RESUMO
Song is considered to play an important role in the maintenance of prezygotic reproductive isolation between closely related songbird species. Therefore, song mixing in a contact zone between closely related species is often considered as evidence of hybridization. The Sichuan Leaf Warbler Phylloscopus forresti and the Gansu Leaf Warbler Phylloscopus kansuensis, which diverged 2 million years ago, have formed a contact zone in the south of the Gansu Province of China, where mixed songs have been observed. In this study, we investigated the potential causes and consequences of song mixing by integrating bioacoustic, morphological, mitochondrial, and genomic data with field ecological observations. We found that the two species display no apparent morphological differences, whereas their songs differ dramatically. We demonstrated that â¼11% of the males in the contact zone sang mixed songs. Two males singing mixed song were genotyped, and both were found to be P. kansuensis. Despite the presence of mixed singers, population genomic analyses detected no signs of recent gene flow between the two species, although two possible cases of mitochondrial introgression were identified. We conclude that the rather limited song mixing does not lead to, or result from, hybridization, and hence does not result in the breakdown of reproductive barriers between these cryptic species.
Assuntos
Passeriformes , Aves Canoras , Masculino , Animais , Aves Canoras/genética , Fluxo Gênico , Passeriformes/genética , Isolamento Reprodutivo , Genômica , Vocalização AnimalRESUMO
Historical specimens from museum collections provide a valuable source of material also from remote areas or regions of conflict that are not easily accessible to scientists today. With this study, we are providing a taxon-complete phylogeny of snowfinches using historical DNA from whole skins of an endemic species from Afghanistan, the Afghan snowfinch, Pyrgilauda theresae. To resolve the strong conflict between previous phylogenetic hypotheses, we generated novel mitogenome sequences for selected taxa and genome-wide SNP data using ddRAD sequencing for all extant snowfinch species endemic to the Qinghai-Tibet Plateau (QTP) and for an extended intraspecific sampling of the sole Central and Western Palearctic snowfinch species (Montifringilla nivalis). Our phylogenetic reconstructions unanimously refuted the previously suggested paraphyly of genus Pyrgilauda. Misplacement of one species-level taxon (Onychostruthus tazcanowskii) in previous snowfinch phylogenies was undoubtedly inferred from chimeric mitogenomes that included heterospecific sequence information. Furthermore, comparison of novel and previously generated sequence data showed that the presumed sister-group relationship between M. nivalis and the QTP endemic M. henrici was suggested based on flawed taxonomy. Our phylogenetic reconstructions based on genome-wide SNP data and on mitogenomes were largely congruent and supported reciprocal monophyly of genera Montifringilla and Pyrgilauda with monotypic Onychostruthus being sister to the latter. The Afghan endemic P. theresae likely originated from a rather ancient Pliocene out-of-Tibet dispersal probably from a common ancestor with P. ruficollis. Our extended trans-Palearctic sampling for the white-winged snowfinch, M. nivalis, confirmed strong lineage divergence between an Asian and a European clade dated to 1.5 - 2.7 million years ago (mya). Genome-wide SNP data suggested subtle divergence among European samples from the Alps and from the Cantabrian mountains.
Assuntos
Genoma Mitocondrial , Passeriformes , Filogenia , Animais , Passeriformes/genética , Passeriformes/classificação , Polimorfismo de Nucleotídeo Único , DNA Mitocondrial/genética , Análise de Sequência de DNA , MuseusRESUMO
Speciation generally involves a three-step process--range expansion, range fragmentation and the development of reproductive isolation between spatially separated populations. Speciation relies on cycling through these three steps and each may limit the rate at which new species form. We estimate phylogenetic relationships among all Himalayan songbirds to ask whether the development of reproductive isolation and ecological competition, both factors that limit range expansions, set an ultimate limit on speciation. Based on a phylogeny for all 358 species distributed along the eastern elevational gradient, here we show that body size and shape differences evolved early in the radiation, with the elevational band occupied by a species evolving later. These results are consistent with competition for niche space limiting species accumulation. Even the elevation dimension seems to be approaching ecological saturation, because the closest relatives both inside the assemblage and elsewhere in the Himalayas are on average separated by more than five million years, which is longer than it generally takes for reproductive isolation to be completed; also, elevational distributions are well explained by resource availability, notably the abundance of arthropods, and not by differences in diversification rates in different elevational zones. Our results imply that speciation rate is ultimately set by niche filling (that is, ecological competition for resources), rather than by the rate of acquisition of reproductive isolation.
