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1.
Aim Cuckoo‐shrikes and allies (Campephagidae) form a radiation of birds widely distributed in the Indo‐Pacific and Africa. Recent studies on the group have been hampered by poor taxon sampling, causing inferences about systematics and biogeography to be rather speculative. With improved taxon sampling and analyses within an explicit spatiotemporal framework, we elucidate biogeographical patterns of dispersal and diversification within this diverse clade of passerine birds. Location Africa, Asia, Australo‐Papua, the Pacific, the Philippines and Wallacea. Methods We use model‐based phylogenetic methods (Mr Bayes and garli ) to construct a phylogenetic hypothesis of the core Campephagidae (Campephagidae with the exclusion of Pericrocotus). The phylogeny is used to assess the biogeographical history of the group with a newly developed Bayesian approach to dispersal–vicariance analysis (Bayes‐diva) . We also made use of a partitioned beast analysis, with several calibration points taken from island ages, passerine mitochondrial substitution rates and secondary calibration points for passerine birds, to assess the timing of diversification and dispersal. Results We present a robust molecular phylogeny that includes all genera and 84% of the species within the core Campephagidae. Furthermore, we estimate divergence dates and ancestral area relationships. We demonstrate that Campephagidae originated in Australo‐Papua with a single lineage (Pericrocotus) dispersing to Asia early. Later, there was further extensive transoceanic dispersal from Australo‐Papua to Africa involving lineages within the core Campephagidae radiation. Main conclusions The phylogenetic relationships, along with the results of the ancestral area analysis and the timing of dispersal events, support a transoceanic dispersal scenario from Australo‐Papua to Africa by the core Campephagidae. The sister group to core Campephagidae, Pericrocotus, dispersed to mainland Asia in the late Oligocene. Asia remained uncolonized by the core Campephagidae until the Pliocene. Transoceanic dispersal is by no means an unknown phenomenon, but our results represent a convincing case of colonization over a significant water gap of thousands of kilometres from Australo‐Papua to Africa.  相似文献   

2.
Because of the difficulties of constructing a robust phylogeny for Charadriiform birds using morphological characters, recent studies have turned to DNA sequences to resolve the systematic uncertainties of family-level relationships in this group. However, trees constructed using nuclear genes or the mitochondrial Cytochrome b gene suggest deep-level relationships of shorebirds that differ from previous studies based on morphology or DNA-DNA hybridization distances. To test phylogenetic hypotheses based on nuclear genes (RAG-1, myoglobin intron-2) and single mitochondrial genes (Cytochrome b), approximately 13,000 bp of mitochondrial sequence was collected for one exemplar species of 17 families of Charadriiformes plus potential outgroups. Maximum likelihood and Bayesian analyses show that trees constructed from long mitochondrial sequences are congruent with the nuclear gene topologies [Chardrii (Lari, Scolopaci)]. Unlike short mitochondrial sequences (such as Cytochrome b alone), longer sequences yield a well-supported phylogeny for shorebirds across various taxonomic levels. Examination of substitution patterns among mitochondrial genes reveals specific genes (especially ND5, ND4, ND2, and COI) that are better suited for phylogenetic analyses among shorebird families because of their relatively homogeneous nucleotide composition among lineages, slower accumulation of substitutions at third codon positions, and phylogenetic utility in both closely and distantly related lineages. For systematic studies of birds in which family and generic levels are examined simultaneously, we recommend the use of both nuclear and mitochondrial sequences as the best strategy to recover relationships that most likely reflect the phylogenetic history of these lineages.  相似文献   

3.
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.  相似文献   

4.
The African wattle-eyes (genera Platysteira and Dyaphorophyia) comprise 10 species endemic to Africa. We analyzed both mitochondrial and nuclear DNA sequence data to test the monophyly of this group and its two genera, provide a preliminary assessment of species limits, and gain insight into the phylogeographic history of the wattle-eye radiation. Analyses based on mitochondrial ND2 sequences failed to recover wattle-eye monophyly, but the alternatives were not well-supported. In contrast, analyses of two nuclear introns (myoglobin intron-2 and beta-fibrinogen intron-5) recovered wattle-eye monophyly, as did combined analyses of mitochondrial and nuclear data. These analyses, however, did not support reciprocal monophyly of the two wattle-eye genera typically recognized, suggesting instead that Platysteira is nested within a paraphyletic Dyaphorophyia. The diversification of most wattle-eye species and many subspecies occurred through the divergence of allopatric populations well before the Pleistocene. Species and subspecies with disjunct distributions are typically characterized by deep genetic divergences, suggesting that many of these populations are evolutionary independent and could be recognized as additional phylogenetic species. In D. castanea and D. chalybea, for example, divergent haplotypes from geographically disjunct populations were paraphyletic with respect to those of D. tonsa and D. jamesoni, respectively. Similarly, Platysteira laticincta is highly divergent from its sister taxon P. peltata ( approximately 9.5% ND2 sequence divergence), consistent with species level recognition of this endangered species. In contrast, more broadly distributed taxa inhabiting a greater diversity of habitats (e.g., P. peltata and P. cyannea) show evidence of gene flow and connectivity among regions, suggesting that previously isolated populations expanded and fused into one another. Our study provides a framework for additional analyses of intraspecific phylogeography and species limits in these colorful birds.  相似文献   

