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1.
Abstract. Phylogenetic relationships of Erotylidae (pleasing fungus beetles) were inferred based on DNA sequence data. Relationships of clades within Erotylidae were examined, as was the relationship of the entire family to Languriidae (lizard beetles). 18S and 28S ribosomal DNA were sequenced for sixty‐one taxa representing major erotylid lineages and outgroups. Phylogenetic analyses under varying parameter settings using standard parsimony and likelihood techniques were performed. These data indicate a paraphyletic Erotylidae and Languriidae. Encaustinae (including Coptengis), Megalodacninae and Erotylinae are supported as monophyletic, whereas Dacninae and Tritominae are paraphyletic. Taxonomic and biological implications are discussed. Gregariousness has arisen at least three times in Erotylidae. The erotylid clade has experienced at least one evolutionary transition from mycophagy (on Aphyllophorales) to phytophagy, three transitions from Aphyllophorales hosts to Euagarics, and one transition from Euagarics hosts to Mucorales (Zygomycetes). There are no recognizable phylogenetic trends in coloration across higher‐level erotylid lineages.  相似文献   

2.
The first comprehensive cladistic analysis of Miridae, the plant bugs, is presented based on analysis of 3935 base pairs of mitochondrial (16S, COI) and nuclear (18S, 28SD3) DNA for 91 taxa in seven subfamilies. Data were analysed using maximum likelihood (ML), parsimony and Bayesian inference (BI) phylogenetic frameworks. The phylogenetic results are compared with previous hypotheses of higher relationships in the family using alternative hypothesis tests. A Bayesian relaxed molecular clock is used to examine divergence times, and ancestral feeding habits are reconstructed using parsimony and a Bayesian approach. Clades recovered in all analyses are as follows: Cimicomorpha, Miroidea and Miridae; Bryocorinae: Bryocorini; Stenodemini; Mirinae; Deraeocorinae (Clevinemini + Deraeocorini); Cylapinae; Isometopinae; Bryocorinae: Dicyphini; Orthotylini; Phylinae (Phylini + Pilophorini), and Phylinae as sister group to all the remaining mirid taxa. These results are largely congruent with former hypotheses based on morphological data with respect to the monophyly of various subfamilies and tribes; however, our results indicate that the subfamily Bryocorinae is not monophyletic, as the two tribes, Dicypini and Bryocorini, were separated in the phylogenetic results. Divergence time estimates indicate that the radiation of the Miridae began in the Permian; most genus‐level radiations within subfamilies began in the late Cretaceous, probably in response to the angiosperm radiation. Ancestral feeding state reconstructions based on Bayesian and parsimony inference were largely congruent and both reconstructed phytophagy as the ancestral state of the Miridae. Furthermore, the feeding habits of the common ancestors of Mirinae + Deraeocorinae, Bryocorinae + Cylapinae + Isometopinae + Orthotylinae, and the remaining taxa excluding Phylinae, were inferred as phytophagous. Therefore, at least three shifts from phytophagy or polyphagy to predation occurred within the Miridae. Additionally, based on the mirid host‐plant records, we discovered several trends, such as a strong relationship between host‐plant ranges and a facultative feeding habit. © The Willi Hennig Society 2011.  相似文献   

