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1.
Partial DNA sequences from two mitochondrial (mt) and one nuclear gene (cytochrome b, 12S rRNA, and C-mos) were used to estimate the phylogenetic relationships among the six extant species of skinks endemic to the Cape Verde Archipelago. The species form a monophyletic unit, indicating a single colonization of the islands, probably from West Africa. Mabuya vaillanti and M. delalandii are sister taxa, as indicated by morphological characters. Mabuya fogoensis and M. stangeri are closely related, but the former is probably paraphyletic. Mabuya spinalis and M. salensis are also probably paraphyletic. Within species, samples from separate islands always form monophyletic groups. Some colonization events can be hypothesized, which are in line with the age of the islands. C-mos variation is concordant with the topology derived from mtDNA.  相似文献   

2.
The Cape Verde Islands are of volcanic origin with most having appeared between the early Miocene and mid-Pleistocene. They contain six known species of Mabuya skinks. Phylogeographical relationships within and among the relatively widespread taxa M. stangeri, M. spinalis and M. delalandii were inferred, based on approximately 1 kbp of the cytochrome b gene (mitochondrial DNA). Reciprocal monophyly of M. spinalis and M. stangeri was established, which may have arisen from an early Pliocene/late Miocene cladogenetic event. Considerable between-island sequence divergence was detected among M. spinalis, which appears to have colonized the older islands (Sal and Boavista) first. Much lower sequence divergence was found in M. delalandii, indicating a more recent range expansion. Here, evidence points to colonization of the younger islands of Brava and Fogo soon after appearance. There are similarities between some of the described patterns and those seen in lizards from the Canary Islands.  相似文献   

3.
Miralles, A., Vasconcelos, R., Perera, A., Harris, D. J. & Carranza, S. (2010). An integrative taxonomic revision of the Cape Verdean skinks (Squamata, Scincidae). —Zoologica Scripta, 40, 16–44. A comprehensive taxonomic revision of the Cape Verdean skinks is proposed based on an integrative approach combining (i) a phylogenetic study pooling all the previously published molecular data, (ii) new population genetic analyses using mitochondrial and nuclear data resulting from additional sampling, together with (iii) a morphological study based on an extensive examination of the scalation and colour patterns of 516 live and museum specimens, including most of the types. All Cape Verdean species of skinks presently recognised, formerly regarded as members of the genera Mabuya Fitzinger, 1826 and Macroscincus Bocage, 1873 are considered as members of the Cape Verdean endemic genus Chioninia Gray, 1845. The new phylogeny and networks obtained are congruent with the previously published phylogenetic studies, although suggesting older colonization events (between 11.6 and 0.8 Myr old), and indicate the need for taxonomic changes. Intraspecific diversity has been analysed and points to a very recent expansion of Chioninia delalandii on the southern islands and its introduction on Maio, to a close connection between Chioninia stangeri island populations due to Pleistocene sea‐level falls and to a generally low haplotypic diversity due to the ecological and geological characteristics of the archipelago. Three new consistent morphological synapomorphies supporting two of the four main clades of the genus have been identified. The complex taxonomic status of Euprepes fogoensis O’Shaughnessy, 1874 has been resolved and a lectotype has been designated for this species; Chioninia fogoensis nicolauensis (Schleich, 1987) is elevated to species rank, whereas Chioninia fogoensis antaoensis (Schleich, 1987) is now regarded as a junior subjective synonym of C. fogoensis. Additionally, one new subspecies of Chioninia vaillanti and two of Chioninia spinalis are described (Chioninia vaillanti xanthotis ssp. n., Chioninia spinalis santiagoensis ssp. n. and Chioninia spinalis boavistensis ssp. n.) and a lectotype has been designated for Mabuia spinalis Boulenger, 1906. Finally, an identification key for the Chioninia species is presented.  相似文献   