5.
Phylogeographic patterns in widespread corvid birds   总被引:1,自引:0,他引:1  
Intraspecific genetic diversity and phylogeography of Corvus corone was investigated using the mitochondrial (mt) control region as a molecular marker. A split into two distinct mt lineages was observed. One represents individuals from a wide geographic range spanning from England to the Russian Far East (Kamchatka), while the other one was found in the Primorye and Khabarovsk regions (southern parts of Russian Far East) as well as Japan. For comparison, we investigated several widespread Palearctic corvid taxa with respect to their phylogeographic patterns. A deep split into two lineages was revealed in five cases: Besides C. corone, within Corvus frugilegus, Pica pica, and between the species pairs Corvus monedula-Corvus dauuricus and Cyanopica cyanus-Cyanopica cooki. Although these taxa display a variety of distribution patterns, from disjunct, para/allopatric to continuous, the genetic pattern and level of divergence between clades is very similar. This implies that the differentiation started in about the same time range. In contrast, no differentiation into highly divergent lineages was detected in Corvus corax, Perisoreus infaustus, and Nucifraga caryocatactes. We try to explain the two phylogeographic patterns in corvid birds with ecological factors accompanying the changing climatic conditions during the Pleistocene. The deep genetic splits within several widely distributed Palearctic corvids are discussed with respect to taxonomic questions.  相似文献   

6.
Cooperative breeding is comparatively rare among birds in the mainly temperate and boreal Northern Hemisphere. Here we test if the distribution of breeding systems reflects a response to latitude by means of a phylogenetic analysis using correlates with geographical range among the corvids (crows, jays, magpies and allied groups). The corvids trace their ancestry to the predominantly cooperative 'Corvida' branch of oscine passerines from the Australo-Papuan region on the ancient Gondwanaland supercontinent, but we could not confirm the ancestral state of the breeding system within the family, while family cohesion may be ancestral. Initial diversification among pair-breeding taxa that are basal in the corvid phylogeny, represented by genera such as Pyrrhocorax and Dendrocitta, indicates that the corvid family in its current form could have evolved from pair-breeding ancestors only after they had escaped the Australo-Papuan shield. Within the family, cooperative breeding (alloparental care/family cohesion) is strongly correlated to latitude and its predominance in species maintaining a southerly distribution indicates a secondary evolution of cooperative breeding in the lineage leading away from the basal corvids. Multiple transitions show plasticity in the breeding system, indicating a response to latitude rather than evolutionary inertia. The evolutionary background to the loss of cooperative breeding among species with a northerly distribution is complex and differs between species, indicating a response to a variety of selection forces. Family cohesion where the offspring provide alloparental care is a main route to cooperatively breeding groups among corvids. Some corvid species lost only alloparental care, while maintaining coherent family groups. Other species lost family cohesion and, as a corollary, they also lost the behaviour where retained offspring provide alloparental care.  相似文献   

7.
The African genus Hyliota includes three or four species of warbler-like birds of uncertain phylogenetic affinities, as it has historically been placed in different avian families that are now known to represent unrelated lineages: Malaconotidae (bush-shrikes), Platysteiridae (batises and wattle-eyes), Muscicapidae (Old World flycatchers) and Sylviidae (Old-World Warblers). To assess the affinities of Hyliota we sequenced a mitochondrial protein-coding gene (ND2, 1018bp) and a nuclear intron (myoglobin intron-2, 685bp). Our analyses suggest that all previous hypotheses concerning the affinities of Hyliota are erroneous. Instead, Hyliota represents a basal branch in the Passerida radiation with no close relatives. Our results, which also include analyses of relationships among other of other atypical songbird genera, lend support to an African origin of the Passerida songbird radiation.  相似文献   