3.
The Gelechioidea, with 18,000 described and many more unnamed species ranks among the most diverse lepidopteran superfamilies. Nevertheless, their taxonomy has remained largely unresolved, and phylogenetic affinities among gelechioid families and lower taxa have been insufficiently understood. We constructed, for the first time, a comprehensive molecular phylogeny for the Gelechioidea. We sampled seven genes, in total 5466 base pairs, of 109 gelechioid taxa representing 32 of 37 recognized subfamilies, and two outgroup taxa. We used maximum likelihood methods and Bayesian inference to construct phylogenetic trees. We found that the families Autostichidae, Lecithoceridae, Xyloryctidae, and Oecophoridae s. str., in this order, are the most basally arising clades. Elachistidae s. l. was found to be paraphyletic, with families such as Gelechiidae and Cosmopterigidae nested within it, and Parametriotinae associated with several families previously considered unrelated to them. Using the phylogenetic trees, we examined patterns of life history evolution and determinants of the success of different lineages. Gelechioids express unusually wide variability in life-history strategies, including herbivorous, saprophagous, fungivorous, and carnivorous lineages. Most species are highly specialized in diet and other life history traits. The results suggest that either saprophagy was the ancestral feeding strategy from which herbivory evolved independently on multiple occasions, or that the ancestor was herbivorous with repeated origins of saprophagy. External feeding is an ancestral trait from which internal feeding evolved independently several times. In terms of species number, saprophages are dominant in Australia, while elsewhere several phytophagous lineages have extensively specialized and diversified. Internal feeding has remained a somewhat less generally adopted feeding mode, although in a few lineages significant radiations of leaf mining species have occurred. We conclude that diverse feeding modes, specialization among saprophages, repeated shifts to phytophagy, and a generally high specialization rate on single plant species (monophagy) are the major factors behind the success of the Gelechioidea.  相似文献   

4.
Characters of the thorax of 30 representatives of all endopterygote orders and four hemimetabolous outgroup taxa were examined. In total, 126 characters potentially useful for phylogenetic reconstruction are discussed and presented as a data matrix. The thoracic features were analysed with different approaches combined with an additional large set of morphological data. Endopterygota were confirmed as monophyletic and new morphological autapomorphies of the group are suggested. The highly controversial Strepsiptera are not placed as sistergroup of Diptera (Halteria‐concept) but consistently as sistergroup of Coleoptera. This clade was mainly supported by characters associated with posteromotorism. The traditionally proposed relationship of Neuropterida + Coleoptera was not confirmed. Hymenoptera was placed as sistergroup of all remaining orders in parsimony analyses. The inclusion of Strepsiptera + Coleoptera in Mecopterida in parsimony analyses is probably artificial and potential thoracic autapomorphies of Mecopterida in the traditional sense are suggested. Mecopterida are confirmed as a clade in Bayesian analyses. Amphiesmenoptera and Antliophora are well supported. The paraphyly of Mecoptera is due to a clade comprising Nannochoristidae and Siphonaptera + Diptera. The phylogenetic reconstruction using characters of the thorax is impeded by functional constraints, parallel losses, a general trend to reinforce the skeleton and to simplify the muscular apparatus, and also by different specializations occurring in potential outgroup taxa. The addition of a large additional morphological data set only partly compensated for these problems. It is apparent that the inclusion of more outgroup and ingroup taxa is required, notably presumably basal representatives of Mecoptera, Trichoptera, and Diptera. This may reduce the effect of an artificial attraction of branches caused by homoplasy, notably character losses occurring within different lineages.© The Willi Hennig Society 2010.  相似文献   

5.
We performed a comparative study of partial rDNA sequences from a variety of Coleoptera taxa to construct an annotated alignment based on secondary structure information, which in turn, provides improved rRNA structure models useful for phylogenetic reconstruction. Subsequent phylogenetic analysis was performed to test monophyly and interfamilial relationships of the megadiverse plant feeding beetle group known as ‘Phytophaga’ (Curculionoidea and Chrysomeloidea), as well as to discover their closest relatives among the Cucujiformia. Parsimony and Bayesian analyses were performed based on the structural alignment of segments of 18S rRNA (variable regions V4‐V5, V7‐V9) and 28S rRNA (expansion segment D2). A total of 104 terminal taxa of Coleoptera were included: 96 species of Cucujiformia beetles, representing the families and most ‘subfamilies’ of weevils and chrysomeloids (Phytophaga), as well as several families of Cleroidea, Tenebrionoidea and Cucujoidea, and eight outgroups from three other polyphagan series: Scarabaeiformia, Elateriformia and Bostrichiformia. The results from the different methods of analysis agree — recovering the monophyly of the ‘Phytophaga’, including Curculionoidea and Chrysomeloidea as sister groups. The curculionoid and chrysomeloid phylogeny recovered from the aligned 18S and 28S rDNA segments, which is independent of morphological data, is in agreement with recent hypotheses or concepts based on morphological evidence, particularly with respect to familial relationships. Our results provide clues about the evolutionary origin of the phytophagan beetles within the megaclade Cucujiformia, suggesting that the sister group of ‘Curculionoidea + Chrysomeloidea’ is a clade of the ‘Cucujoidea’, represented in this study by species in Boganiidae, Erotylidae, Nitidulidae, Cucujidae and Silvanidae. The Coccinellidae and Endomychidae are not grouped with the latter, and the remaining terminal taxa are nested in Tenebrionoidea and Cleroidea. We propose that the combination of structurally aligned ribosomal RNA gene regions 18S (V4‐V5, V7‐V9) and 28S (D2) are useful in testing monophyly and resolving relationships among beetle superfamilies and families.  相似文献   

