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1.
Mol Phylogenet Evol ; 127: 367-375, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-29625229

RESUMO

The widespread Old World avian family Locustellidae ('grassbirds and allies') comprises 62 extant species in 11 genera. In the present study, we used one mitochondrial and, for most species, four nuclear loci to infer the phylogeny of this family. We analysed 59 species, including the five previously unsampled genera plus two genera that had not before been analysed in a densely sampled dataset. This study revealed extensive disagreement with current taxonomy; the genera Bradypterus, Locustella, Megalurus, Megalurulus and Schoenicola were all found to be non-monophyletic. Non-monophyly was particularly pronounced for Megalurus, which was widely scattered across the tree. Three of the five monotypic genera (Amphilais, Buettikoferella and Malia) were nested within other genera; one monotypic genus (Chaetornis) formed a clade with one of the two species of Schoenicola; whereas the position of the fifth monotypic genus (Elaphrornis) was unresolved. Robsonius was confirmed as sister to the other genera. We propose a phylogenetically informed revision of genus-level taxonomy, including one new generic name. Finally, we highlight several non-monophyletic species complexes and deep intra-species divergences that point to conflict in taxonomy and suggest an underestimation of current species diversity in this group.


Assuntos
Passeriformes/classificação , Filogenia , Animais , Teorema de Bayes , Núcleo Celular , Citocromos b/genética , Espectrografia do Som , Especificidade da Espécie , Vocalização Animal
2.
Mol Phylogenet Evol ; 118: 172-183, 2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-28834700

RESUMO

The Long-billed Tailorbird (Artisornis moreaui), one of Africa's rarest birds, has a strikingly disjunct distribution, the origin of which has long puzzled biogeographers. One small population (subspecies moreaui) occurs in sub-montane forest in the East Usambara Mountains, a sky island near the coast of northern Tanzania, and another (subspecies sousae) on Serra Jeci in northwestern Mozambique, 950km away. The African Tailorbird, the putative sister-species of Long-billed Tailorbird, also occurs in the East Usambara Mountains and on Serra Jeci, but in addition occupies all the Eastern Arc Mountain forests between these disjunct sites. Stuart (1981) hypothesized that the two tailorbird distributions could be explained by strong ecological competition, with African Tailorbird populations having eliminated Long-billed Tailorbird populations via competitive exclusion in montane forests between the East Usambara and Serra Jeci. If such competitive exclusion explains these geographic distributions, the co-occurrence of the two species in the East Usambara and at Serra Jeci may be ephemeral, with the status of Long-billed Tailorbird especially in doubt. We sought to (1) determine whether the two species of African tailorbirds are indeed sister-species, and (2) test predictions from Stuart's (1981) competitive exclusion hypothesis using genetic data. Phylogenetic analyses of our seven gene dataset (3 mtDNA, 4 introns; 4784bp) indeed place these two species together in the genus Artisornis. Instead of finding shallow divergence among African Tailorbird populations and deep divergence between Long-billed Tailorbird populations as expected from Stuart's hypothesis, we recover deep genetic divergence and geographic structure among populations of both tailorbird species. This result is consistent with long-term co-existence of the two species at East Usambara and Serra Jeci. Observational data from both the East Usambara and Serra Jeci suggest that the two species have diverged in use of forest canopy strata. From a conservation standpoint, our results suggest that extinction of the Long-billed Tailorbird as a function of competition with African Tailorbird is highly unlikely, and should not be viewed as imminent. Threats to its survival are instead anthropogenic, and conservation measures should take this into account. Finally, our empirical results suggest that mis-specification of the branch-length prior in Bayesian analyses of mitochondrial DNA data can have a profound effect on the overall tree-length (sum of branch-lengths), whereas the topology and support values tend to remain more stable. In contrast, mis-specification of the branch-length prior had a lesser impact on all aspects of the nuclear-only DNA analyses. This problem may be exacerbated when mitochondrial and nuclear DNA analyses are combined in a total evidence approach.