8.
Intestinal spirochetes of genus Brachyspira are commonly isolated from mammalian and avian hosts, and several species have been reported to cause enteric disease in pigs and birds. Except for a previous publication on three isolates from corvid birds (order Passeriformes, family Corvidae, genus Corvus), of which two are further studied in this paper, no other reports exist on Brachyspira spp. of passerine birds. In this study, cloacal and intestinal swabs of small and large intestines were collected from 116 corvid birds of three species, i.e. jackdaws (Corvus monedula), hooded crows (Corvus corone cornix) and rooks (Corvus frugilegus), from four separate geographical locations in Sweden. Isolates were obtained by selective culture from 43 of 116 birds. All isolates were weakly hemolytic, indole-negative and lacked hippurate cleavage capacity. Examination by light microscopy did not indicate association with enteric disease in necropsied birds. Pure spirochete cultures were obtained by serial dilution and subculture, and selected isolates were analyzed by PCR (n=14), randomly amplified polymorphic DNA (RAPD) (n=14), and sequencing of the almost complete 16S rRNA (n=14), and partial nox genes (n=4). Positive reactions were noticed by PCR targeting a hexa-T segment of the 16S rRNA gene, which has been previously reported as a signature characteristic of Brachyspira pilosicoli. By 16S rRNA gene sequencing, the isolates formed a separate cluster related to genus Brachyspira, but not consistent with any presently recognized or proposed Brachyspira sp. The sequence similarity of the 16S rRNA gene among the isolates from corvid birds was 99.7-100%. Compared to 16S rRNA gene sequence data from all presently recognized and several proposed Brachyspira spp. the sequence similarity of the isolates from corvid birds varied between 94.1 and 96.5%. In a radial tree based on nox gene sequences, all four analyzed isolates from corvid birds formed a separate cluster. By RAPD analysis, the banding patterns of the isolates differed from all type strains of Brachyspira spp. Based on the results presented in this paper, we propose that the described isolates from corvid birds belong to a novel species within genus Brachyspira, with the provisional name "Brachyspira corvi" (cor'vi. L gen. n. corvi, of a crow).  相似文献   

9.
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.  相似文献   

10.
The breeding season of long‐distance migratory birds often starts later and is shorter than in resident or short‐distance species breeding at the same latitude, but the reason for this is unclear. Here we investigate the association between migration distance and breeding phenology in a group of passerine birds, the finches and their allies, using phylogenetic comparative methods. We confirm that migration distance is related to aspects of the species’ breeding phenology after controlling for the effect of potentially confounding variables. Directional phylogenetic analyses suggest that evolutionary transitions in migration distance are determined by the breeding phenology. A relatively long migration distance is more likely to evolve in birds with a late, short breeding season, whereas transitions to short distance migration are more likely to occur in lineages with an early, long breeding season. These results suggest that migration distance is constrained by breeding phenology and not vice versa. Thus, breeding phenology may be an important ultimate factor shaping the evolution of migratory strategies.  相似文献   

11.
The red-billed quelea Quelea quelea , one of the most abundant birds in the world, presents two fundamental conundrums that we investigate here with a novel approach using blood parasite assemblages at two spatial scales, landscape and individual. The quelea of southern Africa Q. q. lathamii are split by a hypothesized migratory divide, where birds follow rain fronts in one of two directions (NW or SE). This divide is not detectable in the host population using microsatellite data, and here we show that it is also not apparent from our large-scale phylogeographical analyses of the haematozoan parasite. At a finer scale, the colourful and variable breeding plumage of male red-billed quelea has not previously shown a correlation with predictors of quality, as it does in many other bird species. The male's breeding plumage is partially based on carotenoid colouration, the quality of which has been correlated with haematozoan infection in other bird species. However, we found no correlation between intensity of male carotenoid colouration and haematozoan infection. Our results do not contradict the hypothesis that male breeding plumage in this species serves to identify individuals rather than to indicate quality. Finally, we recovered the greatest number of haematozoan lineages from any phylogenetic survey of a single host species to date. Understanding the reasons for the extreme diversity of parasite lineages in this species may assist in explaining the success of the red-billed quelea in anthropogenic landscapes.  相似文献   