6.
This paper reviews the evolutionary aspects of obligate phytophagy (excluding mycophagy and phycophagy) in the mite suborder Trombidiformes. Phytophagy in the other acariform suborder, Sarcoptiformes, is limited to just a few species, amidst otherwise saprophagous or fungivorous taxa, that attack the living tissues of higher plants. The phylogenetic relationships of lineages that contain taxa of plant-feeding mites are reviewed briefly, to facilitate hypotheses about the number of times that phytophagy has arisen within the Trombidiformes. The relationship between the two most important plant-feeding taxa, the Tetranychoidea and Eriophyoidea, is so distant that their obligate phytophagy represents independent events. Outgroup comparisons allow an estimate of the relative ages when phytophagy arose. This background facilitates analyses of the evolutionary patterns of attributes relevant to phytophagy as a way of life. Styliform modifications of chelate chelicerae for predation or fungivory were fundamental pre-adaptations for effective phytophagy. Dispersal among the major lineages of phytophagous mites seems generally passive, with little evidence of phoretic behaviour. Continued individual mobility seems to be needed during ontogeny and adulthood, such that no scale-like or sac-like instars have arisen. Trends towards physogastric reproduction and ovoviviparity are not evident. Arrhenotokous sex determination predominates among lineages of phytophagous mites. The primary sex ratios are not usually highly female biased. Direct sperm transfer does not seem to have been advantageous or disadvantageous to adaptive radiations of plant-feeding lineages. Adaptive trends towards thelytoky are scattered and do not seem to have played major roles in speciation, diversification or trends towards increasing host specificity in lineages. Alternate asexual and sexual generations and life cycles on different species of hosts, as occur among families of aphid and scale insects, are not known. Among unrelated lineages of trombidiform mites, there appears to have been convergent evolution of attributes, such as those noted above, in response to similar selective pressures for a phytophagous way of life. The patterns of attributes discussed need experimental analysis and detailed documentation to test their accuracy and generality and to understand the selective pressures that have formed them.  相似文献   

7.
Extant terrestrial biodiversity arguably is driven by the evolutionary success of angiosperm plants, but the evolutionary mechanisms and timescales of angiosperm-dependent radiations remain poorly understood. The Scarabaeoidea is a diverse lineage of predominantly plant- and dung-feeding beetles. Here, we present a phylogenetic analysis of Scarabaeoidea based on four DNA markers for a taxonomically comprehensive set of specimens and link it to recently described fossil evidence. The phylogeny strongly supports multiple origins of coprophagy, phytophagy and anthophagy. The ingroup-based fossil calibration of the tree widely confirmed a Jurassic origin of the Scarabaeoidea crown group. The crown groups of phytophagous lineages began to radiate first (Pleurostict scarabs: 108 Ma; Glaphyridae between 101 Ma), followed by the later diversification of coprophagous lineages (crown-group age Scarabaeinae: 76 Ma; Aphodiinae: 50 Ma). Pollen feeding arose even later, at maximally 62 Ma in the oldest anthophagous lineage. The clear time lag between the origins of herbivores and coprophages suggests an evolutionary path driven by the angiosperms that first favoured the herbivore fauna (mammals and insects) followed by the secondary radiation of the dung feeders. This finding makes it less likely that extant dung beetle lineages initially fed on dinosaur excrements, as often hypothesized.  相似文献   