Assuntos
Altitude , Ecossistema , Especiação Genética , Aves Canoras/classificação , Aves Canoras/fisiologia , Animais , Tamanho Corporal , China , Índia , Filogenia , Reprodução , Aves Canoras/anatomia & histologia , TibetRESUMO
A recent full species-level phylogeny of tits, titmice and chickadees (Paridae) has placed the Chinese endemic black-bibbed tit (Poecile hypermelaenus) as the sister to the Palearctic willow tit (P. montanus). Because this sister-group relationship is in striking disagreement with the traditional affiliation of P. hypermelaenus close to the marsh tit (P. palustris) we tested this phylogenetic hypothesis in a multi-locus analysis with an extended taxon sampling including sixteen subspecies of willow tits and marsh tits. As a taxonomic reference we included type specimens in our analysis. The molecular genetic study was complemented with an analysis of biometric data obtained from museum specimens. Our phylogenetic reconstructions, including a comparison of all GenBank data available for our target species, clearly show that the genetic lineage previously identified as P. hypermelaenus actually refers to P. weigoldicus because sequences were identical to that of a syntype of this taxon. The close relationship of P. weigoldicus and P. montanus - despite large genetic distances between the two taxa - is in accordance with current taxonomy and systematics. In disagreement with the previous phylogenetic hypothesis but in accordance with most taxonomic authorities, all our P. hypermelaenus specimens fell in the sister clade of all western and eastern Palearctic P. palustris. Though shared haplotypes among the Chinese populations of the two latter species might indicate mitochondrial introgression in this part of the breeding range, further research is needed here due to the limitations of our own sampling.
Assuntos
Passeriformes/classificação , Animais , China , Código de Barras de DNA Taxonômico , DNA Mitocondrial/genética , Loci Gênicos , Passeriformes/genética , Filogenia , Filogeografia , Especificidade da EspécieRESUMO
We investigated the phylogeny and biogeographic history of the Holarctic harvestmen genus Sabacon, which shows an intercontinental disjunct distribution and is presumed to be a relatively old taxon. Molecular phylogenetic relationships of Sabacon were estimated using multiple gene regions and Bayesian inference for a comprehensive Sabacon sample. Molecular clock analyses, using relaxed clock models implemented in BEAST, are applied to date divergence events. Biogeographic scenarios utilizing S-DIVA and Lagrange C++ are reconstructed over sets of Bayesian trees, allowing for the incorporation of phylogenetic uncertainty and quantification of alternative reconstructions over time. Four primary well-supported subclades are recovered within Sabacon: (1) restricted to western North America; (2) eastern North American S. mitchelli and sampled Japanese taxa; (3) a second western North American group and taxa from Nepal and China; and (4) eastern North American S. cavicolens with sampled European Sabacon species. Three of four regional faunas (wNA, eNA, East Asia) are thereby non-monophyletic, and three clades include intercontinental disjuncts. Molecular clock analyses and biogeographic reconstructions support nearly simultaneous intercontinental dispersal coincident with the Eocene-Oligocene transition. We hypothesize that biogeographic exchange in the mid-Tertiary is likely correlated with the onset of global cooling, allowing cryophilic Sabacon taxa to disperse within and among continents. Morphological variation supports the divergent genetic clades observed in Sabacon, and suggests that a taxonomic revision (e.g., splitting Sabacon into multiple genera) may be warranted.
