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1.
Abstract: Nepenthaceae are an exceptional family with regard to carnivory and the uniformity of characters. This makes it difficult to resolve phylogenetic relationships due to convergent evolution of morphological features. Using comparative sequencing of the chloroplast trnK intron, the monophyly of this complex family and hypotheses of infrageneric relationships were tested. Sequences from 71 Nepenthes taxa, representing all groups and two taxa of the closely related Ancistrocladaceae and Dioncophyllaceae as outgroup, were determined and analysed using maximum parsimony methods. Results of this analysis show that the isolated taxa N. distillatoria (Sri Lanka) and N. pervillei (Seychelles) are the most basal, clearly separated from the Madagascan taxa N. madagascariensis and N. masoalensis which are placed in a distinct subclade. This corresponds with some plesiomorphic characters shared by these taxa. N. khasiana (North India) has an intermediate position between these relic Western species and the remaining taxa. The species of the Malay Archipelago can be referred to three distinct lineages which indicate a correlation to biogeography. Thus the recent disjunct distribution of Nepenthes is interpreted as a result of an incisive extinction of progenitors, a process of migration and a subsequent diversification on the islands of Borneo, Sumatra, Sulawesi and New Guinea. Based on our molecular data, two interpretations concerning the origin of Nepenthes are possible: i) evolution in the Northern Tethys which is supported by fossil pollen records from the European Focene, or, ii) a Gondwanaland origin at a time when the Indian plate was separated from Madagascar. Molecular data indicate that colonization of SE Asia started from an ancient Indian stock. Subsequently, in the Malay Archipelago a new secondary centre of diversity developed. Madagascar, the Seychelles and New Caledonia were probably reached by migration via land bridges, starting from widespead common ancestors with subsequent extinction leaving the current taxa. There is no evidence for long‐distance dispersal. Current infragenic classification of Nepenthes is only partly in accordance with the phylogeny inferred from trnK intron data.  相似文献   

2.
A cladistic analysis of the tropical mimosoid genus Parkia was undertaken to examine relationships among the 31 species and to test the monophyly of the three recognized sections. The implications of the cladogram to the evolution of bat-pollination and biogeography were also explored. The analysis, based on 52 morphological characters, resulted in 408 most parsimonious trees. A consensus tree supports the monophyly of sections Parkia and Platyparkia, but section Sphaeroparkia is paraphyletic. The latter section is distinguished by a capitulum of all fertile flowers, a plesiomorphic attribute in this analysis. Characters supporting the monophyly of section Platyparkia include an inflorescence with distal nectar flowers having exserted styles, and fruits with seeds in two rows. Section Parkia is characterized by having sterile basal flowers with nectar flowers just above them, and calyx lobes included in bud. Bat-pollination was mapped onto one of the most parsimonious cladograms to examine the evolution of pollination syndromes within the genus. Our phylogeny is consistent with a single origin of bat-pollination and indicates that entomophilous species of Parkia are basal rather than secondarily derived. Sections Platyparkia and Parkia are separate lineages within the bat-pollinated clade and have independently developed capitulum types adapted to chiropterophily. Characters that are associated with chiropterophily include specialized nectar-producing flowers and basifixed anthers. Several characters, including presence of a staminodial fringe, a nectar ring, and pollen with verrucate sculpturing on the exine, probably represent increasing specialization for bat-pollination. The cladogram supports a South American origin for Parkia but is not consistent with a Gondwanan vicariance event as is usually hypothesized to explain its amphi-Atlantic distribution.  相似文献   