Assuntos
Passeriformes/classificação , Filogeografia , Estatística como Assunto , Animais , Teorema de Bayes , DNA Mitocondrial/genética , Loci Gênicos , Moçambique , Passeriformes/genética , Filogenia , Tanzânia
3.
Mol Phylogenet Evol ; 110: 19-26, 2017 05.
Artigo em Inglês | MEDLINE | ID: mdl-28249741

RESUMO

We reconstruct the phylogeny of imperial pigeons (genus Ducula) using mitochondrial and nuclear sequence data. We evaluate the most likely biogeographic scenario for the evolution of this group that colonized many islands of the Pacific Ocean. The divergence time analysis suggests that the basal divergences within Ducula occurred more recently than in the fruit doves (genus Ptilinopus), a group that is also well diversified in Oceania. The imperial pigeons colonized the Melanesian region several times independently, and the diversification within this region led to several species in sympatry, in particular in the Bismarck archipelago. Central Polynesia was also colonized several times, first by a lineage during the Miocene that led to the large D. latrans, sister to the New Caledonian endemic D. goliath, then more recently by the widespread D. pacifica, during the Pleistocene. The phylogenetic pattern obtained with the extant Ducula species showed that the Eastern Polynesian endemics do not form a monophyletic group, with the Pacific Imperial Pigeon D. pacifica sister species with good support to the Polynesian Imperial Pigeon D. aurorae. However, the impact of recent anthropic extinctions has been important for the imperial pigeons, more than for the smaller fruit doves, suggesting that several Ducula lineages might be missing today.


Assuntos
Columbidae/classificação , Columbidae/genética , Filogenia , Filogeografia , Animais , Teorema de Bayes , Oceano Pacífico , Fatores de Tempo
4.
Mitochondrial DNA A DNA Mapp Seq Anal ; 27(5): 3640-1, 2016 09.
Artigo em Inglês | MEDLINE | ID: mdl-26357914

RESUMO

The mitochondrial genome of the white-browed piculet Sasia ochracea (Piciformes, Picidae) and the pale-billed woodpecker Campephilus guatemalensis (Piciformes, Picidae) were sequenced using a mixed strategy of Sanger and next-generation sequencing methods. The size of the circular mitochondrial genomes were 16 908 and 16 856 bp, respectively, and include 13 protein-coding genes, 22 transfer tRNAs, 2 ribosomal RNAs, a control region and a reduced pseudo control region. The functional control region was located between the tRNAThr and tRNAPro, as found in the two other Piciformes for which complete mtDNA data are available. The length of the pseudo-control region in the white-browed piculet (103 bp) and pale-billed woodpecker (87 bp) is similar to the size of that region in Dryocopus pileatus (60 bp) and much shorter that the length of this region in Pteroglossus azara (1493 bp), suggesting that size reduction occurred before the last common ancestor of the piculets and woodpeckers.


Assuntos
Aves/genética , Genoma Mitocondrial , Animais , Proteínas Aviárias/genética , Composição de Bases , Sequência de Bases , Evolução Molecular , Especiação Genética , Região de Controle de Locus Gênico , Proteínas Mitocondriais/genética , Filogenia , RNA de Transferência/genética , Sequenciamento Completo do Genoma
5.
Mol Ecol ; 24(21): 5460-74, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26224534

RESUMO

The Indo-Malayan bioregion has provided some of the most spectacular discoveries of new vertebrate species (e.g. saola, khanyou, bare-faced bulbul) over the last 25 years. Yet, very little is known about the processes that led to the current biodiversity in this region. We reconstructed the phylogeographic history of a group of closely related passerines, the Alophoixus bulbuls. These birds are continuously distributed in Indo-Malaya around the Thailand lowlands such that their distribution resembles a ring. Our analyses revealed a single colonization event of the mainland from Sundaland with sequential divergence of taxa from southwest to northeast characterized by significant gene flow between parapatric taxa, and reduced or ancient gene flow involving the two taxa at the extremities of the ring. We detected evidence of population expansion in two subspecies, including one that was involved in the closing of the ring. Hence, our analyses indicate that the diversification pattern of Alophoixus bulbuls fits a ring species model driven by geographic isolation. To our knowledge, the Alophoixus bulbuls represent the first case of a putative broken ring species complex in Indo-Malaya. We also discuss the implications of our results on our understanding of the biogeography in Indo-Malaya.


