountain range that marks a shift in ecoregions and acts as a barrier to dispersion. The species richness was higher in the lowlands and at lower latitudes, with such areas populated by up to 11 species, while more northern regions were characterised by species richness of about half of that value. The combination of ecological models and known threats resulted in the recommendation of ten species as threatened at the national level following the IUCN Red List categories and criteria. This high number of threatened species was anticipated based on the high threat level to amphibians in bordering nations and globally. While the ecology of species in the DPR Korea is still understudied, we argue that species relying on agricultural wetlands such as rice paddies are not under imminent threat due to the enduring presence of extensive agricultural landscapes with low rates of chemical use and mechanisation. The maintenance of such landscapes is a clear benefit to amphibian species, in contrast to more industrialised agricultural landscapes in neighbouring nations. In comparison, the status of species dependent on forested habitats is unclear and threat levels are likely to be higher because of deforestation, as in neighbouring nations.
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We have determined mitochondrial genome of A. gossypii isolated from Plantago asiatica in Korea. The circular mitogenome of A. gossypii is 16,045 bp including 13 protein-coding genes, two ribosomal RNA genes, 22 transfer RNAs, and a single control region of 798 bp. Its AT ratio is 83.8%. In comparison this mitogenome to Chinese and Korean A. gossypii mitogenomes, 66 single nucleotide polymorphisms (SNPs) and 176 insertions and deletions (INDELs) and 11 SNPs and 173 INDELs are identified, respectively, presenting similar level to those of Nilaparvata lugens, Laodelphax striatellus, and Spodoptera frugiperda and lower than that of Chilo suppresallis.
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Rapid anthropogenic alterations caused by urbanization are increasing temperatures in urban cores, a phenomenon known as the urban heat island (UHI) effect. Two cicada species, Cryptotympana atrata and Hyalessa fuscata (Hemiptera: Cicadidae), are abundant in metropolitan Seoul where their population densities correlate strongly with UHI intensities. Such a positive correlation between cicada density and UHI intensity may be possible if cicada abundance is linked to a certain thermal tolerance. We tested this hypothesis by investigating variation in morphology and thermal responses of two cicada species along a thermal gradient in Seoul and surrounding areas. The morphological responses were measured by metrics such as length, thorax width and depth, and mass. The thermal responses were measured in terms of minimum flight temperature, maximum voluntary temperature and heat torpor temperature. First, we observed a species-specific variation in thermal responses, in which C. atrata displayed a higher thermal threshold for maximum voluntary and heat torpor temperatures than H. fuscata. Second, a positive association between temperature conditions and body sizes were displayed in females H. fuscata, but not in either conspecific males or C. atrata individuals. Third, C. atrata exhibited similar thermal responses regardless of habitat temperature, while H. fuscata in warmer areas showed an increase in heat tolerance. In addition, H. fuscata individuals with bigger thorax sizes were more heat-tolerant than those with smaller thoraxes. Overall, our research is the first to detect a variation in thermal responses and body size of H. fuscata individuals at a local scale. More investigations would be needed to better understand the adaptation mechanisms of insects linked to UHI effects.
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Adaptação Biológica , Hemípteros/fisiologia , Temperatura , Animais , Feminino , Variação Genética , Modelos Lineares , Masculino , Método de Monte Carlo , Mutação , Seul/epidemiologiaRESUMO
While comparatively few amphibian species have been described on the North East Asian mainland in the last decades, several species have been the subject of taxonomical debates in relation to the Yellow sea. Here, we sampled Dryophytes sp. treefrogs from the Republic of Korea, the Democratic People's Republic of Korea and the People's Republic of China to clarify the status of this clade around the Yellow sea and determine the impact of sea level change on treefrogs' phylogenetic relationships. Based on genetics, call properties, adult morphology, tadpole morphology and niche modelling, we determined the segregated status species of D. suweonensis and D. immaculatus. We then proceeded to describe a new treefrog species, D. flaviventris sp. nov., from the central lowlands of the Republic of Korea. The new species is geographically segregated from D. suweonensis by the Chilgap mountain range and known to occur only in the area of Buyeo, Nonsan and Iksan in the Republic of Korea. While the Yellow sea is the principal element to the current isolation of the three clades, the paleorivers of the Yellow sea basin are likely to have been the major factor for the divergences within this clade. We recommend conducting rapid conservation assessments as these species are present on very narrow and declining ranges.
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Anuros/classificação , Anuros/genética , Oceanos e Mares , Migração Animal , Animais , Anuros/anatomia & histologia , Ásia , Larva/anatomia & histologia , Filogenia , Dinâmica PopulacionalRESUMO
Populations see their range fluctuate in relation to environmental variations, including climate change, and their survival is linked to the maintenance of large enough populations and broad enough distributions during these variations. Most amphibian populations are threatened by numerous ecological and anthropogenic variables acting in synergy with climate change. Accumulating basic ecological data such as range enables the development of population and range dynamics, themselves resulting on adequate conservation plans. Karsenia koreana is the only known Asian plethodontic salamander, occurring in a very restricted area only. Based on presence data, we created an ecological model using six bioclimatic factors with low multicollinearity to define the adequate habitat of the species, and we modelled the predicted suitability of the Korean landscape following four Representative Concentration Pathways (RCPs) predicting climate change scenarios based on CO2 concentrations in 2050 and 2070. The maximum entropy model for the current distribution produced a landscape suitability considerably wider than the current known distribution. The projected ranges for each RCP indicated marked increases, decreases and shifts in areas with suitable landscapes due to climate change. The lowest RCP prediction resulted in an increase in suitable area, although potentially without connectivity with current populations, while the highest RCP predictions resulted in a decrease. Our results highlight the potential negative impact of climate change, thus requiring updates in conservation plans for K. koreana. The methods used here can be replicated with any land-dwelling species, and our results reflect expected range shifts for most amphibians of the northern hemisphere.
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Mudança Climática , Ecossistema , Modelos Teóricos , Urodelos/fisiologia , Animais , Clima , Geografia , República da CoreiaRESUMO
The effects of ice ages on speciation have been well documented for many European and North American taxa. In contrast, very few studies have addressed the consequences of such environmental and topographical changes in North East Asian species. More precisely, the Korean Peninsula offers a unique model to assess patterns and processes of speciation as it hosts the northern- and eastern-most distribution limit of some widespread Asian taxa. Despite this, studies addressing phylogeographic patterns and population genetics in the peninsula and surrounding countries are few and studies for most families are lacking. Here we inferred the phylogenetic relationships of the common toad (Bufo gargarizans) from South Korea and their North East Asian counterpart populations, based on mitochondrial data. Korean B. gargarizans GenBank BLASTs matched few individuals from nearby China, but the presence of a Korean clade suggests isolation on the Korean Peninsula, previous to the last glacial maximum, linked to sea level resurgence. Molecular clock calibrations within this group were used to date the divergence between clades and their relationship to paleo-climatic events in the area. Lack of genetic structure among South Korean populations and strong homogeneity between the Korean and some Chinese localities suggest weak isolation and recent expansion. Geographical projection of continuous coalescent maximum-clade-credibility trees shows an original Chinese expansion towards the Korean Peninsula through the Yellow Sea circa two million years ago with colonisation events dating circa 800 thousand years ago (K. y. a.). Following this colonisation, the data point to outgoing Korean Peninsula dispersal events throughout different periods, towards the North through land, and West through land bridge formations over the Yellow Sea during sea level falls. In accordance, demographic analyses revealed a population expansion in the Koran Peninsula circa 300 K. y. a., likely attributed to glacial cycle fluctuations.