3.
David J. Hearn 《Brittonia》2007,59(4):308-327
Four new species and one new combination ofAdenia are presented, along with a vegetative key and diagnostic characters of the Madagascan species. Additional notes are provided about unusual specimens and field observations.Adenia kigogoensis from Tanzania is shown to be distinct fromA. stenodactyla (its putative closest relative) andA. digitata based on anther connation and other floral traits. The remaining new taxa are from Madagascar.Adenia litoralis has been observed from one coastal locality in northern Madagascar. It is distinctive in fruit size and leaf form.Adenia metamorpha is the only Madagascan taxon with a narrow cylindrical trunk and large napiform tuber; it is also known from only one locality in Madagascar in the Ankarana Reserve.Adenia mcdadiana is a robust liana with highly reduced glands and leaves that appear to be neotenic compared to its closest putative relative,A. sphaerocarpa. Finally, the position ofA. stylosa has been clarified. This species was once treated asA. firingalavensis var.stylosa, and prior to that asA. epigea var.stylosa, but molecular and morphological data suggest it is separate from these species.  相似文献   

4.
The phylogenetic relationships, biogeography and classification of, and morpho‐behavioral (M/B) evolution in, gamebirds (Aves: Galliformes) are investigated. In‐group taxa (rooted on representatives of the Anseriformes) include 158 species representing all suprageneric galliform taxa and 65 genera. The characters include 102 M/B attributes and 4452 nucleic acid base pairs from mitochondrial cytochrome b (CYT B), NADH dehydrogenase subunit 2 (ND2), 12S ribosomal DNA (12S) and control region (CR), and nuclear ovomucoid intron G (OVO‐G). Analysis of the combined character data set yielded a single, completely resolved cladogram that had the highest levels of jackknife support, which suggests a need for a revised classification for the phasianine galliforms. Adding 102 M/B characters to the combined CYT B and ND2 partitions (2184 characters) decisively overturns the topology suggested by analysis of the two mtDNA partitions alone, refuting the view that M/B characters should be excluded from phylogenetic analyses because of their relatively small number and putative character state ambiguity. Exclusion of the OVO‐G partition (with > 70% missing data) from the combined data set had no effect on cladistic structure, but slightly lowered jackknife support at several nodes. Exclusion of third positions of codons in an analysis of a CYT B + ND2 partition resulted in a massive loss of resolution and support, and even failed to recover the monophyly of the Galliformes with jackknife support. A combined analysis of putatively less informative, “non‐coding” characters (CYT B/ND2 third position sites + CR +12S + OVO‐G sequences) yielded a highly resolved consensus cladogram congruent with the combined‐evidence cladogram. Traditionally recognized suprageneric galliform taxa emerging in the combined cladogram are: the families Megapodiidae (megapodes), Cracidae (cracids), Numididae (guineafowls), Odontophoridae (New World quails) and Phasianidae (pheasants, pavonines, partridges, quails, francolins, spurfowls and grouse) and the subfamilies Cracinae (curassows, chachalacas and the horned guan), Penelopinae (remaining guans), Pavoninae sensu lato (peafowls, peacock pheasants and argus pheasants), Tetraoninae (grouse) and Phasianinae (pheasants minus Gallus). The monophyly of some traditional groupings (e.g., the perdicinae: partridges/quails/francolins) is rejected decisively, contrasted by the emergence of other unexpected groupings. The most remarkable phylogenetic results are the placement of endemic African galliforms as sisters to geographically far‐distant taxa in Asia and the Americas. Biogeographically, the combined‐data cladogram supports the hypothesis that basal lineages of galliforms diverged prior to the Cretaceous/Tertiary (K‐T) Event and that the subsequent cladogenesis was influenced by the break‐up of Gondwana. The evolution of gamebirds in Africa, Asia and the Americas has a far more complicated historical biogeography than suggested to date. With regard to character evolution: spurs appear to have evolved at least twice within the Galliformes; a relatively large number of tail feathers (≥ 14) at least three times; polygyny at least twice; and sexual dimorphism many times. © The Willi Hennig Society 2006.  相似文献   