Assuntos
Especiação Genética , Modelos Genéticos , Passeriformes/classificação , Animais , Teorema de Bayes , Núcleo Celular/genética , DNA Mitocondrial/genética , Fluxo Gênico , Genética Populacional , Filogeografia , Análise de Sequência de DNA , Tailândia
6.
Mol Phylogenet Evol ; 70: 442-53, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24012584

RESUMO

We reconstruct the phylogeny of fruit doves (genus Ptilinopus) and allies with a dense sampling that includes almost all species, based on mitochondrial and nuclear sequence data. We evaluate the most likely biogeographic scenario for the evolution of this group that colonized many islands of the Pacific Ocean. We also investigate the evolution of one of the main plumage character of fruit doves (the color of the crown), and we propose several revisions of the group's systematics. All Ptilinopus taxa formed a monophyletic group that includes two morphologically distinct genera, Alectroenas and Drepanoptila, confirming a previous result found with less species and genes. The divergence time analysis suggests that the basal divergences within Ptilinopus dated to the Early Oligocene, and the biogeographic analysis indicates that fruit doves originated most probably from the proto New Guinea region. The earliest dispersals from the New Guinea region to Oceania occurred with the colonization of New Caledonia and Fiji. A large group of Polynesian species (Central and Eastern), as well as the three taxa found in Micronesia and four species from the Guinean-Moluccan region, form the "purpuratus" clade, the largest diversification of fruit doves within Oceania, which also has a New Guinean origin. However, the eastbound colonization of fruit doves was not associated with a significant increase of their diversification rate. Overall, the Melanesian region did not act as a cradle for fruit doves, in contrast to the New Guinea region which is found as the ancestral area for several nodes within the phylogeny.


Assuntos
Columbidae/genética , Filogenia , Animais , Núcleo Celular/genética , DNA Mitocondrial/genética , Fiji , Nova Caledônia , Nova Guiné , Oceania , Oceano Pacífico , Filogeografia , Análise de Sequência de DNA
7.
Mol Phylogenet Evol ; 67(3): 578-88, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23485917

RESUMO

The ever increasing number of analysed loci in phylogenetics has not only allowed resolution of some parts of the Tree of Life but has also highlighted parts of the tree where incongruent signals among loci were detected. Previous molecular studies suggested conflicting relationships for the New World genus Campephilus, being either associated to the Megapicini or Dendropocini. Yet, the limited number of analysed loci and the use of the concatenation approach to reconstruct the phylogeny prevented the disentanglement of lineage sorting and introgression as causal explanation of this topological conflict. We sequenced four mitochondrial, nine autosomal and three Z-linked loci and used a method that incorporates population level processes into the phylogenetic framework to understand which process (lineage sorting of genetic polymorphism or hybridization/introgression) best explains this conflict. Our analyses revealed that the autosomal FGB intron-7 and to a lesser extent the Z-linked loci have a different phylogenetic history from the mitochondrial loci and some other nuclear loci we analysed. We suggest that this conflicting pattern is the result of introgression consecutive to a hybridization event at the time when members of the Campephilus and melanerpine (Melanerpes and Sphyrapicus) lineages colonized the New World. The case of Campephilus highlights that the mitochondrial genome does not always carry the 'wrong' phylogenetic signal after a past hybridization event. Indeed, we here emphasise that the signature of such event can also be detected in the nuclear genome. With the ongoing increase in the number of loci analysed in phylogenetic studies, it is very likely that further cases will be discovered. Our current results indicate that (1) the genus Campephilus is related to the Asian genera Blythipicus, Chrysocolaptes and Reinwardtipicus, in accordance with morphological data and (2) that the nuclear genome of Campephilus is likely the mixture of two unrelated lineages. Yet, further work with a denser sampling of loci is necessary to evaluate the extant of the Sphyrapicus/Melanerpes lineage nuclear genome that introgressed into the Campephilus genome.