8.
Although nuclear protein-coding genes have proven broadly useful for phylogenetic inference, relatively few such genes are regularly employed in studies of Coleoptera, the most diverse insect order. We increase the number of loci available for beetle systematics by developing protocols for three genes previously unused in beetles (alpha-spectrin, RNA polymerase II and topoisomerase I) and by refining protocols for five genes already in use (arginine kinase, CAD, enolase, PEPCK and wingless). We evaluate the phylogenetic performance of each gene in a Bayesian framework against a presumably known test phylogeny. The test phylogeny covers 31 beetle specimens and two outgroup taxa of varying age, including three of the four extant beetle suborders and a denser sampling in Adephaga and in the carabid genus Bembidion. All eight genes perform well for Cenozoic divergences and accurately separate closely related species within Bembidion, but individual genes differ markedly in accuracy over the older Mesozoic and Permian divergences. The concatenated data reconstruct the test phylogeny with high support in both Bayesian and parsimony analyses, indicating that combining data from multiple nuclear loci will be a fruitful approach for assembling the beetle tree of life.  相似文献   

9.
Lachnine aphids are unusual among phytophagous insects because they feed on both leafy and woody parts of both angiosperm and conifer hosts. Despite being piercing‐sucking phloem‐feeders, these aphids are most speciose on woody parts of coniferous hosts. To evaluate the significance of this unusual biology on their evolution, we reconstructed the ancestral host and feeding site of the lachnine aphids and estimated important host shifts during their evolution. We sampled 78 species representing 14 of the 18 genera of Lachninae from Asia and North America. We performed parsimony, Bayesian and likelihood phylogenetic analyses of combined mitochondrial Cox1, Cox2, CytB and nuclear EF1a1 DNA sequences. We dated the resulting phylogram's important nodes using Bayesian methods and multiple fossil and secondary calibrations. Finally, we used parsimony and Bayesian ancestral state reconstruction to evaluate ancestral feeding ecology. Our results suggest the lachnine common ancestor fed on a woody part of an angiosperm host in the mid‐Cretaceous. A shift to conifer hosts in the Late Cretaceous is correlated with a subsequent increased diversification in the Palaeogene, but a switch to leafy host tissues did not engender a similar burst of diversification. Extant lachnine lineages exhibit the full range of historical association with their hosts: some appeared before, some concomitant with and some after the appearance of their hosts. We conclude our study by placing all the lachnine genera in five tribes.  相似文献   

10.
Basal relationships of Coleoptera inferred from 18S rDNA sequences   总被引:5,自引:2,他引:3  
The basal relationships of the hyperdiverse insect order Coleoptera (beetles) have proven difficult to resolve. Examination of beetle suborder relationships using 18S ribosomal DNA reveals a previously unproposed relationship among the four major lineages: [(Archostemata(Myxophaga(Adephaga, Polyphaga)))]. Adding representatives of most other insect orders results in a non-monophyletic Coleoptera. However, constraining Coleoptera and its suborders to be monophyletic, in analyses of beetle and outgroup sequences, also results in the above beetle relationships, with the root placed between Archostemata and the remaining suborders.  相似文献   