5.
Pollen characters of Madagascan and continental African Viscum are described and compared to those in Asia and Australia. The subprolate, tricolporate, nonuniformly sculptured pollen of Madagascan taxa is most similar to that of Asian species. Ultrastructurally, however, the completely granular equatorial ektexine of Madagascan Viscum is most similar to that of continental African taxa. Continental African Viscum, in contrast to Madagascan and Asian species, display a wide variation in pollen shape and apertures. Pollen shape ranges from subprolate to oblate, the latter unique to Africa. The most striking feature of continental Viscum is their variability in aperture number and aperture type. Aperture number varies at both the intra- and interpopulational levels with such variation resolvable to the individual flower—a condition unique to the continent. The only simple (colpate) aperture type in the genus is restricted to Africa. The continental species can be divided into two species groups based on pollen characters: Group I (4 spp.) characterized by strictly tricolporate rounded convex pollen with a rodlet/granular equatorial ektexine structure and Group II (most continental species) possessing multiapertures, concave lobate shape, uniform sculpturing and granular equatorial ektexine. The African V. menyharthii, V. fischeri, V. rotundifolium and V. minimum exhibit no clear Group I or II affinities. An analysis of overall pollen characters in Viscum indicates a trend towards spheroidal shape, multiapertures and uniform sculpturing and ektexine organization. Though pollen characters suggest ties between Australia, Asia and Madagascar, they indicate an even stronger relationship between Madagascar and continental Africa, particularly eastern Africa. The relationship of the majority of African Viscum, excluding those with obvious Madagascan affinities, remains obscure. The unique palynological features of Group II species coupled with their inflorescence structure suggest an independently evolving group.  相似文献   

6.
A morphological data set for the histerid beetle subfamily Saprininae comprising 95 adult morphological characters scored (multistate coding) from 72 terminal taxa and four outgroups was developed in order to analyse and determine the relationships amongst the genera and subgenera of the Saprininae subfamily. Cladograms were rooted with exemplars of Dendrophilinae (genus Dendrophilus), Bacaniini (genus Bacanius), Abraeinae (genus Chaetabraeus), and Anapleini (genus Anapleus). Parsimony‐based phylogenetic analyses were performed based on the type species of each genus and subgenus of the Saprininae occurring around the world, with the exception of three taxa: Paramyrmetes foveipennis (type species of the genus Paramyrmetes), Satrapister nitens (type species of the genus Satrapister) and Xerosaprinus (Auchmosaprinus) laciniatus (type species of the subgenus Auchmosaprinus) that were not available. In addition, in order to test the monophyly of several questionable genera, multiple exemplars were added in a few cases. The analysis also included an exemplar of an apparently undescribed genus. The results of the analysis confirm the monophyly of the subfamily supported by two unique synapomorphies: (1) presence of sensory structures of the antenna; and (2) presence of the antennal cavity, as well as several other weaker synapomorphies. However, the phylogeny inferred here shows mostly low support for the deeper branches and consequently no major changes in the Saprininae classification are proposed. The presented cladogram is discussed together with its implications for the evolution of the subfamily. The most informative characters and their respective states are outlined. Multiple shifts in lifestyles have evolved during the evolutionary history of the group. Taxa found near the root of the cladogram are mostly nidicolous or myrmecophilous, and inquiliny is presumed to be the plesiomorphic lifestyle of the subfamily. The nidicolous lifestyle has undergone several transformations to other lifestyles and myrmecophily has evolved three times independently during the evolution of the subfamily. Termitoxeny has evolved two times independently in the group whereas ecological adaptation for life in caves has likewise evolved two times independently. The analyses yielded a large clade of predominantly psammophilous taxa; psammophily is thought to have evolved once and has been subsequently lost several times. © 2014 The Linnean Society of London  相似文献   

7.
The aim of this study is to present a cladogram and phylogenetic system and to use this to discuss the phylogeny and biogeography of the Amblypygi. A total of 29 morphological structures were studied, their plesiomorphic and apomorphic characters or character states were identified, and the resulting data matrix was analysed. As a result, the ‘old’Charontidae or Pulvillata emerge as a paraphyletic group; the genus Paracharon is the sister group of all other amblypygids, which are now termed Euamblypygi. The ‘new’Charontidae (sensu Quintero: the genera Stygophrynus and Charon) are the sister group of the Phrynida or Apulvillata; together they form the Neoamblypygi. The relationships of the genera of the Charinidae cannot be resolved with the available data. They may be a paraphyletic group. The genus Catageus is a possible candidate for being the sister group of the Neoamblypygi. The new system allows a discussion of the phylogeny and biogeography of whip spiders. It also points to unresolved taxa and thus indicates the questions future research should address.  相似文献   