Assuntos
Aves/classificação , Aves/genética , Hibridização Genética , Tipagem de Sequências Multilocus , Filogenia , Animais , DNA Mitocondrial , Evolução Molecular , Loci Gênicos
8.
Mol Phylogenet Evol ; 65(1): 35-45, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-22634240

RESUMO

Open-habitat chats (genera Myrmecocichla, Cercomela, Oenanthe and relative) are a morphologically and ecologically cohesive group of genera with unclear phylogenetic relationships. They are distributed mostly in open, arid and/or rocky habitats of Africa and Eurasia. Here, we present the most comprehensive molecular phylogenetic analysis of this group to date, with a complete taxon sampling at the species level. The analysis, based on a multilocus dataset including three mitochondrial and three nuclear loci, allows us to elucidate the phylogenetic relationships and test the traditional generic limits. All genera are non-monophyletic, suggesting extensive convergence on similar plumage patterns in unrelated species. While the colour pattern appear to be a poor predictor of the phylogenetic relationships, some of the ecological and behavioural traits agree relatively well with the major clades. Following our results, we also propose a revised generic classification for the whole group.


Assuntos
Evolução Biológica , Passeriformes/classificação , Filogenia , Animais , Teorema de Bayes , Núcleo Celular/genética , DNA Mitocondrial/genética , Ecologia , Funções Verossimilhança , Passeriformes/genética , Análise de Sequência de DNA
9.
Mol Phylogenet Evol ; 64(1): 93-105, 2012 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-22475817

RESUMO

The Malaconotidea (e.g., butcherbirds, bush-shrikes, batises, vangas) represent an Old World assemblage of corvoid passerines that encompass many different foraging techniques (e.g., typical flycatchers, flycatcher-shrikes, canopy creepers, undergrowth skulkers). At present, relationships among the primary Malaconotidea clades are poorly resolved, a result that could either be attributed to a rapid accumulation of lineages over a short period of time (hard polytomy) or to an insufficient amount of data having been brought to bear on the problem (soft polytomy). Our objective was to resolve the phylogenetic relationships and biogeographic history of the Malaconotidea using DNA sequences gathered from 10 loci with different evolutionary properties. Given the range of substitution rates of molecular markers we sequenced (mitochondrial, sex-linked, autosomal), we also sought to explore the effect of altering the branch-length prior in Bayesian tree estimation analyses. We found that changing the branch-length priors had no major effect on topology, but clearly improved mixing of the chains for some loci. Our phylogenetic analyses clarified the relationships of several genera (e.g., Pityriasis, Machaerirhynchus) and provide for the first time strong support for a sister-group relationship between core platysteirids and core vangids. Our biogeographic reconstruction somewhat unexpectedly suggests that the large African radiation of malaconotids originated after a single over-water dispersal from Australasia around 45-33.7 mya, shedding new light on the origins of the Afrotropical avifauna.


Assuntos
Especiação Genética , Passeriformes/classificação , Passeriformes/genética , Filogenia , Animais , Sequência de Bases , Teorema de Bayes , Primers do DNA/genética , Modelos Genéticos , Dados de Sequência Molecular , Filogeografia , Alinhamento de Sequência , Análise de Sequência de DNA
10.
Proc Natl Acad Sci U S A ; 109(17): 6620-5, 2012 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-22505736

RESUMO

Adaptive radiation is the rapid diversification of a single lineage into many species that inhabit a variety of environments or use a variety of resources and differ in traits required to exploit these. Why some lineages undergo adaptive radiation is not well-understood, but filling unoccupied ecological space appears to be a common feature. We construct a complete, dated, species-level phylogeny of the endemic Vangidae of Madagascar. This passerine bird radiation represents a classic, but poorly known, avian adaptive radiation. Our results reveal an initial rapid increase in evolutionary lineages and diversification in morphospace after colonizing Madagascar in the late Oligocene some 25 Mya. A subsequent key innovation involving unique bill morphology was associated with a second increase in diversification rates about 10 Mya. The volume of morphospace occupied by contemporary Madagascan vangas is in many aspects as large (shape variation)--or even larger (size variation)--as that of other better-known avian adaptive radiations, including the much younger Galapagos Darwin's finches and Hawaiian honeycreepers. Morphological space bears a close relationship to diet, substrate use, and foraging movements, and thus our results demonstrate the great extent of the evolutionary diversification of the Madagascan vangas.