4.
Mitochondrial (cytochrome b and 12S rRNA) and nuclear (c-mos) genes, analyzed by a variety of methods, indicate that the distinctive northwest African gecko Geckonia chazaliae is a member of the Tarentola clade, being most closely related to the species of the western Canary and Cape Verde islands. Relationships in Tarentola as a whole are as follows: (T. americana ((T. mauritanica, T. angustimentalis) ((T. deserti, T. boehmei) ((T. b. boettgeri-South (T. b. boettgeri-North (T. b. bischoffi, T. b. hierrensis))) ((T. annularis, T. ephippiata) (Geckonia, T. delalandii, T. gomerensis, Cape Verde species)))))); nearly all nodes have high bootstrap support. Results confirm that T. americana of Cuba and the Bahamas separated at the most basal dichotomy of the phylogeny and give no positive support for the monophyly of the subgenera Tarentola s. str. and Makariogecko. The latter includes Geckonia and the subgenus Sahelogecko. Continental Tarentola appear to have invaded the Sahara desert from its northern edge. They have also colonized groups of Atlantic islands five times: a single invasion of the West Indies and three of the Canary islands, one of which then went on to invade the Cape Verde archipelago. The phylogeny corroborates anatomical evidence that the ground-dwelling Geckonia had a climbing ancestry, something that is paralleled in some southern African terrestrial gekkonids related to Pachydactylus. Distinctive derived features of Geckonia occur in other gekkonids that are ground dwelling in arid habitats and may be functionally related to this environment. The evolution of such features indicates that, although Tarentola is generally very uniform and may have been so for over 10 million years, this is not due to any overwhelming phylogenetic constraint. G. chazaliae should be included in Tarentola, as Tarentola chazaliae.  相似文献   

5.
A total of 1854 bp of mitochondrial DNA (669 bp of cytochrome b (cyt b) and 386 bp of 12S rRNA), and 804 bp of a nuclear gene (RAG2) were investigated in endemic Hemidactylus from eight Cape Verde Islands, and used to explore their phylogeny, biogeography and evolution. Maximum‐likelihood, maximum‐parsimony and Bayesian analyses based on mtDNA revealed four well‐supported clades with uncorrected genetic divergences of 7.8–12.4% in the cyt b plus 12S rRNA genes, which were also supported by nuclear DNA. A population from the southern island of Fogo is the most divergent in both molecules and morphology and is described as Hemidactylus lopezjuradoi sp. n., and the populations on Sal and Boavista are also assigned species status as H. boavistensis. Although divergent in their DNA, the clade on S. Nicolau and that in the north‐western islands are morphologically similar and both are assigned to H. bouvieri for the present. Hemidactylus b. razoensis from Raso is genetically similar to H. b. bouvieri and differs only in its smaller body size. A molecular clock suggests that the ancestor of the endemic Hemidactylus of the Cape Verde Islands colonized the archipelago approximately 10 ± 2.48 Mya, perhaps reaching the north‐eastern islands first. The H. lopezjuradoi lineage separated soon after, and the north‐western islands were colonized progressively but slowly, S. Nicolau probably being reached first, then S. Vicente and islands on the same bank, and finally Sto. Antão, which is likely to have been colonized less than 1 Mya. Hemidactylus boavistensis is abundant on the arid islands where it occurs, but H. bouvieri appears to have been uncommon at least since it was described 130 years ago, and the same may be true of H. lopezjuradoi sp. n. The impact of introduced H. angulatus and H. mabouia on the endemic Hemidactylus of the Cape Verde Islands is not clear, but the discovery of substantial genetic diversity in endemic Cape Verde Hemidactylus means that the conservation requirements of the group should be reassessed.  相似文献   

6.
Morphological systematics makes it clear that many non-volant animal groups have undergone extensive transmarine dispersal with subsequent radiation in new, often island, areas. However, details of such events are often lacking. Here we use partial DNA sequences derived from the mitochondrial cytochrome b and 12S rRNA genes (up to 684 and 320 bp, respectively) to trace migration and speciation in Tarentola geckos, a primarily North African clade which has invaded many of the warmer islands in the North Atlantic Ocean. There were four main invasions of archipelagos presumably by rafting. (i) The subgenus Neotarentola reached Cuba up to 23 million years (Myr) ago, apparently via the North Equatorial current, a journey of at least 6000 km. (ii) The subgenus Tarentola invaded the eastern Canary Islands relatively recently covering a minimum of 120 km. (iii) The subgenus Makariogecko got to Gran Canaria and the western Canary Islands 7-17.5 Myr ago, either directly from the mainland or via the Selvages or the archipelago of Madeira, an excursion of 200-1200 km. (iv) A single species of Makariogecko from Gomera or Tenerife in the western Canaries made the 1400 km journey to the Cape Verde Islands tip to 7 Myr ago by way of the south-running Canary current. Many journeys have also occurred within archipelagos, a minimum of five taking place in the Canaries and perhaps 16 in the Cape Verde Islands. Occupation of the Cape Verde archipelago first involved an island in the northern group, perhaps São Nicolau, with subsequent spread to its close neighbours. The eastern and southern islands were colonized from these northern islands, at least two invasions widely separated in time being involved. While there are just three allopatric species of Makariogecko in the Canaries, the single invader of the Cape Verde Islands radiated into five, most of the islands being inhabited by two of these which differ in size. While size difference may possibly be a product of character displacement in the northern islands, taxa of different sizes reached the southern islands independently.  相似文献   