8.
Aim Grasslands and savannas, which make up > 75% of Madagascar’s land area, have long been viewed as anthropogenically derived after people settled on the island c. 2 ka. We investigated this hypothesis and an alternative – that the grasslands are an insular example of the post‐Miocene spread of C4 grassy biomes world‐wide. Location Madagascar, southern Africa, East Africa. Methods We compared the number of C4 grass genera in Madagascar with that in southern and south‐central African floras. If the grasslands are recent we would expect to find fewer species and genera in Madagascar relative to Africa and for these species and genera to have very wide distribution ranges in Madagascar. Secondly, we searched Madagascan floras for the presence of endemic plant species or genera restricted to grasslands. We also searched for evidence of a grassland specialist fauna with species endemic to Madagascar. Plant and animal species endemic to C4 grassy biomes would not be expected if these are of recent origin. Results Madagascar has c. 88 C4 grass genera, including six endemic genera. Excluding African genera with only one or two species, Madagascar has 86.6% of southern Africa’s and 89.4% of south‐central Africa’s grass genera. C4 grass species make up c. 4% of the flora of both Madagascar and southern Africa and species : genus ratios are similar (4.3 and 5.1, respectively). Turnover of grasses along geographical gradients follows similar patterns to those in South Africa, with Andropogoneae dominating in mesic biomes and Chlorideae in semi‐arid grassy biomes. At least 16 monocot genera have grassland members, many of which are endemic to Madagascar. Woody species in frequently burnt savannas include both Madagascan endemics and African species. A different woody flora, mostly endemic, occurs in less frequently burnt grasslands in the central highlands, filling a similar successional niche to montane C4 grasslands in Africa. Diverse vertebrate and invertebrate lineages have grassland specialists, including many endemic to Madagascar (e.g. termites, ants, lizards, snakes, birds and mammals). Grassland use of the extinct fauna is poorly known but carbon isotope analysis indicates that a hippo, two giant tortoises and one extinct lemur ate C4 or CAM (crassulacean acid metabolism) plants. Main conclusions The diversity of C4 grass lineages in Madagascar relative to that in Africa, and the presence of plant and animal species endemic to Madagascan grassy biomes, does not fit the view that these grasslands are anthropogenically derived. We suggest that grasslands invaded Madagascar after the late Miocene, part of the world‐wide expansion of C4 grassy biomes. Madagascar provides an interesting test case for biogeographical analysis of how these novel biomes assembled, and the sources of the flora and fauna that now occupy them. A necessary part of such an analysis would be to establish the pre‐settlement extent of the C4 grassy biomes. Carbon isotope analysis of soil organic matter would be a feasible method for doing this.  相似文献   

9.
Abstract. Within a framework for historical analysis of Eneopterinae biogeography the New Caledonian endemic cricket genus Agnotecous Saussure, 1878 is revised: the eight already known species are diagnosed and six new species described, A. azurensis Desutter‐Grandcolas sp.n. , A. chopardi Desutter‐Grandcolas sp.n. , A. clarus Desutter‐Grandcolas sp.n. , A. doensis Desutter‐Grandcolas sp.n. , A. meridionalis Desutter‐Grandcolas sp.n. and A. occidentalis Desutter‐Grandcolas sp.n. Four species groups are characterized by male genitalic structures. Identification keys are provided for both males and females. A cladistic analysis was performed using fifty‐eight morphological characters. The two resultant topologies, which differ only in topology of three apical species, support the monophyly of Agnotecous and that of the four species groups. Preliminary hypotheses of Eneopterinae historical biogeography are derived from phylogenetic and distributional data.  相似文献   