Assuntos
Aracnídeos/classificação , Evolução Molecular , Filogenia , Animais , Aracnídeos/genética , Teorema de Bayes , Ásia Oriental , Modelos Genéticos , América do Norte , Análise de Sequência de DNARESUMO
Afrocanarian blue tits (Cyanistes teneriffae) have a scattered distribution on the Canary Islands and on the North African continent. To date, the Canary Islands have been considered the species' main Pleistocene evolutionary center, but their colonization pathways remain uncertain. We set out to reconstruct a dated multi-gene phylogeny and ancestral ranges for Cyanistes tit species including the currently unstudied, peripheral Libyan population of C. t. cyrenaicae. In all reconstructions the most easterly and westerly peripheral populations (in Libya and on La Palma) represented basal offshoots of C. teneriffae. These two peripheral populations shared all four major indels and differed in this respect from all other members of the Afrocanarian core group. The basal split of Afrocanarian blue tits from their European relatives was dated to the early Pliocene. The two ancestral area reconstructions were contradictory and suggested either a Canarian or a North African origin of C. teneriffae - but unambiguously ruled out a continental European ancestral range. We conclude that the peripheral populations of C. teneriffae represent relic lineages of a first faunal interchange, presumably downstream colonization from North Africa to the Canary Islands. Subsequent eastward stepping-stone colonization within the Canarian Archipelago culminated in a very recent late (possibly even post-) Pleistocene back-colonization from the Canary Islands to North Africa.
Assuntos
Migração Animal , DNA Mitocondrial/genética , Filogenia , África do Norte , Animais , Aves , Genética Populacional , EspanhaRESUMO
A cavernicolous harvestman species, Nemaspela kotia sp. nov., is described from the Kotia Cave (=Kotiasklde Cave) in Zemo Imereti plateau, Imereti Region, West Georgia. Its males lack a cheliceral apophysis, a feature shared with the Georgian cave-dwelling Nemaspela femorecurvata Martens, 2006 and N. prometheus Martens, Maghradze & Barjadze, 2021. Besides, Nemaspela melouri Martens, Maghradze & Barjadze, 2021, known only from its type locality, is found in Solkota Cave (Tskaltubo Municipality, Sataplia-Tskaltubo karst massif, Imereti region, West Georgia). A key for the identification of the known species of Nemaspela is provided.
Assuntos
Aracnídeos , Mustelidae , Animais , Masculino , República da GeórgiaRESUMO
Tegestria altmannae sp. nov. is described and illustrated based on male and female specimens collected in Malaysia. It is characterized by the unarmed dorsal scutum, and basal segment of chelicerae dorsally with three seta-tipped tubercles. The type species of the monotypic genus Gintingius Roewer, 1938, G. robustus Roewer, 1938, is treated as a new synonym of Tegestria coniata Roewer, 1938 and the genus Gintingius as a new synonym of Tegestria Roewer, 1936, accordingly.
Assuntos
Aracnídeos , Animais , Feminino , Masculino , Aracnídeos/classificaçãoRESUMO
We provide a molecular phylogeny for Old World swifts of genera Apus and Tachymarptis (tribe Apodini) based on a taxon-complete sampling at the species level. Phylogenetic reconstructions were based on two mitochondrial (cytochrome b, 12S rRNA) and three nuclear markers (introns of fibrinogen and glyceraldehyde 3-phosphate dehydrogenase plus anonymous marker 12884) while the myoglobin intron 2 did not show any intergeneric variation or phylogenetic signal among the target taxa at all. In contrast to previous hypotheses, the two genera Apus and Tachymarptis were shown as reciprocally monophyletic in all reconstructions. Apus was consistently divided into three major clades: (1) East Asian clade of A. pacificus and A. acuticauda, (2) African-Asian clade of A. caffer, A. batesi, A. horus, A. affinis and A. nipalensis, (3) African-Palearctic clade of eight currently accepted species among which sequences of A. apus and A. pallidus clustered in a terminal crown clade. Phylogenetic signal of all four nuclear markers was extremely shallow within and among species of tribe Apodini and even among genera, such that intra- and intergeneric relationships of Apus, Tachymarptis and Cypsiurus were poorly resolved by nuclear data alone. Four species, A. pacificus, A. barbatus, A. affinis and A. caffer were consistently found to be paraphyletic with respect to their closest relatives and possible taxonomic consequences are discussed without giving particular recommendations due to limitations of sampling. Incomplete mitochondrial lineage sorting with cytochrome-b haplotypes shared among species and across large geographic distances was observed in two species pairs: A. affinis/A. nipalensis and A. apus/A. pallidus. Mitochondrial introgression caused by extant or past gene flow was ruled out as an explanation for the low interspecific differentiation in these two cases because all nuclear markers appeared to be highly unsorted among Apus species, too. Apparently, the two extant species pairs originated from very recent dispersal and/or speciation events. The currently accepted superspecies classification within Apus was not supported by our results.
