广义竹叶青蛇属Trimeresurus (sensu lato)的分类和系统学研究进展

广义的竹叶青蛇属于Trimeresurus(sensu lato)包含有40多个物种,广泛分布在南亚和东南亚国家和地区。目前,该类群已经相继被划分为6个属：Trimeresurus(sensu stricto)、Tropidolaemus、Ovophis Protobothrops,Triceratolepidophis,Zhaoermia本文从形态、细胞以及分了系统学等方面对Trimeresurus(sensu lato)的分类和系统学研究进行综述。     

亚洲蝮亚科蛇属间系统发生支序分析 (蛇亚目：蝰科)

在大量比较形态研究的基础上,选择了５个特征方面２８个性状,以支序分析方法探讨了分布于亚洲蝮亚科蛇５属１４种的系统发生关系,结果表明：该亚科蛇类可以划分为３个不同的类群,第一个类群包括尖吻蝮属、瘤鼻蝮属、红口腹属,它们具有较多的祖征,代表了该科中原始一类,基中红口蝮可能是最原始的一属;亚洲蝮属单独形成一个类群;第三个类群为原广义的烙铁头蛇属,包括竹叶青蛇属、原矛蝮属、烙铁头蛇属、黑绿烙铁头蛇属、莽山     

A phylogeny of four mitochondrial gene regions suggests a revised taxonomy for Asian pitvipers (Trimeresurus and Ovophis)

We present a phylogeny of the Asian pitvipers, based on 2403 bp of four mitochondrial gene regions. All but six known species of Trimeresurus sensu stricto (s.s.) as currently defined, as well as multiple populations of widespread species, which may yet be described as full species, and representatives of all other Asian pitviper genera, are included. Both the greater sampling and larger dataset provide improved resolution over previous studies and support the existence of distinct species groups within Trimeresurus s.s. Although all but two species currently referred to this genus form a monophyletic group, morphological and molecular analyses identify four subgroups that warrant recognition at the generic level. We propose a new generic arrangement to reflect these findings. We also highlight the non-monophyly of Ovophis, and propose a new genus to accommodate a species formerly assigned to Ovophis.     

An evaluation of the systematic value of skull morphology in the Trimeresurus radiation (Serpentes: Viperidae: Crotalinae) of Asian pitvipers

Trimeresurus (in its widest sense) is a very diverse and widespread radiation of Asian pitvipers, which has been subject to numerous taxonomic revisions, some of which have been based on characteristics of the skull. In order to evaluate the taxonomic utility of such characters, we conducted a comparison of the skulls of 57 specimens representing nine genera, and two currently unassigned species that are very closely related to each other. A canonical variate analysis reveals three distinct phenetic groups: the Protobothrops group, a group containing Ovophis monticola , ' Ovophis ' okinavensis , and ' Trimeresurus ' gracilis , and finally a group comprising the remaining species and characterized by considerable overlap between most genera with the exception of the monotypic Peltopelor and Himalayophis . Agreement between phenetic similarity based on skull characteristics and phylogenetic relationships based on molecular evidence varies between different groups: the morphological similarity of the skull of Protobothrops sieversorum to the other Protobothrops species is congruent with their recent synonymization while the phenetic similarity among the species within the second group does not reflect current molecular phylogenetic relationships and indicates that convergent or parallel evolution may be responsible for at least some of the phenetic similarity detected among skulls of the Asian pit vipers examined. A test of phylogenetic independence, however, indicates that there is still a significant phylogenetic signal that can be recovered from several skull characteristics. Thus, we conclude that skull morphology can contribute to an overall understanding of pitviper taxonomy, but that it would be unwise to rely on skull characteristics alone.     