10.
11.
A phylogenetic analysis was performed to determine the monophyly of non‐monotypic genera of the terebelliform family Polycirridae, i.e. Polycirrus, Amaeana, Lysilla, and Hauchiella, and the evolution of characters among members of this clade. The monotypic genera, Enoplobranchus and Biremis, were also included, together with members of both known species in Hauchiella. Representative species were included for remaining genera: 14 species of Polycirrus, six species of Amaeana, and six species of Lysilla. Out‐groups consisted of representatives of Spionidae, Cirratulidae, and Sabellariidae, as well as several species of Telothelepodidae. A total of 40 in‐ and out‐group species were coded for 50 subjects (‘characters’) and 117 subject–predicate relationships (‘states’). Although results are consistent with recent phylogenetic studies within Terebelliformia that suggest Polycirridae monophyly, only Hauchiella was found to be monophyletic, albeit part of the more inclusive clade comprising remaining polycirrid genera. Evolutionary transformation series are discussed for selected characters in relation to the non‐monophyly of Polycirrus, Lysilla, and Amaeana. Implications for the use of supraspecific taxa as ‘taxonomic surrogates’ are highlighted. The definition of Polycirridae is emended. © 2015 The Linnean Society of London  相似文献   

12.
13.
14.
Eulophiinae comprise c. 270 species divided into nine genera, with the species‐rich terrestrial genus Eulophia representing 60% of this diversity. Remarkable ecological and morphological variation, and an absence of clear diagnostic characters have led to uncertain generic delimitation in the subtribe. Using a combination of new and previously published DNA sequences, we created a dataset representing 122 taxa and all genera of Eulophiinae and inferred a complete generic‐level phylogeny for the subtribe for the first time. Our sampling focused on analysing Afro‐Madagascan taxa and therefore included representatives of the four mostly epiphytic Madagascan endemic genera, the near Madagascan endemic Oeceoclades and additional sampling of the predominantly African genera Eulophia and Orthochilus. In total, 104 new accessions were collected for this study in Zambia and Madagascar (88 of which represented 36 Eulophia spp. and 12 Oeceoclades spp.). Independent plastid and nuclear phylogenetic trees were inferred using Bayesian and maximum‐likelihood algorithms, which recovered strong support for a monophyletic Eulophiinae, the first‐branching position of the mostly epiphytic Madagascan endemic genera, and increased support for recognition of the terrestrial genera Oeceoclades and Orthochilus. Eulophia, the largest genus in the group, was recovered as polyphyletic, but with implications for its classification and that of Geodorum, that was nested in the main Eulophia clade. Although relationships among several genera were resolved with some confidence, the positions of the South African endemic genus Acrolophia and the epiphytic Madagascan endemic Paralophia require further work. Taxon sampling of Asian Eulophia is a priority for future work on the systematics of this group. © 2015 The Linnean Society of London, Botanical Journal of the Linnean Society, 2015, 179 , 43–56.  相似文献   

15.
By analysing key morphological characters (with emphasis on shell, radula and stomach anatomy) and a partial fragment of the mitochondrial 16S rRNA gene (alignment length 860 bp), we examined patterns of diversity and differentiation of a previously overlooked radiation of Madagascan pachychilid freshwater gastropods. These analyses resulted in the discovery of three new species in addition to the two species that were already recognized. The complex nomenclatural and taxonomic implications are discussed and the finding of a viviparous reproductive mode in at least one among otherwise oviparous species is reported. Using a mitochondrial phylogeny that includes all currently accepted pachychilid genera and a strict molecular clock approach, we address the historical biogeography of the Madagascan species with respect to vicariant versus dispersalist biogeographical models. Using two alternative calibrations that were previously suggested for other gastropods, the molecular clock tree suggested that the origin of the Pachychilidae dates back to no more than 50 Mya, whereas the origin of the Madagascan lineage is estimated to date to a period between 15.6–31.5 Mya. These estimates are approximately concurrent with the dating of colonization events in a number of other Madagascan animal taxa. The pachychilid radiation on Madagascar appears not to be older than 3–5 Mya. Thus, although the global patterns of pachychilid distribution have earlier been interpreted to suggest a Gondwanan origin of the family, the present study does not support this postulate. Neither the topology of the molecular phylogeny, nor the timing of events as suggested from a molecular clock were found to be congruent with a vicariance scenario within the framework of Gondwanan fragmentation during the Mesozoic but, instead, imply overseas dispersal during the Cenozoic. © 2010 The Linnean Society of London, Biological Journal of the Linnean Society, 2010, 99 , 867–894.  相似文献   