11.
The Coleoptera provides an excellent example of the value of fossils for understanding the evolutionary patterns of recent lineages. We reevaluate the morphology of the Early Permian †Tshekardocoleidae to test alternative phylogenetic hypotheses relating to the Palaeozoic evolution of the order. We discuss prior interpretations and revise an earlier data matrix. Both Bayesian and parsimony analyses support the monophyly of Coleoptera excluding †Tshekardocoleidae (= Mesocoleoptera), and of Coleoptera excluding †Tshekardocoleidae and †Permocupedidae (= Metacoleoptera). Plesiomorphies preserved in †Tshekardocoleidae are elytra, which rest over the body in a loose tent-like manner, with flat lateral flanges, projecting beyond the abdominal apex, and abdomens that are flexible and nearly cylindrical. Apomorphies of Mesocoleoptera include shortening of the elytra and a closer fit with the flattened and probably more rigid abdomen. A crucial synapomorphy of Metacoleoptera is the tightly sealed subelytral space, which may have been advantageous during the Permian aridification. Taxon exclusion experiments show that †Tshekardocoleidae is crucial for understanding the early evolution of Coleoptera and that its omission strongly affects ancestral state polarities as well as topology, including crown-group taxa. By constraining the relationships of extant taxa to match those supported by phylogenomic analysis, we demonstrate that features shared by Archostemata with Permian stem groups are most reasonably supported as plesiomorphic and that the smooth and simplified body forms of Polyphaga, Adephaga, Myxophaga, and Micromalthidae were derived in parallel. Our study highlights the reciprocal illumination of molecular, morphological, and paleontological data, and paves the way for tip-dating analysis across the order.  相似文献   

12.
Phylogenetic relationships among the five key angiosperm lineages,Ceratophyllum,Chloranthaceae,eudicots,magnoliids,and monocots,have resisted resolution despite several large-scale analyses sampling taxa and characters extensively and using various analytical methods.Meanwhile,compatibility methods,which were explored together with parsimony and likelihood methods during the early development stage of phylogenetics.have been greatly under-appreciated and not been used to analyze the massive amount of sequence data to reconstruct thye basal angiosperm phylogeny.In this study,we used a compatibility method on a data set of eight genes (mitochondrial atp1,matR,and nad5,plastid atpB,marK,rbcL,and rpoC2,and nuclear 18S rDNA)gathered in an earlier study.We selected two sets of characters that are compatible with more of the other characters than a random character would be with at probabilities of pM<0.1 and p<0.5 respectively.The resulting data matrices were subjected to parsimony and likelihood bootstrap analyses.Our unrooted parsimony analyses showed that Ceratophyllum was immediately related to eudicots,this larger lineage was immediately related to magnoliids,and monocots were closely related to Chloranthaceae.All these relationships received 76%-96% bootstrap support.A likelihood analysis of the 8 gene pM<0.5 compatible site matrix recovered the same topology but with low support.Likelihood analyses of other compatible site matrices produced different topologies that were all weakly supported.The topology reconstructed in the parsimony analyses agrees with the one recovered in the previous study using both parsimony and likelihood methods when no character was eliminated.Parts of this topology have also been recovered in several earlier studies.Hence,this topology plausibly reflects the true relationships among the five key angiosperm lineages.  相似文献   

13.
We constructed a phylogeny of the ground beetle subgenus Nialoe ( s. lat. ), genus Pterostichus (Coleoptera: Carabidae) based on two mitochondrial (cytochrome oxidase I and 16S ribosomal DNA) and one nuclear (28S ribosomal DNA) gene sequences. Thirty-three representative species of the group and three outgroup species were analyzed. The resultant trees (maximum parsimonious, maximum likelihood and Bayesian trees of the combined data of the three gene sequences) indicated that there are two large and three small lineages in the group, some of which were supported by a previous morphology-based phylogeny. In all the analyses, the small lineage composed of two Korean species is sister to the rest of the subgenus, but relationships of other four lineages differed among the analyses and remained unresolved. The implications of the present results are discussed in terms of taxonomy and biogeography of the group.  相似文献   

14.
Charadrii (shorebirds, gulls, and alcids) have exceptional diversity in ecological, behavioral, and life-history traits. A phylogenetic framework is necessary to fully understand the relationships among these traits. Despite several attempts to resolve the phylogeny of the Charadrii, none have comprehensively utilized molecular sequence data. Complete and partial cytochrome-b gene sequences for 86 Charadrii and five Falconides species (as outgroup taxa) were obtained from GenBank and aligned. We analyzed the resulting matrices using parsimony, Bayesian inference, minimum evolution, and quartet puzzling methods. Posterior probabilities, decay indices, and bootstrapping provide strong support for four major lineages consisting of gulls, alcids, plovers, and sandpipers, respectively. The broad structure of the trees differ significantly from all previous hypotheses of Charadrii phylogeny in placing the plovers at the base of the tree below the sandpipers in a pectinate sequence towards a large clade of gulls and alcids. The parsimony, Bayesian, and minimum evolution models provide strong evidence for this phylogenetic hypothesis. This is further corroborated by non-tree based measures of support and conflict (Lento plots). The quartet puzzling trees are poorly resolved and inconclusive.  相似文献   