12.
The Diplostomidae Poirier, 1886 is a large, globally distributed family of digeneans parasitic in intestines of their definitive hosts. Diplostomum and Tylodelphys spp. are broadly distributed, commonly reported, and the most often sequenced diplostomid genera. The majority of published DNA sequences from these genera originated from larval stages only, which typically cannot be identified to the species level based on morphology alone. We generated partial large ribosomal subunit (28S) rRNA and cytochrome c oxidase subunit 1 (cox1) mtDNA gene sequences from 14 species/species-level lineages of Diplostomum, six species/species-level lineages of Tylodelphys, two species/species-level lineages of Austrodiplostomum, one species previously assigned to Paralaria, two species/species-level lineages of Dolichorchis and one unknown diplostomid. Our DNA sequences of 11 species/species-level lineages of Diplostomum (all identified to species), four species/species-level lineages of Tylodelphys (all identified to species), Austrodiplostomum compactum, Paralaria alarioides and Dolichorchis lacombeensis originated from adult specimens. 28S sequences were used for phylogenetic inference to demonstrate the position of Paralaria alarioides and Dolichorchis spp. within the Diplostomoidea and study the interrelationships of Diplostomum, Tylodelphys and Austrodiplostomum. Our results demonstrate that two diplostomids from the North American river otter (P. alarioides and a likely undescribed taxon) belong within Diplostomum. Further, our results demonstrate the non-monophyly of Tylodelphys due to the position of Austrodiplostomum spp., based on our phylogenetic analyses and morphology. Furthermore, the results of phylogenetic analysis of 28S confirmed the status of Dolichorchis as a separate genus. The phylogenies suggest multiple definitive host-switching events (birds to otters and among major avian groups) and a New World origin of Diplostomum and Tylodelphys spp. Our DNA sequences from adult digeneans revealed identities of 10 previously published lineages of Diplostomum and Tylodelphys, which were previously identified to genus only. The novel DNA data from this work provide opportunities for future comparisons of larval diplostomines collected in ecological studies.  相似文献   

13.
Environmental changes over the Plio‐Pleistocene have been key drivers of speciation patterns and genetic diversification in high‐latitude and mesic environments, yet comparatively little is known about the evolutionary history of species in arid environments. We applied phylogenetic and phylogeographic analyses to understand the evolutionary history of Warramaba grasshoppers from the Australian arid zone, a group including sexual and parthenogenetic lineages. Sequence data (mitochondrial COI) showed that the four major sexual lineages within Warramaba most likely diverged in the Pliocene, around 2–7 million years ago. All sexual lineages exhibited considerable phylogenetic structure. Detailed analyses of the hybrid parthenogenetic species W. virgo and its sexual progenitors showed a pattern of high phylogenetic diversity and phylogeographic structure in northern lineages, and low diversity and evidence for recent expansion in southern lineages. Northern sexual lineages persisted in localized refugia over the Pleistocene, with sustained barriers promoting divergence over this period. Southern parts of the present range became periodically unsuitable during the Pleistocene, and it is into this region that parthenogenetic lineages have expanded. Our results strongly parallel those for sexual and parthenogenetic lineages of the gecko Heteronotia from the same region, indicating a highly general effect of Plio‐Pleistocene environmental change on diversification processes in arid Australia.  相似文献   

14.
Recent molecular studies addressing the phylogenetic relationships of avian orders have had conflicting results. While studies using nuclear DNA sequences tend to support traditional taxonomic views, also supported by morphological data [(paleognaths (galloanseres (all other birds)))], with songbirds forming a clade within Neoaves (all other birds), analyses with complete mtDNA genomes have resulted in topologies that place songbirds as one of the earliest-diverging avian lineages. Considering that over half of the extant bird species are songbirds, these different results have very different implications for our understanding of avian evolution. We analyzed data sets comprising nearly 4 kb of mitochondrial DNA (mtDNA) (complete 12S, ND1, ND2, and cytochrome b) plus 600 bp of the nuclear gene c-mos for 15 birds that were chosen to represent all major avian clades and to minimize potential long-branch attraction problems; we used a partition-specific maximum likelihood approach. Our results show congruence with respect to the ingroup among phylogenies obtained with mtDNA and the nuclear gene c-mos, separately or combined. The data sets support a traditional avian taxonomy, with paleognaths (ratites and tinamous) occupying a basal position and with songbirds more derived and forming a monophyletic group. We also show that, for mtDNA studies, turtles may be a better outgroup for birds than crocodilians because of their slower rate of sequence evolution.  相似文献   