16.
Aim To investigate the historical biogeography of the pantropical flowering plant family Hernandiaceae (Laurales), which today comprises 62 species in five genera. Location Hernandiaceae occur in Africa (9 species), Madagascar (4), the Neotropics (25), Australia (3), southern China, Indochina, Malesia, and on numerous Pacific Islands (32). These numbers include two widespread species, Hernandia nymphaeifolia, which ranges from East Africa to the Ogasawara Islands and New Caledonia, and Gyrocarpus americanus, thought to have a pantropical range. Methods We sampled 37 species from all genera, the widespread ones with multiple accessions, for a chloroplast DNA matrix of 2210 aligned nucleotides, and used maximum likelihood to infer species relationships. Divergence time estimation relied on an uncorrelated‐rates relaxed molecular clock calibrated with outgroup fossils of Lauraceae and Monimiaceae. Results The deepest split in the family is between a predominantly African–Madagascan–Malesian lineage comprising Hazomalania, Hernandia and Illigera, and an African–Neotropical lineage comprising Gyrocarpus and Sparattanthelium; this split may be 122 (110–134) Myr old. The stem lineages of the five genera date back at least to the Palaeocene, but six splits associated with transoceanic range disjunctions date only to the Oligocene and Miocene, implying long‐distance dispersal. It is inferred that Hernandia beninensis reached the West African islands of São Tomé and Bioko from the West Indies or the Guianas; Hernandia dispersed across the Pacific; and Illigera madagascariensis reached Madagascar from across the Indian Ocean. Main conclusions The disjunct ranges and divergence times of sister clades in the Hernandiaceae are partly congruent with the break‐up of West Gondwana, but mostly with later transoceanic dispersal. An exceptional ability to establish following prolonged oceanic dispersal may be largely responsible for the evolutionary persistence of this small clade.  相似文献   

17.
We present a cladistic analysis of the subtribe Megalostomina, a Neotropical group of ‘case‐bearer’ leaf beetles. A comparative study of the external and internal adult morphology of Clytrini was undertaken. New characters are described for the subtribe Megalostomina, from the internal sac of aedeagus, which provide a useful phylogenetic signal. More than 180 photographs illustrating the most important characters (74 characters and their respective states) used in the cladistic analysis are provided. The cladistic analysis of 57 terminal taxa and 95 characters was undertaken, under equal weights, and also using implied weights as a means to down‐weight homoplasious characters. We test the monophyly and explore intergeneric relationships of the subtribe Megalostomina, and reconstruct the relationships among the species of Megalostomis Chevrolat. The 42 species recognized can be assigned either to a group mostly containing species of North and Central America, or to a larger one of mostly South American species. Support is low, and the formal naming of groups is deferred pending a revision of all Megalostomina. We confirm the subgenera of Megalostomis of previous classifications are unnatural, and the following changes in the generic classification of the subtribe Megalostomina are proposed: Coleorozena Moldenke syn.n. of Coscinoptera Lacordaire; Coleothorpa Moldenke syn.n. of Coscinoptera Lacordaire; and Euryscopa (Coleoguerina) Moldenke syn.n. of Coscinoptera Lacordaire. Furthermore, six formerly recognized subgenera of Megalostomis are considered junior synonyms of Megalostomis Chevrolat: Megalostomis (Minturnia) Lacordaire syn.n. ; Megalostomis (Heterostomis) Lacordaire syn.n. ; Megalostomis (Scaphigenia) Lacordaire syn.n. ; Megalostomis (Snellingia) Moldenke syn.n. ; Megalostomis (Coleobyersa) Moldenke syn.n. ; and Megalostomis (Pygidiocarina) Moldenke syn.n. Thus, no subgenera are recognized within Megalostomis. Previous hypotheses on Clytrini biogeography were revisited in the light of new biogeographic and phylogenetic knowledge. We hypothesize an origin of Clytrini in tropical/subtropical Gondwana, when South America, Africa, Madagascar and India were connected. Changes in the configuration of the tectonic plates in the Cenozoic allowed the dispersal of Clytrina to the Palaearctic and Nearctic regions, and dispersion of Babiina and Megalostomina through the Nearctic region.  相似文献   