15.
This study analyzed 76 species of Carnivora using a concatenated sequence of 6243 bp from six genes (nuclear TR-i-I, TBG, and IRBP; mitochondrial ND2, CYTB, and 12S rRNA), representing the most comprehensive sampling yet undertaken for reconstructing the phylogeny of this clade. Maximum parsimony and Bayesian methods were remarkably congruent in topologies observed and in nodal support measures. We recovered all of the higher level carnivoran clades that had been robustly supported in previous analyses (by analyses of morphological and molecular data), including the monophyly of Caniformia, Feliformia, Arctoidea, Pinnipedia, Musteloidea, Procyonidae + Mustelidae sensu stricto, and a clade of (Hyaenidae + (Herpestidae + Malagasy carnivorans)). All of the traditional "families," with the exception of Viverridae and Mustelidae, were robustly supported as monophyletic groups. We further have determined the relative positions of the major lineages within the Caniformia, which previous studies could not resolve, including the first robust support for the phylogenetic position of marine carnivorans (Pinnipedia) within the Arctoidea (as the sister-group to musteloids [sensu lato], with ursids as their sister group). Within the pinnipeds, Odobenidae (walrus) was more closely allied with otariids (sea lions/fur seals) than with phocids ("true" seals). In addition, we recovered a monophyletic clade of skunks and stink badgers (Mephitidae) and resolved the topology of musteloid interrelationships as: Ailurus (Mephitidae (Procyonidae, Mustelidae [sensu stricto])). This pattern of interrelationships of living caniforms suggests a novel inference that large body size may have been the primitive condition for Arctoidea, with secondary size reduction evolving later in some musteloids. Within Mustelidae, Bayesian analyses are unambiguous in supporting otter monophyly (Lutrinae), and in both MP and Bayesian analyses Martes is paraphyletic with respect to Gulo and Eira, as has been observed in some previous molecular studies. Within Feliformia, we have confirmed that Nandinia is the outgroup to all other extant feliforms, and that the Malagasy Carnivora are a monophyletic clade closely allied with the mongooses (Herpestidae [sensu stricto]). Although the monophyly of each of the three major feliform clades (Viverridae sensu stricto, Felidae, and the clade of Hyaenidae + (Herpestidae + Malagasy carnivorans)) is robust in all of our analyses, the relative phylogenetic positions of these three lineages is not resolvable at present. Our analyses document the monophyly of the "social mongooses," strengthening evidence for a single origin of eusociality within the Herpestidae. For a single caniform node, the position of pinnipeds relative to Ursidae and Musteloidea, parsimony analyses of data for the entire Carnivora did not replicate the robust support observed for both parsimony and Bayesian analyses of the caniform ingroup alone. More detailed analyses and these results demonstrate that outgroup choice can have a considerable effect on the strength of support for a particular topology. Therefore, the use of exemplar taxa as proxies for entire clades with diverse evolutionary histories should be approached with caution.The Bayesian analysis likelihood functions generally were better able to reconstruct phylogenetic relationships (increased resolution and more robust support for various nodes) than parsimony analyses when incompletely sampled taxa were included. Bayesian analyses were not immune, however, to the effects of missing data; lower resolution and support in those analyses likely arise from non-overlap of gene sequence data among less well-sampled taxa. These issues are a concern for similar studies, in which different gene sequences are concatenated in an effort to increase resolving power.  相似文献   