15.
Few studies to date have examined genetic variability of widespread tropical amphibian species over their distributional range using different kinds of molecular markers. Here, we use genetic data in an attempt to delimit evolutionary entities within two groups of Neotropical frogs, the Scinax ruber species group and the Rhinella margaritifera species group. We combined mitochondrial and nuclear markers for a phylogenetic (a total of approximately 2500 bp) and phylogeographic study (approximately 1300 bp) to test the reliability of the currently accepted taxonomic assignments and to explore the geographic structure of their genetic variation, mainly based upon samples from the French Guianan region. Phylogenetic analyses demonstrated the polyphyly of Scinax ruber and Rhinella margaritifera. S. ruber consists of six lineages that may all merit species status. Conflicting signals of mitochondrial and nuclear markers indicated, among some Scinax lineages and species, the possibility of ongoing hybridization processes. R. margaritifera consisted of 11 lineages which might represent distinct species as well. Phylogeographic analyses added further information in support of the specific status of these lineages. Lineages of low divergence were found in sympatry and were reciprocally monophyletic for mitochondrial as well as nuclear genes, indicating the existence of young lineages that should be awarded species status. Our results highlight the utility of combining phylogenetic and phylogeographic methods, as well as the use of both mitochondrial and nuclear markers within one study. This approach helped to better understand the evolutionary history of taxonomically complex groups of species. The assessment of the geographic distribution of genetic diversity in tropical amphibian communities can lead to conclusions that differ strongly from prior analyses based on the occurrence of currently recognized species alone. Such studies, therefore, hold the potential to contribute to a more objective assessment of amphibian conservation priorities in tropical areas.  相似文献   

16.
Current understanding of the diversification of birds is hindered by their incomplete fossil record and uncertainty in phylogenetic relationships and phylogenetic rates of molecular evolution. Here we performed the first comprehensive analysis of mitogenomic data of 48 vertebrates, including 35 birds, to derive a Bayesian timescale for avian evolution and to estimate rates of DNA evolution. Our approach used multiple fossil time constraints scattered throughout the phylogenetic tree and accounts for uncertainties in time constraints, branch lengths, and heterogeneity of rates of DNA evolution. We estimated that the major vertebrate lineages originated in the Permian; the 95% credible intervals of our estimated ages of the origin of archosaurs (258 MYA), the amniote-amphibian split (356 MYA), and the archosaur-lizard divergence (278 MYA) bracket estimates from the fossil record. The origin of modern orders of birds was estimated to have occurred throughout the Cretaceous beginning about 139 MYA, arguing against a cataclysmic extinction of lineages at the Cretaceous/Tertiary boundary. We identified fossils that are useful as time constraints within vertebrates. Our timescale reveals that rates of molecular evolution vary across genes and among taxa through time, thereby refuting the widely used mitogenomic or cytochrome b molecular clock in birds. Moreover, the 5-Myr divergence time assumed between 2 genera of geese (Branta and Anser) to originally calibrate the standard mitochondrial clock rate of 0.01 substitutions per site per lineage per Myr (s/s/l/Myr) in birds was shown to be underestimated by about 9.5 Myr. Phylogenetic rates in birds vary between 0.0009 and 0.012 s/s/l/Myr, indicating that many phylogenetic splits among avian taxa also have been underestimated and need to be revised. We found no support for the hypothesis that the molecular clock in birds "ticks" according to a constant rate of substitution per unit of mass-specific metabolic energy rather than per unit of time, as recently suggested. Our analysis advances knowledge of rates of DNA evolution across birds and other vertebrates and will, therefore, aid comparative biology studies that seek to infer the origin and timing of major adaptive shifts in vertebrates.  相似文献   