Assuntos
Aves/genética , Núcleo Celular/genética , Mitocôndrias/genética , Filogenia , Animais , Proteínas Aviárias/genética , Teorema de Bayes , Aves/classificação , Citocromos b/genética , Marcadores Genéticos , Funções Verossimilhança , Modelos Genéticos , Tipagem de Sequências Multilocus , RNA Ribossômico/genéticaRESUMO
Filopalpinae subfam. nov. is proposed as a new subfamily within family Assamiidae based on a new genus, Filopalpus gen. nov. and on five new species: F. joschmidti sp. nov., F. bale sp. nov., F. kakaensis sp. nov., F. altomontanus sp. nov. and F. niger sp. nov. All originate from the highlands of Ethiopia, namely the Bale Mountains and adjacent volcanoes in Oromia State. Species of the new subfamily are characterized by dense body cover with pointed tubercles causing a hedgehog appearance of the body (dorsal side, partly ventral side), extreme sexual dimorphism in pedipalps (in males thread-like long and thin surpassing body length by about four to six times, devoid of apophyses and thorns; in females short and stout about body length, with a distal grasping hand formed by apophyses and strong setae of tibia and tarsus, and tarsal claw). Male genital morphology is characterized by a hemolymph-pressure system of truncus penis and glans, a dorsal sub-distal tube-like glans with an inner prickly funnel, which is everted by hemolymph pressure during courtship. These male genital characters place the present species in Assamiidae, but external morphology points to a strongly different separate evolutionary unit within this family. The five species known to date were secured at altitudes between 2830 and 4100 m. At least two of the collecting areas are now devoid of forest due to human impact. To secure the present specimens at high-altitude localities was possible only by searching in remote microhabitats unavailable for cattle and man-made fire. A perspective on current subfamilies of Assamiidae and on pedipalpal morphology and evolution is presented.
Assuntos
Aracnídeos , Animais , Bovinos , Etiópia , Feminino , Florestas , Genitália , Humanos , Masculino , SensilasRESUMO
Bird-mediated seed dispersal is crucial for the regeneration and viability of ecosystems, often resulting in complex mutualistic species networks. Yet, how this mutualism drives the evolution of seed dispersing birds is still poorly understood. In the present study we combine whole genome re-sequencing analyses and morphometric data to assess the evolutionary processes that shaped the diversification of the Eurasian nutcracker (Nucifraga), a seed disperser known for its mutualism with pines (Pinus). Our results show that the divergence and phylogeographic patterns of nutcrackers resemble those of other non-mutualistic passerine birds and suggest that their early diversification was shaped by similar biogeographic and climatic processes. The limited variation in foraging traits indicates that local adaptation to pines likely played a minor role. Our study shows that close mutualistic relationships between bird and plant species might not necessarily act as a primary driver of evolution and diversification in resource-specialized birds.