Extensive paraphylies within sharks of the order Carcharhiniformes inferred from nuclear and mitochondrial genes

Using nuclear coding and mitochondrial ribosomal genes we try to clarify relationships within Carcharhiniformes with special focus on the two most problematic groups: scyliorhinids and triakids. The mitochondrial aligned sequences are 1542 bp long, and include principally portion of 16S rRNA gene. They are obtained for two outgroup species and 43 Carcharhiniformes species, covering 5 of the 8 families and 15 of the 48 genera of the order. The nuclear RAG1 sequences are 1454 bp long, and are obtained for 17 species representative of the diversity of all species sampled. We used Maximum Parsimony and Maximum Likelihood criteria for tree reconstruction. Paraphylies within the family Scyliorhinidae was proposed for the first time by Maisey [Zool. J. Linn. Soc. 82, 33, 1984] in a morphological cladistic analysis. This result has never been proposed again until recently from molecular phylogenies [Mol. Phylogenet. Evol. 31, 214, 2004]. Here, independent and simultaneous analyses of nuclear and mitochondrial data are congruent in supporting the paraphyly of scyliorhinids. Two groups of scyliorhinids are obtained, thoroughly in line with discrimination proposed by previous authors, based on presence/absence of supraorbital crests on the chondrocranium. The first group (Scyliorhinus+Cephaloscyllium) is basal within carcharhiniforms and the second group (Apristurus+Asymbolus+Cephalurus+Galeus+Parmaturus) is sister group of all the other families investigated (Carcharhinidae, Proscyllidae, Pseudotriakidae, and Triakidae). The paraphyly of triakids appeared probable but more investigations are needed. In conclusion several independent morphological and molecular phylogenetic studies support paraphyly within scyliorhinids. So we propose a new classification for the group, with the redefinition of the family Scyliorhinidae sensu stricto and the resurrection of the family Pentanchidae with a new definition.     

广义烙铁头属三种烙铁头的核型及分类地位初步探讨

报道３种烙铁头蛇的核型。其中,烙铁头２ｎ＝３６＝１６Ｍ（１４Ｖ＋２ＳＶ／Ｖ）＋２０ｍ,ＺＷ型性决定,Ｚ为Ｖ型,Ｗ为ＳＩ／ＳＶ型,Ｚ明显大于Ｗ;菜花烙铁头２居群２ｎ＝３６＝１６Ｍ（１４Ｖ＋２ＳＩ）＋２０ｍ,ＺＷ型性决定,Ｚ为Ｖ型,Ｗ为ＳＩ型,Ｚ明显大于Ｗ;云南竹叶青２ｎ＝３６＝１６Ｍ（１２Ｖ／ＳＶ＋２ＳＶ／ＳＩ＋２ＳＩ）＋２ｍ,无异型性染本,对３种的核型及烙铁头属已知核型进行了比较分析,并对云南竹叶     

Molecular systematics of New World suboscine birds

Phylogenetic relationships among New World suboscine birds were studied using nuclear and mitochondrial DNA sequences. New World suboscines were shown to constitute two distinct lineages, one apparently consisting of the single species Sapayoa aenigma, the other made up of the remaining 1000+ species of New World suboscines. With the exception of Sapayoa, monophyly of New World suboscines was strongly corroborated, and monophyly within New World suboscines of a tyrannoid clade and a furnarioid clade was likewise strongly supported. Relationships among families and subfamilies within these clades, however, differed in several respects from current classifications of suboscines. Noteworthy results included: (1) monophyly of the tyrant-flycatchers (traditional family Tyrannidae), but only if the tityrines (see below) are excluded; (2) monophyly of the pipromorphine flycatchers (Pipromorphinae of ) as one of two primary divisions of a monophyletic restricted Tyrannidae; (3) monophyly of the tityrines, consisting of the genus Tityra plus all sampled species of the Schiffornis group (), as sister group to the manakins (traditional family Pipridae); (4) paraphyly of the ovenbirds (traditional family Furnariidae), if woodcreepers (traditional family Dendrocolaptidae) are excluded; and (5) polyphyly of the antbirds (traditional family Formicariidae) and paraphyly of the ground antbirds (Formicariidae sensu stricto). Genus Melanopareia (the crescent-chests), although clearly furnarioid, was found to be distant from other furnarioids and of uncertain affinities within the Furnarii. Likewise, the species Oxyruncus cristatus (the Sharpbill), although clearly tyrannoid, was distantly related to other tyrannoids and of uncertain affinities within the Tyranni. Results of this study provide support for some of the more novel features of the suboscine phylogeny of, but also reveal key differences, especially regarding relationships among suboscine families and subfamilies. The results of this study have potentially important implications for the reconstruction of character evolution in the suboscines, especially because the behavioral evolution of many suboscine groups (e.g., Furnariidae) is of great interest.     