7.
Isolated oceanic archipelagos are excellent model systems to study speciation, biogeography, and evolutionary factors underlying the generation of biological diversity. Despite the wealth of studies documenting insular speciation, few of them focused on marine organisms. Here, we reconstruct phylogenetic relationships among species of the marine venomous gastropod genus Conus from the Cape Verde archipelago. This small island chain located in the Central Atlantic hosts 10% of the worldwide species diversity of Conus. Analyses were based on mtDNA sequences, and a novel nuclear marker, a megalin-like protein, member of the low-density lipoprotein receptor gene family. The inferred phylogeny recovered two well-defined clades within Conus. One includes Cape Verde endemic species with larger shells, known as the "venulatus" complex together with C. pulcher from the Canary Islands. The other is composed of Cape Verde endemic and West Africa and Canary Island "small" shelled species. In both clades, nonendemic Conus were resolved as sister groups of the Cape Verde endemics, respectively. Our results indicate that the ancestors of "small" and "large" shelled lineages independently colonized Cape Verde. The resulting biogeographical pattern shows the grouping of most Cape Verde endemics in monophyletic island assemblages. Statistical tests supported a recent radiation event within the "small shell" clade. Using a molecular clock, we estimated that the colonization of the islands by the "small" shelled species occurred relatively close to the origin of the islands whereas the arrival of "large" shelled Conus is more recent. Our results suggest that the main factor responsible for species diversity in the archipelago may be allopatric speciation promoted by the reduced dispersal capacity of nonplanktonic lecithotrophic larvae.  相似文献   

8.
The human immunodeficiency virus type 1 (HIV-1) subtype G is the most prevalent and second most prevalent HIV-1 clade in Cape Verde and Portugal, respectively; but there is no information about the origin and spatiotemporal dispersal pattern of this HIV-1 clade circulating in those countries. To this end, we used Maximum Likelihood and Bayesian coalescent-based methods to analyze a collection of 578 HIV-1 subtype G pol sequences sampled throughout Portugal, Cape Verde and 11 other countries from West and Central Africa over a period of 22 years (1992 to 2013). Our analyses indicate that most subtype G sequences from Cape Verde (80%) and Portugal (95%) branched together in a distinct monophyletic cluster (here called GCV-PT). The GCV-PT clade probably emerged after a single migration of the virus out of Central Africa into Cape Verde between the late 1970s and the middle 1980s, followed by a rapid dissemination to Portugal a couple of years later. Reconstruction of the demographic history of the GCV-PT clade circulating in Cape Verde and Portugal indicates that this viral clade displayed an initial phase of exponential growth during the 1980s and 1990s, followed by a decline in growth rate since the early 2000s. Our data also indicate that during the exponential growth phase the GCV-PT clade recombined with a preexisting subtype B viral strain circulating in Portugal, originating the CRF14_BG clade that was later disseminated to Spain and Cape Verde. Historical and recent human population movements between Angola, Cape Verde and Portugal probably played a key role in the origin and dispersal of the GCV-PT and CRF14_BG clades.  相似文献   

9.
Nearly 50 species of the marine gastropod genus Conus are restricted to the Cape Verde archipelago. This unusual concentration of endemics within a single set of oceanic islands is extremely uncharacteristic of marine taxa. Here we used phylogenetic analyses of 90 Conus species, including 30 endemics from Cape Verde, to reveal the relationships and origins of the endemic Cape Verde Conus. Results show that these species group in two distinct clades and represent a marine species flock that is restricted to a very narrowly confined geographical area. Species' originations occurred in exceptionally limited parts of the archipelago and in some cases radiations took place solely within single islands. Finally, comparison of levels of divergence between Cape Verde endemics and other Conus species suggests that the radiation of Conus in Cape Verde occurred during the last few million years.  相似文献   