Assuntos
Passeriformes , Pinus , Dispersão de Sementes , Animais , Ecossistema , Passeriformes/genética , Sementes/genética , SimbioseRESUMO
Quaternary climatic oscillations have been considered decisive in shaping much of the phylogeographic structure around the Mediterranean Basin. Within this paradigm, peripheral islands are usually considered as the endpoints of the colonization processes. Here, we use nuclear and mitochondrial markers to investigate the phylogeography of the blue tit complex (blue tit Cyanistes caeruleus, Canary blue tit C. teneriffae and azure tit C. cyanus), and assess the role of the Canary Islands for the geographic structuring of genetic variation. The Canary blue tit exhibits strong genetic differentiation within the Canary Islands and, in combination with other related continental species, provides an ideal model in which to examine recent differentiation within a closely related group of continental and oceanic island avian species. We analysed DNA sequences from 51 breeding populations and more than 400 individuals in the blue tit complex. Discrepancies in the nuclear and mitochondrial gene trees provided evidence of a complex evolutionary process around the Mediterranean Basin. Coalescent analyses revealed gene flow between C. caeruleus and C. teneriffae suggesting a dynamic process with multiple phases of colonization and geographic overlapping ranges. Microsatellite data indicated strong genetic differentiation among the Canary Islands and between the Canary archipelago and the close continental areas, indicating limited contemporary gene flow. Diversification of the blue tit complex is estimated to have started during the early Pliocene (≈ 5 Ma), coincident with the end of Messinian salinity crisis. Phylogenetic analyses indicated that the North African blue tit is derived from the Canary blue tits, a pattern is avian 'back colonization' that contrasts with more traditionally held views of islands being sinks rather than sources.
Assuntos
Evolução Biológica , Passeriformes/genética , Animais , Teorema de Bayes , DNA Mitocondrial/química , Fluxo Gênico , Especiação Genética , Geografia , Região do Mediterrâneo , Repetições de Microssatélites , Filogenia , Dinâmica Populacional , Isolamento Reprodutivo , EspanhaRESUMO
One new genus and two new species of oribatid mites (Oribatida) of the family Galumnidae are described from soil in Nepal. Anomalogalumna gen. nov. (with type species Anomalogalumna dungeri sp. nov.) differs from Flagellozetes Balogh, 1970 by the absence of octotaxic system, and the presence of short, notogastral setae and areolate-reticulate surface of the notogaster and anogenital region. Allogalumna beateae sp. nov. differs from all other species of the genus by the presence of thickened rostral, lamellar and interlamellar setae, and the position of rostral seta (close to lamellar seta and distant from the rostrum).
Assuntos
Ácaros , Animais , Nepal , SoloRESUMO
Two highly specialized endemic troglobiotic harvestman species of the genus Nemaspela Silhavý, 1966 are described. N. melouri sp. nov. from Melouri Cave and N. prometheus sp. nov. from Prometheus Cave (Sataplia-Tskaltubo karst massif, Imereti region, western Georgia), respectively. Despite the fact that the entrances of the caves are positioned only 2.5 km apart, the new taxa differ from each other distinctly by presence vs. absence of male cheliceral apophysis, which is lacking in the second species. A key to the Caucasian species of the genus is provided. Relationships of Nemaspela species within the genus and with hypothetical epigean ancestors are discussed.
Assuntos
Aracnídeos , Animais , Aracnídeos/classificação , Cavernas , Georgia , República da Geórgia , MasculinoRESUMO
In the Himalayas, a number of secondary contact zones have been described for vicariant vertebrate taxa. However, analyses of genetic divergence and admixture are missing for most of these examples. In this study, we provide a population genetic analysis for the coal tit (Periparus ater) hybrid zone in Nepal. Intermediate phenotypes between the distinctive western "spot-winged tit" (P. a. melanolophus) and Eastern Himalayan coal tits (P. a. aemodius) occur across a narrow range of <100 km in western Nepal. As a peculiarity, another distinctive cinnamon-bellied form is known from a single population so far. Genetic admixture of western and eastern mitochondrial lineages was restricted to the narrow zone of phenotypically intermediate populations. The cline width was estimated 46 km only with a center close to the population of the cinnamon-bellied phenotype. In contrast, allelic introgression of microsatellite loci was asymmetrical from eastern P. a. aemodius into far western populations of phenotypic P. a. melanolophus but not vice versa. Accordingly, the microsatellite cline was about 3.7 times wider than the mitochondrial one.