Molecular phylogenetic analysis of the dragonfly genera Libellula, Ladona, and Plathemis (Odonata: Libellulidae) based on mitochondrial cytochrome oxidase I and 16S rRNA sequence data

Molecular phylogenetic relationships among members of the odonate genus Libellula (Odonata: Anisoptera: Libellulidae) were examined using 735 bp of mitochondrial COI and 416 bp of 16S ribosomal RNA gene sequences. Considerable debate exists over several relationships within Libellula, as well over the status of two putative genera often placed as subgenera within Libellula: Ladona and Plathemis. Parsimony and maximum-likelihood analyses of the separate and combined data sets indicate that Plathemis is basal and monophyletic and that Ladona is the sister clade to the remainder of Libellula sensu stricto (s.s.) (all species within the genus Libellula, excluding Plathemis and Ladona). Moreover, two European taxa, Libellula fulva and L. depressa, were found to occupy a sister group relationship within the Ladona clade. Relationships within Libellula s.s. are less well resolved. However, monophyletic lineages within the genus are largely consistent with morphologically based subgeneric classifications. Although tree topologies from each analysis differed in some details, the differences were in no case statistically significant. The analysis of the combined COI and 16S data yielded trees with overall stronger support than analyses of either gene alone. Several analyses failed to support the monophyly of Libellula sensu lato due to the inclusion of one or more outgroup species. However, statistical comparisons of topologies produced by unconstrained analyses and analyses in which the monophyly of Libellula was constrained indicate that any differences are nonsignificant. Based on morphological data, we therefore reject the paraphyly of Libellula and accept the outgroup status of Orthemis ferruginea and Pachydiplax longipennis.     

Phylogeny of swallows (Aves: Hirundinidae) estimated from nuclear and mitochondrial DNA sequences

The phylogeny of swallows was reconstructed by comparing segments of three genes, nuclear beta-fibrinogen intron 7 (betafib7), mitochondrial cytochrome b (cytb), and mitochondrial ND2, in a variety of combinations using maximum likelihood and Bayesian methods. betafib7 was sequenced for 47 species, cytb for 74 species, and ND2 for 61 species to yield comparisons among 75 of the 84 currently recognized swallow species. The family Hirundinidae was confirmed to consist of two clades, Pseudochelidoninae (river martins) and Hirundininae (typical swallows). The Hirundininae is further divided into mud nesters (Hirundo sensu lato), core martins (Phedina, Riparia, and New World endemic genera), and basal relicts (Psalidoprocne, Cheramoeca, and Pseudhirundo). We did not resolve the hierarchy among these three hirundinine groups, but discovered many relationships within them. Mud-nesting genera have the following relationships: (Hirundo sensu stricto, Ptyonoprogne), (Delichon, (Petrochelidon, Cecropis)). Core martins have the following topology: (Phedina, Riparia cincta), (Riparia sensu stricto, Tachycineta, ((Stelgidopteryx, Progne), (Neotropical endemic genera))). Interspecific relationships among the Neotropical endemics were resolved completely; Atticora and Notiochelidon are paraphyletic, and all Neotropical endemics probably should be lumped into one or two genera. The final group of hirundinines, the basal relicts, consists of a sister pair, the Australian Cheramoeca and African Pseudhirundo. The African saw-wings (Psalidoprocne) are their likely sister group.     