17.
Haemoproteus (Parahaemoproteus) micronuclearis n. sp., Haemoproteus (Parahaemoproteus) nucleofascialis n. sp., Haemoproteus (Parahaemoproteus) paranucleophilus n. sp., and Haemoproteus (Parahaemoproteus) homobelopolskyi n. sp. (Haemosporida, Haemoproteidae) are described from African passeriform birds based on the morphology of their blood stages and segments of the mitochondrial cytochrome b gene. Red-billed quelea (Quelea quelea), red-headed malimbe (Malimbus rubricollis), and black-headed weaver (Ploceus melanocephalus) are the type vertebrate hosts of new hemoproteids. It is probable that new species have wide distribution in weavers in sub-Saharan Africa. Both H. micronuclearis and H. nucleofascialis can be readily distinguished from other avian hemoproteids by tiny, compact microgametocyte nuclei that are significantly smaller than macrogametocyte nuclei and are a rare character of hemosporidian parasites. Gametocytes of H. paranucleophilus are closely appressed to the erythrocyte nuclei and do not touch the erythrocyte envelope along their entire margin at all stages of their development, including fully grown gametocytes. A particularly distinctive feature of H. homobelopolskyi development is the presence of circumnuclear dumbbell-shaped macrogametocytes. Illustrations of blood stages of the new species are given, and morphological and phylogenetic analyses identify the DNA lineages that are associated with these parasites. Numerous recent studies show that some lineages of hemoproteids are often present in birds belonging to different families. As a result, the use of the host family as a taxonomic character should be questioned and preferably discouraged in hemoproteid taxonomy, particularly with regard to the parasites of passerine birds. Microscopic identification of avian hemoproteids requires comparison of Haemoproteus species described from birds of different families, as is an established practice with avian Plasmodium spp. Development of bar-coding techniques remains essential in taxonomic and field studies of hemosporidian parasites.  相似文献   

18.
Cytochrome b and D-loop nucleotide sequences were used to study patterns of molecular evolution and phylogenetic relationships between the pheasants and the partridges, which are thought to form two closely related monophyletic galliform lineages. Our analyses used 34 complete cytochrome b and 22 partial D-loop sequences from the hypervariable domain I of the D-loop, representing 20 pheasant species (15 genera) and 12 partridge species (5 genera). We performed parsimony, maximum likelihood, and distance analyses to resolve these phylogenetic relationships. In this data set, transversion analyses gave results similar to those of global analyses. All of our molecular phylogenetic analyses indicated that the pheasants and partridges arose through a rapid radiation, making it difficult to establish higher level relationships. However, we were able to establish six major lineages containing pheasant and partridge taxa, including one lineage containing both pheasants and partridges (Gallus, Bambusicola and Francolinus). This result, supported by maximum likelihood tests, indicated that the pheasants and partridges do not form independent monophyletic lineages.  相似文献   

19.
At a regional scale, the high species numbers (gamma diversity) of tropical forests have been explained by either a gradual accumulation of species through time (museum hypothesis) or, by contrast, rapid recent speciation in large genera. However, the origins of local rain forest diversity (alpha diversity) have been given little attention. Cyrtandra (Gesneriaceae), an understorey genus in the highly species-rich Indo-Malayan rain forest, has considerable capacity for producing local endemics, making it particularly suitable for studying diversity on a local scale. We sampled Cyrtandra species from one community on Mount Kerinci, Sumatra, and phylogenetic analyses of ITS sequences suggest that this community is an assembly of three distinct phyletic lineages: (1) a group of herbaceous or subshrub plants of Bornean affinity, (2) one member of a group of widespread shrubs forming Cyrtandra section Dissimiles and (3) a second group of shrubs. The evolutionary origin of this community is therefore not a result of rapid and recent speciation: it is assembled from species resulting from a gradual accumulation of diversity through time (museum hypothesis), although one lineage shows evidence of more recent, continuing speciation than the other two. The community includes two distantly related, apparently endemic species, but there is no evidence for a local adaptive radiation. The protection of representative species from each lineage would allow the conservation of genetic diversity.  © 2004 The Linnean Society of London, Biological Journal of the Linnean Society , 2004, 81 , 49–62.  相似文献   

20.
Brood parasitic birds, their foster species and their ectoparasites form a complex coevolving system composed of three hierarchical levels. However, effects of hosts’ brood parasitic life‐style on the evolution of their louse (Phthiraptera: Amblycera, Ischnocera) lineages have never been tested. We present two phylogenetic analyses of ectoparasite richness of brood parasitic clades. Our hypothesis was that brood parasitic life‐style affects louse richness negatively across all avian clades due to the lack of vertical transmission routes. Then, narrowing our scope to brood parasitic cuckoos, we explored macroevolutionary factors responsible for the variability of their louse richness. Our results show that taxonomic richness of lice is lower on brood parasitic clades than on their nonparasitic sister clades. However, we found a positive covariation between the richness of cuckoos’ Ischnoceran lice and the number of their foster species, possibly due to the complex and dynamic subpopulation structure of cuckoo species that utilize several host species. We documented diversity interactions across a three‐level host parasite system and we found evidence that brood parasitism has opposing effects on louse richness at two slightly differing macroevolutionary scales, namely the species richness and the genera richness.  相似文献   

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