RESUMO
This is the first comprehensive study to evaluate the relationships between the western palearctic harvestman families Dicranolasmatidae, Trogulidae and Nemastomatidae with focus on the phylogeny and systematics of Trogulidae, using combined sequence data of the nuclear 28S rRNA and the mitochondrial cytochrome b gene. Bayesian analysis and Maximum parsimony do not reliably resolve Dicranolasma as distinct family but place it on a similar phylogenetic level as several lineages of Trogulidae. Nemastomatidae and Trogulidae turned out to be monophyletic, as did genera Anelasmocephalus and Trogulus within the Trogulidae. The genera Calathocratus, Platybessobius and Trogulocratus each appeared para or polyphyletic, respectively and are synonymized with Calathocratus. The monotypic genus Kofiniotis is well supported. We show molecular data to be in general concordance with taxa characterized by morphology. Molecular data are especially useful to calibrate morphological characters for systematic purposes within homogeneous taxa. In the majority of closely related valid species we show the lowest level of genetic distance to be not lower than 5%. By this threshold in terms of traditionally accepted species the estimated number of species turns out to be 1.5-2.4 times higher than previously believed. With respect to European fauna cryptic diversity in Trogulidae is obviously extraordinarily high and hitherto largely underestimated.
Assuntos
Aracnídeos/genética , Evolução Molecular , Filogenia , Animais , Aracnídeos/anatomia & histologia , Aracnídeos/classificação , Teorema de Bayes , DNA Mitocondrial/genética , Especiação Genética , RNA Ribossômico 28S/genética , Alinhamento de Sequência , Análise de Sequência de DNARESUMO
In this paper we provide a molecular phylogeny based on three mitochondrial and three nuclear markers for all long-tailed tit species of the genus Aegithalos including several doubtful subspecies (17 taxa) plus three close allies of SE Asian Leptopoecile and North American Psaltriparus. Genus Aegithalos is divided into three major clades, two of them showing only minor differentiation. Separation of two mitchondrial haploytpe clusters in the N Palearctic Long-tailed Tit, Ae. caudatus, was dated back to the Late Pleistocene, however, descendants from both lineages underwent a rapid post-Pleistocene range expansion and largely mixed over the entire distribution area. The Chinese populations of the glaucogularis subspecies group represent a slightly earlier Pleistocene split from the Ae. caudatus clade. Genetic differentiation among several doubtful SE Asian species taxa on the sister clade of the latter N Palearctic/Chinese clade matches the intraspecific differentiation within Ae. caudatus. Unexpectedly, cytochrome-b distances among Himalayan Ae. iouschistos (including the subspecies bonvaloti from China and sharpei from Myanmar) and the Chinese endemic Ae. fuliginosus range at approximately 0.5% and apparently all these extant populations separated only very recently during late Pleistocene times, too. W Himalayan Ae. niveogularis clearly appeared as the sister species of the latter taxon assemblage. Unlike the two latter major clades, Ae. concinnus shows strong intraspecific differentiation with cyt-b distances as high as 6% among two Himalayan populations of ssp. iredalei, ssp. manipurensis from Myanmar and a fourth lineage from SW and SC China including ssp. talifuensis and nominate concinnus. A sister-group relationship between all Ae. concinnus and Ae. leucogenys was strongly supported. N American bushtits of genus Psaltriparus represent the sister clade to Palearctic genus Aegithalos, including a clear split between the minimus and the plumbeus subspecies group which was again dated back to Pleistocene times. The two tit-warbler species of genus Leptopoecile are strongly differentiated from one another and represent an early split from the Aegithalidae tree.