10.
Tolpis consists of ~13 species native to Africa, Europe, and Macaronesia, with at least one species endemic to each of the four major archipelagos of the Azores, Madeira Islands, Canary Islands, and Cape Verde Islands. All but two of these species develop woody stems by maturity. Chloroplast DNA restriction site variation was analyzed for all species of Tolpis and four outgroups in order to understand the patterns of island colonization and evolution of woodiness in this genus. Parsimony analyses revealed a strongly supported monophyletic Tolpis. Within the genus, the following three well-supported groups were detected: all species from the Canary Islands and Cape Verde Islands, both Azorean species, and both continental species. The Canary Island/Cape Verde clade was sister to the two continental species, and the Azorean clade was sister to this group. The two Madeiran species of Tolpis occupied the basalmost positions within the genus. When biogeography was mapped onto this phylogeny, nine equally parsimonious reconstructions (five steps each) of dispersal history were detected, which fell into two groups: eight reconstructions implied that Tolpis colonized Madeira from the continent, followed by continental extinction and subsequent continental recolonization, while one reconstruction implied that Tolpis colonized Macaronesia four times. Two of the reconstructions involving continental extinction required the least amount of overall dispersal distance. The cpDNA phylogeny also suggests that woodiness arose in the common ancestor of all extant Tolpis, followed by two independent reversals to an herbaceous habit. Assuming that one of the eight reconstructions favoring continental extinction and recolonization is true, our results suggest that Tolpis may represent the first documented example of a woody plant group in Macaronesia that has recolonized the mainland in herbaceous form.  相似文献   

11.
Shallow subtidal macroalgal communities in the North-eastern Atlantic archipelagos (Azores, Madeira, Canaries and Cape Verde) were studied in order to identify their spatial organization patterns and the main drivers of change. Fifteen islands and 145 sites across 15º of latitude and 2850 km were sampled. We found high spatial variability across the scales considered (archipelago, island and site). The structure of macroalgal communities differed among archipelagos, except between Madeira and the Canaries, which were similar. Across a latitudinal gradient, macroalgal communities in the Azores were clearly separated from the other archipelagos; communities in Madeira and the Canaries occupied an intermediate position, while those in Cape Verde appeared at the opposite end of the gradient. In the Azores, species with warm-temperate affinities dominated communities. Cape Verde communities were, in contrast, dominated by tropical taxa, whereas in the subtropical Canaries and Madeira there was a mixture of species with colder and warmer affinities. Apart from crustose coralline algae, the Dictyotales were the group with greatest cover; larger and longer-lived species were progressively replaced by short-lived species along a latitudinal gradient from north to south. The perennial species Zonaria tournefortii dominated the sea-bottom in the Azores, the semi-perennial Lophophora variegata in the Canaries, the filamentous algae in Madeira and the ephemeral Dictyota dichotoma in Cape Verde. We hypothesized that the differences among archipelagos could be explained by synergies between temperature and herbivory, which increased in diversity southwards, especially in Cape Verde. This was supported by the predominance of non-crustose macroalgae in the Azores and of crustose macroalgae in Cape Verde, as would be predicted from the greater herbivore activity. At the scale of islands and sites, the same set of environmental variables drove differences in macroalgal community structure across all the Macaronesian archipelagos.  相似文献   

12.
The helminth fauna of two sympatric congeneric skinks (Mabuya agilis and M. macrorhyncha) from two distinct "restinga" habitats (Praia das Neves and Grussaí) in southeastern Brazil were studied, totalling four data sets (sample sizes ranging from 11 to 28). A total of ten helminth species were associated with the skinks: Raillietiella sp., Paradistomum parvissimum, Pulchrosomoides elegans, Oochoristica ameivae, Hexametra boddaertii, Parapharyngodon sceleratus, Physalopteroides venancioi, Physaloptera sp., an unidentified acuariid nematode and an unidentified centrorhynchid acanthocephalan. Except for Hexametra boddaertii (found only in Grussaí) and Pulchrosomoides elegans (found only in Praia das Neves), all helminth species were present at both localities. Half of the helminth species were present only as larvae and, in most cases, appear to represent paratenic parasitism. Overall prevalences of infection were high for both host species in both localities. Mabuya agilis tended to have richer and more diverse infracommunities than M. macrorhyncha. Some parameters of infection by individual helminth species seem to be related to the ecology of each Mabuya species. The parasite faunas were qualitatively very similar among species and/or localities, but quantitative similarities were more varied, due to differential representativeness of individual helminth species among host populations. The helminth communities of both skink species can be classified as non-interactive, being composed of site-specialists and immature stages of non-lizard parasites.  相似文献   