Phylogenetic relationships and the temporal context for the diversification of African characins of the family Alestidae (Ostariophysi: Characiformes): evidence from DNA sequence data

Phylogenetic relationships within the family Alestidae were investigated using parsimony, maximum likelihood, and Bayesian approaches based on a molecular dataset that included both nuclear and mitochondrial markers. Multiple representatives of all but two of the recognized alestid genera were included, which allowed for testing previous hypotheses of intergeneric relationships and the monophyly of several genera. The phylogenetic position of the Neotropical genus Chalceus with respect to the family Alestidae was also examined. In order to understand the temporal context of alestid diversification, Bayesian methods of divergence time estimation using fossil data in the form of calibration priors were used to date the nodes of the phylogenetic tree. Our results rejected the monophyly of the family as currently recognized (Alestidae sensu lato) and revealed several instances of poly- and paraphyly among genera. The genus Chalceus was recovered well nested within Neotropical characiforms, thus rejecting the hypothesis that this taxon is the most basal alestid. The estimated mean divergence time for the alestid clade (Alestidae sensu stricto) was 54 Mya with a 95% credibility interval of 63-49 Mya. These results are incongruent with the hypothesis that the origin of the family Alestidae predates the African-South American Drift-Vicariance event.     

Phylogenetic affiliations of members of the heterogeneous lichen-forming fungi of the genus Lecidea sensu Zahlbruckner (Lecanoromycetes, Ascomycota)

The genus Lecidea Ach. sensu lato (sensu Zahlbruckner) includes almost 1200 species, out of which only 100 species represent Lecidea sensu stricto (sensu Hertel). The systematic position of the remaining species is mostly unsettled but anticipated to represent several unrelated lineages within Lecanoromycetes. This study attempts to elucidate the phylogenetic placement of members of this heterogeneous group of lichen-forming fungi and to improve the classification and phylogeny of Lecanoromycetes. Twenty-five taxa of Lecidea sensu lato and 22 putatively allied species were studied in a broad selection of 268 taxa, representing 48 families of Lecanoromycetes. Six loci, including four ribosomal and two protein-coding genes for 315- and 209-OTU datasets were subjected to maximum likelihood and Bayesian analyses. The resulting well supported phylogenetic relationships within Lecanoromycetes are in agreement with published phylogenies, but the addition of new taxa revealed putative rearrangements of several families (e.g. Catillariaceae, Lecanoraceae, Lecideaceae, Megalariaceae, Pilocarpaceae and Ramalinaceae). As expected, species of Lecidea sensu lato and putatively related taxa are scattered within Lecanoromycetidae and beyond, with several species nested in Lecanoraceae and Pilocarpaceae and others placed outside currently recognized families in Lecanorales and orders in Lecanoromycetidae. The phylogenetic affiliations of Schaereria and Strangospora are outside Lecanoromycetidae, probably with Ostropomycetidae. All species referred to as Lecidea sensu stricto based on morphology (including the type species, Lecidea fuscoatra [L.] Ach.) form, with Porpidia species, a monophyletic group with high posterior probability outside Lecanorales, Peltigerales and Teloschistales, in Lecanoromycetidae, supporting the recognition of order Lecideales Vain. in this subclass. The genus name Lecidea must be redefined to apply only to Lecidea sensu stricto and to include at least some members of the genus Porpidia. Based on morphological and chemical similarities, as well as the phylogenetic relationship of Lecidea pullata sister to Frutidella caesioatra, the new combination Frutidella pullata is proposed here.     

Phylogeny of Adeleid Blood Parasites with a Partial Systematic Revision of the Haemogregarine Complex

ABSTRACT. The phylogenetic relationships of taxa representative of blood parasitic adeleids were investigated in a cladistic analysis. Two phylogenetic analyses were performed. Monophyly of species of Haemogregarina (sensu lato) of some marine fishes with species of Haemogregarina (sensu stricto) was not supported in either analysis. A new genus, Desseria n. g., was created to accommodate these species. The historical burden placed on the genus Haemogregarina Danilewsky, 1885 as a repository for poorly known and inadequately described species is partially relieved through taxonomic revisions involving the genera Haemogregarina , and Desseria n. g.     