16.
Abstract.  Fifty-four genera of the bee family Apidae comprising almost all tribes were analysed based on 77 traditional and one new character of the mature larvae. Nine, especially cleptoparasitic species, were newly added. Analyses were performed by maximum parsimony and Bayesian inference. Trees inferred from the analysis of the complete dataset were rooted by taxa from the families Melittidae and Megachilidae. Unrooted trees inferred from the analysis of the partial dataset (excluding outgroup taxa) are also presented to preclude possible negative effects of the outgroup on the topology of the ingroup. Only the subfamily Nomadinae was statistically well supported. The monophyly of the subfamilies Xylocopinae and Apinae was not topologically recovered. The monophyly of the tribe Tetrapediini was supported, and this tribe was found to be related to xylocopine taxa. At the very least, larval morphology suggests that Tetrapedia is not a member of the subfamily Apinae. Our analyses support the monophyly of the Eucerine line (Emphorini, Eucerini, Exomalopsini, Tapinotaspidini) and of the Apine line (Anthophorini, Apini, Bombini, Centridini, Euglossini, Meliponini). All analyses support the monophyly of totally cleptoparasitic tribes of the subfamily Apinae. We named this group the Melectine line (Ericrocidini, Isepeolini, Melectini, Osirini, Protepeolini, Rhathymini). In previous studies all these cleptoparasitic tribes were considered independent evolutionary lineages. Our results suggest that their similarities with hosts in morphology and pattern are probably the result of convergence and host–parasite co-evolution than phylogenetic affinity. According to the present analysis, the cleptoparasitism has evolved independently only six times within the family Apidae.  相似文献   

17.
MAJOR CLADES OF THE ANGIOSPERMS   总被引:2,自引:0,他引:2  
Abstract— Our knowledge of fundamental angiosperm interrelationships is still very incomplete. The absence of a narrowly circumscribed gymnosperm outgroup, ideally the sister group, makes character evaluation, necessary for a cladistic analysis, difficult. According to current views the superorder Magnoliiflorae with a number of other groups, for example the monocotyledons, may represent a complex of families near the base of the angiosperms. Interrelationships of groups within the monocotyledons are much better understood than those between groups within the dicotyledons. A cladogram of monocotyledon orders based on earlier work by R. Dahlgren, H. T. Clifford, and F. N. Rasmussen is presented. A data matrix for a sample of the angiosperms with 61 characters for 49 taxa, mostly magnoliifloran and related families, is presented. The characters are polarized mainly according to the current view that the primitive angiosperm morphotype is a woody dicotyledon with strobiloid flowers. As an alternative the matrix is adjusted following W. C. Burger's conjecture that the primitive angiosperm was a herbaceous monocotyledon with trimerous flowers. Both matrices were run in a computerized parsimony analysis, resulting in numerous equally parsimonious solutions. This result is illustrative of the great homoplasy in the available character information, and also of how little actually is known about fundamental angiosperm interrelationships or phylogeny.  相似文献   

18.
Rojas D  Vale A  Ferrero V  Navarro L 《Molecular ecology》2011,20(10):2217-2228
A great proportion of bats of the New World family Phyllostomidae feed on fruit, nectar and pollen, and many of them present adaptations to feed also on insects and small vertebrates. So far, attempts to examine the diversification of feeding specialization in this group, and particularly the evolution of nectarivory and frugivory, have provided contradictory results. Here we propose a molecular phylogenetic hypothesis for phyllostomids. On the basis of a matrix of feeding habits that takes into account geographical and seasonal variation, we tested different hypotheses of the evolution of feeding specializations in the group. We find strong support for the evolutionary model of a direct dietary diversification from insectivory. The estimates of divergence times of phyllostomid bats and the reconstruction of ancestral states with a Bayesian approach support the parallel evolution of frugivory in five lineages and of nectarivory in three lineages during the Miocene. On the basis of these findings, and recent dietary studies, we propose that during the evolution of phyllostomids switches to new feeding mechanisms to access to abundant and/or underexploited resources provided selective advantages that favoured the appearance of ecological innovations independently in different lineages of the family. We did not find evidences to support or reject the hypothesis that the insectivorous most recent common ancestor of all phyllostomids was also phytophagous.  相似文献   