13.
Abstract In a restinga habitat of southeastern Brazil, we studied some aspects of the thermal biology of two sympatric skinks (Mabuya macrorhyncha and Mabuya agilis) with distinct microhabitat preferences. The two species did not differ significantly in their mean body temperature. Sex and body size did not explain body temperature variation within either species. The body temperature of both species is significantly affected by air temperature, but only that of M. agilis is significantly influenced by sand surface temperature, presumably due to its more terrestrial habit compared to M. macrorhyncha. We found no significant seasonal variation in body temperature for either species, although environmental temperatures varied seasonally, indicating that both species may be selecting an optimal range of body temperatures, possibly through behavioural thermoregulation.  相似文献   

14.
J Straka  MS Engel 《ZooKeys》2012,(218):77-109
The apid cuckoo bees of the Cape Verde Islands (Republic of Cape Verde) are reviewed and five species recognized, representing two genera. The ammobatine genus Chiasmognathus Engel (Nomadinae: Ammobatini), a specialized lineage of cleptoparasites of nomioidine bees is recorded for the first time. Chiasmognathus batelkaisp. n. is distinguished from mainland African and Asian species. The genus Thyreus Panzer (Apinae: Melectini) is represented by four species - Thyreus denoliisp. n., Thyreus batelkaisp. n., Thyreus schwarzisp. n., and Thyreus aistleitnerisp. n. Previous records of Thyreus scutellaris (Fabricius) from the islands were based on misidentifications.  相似文献   

15.

Although the hydrocoral Millepora alcicornis is a prominent and ecologically relevant amphi-Atlantic reef builder, little attention has been given to its endosymbionts which are also involved in the survival and adaptation success of the species in different environments. In this study, we resolve the genetic relationships between M. alcicornis and its symbionts (Symbiodiniaceae) within both sides and across the Atlantic. The COI and 16S-rDNA regions were selected for the host tissues, and the 23S-rDNA and ITS regions were chosen for the symbionts. Phylogenetic networks consistently showed that host populations from the eastern Atlantic archipelagos (Canary and Cape Verde Islands) were more related to western Atlantic populations than they were between them. However, results for Symbiodiniaceae species varied according to the molecular marker used. Samples from Mexico were grouped as Symbiodinium sp. (formerly Symbiodinium clade A) by both markers. Specimens from Puerto Rico were grouped as either Symbiodinium sp. or Breviolum sp. (formerly Symbiodinium clade B), according to the molecular marker used. Most samples from the eastern Atlantic were identified as Breviolum sp. by both markers, except for one sample from the Canary Islands and two samples from the Cape Verde Islands, which were identified as Cladocopium sp. (formerly Symbiodinium clade C) using ITS-rDNA. These results suggest that these two genera of Symbiodiniaceae may cohabit the same M. alcicornis colony. Because hydrocorals from the Canary Islands were phylogenetically related to the western Atlantic, but symbionts were more related to those of the Cape Verde Islands, the origin of the coral and its symbionts is probably different. This may be explained either by “horizontal” transmission, i.e. acquisition from the environment, or by a change in the dominant symbiont composition within the host. The flexibility of this hydrocoral to select symbionts, depending on environmental conditions, can provide new insight to understand how this coral may face ongoing climate change.

  相似文献   

16.
A new nematode species, Spauligodon nicolauensis n. sp., is described from geckos Tarentola bocagei and Tarentola nicolauensis on the island of S?o Nicolau, Cape Verde. The new nematode was found in the pellets obtained directly from the geckos in a non-invasive fashion, and its identity was assessed both at morphologic and genetic levels. The new species has morphological similarities with Spauligodon tarentolae Spaul, 1926, also parasitizing geckos from the Canary Islands. However, the male cloacal region in the new species is distinct, presenting a different shape of the caudal papillae. The overall resemblance probably resulted from colonization via descent from an ancestor of S. tarentolae carried by the ancestor of Cape Verde Tarentola. The analysis of nuclear DNA sequences confirms that the new species is phylogenetically distinct from all other Spauligodon species already analyzed, forming a group clearly separated from species parasitizing lacertid lizards. The COI genetic distance suggests that the S. nicolauensis n. sp. found in the 2 species of geckos in S?o Nicolau Island may have resulted from a host-switching event, when they came into contact after the unification of the island.  相似文献   