Assuntos
Evolução Molecular , Passeriformes/classificação , Filogenia , Animais , Núcleo Celular/genética , China , DNA Mitocondrial/genética , Geografia , Haplótipos , Modelos Genéticos , América do Norte , Passeriformes/genética , Análise de Sequência de DNARESUMO
The South-East Asian opilionid family Epedanidae Sørensen, 1886 has one of its strongholds in Thailand from where a multitude of genera and species have been described but the epedanid fauna of the country is still poorly known. This paper records four species from this country, three of which are new: Euepedanus dashdamirovi sp. nov. (male and female), Plistobunus jaegeri sp. nov. (male and female), and Toccolus kuryi sp. nov. (male and female). Toccolus globitarsis Suzuki, 1969 was previously known only from the type locality in Thailand and is redescribed here. Functional aspects of epedanid penial morphology are highlighted.
RESUMO
Encompassing some of the major hotspots of biodiversity on Earth, large mountain systems have long held the attention of evolutionary biologists. The region of the Qinghai-Tibet Plateau (QTP) is considered a biogeographic source for multiple colonization events into adjacent areas including the northern Palearctic. The faunal exchange between the QTP and adjacent regions could thus represent a one-way street ("out of" the QTP). However, immigration into the QTP region has so far received only little attention, despite its potential to shape faunal and floral communities of the QTP. In this study, we investigated centers of origin and dispersal routes between the QTP, its forested margins and adjacent regions for five clades of alpine and montane birds of the passerine superfamily Passeroidea. We performed an ancestral area reconstruction using BioGeoBEARS and inferred a time-calibrated backbone phylogeny for 279 taxa of Passeroidea. The oldest endemic species of the QTP was dated to the early Miocene (ca. 20 Ma). Several additional QTP endemics evolved in the mid to late Miocene (12-7 Ma). The inferred centers of origin and diversification for some of our target clades matched the "out of Tibet hypothesis' or the "out of Himalayas hypothesis" for others they matched the "into Tibet hypothesis." Three radiations included multiple independent Pleistocene colonization events to regions as distant as the Western Palearctic and the Nearctic. We conclude that faunal exchange between the QTP and adjacent regions was bidirectional through time, and the QTP region has thus harbored both centers of diversification and centers of immigration.
RESUMO
The Mediterranean Basin represents a Global Biodiversity Hotspot where many organisms show high inter- and intraspecific differentiation. Extant phylogeographic patterns of terrestrial circum-Mediterranean faunas were mainly shaped through Pleistocene range shifts and range fragmentations due to retreat into different glacial refugia. Thus, several extant Mediterranean bird species have diversified by surviving glaciations in different hospitable refugia and subsequently expanded their distribution ranges during the Holocene. Such a scenario was also suggested for the Eurasian Wren (Nannus troglodytes) despite the lack of genetic data for most Mediterranean subspecies. Our phylogenetic multi-locus analysis comprised 18 out of 28 currently accepted subspecies of N. troglodytes, including all but one subspecies which are present in the Mediterranean Basin. The resulting phylogenetic reconstruction dated the onset of the entire Holarctic radiation of three Nannus species to the early Pleistocene. In the Eurasian Wren, two North African subspecies represented separate basal lineages from the Maghreb (N. t. kabylorum) and from the Libyan Cyrenaica (N. t. juniperi), being only distantly related to other Mediterranean populations. Although N. troglodytes appeared to be paraphyletic with respect to the Nearctic Winter Wren (N. hiemalis), respective nodes did not receive strong statistical support. In contrast, paraphyly of the Ibero-Maghrebian taxon N. t. kabylorum was strongly supported. Southern Iberian populations of N. t. kabylorum did not clade with Maghrebian populations of the same subspecies but formed a sister clade to a highly diverse European clade (including nominate N. t. troglodytes and eight further taxa). In accordance with a pattern also found in other birds, Eurasian populations were split into a western clade (Europe, Caucasus) and an eastern clade (Central Asia, Sino-Himalayas, East Asia). This complex phylogeographic pattern revealed cryptic diversification in N. troglodytes, especially in the Iberio-Maghrebian region.