Assuntos
Adaptação Fisiológica , Evolução Biológica , Aves/fisiologia , Ecologia , Animais , Aves/classificação , Aves/genética , Madagáscar , Dados de Sequência Molecular , Filogenia
11.
PLoS One ; 6(9): e24317, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21931679

RESUMO

The New Zealand Thrush, or Piopio, is an extinct passerine that was endemic to New Zealand. It has often been placed in its own family (Turnagridae), unresolved relative to other passerines, but affinities with thrushes, Australaian magpies, manucodes, whistlers, birds-of-paradise and bowerbirds has been suggested based on morphological data. An affinity with the bowerbirds was also indicated in an early molecular study, but low statistical support make this association uncertain. In this study we use sequence data from three nuclear introns to examine the phylogenetic relationships of the piopios. All three genes independently indicate an oriole (Oriolidae) affinity of the piopios, and the monophyly of the typical orioles (Oriolus), figbirds (Sphecotheres), and the piopios is strongly supported in the Bayesian analysis of the concatenated data set (posterior probability = 1.0). The exact placement of the piopios within Oriolidae is, however, more uncertain but in the combined analysis and in two of the gene trees the piopios are placed basal to the typical orioles while the third gene suggest a sister relationship with the figbirds. This is the first time an oriole affinity has been proposed for the piopios. Divergence time estimates for the orioles suggest that the clade originated ca 20 million years ago, and based on these estimates it is evident that the piopios must have arrived on New Zealand by dispersal across the Tasman Sea and not as a result of vicariance when New Zealand separated from Gondwana in the late Cretaceous.


Assuntos
Extinção Biológica , Aves Canoras/fisiologia , Animais , Teorema de Bayes , Núcleo Celular/genética , Íntrons/genética , Modelos Genéticos , Nova Zelândia , Filogenia , Aves Canoras/genética
12.
Proc Biol Sci ; 277(1699): 3445-51, 2010 Nov 22.
Artigo em Inglês | MEDLINE | ID: mdl-20554555

RESUMO

Little is known about the effect of quaternary climate variations on organisms that inhabited carbonate islands of the Pacific Ocean, although it has been suggested that one or several uplifted islands provided shelter for terrestrial birds when sea-level reached its highest. To test this hypothesis, we investigated the history of colonization of the Tuamotu reed-warbler (Acrocephalus atyphus) in southeastern Polynesia, and found high genetic structure between the populations of three elevated carbonate islands. Estimates of time since divergence support the hypothesis that these islands acted as refugia during the last interglacial maximum. These findings are particularly important for defining conservation priorities on atolls that endure the current trend of sea-level rise owing to global warming.


Assuntos
Ecossistema , Passeriformes/genética , Passeriformes/fisiologia , Animais , Evolução Biológica , DNA Mitocondrial/genética , Aquecimento Global , Repetições de Microssatélites , Oceanos e Mares , Ilhas do Pacífico , Densidade Demográfica
13.
Mol Phylogenet Evol ; 53(2): 384-93, 2009 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-19576994

RESUMO

Recent molecular studies on passerine birds have highlighted numerous discrepancies between traditional classification and the phylogenetic relationships recovered from sequence data. Among the traditional families that were shown to be highly polyphyletic are the Muscicapidae Old World flycatcher. This family formerly included all Old World passerines that forage on small insects by performing short sallies from a perch. Genera previously allocated to the Muscicapidae are now thought to belong to at least seven unrelated lineages. While the peculiarity of most of these lineages has been previously recognized by Linnean classification, usually at the rank of families, one, the so-called Stenostiridae, a clade comprising three Afrotropical and Indo-Malayan genera, has only recently been discovered. Here, we address in greater detail the phylogenetic relationships and biogeographic history of the Stenostiridae using a combination of mitochondrial and nuclear data. Our analyses revealed that one species, Rhipidura hypoxantha, previously attributed to the Rhipiduridae (fantails), is in fact a member of the Stenostiridae radiation and sister to the South African endemic genus Stenostira (Fairy Flycatcher). Our dating analyses, performed in a relative-time framework, suggest that the splits between Stenostira/R. hypoxantha and Culicicapa/Elminia occurred synchronously. Given that the Stenostiridae assemblage has been consistently recovered by independent studies, we clarify its taxonomic validity under the rules of the International Code of Zoological Nomenclature.