19.
Here we present a phylogeny of beetles (Insecta: Coleoptera) based on DNA sequence data from eight nuclear genes, including six single‐copy nuclear protein‐coding genes, for 367 species representing 172 of 183 extant families. Our results refine existing knowledge of relationships among major groups of beetles. Strepsiptera was confirmed as sister to Coleoptera and each of the suborders of Coleoptera was recovered as monophyletic. Interrelationships among the suborders, namely Polyphaga (Adephaga (Archostemata, Myxophaga)), in our study differ from previous studies. Adephaga comprised two clades corresponding to Hydradephaga and Geadephaga. The series and superfamilies of Polyphaga were mostly monophyletic. The traditional Cucujoidea were recovered in three distantly related clades. Lymexyloidea was recovered within Tenebrionoidea. Several of the series and superfamilies of Polyphaga received moderate to maximal clade support in most analyses, for example Buprestoidea, Chrysomeloidea, Coccinelloidea, Cucujiformia, Curculionoidea, Dascilloidea, Elateroidea, Histeroidea and Hydrophiloidea. However, many of the relationships within Polyphaga lacked compatible resolution under maximum‐likelihood and Bayesian inference, and/or lacked consistently strong nodal support. Overall, we recovered slightly younger estimated divergence times than previous studies for most groups of beetles. The ordinal split between Coleoptera and Strepsiptera was estimated to have occurred in the Early Permian. Crown Coleoptera appeared in the Late Permian, and only one or two lineages survived the end‐Permian mass extinction, with stem group representatives of all four suborders appearing by the end of the Triassic. The basal split in Polyphaga was estimated to have occurred in the Triassic, with the stem groups of most series and superfamilies originating during the Triassic or Jurassic. Most extant families of beetles were estimated to have Cretaceous origins. Overall, Coleoptera experienced an increase in diversification rate compared to the rest of Neuropteroidea. Furthermore, 10 family‐level clades, all in suborder Polyphaga, were identified as having experienced significant increases in diversification rate. These include most beetle species with phytophagous habits, but also several groups not typically or primarily associated with plants. Most of these groups originated in the Cretaceous, which is also when a majority of the most species‐rich beetle families first appeared. An additional 12 clades showed evidence for significant decreases in diversification rate. These clades are species‐poor in the Modern fauna, but collectively exhibit diverse trophic habits. The apparent success of beetles, as measured by species numbers, may result from their associations with widespread and diverse substrates – especially plants, but also including fungi, wood and leaf litter – but what facilitated these associations in the first place or has allowed these associations to flourish likely varies within and between lineages. Our results provide a uniquely well‐resolved temporal and phylogenetic framework for studying patterns of innovation and diversification in Coleoptera, and a foundation for further sampling and resolution of the beetle tree of life.  相似文献   

20.
This study presents the first phylogenetic analysis of Dicranophoridae (Rotifera: Monogononta), a species rich rotifer family of about 230 species currently recognized. It is based on a maximum parsimony analysis including 77 selected ingroup and three outgroup taxa and a total of 59 phylogenetically informative morphological characters. Character coding is based on personal investigation of material collected by the authors and an extensive survey of the literature. Apart from covering general body organization, character coding primarily relies on scanning electron microscopic preparations of the mastax jaw elements. Our study suggests monophyly of Dicranophoridae with a clade of Dicranophorus and Dorria as the sister taxon of all other dicranophorid species. Monophyly of Encentrum , the most species rich genus within Dicranophoridae, cannot be demonstrated. Within Dicranophoridae our study identifies the monophyletic taxa Caudosubbasifenestrata, Intramalleata, Praeuncinata and Proventriculata, each based on unambiguous character transformations evolved in their stem lineages. However, resolution within Praeuncinata and Proventriculata is very limited. Although some terminal clades within Praeuncinata and Proventriculata are recognized, basal splits remain obscure. Probably, other characters such as DNA sequence data are needed to further our understanding of phylogenetic relationships within these poorly resolved taxa.  相似文献   

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