17.
Phylogenetic relationships among the lygosomine skinks were inferred from 1249 base positions of mitochondrial DNA sequences of 12S and 16S rRNA genes. The monophyly of this subfamily was confirmed and the presence of five distinct infrasubfamilial lineages detected. Of these, the Sphenomorphus group appears to have diverged first, followed by the Lygosoma and Egernia groups in order, leaving the Eugongylus and Mabuya groups as sister groups. Our results did not support monophyly of the Mabuya group sensu lato (i.e., an assemblage of the Lygosoma, Egernia, and Mabuya groups), for which a number of morphological and karyological studies demonstrated a considerable similarity. Our results also contradict the previous hypothesis, formulated on the basis of morphological and immunological data, which argued for the sister relationship between the Egernia and the Eugongylus groups. Morphological and karyological characters used to define the Mabuya group (sensu lato) may actually represent plesiomorphic states. The phylogenetic diversity of lygosomine skinks in the Australian region appears to have increased through multiple colonizations from Southeast Asia.  相似文献   

18.
In 1982 I studied the changes which had taken place in the fauna of the Krakatau Islands over the last fifty years, and elucidated the roles of terrestrial consumers and reducers in the developing ecosystems of these islands. Only two species of rat were found (Rattus rattus andR. tiomanicus) as observed by Dammerman (1948) in 1933, butR. tiomanicus had newly established its population on Sertung. No rats were found on Anak Krakatau. Although many skinks (Mabuya multifasciata) were observed on R. Besar, this species was not found on the other islands. The rat and skink are considered strong competitors to the sand crab (Ocypode kuhli), because while the crab was restricted to the sandy beach on the three islands where rat and skink live it had expanded inland on Anak Krakatau where there are no rats and skinks. The two banded monitor (Varanus sarvator) was found on every island and it mainly fed on crabs (Gecarcoidea natalis andMetasesarma aubryi). Thus it is suggested that the crab plays an important role in the process of faunal succession on the Krakatau Islands.  相似文献   

19.
Isolated oceanic islands are excellent natural laboratories to test the relative role of historical contingency and determinism in evolutionary diversification. Endemics of the marine venomous snail Conus in the Cape Verde archipelago were originated from at least two independent colonizations of 'small' and 'large' shelled species separated by 12 million years. In this study, we have reconstructed phylogenetic relationships within large-shelled Conus ( C . ateralbus , C . pseudonivifer , C. trochulus , and C. venulatus ) based on mitochondrial cox1 and nad4 haplotype sequences. The reconstructed molecular phylogeny revealed three well-supported and relatively divergent clades (A, B, and C) that do not correspond to current species classification based on shell colour and banding patterns. Clade A grouped specimens assigned either to C. pseudonivifer or C. trochulus , clade B is composed of specimens assigned to C. venulatus , and clade C comprises specimens assigned either to C. venulatus or C. ateralbus . Geometric morphometric analyses found significant differences between the radular teeth shape of C. pseudonivifer / C. trochulus and C. venulatus / C. ateralbus . In clades A and B, northwestern Boavista and Maio specimens cluster together to the exclusion of eastern Boavista samples. In Sal, populations form a monophyletic island assemblage (clade C). The large-shelled Conus have remarkably replicated biogeographical patterns of diversification of small-shelled Conus . Similar selective forces (i.e. nonplanktonic lecithotrophy with limited larval dispersal and allopatric diversification) together with repeated instances of low sea level stands during glacial maxima that allowed connection between islands, have overcome the effect of historical contingency, and explain the observed recurring biogeographical patterns.  相似文献   

20.
We investigated phylogenetic relationships and the biogeographic history of the Calonectris species complex, using both molecular and biometric data from one population of the Cape Verde shearwater Calonectris edwardsii (Cape Verde Islands), one from the streaked shearwater C. leucomelas (western Pacific Ocean) and 26 from Cory's shearwater populations distributed across the Atlantic (C. d. borealis) and the Mediterranean (C. d. diomedea). The streaked shearwater appeared as the most basal and distant clades, whereas the genetic divergences among the three main clades within the Palearctic were similar. Clock calibrations match the first speciation event within Calonectris to the Panama Isthmus formation, suggesting a vicariant scenario for the divergence of the Pacific and the Palearctic clades. The separation between the Atlantic and Mediterranean clades would have occurred in allopatry by range contraction followed by local adaptation during the major biogeographic events of the Pleistocene. The endemic form from Cape Verde probably evolved as a result of ecological divergence from the Mediterranean subspecies. Finally, one Mediterranean population (Almeria) was unexpectedly grouped into the Atlantic subspecies clade, both by genetic and by morphometric analyses, pointing out the Almeria-Oran oceanographic front (AOOF) as the actual divide between the two Cory's shearwater subspecies. Our results highlight the importance of oceanographic boundaries as potentially effective barriers shaping population and species phylogeographical structure in pelagic seabirds.  相似文献   

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