Assuntos
Evolução Molecular , Filogenia , Aves Canoras/genética , Animais , Núcleo Celular/genética , DNA Mitocondrial/genética , Geografia , Análise de Sequência de DNA , Aves Canoras/classificação
14.
Mol Phylogenet Evol ; 51(2): 169-81, 2009 May.
Artigo em Inglês | MEDLINE | ID: mdl-19027082

RESUMO

Relationships of the 133 species of the subfamily Carduelinae (Fringillidae) are poorly resolved. For a more robust phylogenetic resolution, we sequenced two mitochondrial protein-coding genes (ATPase 6 and ND3), two nuclear introns (myoglobin intron 2 and transforming growth factor-beta2 intron 5) and one nuclear protein-coding gene (c-mos) from 50 cardueline taxa representing especially the large genera Serinus and Carduelis. A total of 2934bp obtained was subjected to maximum likelihood and Bayesian inference. Three of the five loci, as well as the combined dataset recovered the monophyly of the basal placement of Fringilla in the monophyletic Fringillidae, and the monophyly of the Carduelinae. While relationships within this group are moderately resolved by some individual gene trees (myoglobin and c-mos loci), high nodal support is provided in other individual gene trees and the combined tree. Among the well resolved terminal cardueline groups, Linurgus, Loxia and Pyrrhula are found to be monophyletic while genera Carpodacus, Carduelis and Serinus appear para- or polyphyletic. Within Serinus and Carduelis, the obtained phylogenetic structure corresponds well with the subdivisions suggested by H.E. Wolters, based on traditional methods. Thus, we support his generic subdivision (Ochrospiza, Dendrospiza and Crithagra for Serinus, and Chloris, Spinus, Sporagra, Pseudomitris, Acanthis and Linaria for Carduelis). Otherwise, we notice several cases of significant genetic divergence within traditional species suggesting incipient speciation in Linurgus olivaceus, Loxia curvirostra, Serinus mozambicus and Serinus burtoni. Some of these cases need a further phylogeographical study with a denser geographical sampling but for the case the most noteworthy, that of Serinus burtoni, we suggest a taxonomic change in this study.


Assuntos
Evolução Molecular , Tentilhões/genética , Especiação Genética , Filogenia , Animais , Teorema de Bayes , Núcleo Celular/genética , DNA Mitocondrial/genética , Tentilhões/classificação , Genes Mitocondriais , Funções Verossimilhança , Modelos Genéticos , Análise de Sequência de DNA
15.
BMC Evol Biol ; 8: 197, 2008 Jul 09.
Artigo em Inglês | MEDLINE | ID: mdl-18611281

RESUMO

BACKGROUND: The island of Madagascar and surrounding volcanic and coralline islands are considered to form a biodiversity hotspot with large numbers of unique taxa. The origin of this endemic fauna can be explained by two different factors: vicariance or over-water-dispersal. Deciphering which factor explains the current distributional pattern of a given taxonomic group requires robust phylogenies as well as estimates of divergence times. The lineage of Indian Ocean scops-owls (Otus: Strigidae) includes six or seven species that are endemic to Madagascar and portions of the Comoros and Seychelles archipelagos; little is known about the species limits, biogeographic affinities and relationships to each other. In the present study, using DNA sequence data gathered from six loci, we examine the biogeographic history of the Indian Ocean scops-owls. We also compare the pattern and timing of colonization of the Indian Ocean islands by scops-owls with divergence times already proposed for other bird taxa. RESULTS: Our analyses revealed that Indian Ocean islands scops-owls do not form a monophyletic assemblage: the Seychelles Otus insularis is genetically closer to the South-East Asian endemic O. sunia than to species from the Comoros and Madagascar. The Pemba Scops-owls O. pembaensis, often considered closely related to, if not conspecific with O. rutilus of Madagascar, is instead closely related to the African mainland O. senegalensis. Relationships among the Indian Ocean taxa from the Comoros and Madagascar are unresolved, despite the analysis of over 4000 bp, suggesting a diversification burst after the initial colonization event. We also highlight one case of putative back-colonization to the Asian mainland from an island ancestor (O. sunia). Our divergence date estimates, using a Bayesian relaxed clock method, suggest that all these events occurred during the last 3.6 myr; albeit colonization of the Indian Ocean islands were not synchronous, O. pembaensis diverged from O. senegalensis about 1.7 mya while species from Madagascar and the Comoro diverged from their continental sister-group about 3.6 mya. We highlight that our estimates coincide with estimates of diversification from other bird lineages. CONCLUSION: Our analyses revealed the occurrence of multiple synchronous colonization events of the Indian Ocean islands by scops-owls, at a time when faunistic exchanges involving Madagascar was common as a result of lowered sea-level that would have allowed the formation of stepping-stone islands. Patterns of diversification that emerged from the scops-owls data are: 1) a star-like pattern concerning the order of colonization of the Indian Ocean islands and 2) the high genetic distinctiveness among all Indian Ocean taxa, reinforcing their recognition as distinct species.