18.
The phylogenetic relationships among two Paracyprichromis and five Cyprichromis species, included in the Tanganyikan cichlid tribe Cyprichromini, were investigated using morphological features. The previously proposed diagnostic characters of Paracyprichromis are not synapomorphies, because the nonelongated swim bladder is plesiomorphic, the numbers of dorsal and anal fin rays and scales on longitudinal line and around the caudal peduncle overlap with those of Cyprichromis, and these counts and number of vertebrae are all included within the ranges of other Tanganyikan cichlids. The monophyly of Paracyprichromis is supported by a unique condition of infraorbitals to this genus. Additionally, the monophyly of Cyprichromis was reconfirmed by one of the previously proposed diagnostic characters, the presence of an elongated swim bladder.  相似文献   

19.
The phylogeny of the temperate Gondwanan harvestman family Pettalidae is investigated by means of a new morphological matrix of 45 characters, and DNA sequence data from five markers, including two nuclear ribosomal genes (18S rRNA and 28S rRNA), one nuclear protein coding gene (histone H3), and two mitochondrial genes–one protein coding (cytochrome c oxidase subunit I) and one ribosomal (16S rRNA). Phylogenetic analyses using an array of homology schemes (dynamic and static), criteria (parsimony and maximum likelihood), and sampling strategies (optimal trees versus Bayesian phylogenetics) all agree on the monophyly of Pettalidae as well as several of its subclades, each of which is restricted to a modern landmass. While most genera as traditionally defined are monophyletic, Rakaia and Neopurcellia, distributed across Queensland (Australia) and New Zealand, are not. Instead, the species from Queensland, previously described under three genera, constitute a well‐supported clade, suggesting that in this case biogeography prevails over traditional taxonomy. A taxonomic emendation of the genera from Queensland and New Zealand is presented, and the new genus Aoraki is erected to include the species of the New Zealand denticulata group. A biogeographical hypothesis of the relationships of the former temperate Gondwana landmasses (with the exception of Madagascar) is presented, although ambiguity in the deep nodes of the pettalid tree renders such inference provisional. The data suggest that neither the South African fauna, the New Zealand fauna nor the Australian fauna is monophyletic but instead monophyly is found at smaller geographic scales (e.g., Western Australia, Queensland, NE South Africa). © The Willi Hennig Society 2007.  相似文献   

20.
A taxonomically difficult purple-flowered group within the genusErysimum, restricted to the Iberian Peninsula, is analyzed by multivariate and cladistic analyses. 51 specimens have been scored for 14 characters. Both principal components and discriminant analyses provide support to the recognition of the five species considered by the author, namelyE. linifolium, E. lagascae, E. baeticum, E. popovii, andE. cazorlense. Cladistic analysis, using 7 characters resulted in a single most parsimonious cladogram containing no homoplasies. The pattern of morphologic divergence follows a clear NW.-SE. trend, which is congruent with the topology of the cladogram. This trend significantly affects growth-form as well as fruit characters, both providing the main grounds for species recognition. The different behavior and significance of several characters in both kinds of analysis is discussed. The co-occurrence of morphologically similar individuals differing in the flower color is discussed, too. Possible explanations for this phenomenon involve hybridization in a wide sense or, alternatively, rejecting the assumption of monophyly for the group.  相似文献   

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