Assuntos
Filogenia , Estrigiformes/fisiologia , Animais , DNA Intergênico/genética , DNA Mitocondrial/genética , Geografia , Oceano Índico , Madagáscar , Dados de Sequência Molecular , Dinâmica Populacional , Análise de Sequência de DNA , Estrigiformes/genética , Fatores de Tempo
17.
Mol Phylogenet Evol ; 48(2): 396-407, 2008 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-18514549

RESUMO

Laniarius is one of the larger genera within the avian bush-shrike radiation, the family Malaconotidae. Fairly homogenous by size and shape but highly variable by colours, these have been classified mainly on basis of plumage colours. In the present study, which is the first taxon-dense analysis of the genus Laniarius based on molecular sequence data (nuclear BRM15 intron-15, and mitochondrial ND2 and ATPase6 genes), we investigate interrelationships between 16 species and 34 subspecies of Laniarius. Altogether 2094bp were aligned and subjected to maximum likelihood and Bayesian inference analyses. Results strongly support the monophyly of Laniarius, and place it close to Chlorophoneus, but without outlining a precise sister-group. In a generally well-resolved phylogeny of Laniarius, L. leucorhynchus and L. atrococcineus constitute deep branches and the remaining species form five clades which are not concordant with previously defined superspecies. The black and white boubous belong to two different clades. L. aethiopicus appears polyphyletic and our results support the resurrection of Laniarius major, Laniarius erlangeri and Laniarius sublacteus. We also find that L. liberatus, described in 1991 based on the only known live individual, is identified as an unusual colour morph from L. erlangeri. The black boubous are not monophyletic; L. funebris and L. leucorhynchus appear as isolated species whereas L. poensis and L. fuelleborni are sister-taxa. We recovered the polyphyly of crimson boubous and new hypotheses on their relationships have been generated. Overall, the variation in pigments and patterns does not follow phylogenetic lineages. The plumage coloration could be thoroughly subject to modification and it could not reflect exactly colour plumages of the parents. From then on, the plumage coloration appears as an unreliable morphological character for defining species and species groups.


Assuntos
Passeriformes/genética , Filogenia , Animais , Teorema de Bayes , Núcleo Celular/genética , DNA Mitocondrial/química , DNA Mitocondrial/genética , Íntrons/genética , Funções Verossimilhança , Dados de Sequência Molecular , Passeriformes/classificação , Análise de Sequência de DNA
18.
Mol Phylogenet Evol ; 48(1): 34-46, 2008 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-18487062

RESUMO

Previous studies have suggested that the woodpecker genus Picus (Aves: Picidae) may not be monophyletic. In order to evaluate this hypothesis, we analyzed DNA sequences from all but two species of Picus, as well as from representatives of all genera in the tribe Malarpicini, within which Picus is nested. We sequenced seven loci (four autosomal, one Z-linked and two mitochondrial) with different evolutionary dynamics. The species currently placed in Picus fall into two subclades that may not form a monophyletic assemblage. Consequently, we propose to place miniaceus Pennant 1769, flavinucha Gould 1834 and mentalis Temminck 1825 in the genus Chrysophlegma Gould, 1850, while the remaining species are retained in Picus. The inclusion in our study of representatives of all genera included in the tribe Malarpicini, a group of woodpeckers which has proven difficult to resolve in several previous molecular studies, also allowed us to determine the earliest divergences within this clade. The results suggest that the low level of basal resolution in Malarpicini is attributable to multiple cladogenetic events in a short period of time rather than insufficient character sampling. This conclusion is supported by the observation of nucleotide insertion-deletions that support mutually exclusive phylogenetic hypotheses in different gene trees. We attribute this pattern of incongruent indels, together with short internodes in the tree, to incomplete lineage sorting.


Assuntos
Aves/classificação , Aves/genética , Animais , Sequência de Bases , Especiação Genética , Filogenia , Alinhamento de Sequência
19.
Mol Phylogenet Evol ; 47(1): 221-36, 2008 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-18295511

RESUMO

The systematic relationships among avian families within Crown Corvida have been poorly studied so far and as such been of limited use for biogeographic interpretations. The group has its origin in Australia and is thought to have colonized Africa and the New World via Asia beginning some 35 Mya when terranes of Australian origin approached Asian landmasses. Recent detailed tectonic mapping of the origin of land masses in the region around Wallace's line have revealed a particularly complex movement of terranes over the last 20-30 Myr. Thus the biogeographic dispersal pattern of Crown Corvida is a particularly exciting case for linking vicariance and dispersal events with Earth history. Here we examine phylogenetic affinities among 72 taxa covering a broad range of genera in the basal radiations within Crown Corvida with an emphasis on Campephagidae and Pachycephalidae. Bayesian analyses of nuclear DNA sequence data identified the family Campephagidae as monophyletic but the large genus Coracina is not. Within the family Pachycephalidae the genera Pachycephala and Colluricincla are paraphyletic with respect to each other. The resulting phylogeny suggests that patterns of dispersal across Wallace's line are complex and began at least 25 Mya. We find evidence of explosive radiations and multi-directional dispersal within the last 10 Myr, and three independent long distance ocean dispersal events between Wallacea and Africa at 10-15 Mya. Furthermore, the study reveals that in the Campephagidae a complex series of dispersal events rather than vicariance is the most likely explanation for the current biogeographic pattern in the region.


Assuntos
Aves/classificação , Filogenia , Animais , Sequência de Bases , Primers do DNA
20.
Mol Phylogenet Evol ; 45(1): 158-67, 2007 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-17468015

RESUMO

We address the phylogenetic relationships of the drongos (Dicruridae) at the species-level using sequences from two nuclear (myoglobin intron-2 and c-mos) and two mitochondrial (ND2 and cytochrome b) loci. The resulting phylogenetic tree shows that the most basal species is D. aeneus, followed in the tree by a trichotomy including (1) the Asian D. remifer, (2) a clade of all African and Indian Ocean islands species as well as two Asian species (D. macrocercus and D. leucophaeus) and (3) a clade that includes all other Asian species as well as two Australasian species (D. megarhynchus and D. bracteatus). Our phylogenetic hypotheses are compared to [Mayr, E., Vaurie, C., 1948. Evolution of the family Dicruridae (Birds). Evolution 2, 238-265.] hypothetical family "tree" based on traditional phenotypic analysis and biogeography. We point out a general discrepancy between the so-called "primitive" or "unspecialized" species and their position in the phylogenetic tree, although our results for other species are congruent with previous hypotheses. We conduct dating analyses using a relaxed-clock method, and propose a chronology of clades formation. A particular attention is given to the drongo radiation in Indian Ocean islands and to the extinction-invasion processes involved. The first large diversification of the family took place both in Asia and Africa at 11.9 and 13.3Myr, respectively, followed by a dispersal event from Africa to Asia at ca 10.6Myr; dispersal over Wallace line occurred later at ca 6Myr. At 5Myr, Principe and Indian Ocean Islands have been colonized from an African ancestor; the most recent colonization event concerned Anjouan by an immigrating population from Madagascar.


Assuntos
Evolução Molecular , Geografia , Passeriformes/classificação , Passeriformes/genética , Filogenia , Clima Tropical , Animais , Especiação Genética , Fatores de Tempo
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