A phylogenetic study of the 'bombycoid complex' (Lepidoptera) using five protein-coding nuclear genes, with comments on the problem of macrolepidopteran phylogeny

Abstract This study had two aims. First, we tested the monophyly of and relationships within the ‘bombycoid complex’, an assembly of approximately 5300 species postulated by Minet to represent 12 families in three superfamilies, by sequencing five protein‐coding nuclear gene regions (CAD, DDC, enolase, period, wingless; approximately 6750 bp total) in 66 representatives of most of the subfamilies and tribes. Second, we sought initial evidence on the utility of these genes for estimating relationships among Macrolepidoptera more broadly (11 superfamilies total), by adding representatives of eight families from four other superfamilies, and by assessing the phylogenetic information content of the individual genes and partitions thereof. Analysis of the combined data by likelihood and parsimony upholds monophyly for the bombycoid complex and for Bombycoidea sensu stricto (includes Anthelidae, see below), but with weak bootstrap support. Minet’s assignment of Phiditiinae to Bombycoidea rather than to Noctuoidea is strongly upheld, but Anthelidae, placed in Lasiocampoidea by Minet, group securely within Bombycoidea sensu stricto. Within the latter, the basal split segregates a strongly supported ‘BALE’ group [Apatelodinae + (Eupterotidae + (Brahmaeidae + Lemoniidae))]. The remaining families form a consistently but weakly supported clade, within which the basal split segregates the very strongly supported ‘CAPOPEM’ group [Carthaeidae, Anthelidae, Phiditiinae, (Prismostictini + (Endromidae + (Oberthueriini + Mirinidae)))]. The remaining bombycoids are grouped, very weakly, as Sphingidae + (Bombycinae + Saturniidae). All multiply‐sampled families are strongly recovered, in both outgroups and ingroups, except that Bombycidae sensu Minet are rendered decisively polyphyletic. All genes make important contributions to the combined data results, and there is little strong conflict among genes or between synonymous and nonsynonymous change, although two instances of inter‐gene conflict were notable, one in Lasiocampidae and one in Mimallonidae. Overall, about 75% of nodes are strongly supported (i.e. bootstrap value ≥80%). Superfamilies are recovered, but not always strongly, whereas relationships among superfamilies are recovered only weakly and inconsistently; even within the reasonably well‐sampled Bombycoidea sensu stricto, a (to us) surprising number of interfamily relationships remain uncertain. Thus, it seems clear that substantially more genes, plus additional taxon sampling in most superfamilies, will be required to resolve macrolepidopteran phylogeny.     

Mitochondrial genomes suggest that hexapods and crustaceans are mutually paraphyletic

For over a century the relationships between the four major groups of the phylum Arthropoda (Chelicerata, Crustacea, Hexapoda and Myriapoda) have been debated. Recent molecular evidence has confirmed a close relationship between the Crustacea and the Hexapoda, and has included the suggestion of a paraphyletic Hexapoda. To test this hypothesis we have sequenced the complete or near-complete mitochondrial genomes of three crustaceans (Parhyale hawaiensis, Squilla mantis and Triops longicaudatus), two collembolans (Onychiurus orientalis and Podura aquatica) and the insect Thermobia domestica. We observed rearrangement of transfer RNA genes only in O. orientalis, P. aquatica and P. hawaiensis. Of these, only the rearrangement in O. orientalis, an apparent autapomorphy for the collembolan family Onychiuridae, was phylogenetically informative.We aligned the nuclear and amino acid sequences from the mitochondrial protein-encoding genes of these taxa with their homologues from other arthropod taxa for phylogenetic analysis. Our dataset contains many more Crustacea than previous molecular phylogenetic analyses of the arthropods. Neighbour-joining, maximum-likelihood and Bayesian posterior probabilities all suggest that crustaceans and hexapods are mutually paraphyletic. A crustacean clade of Malacostraca and Branchiopoda emerges as sister to the Insecta sensu stricto and the Collembola group with the maxillopod crustaceans. Some, but not all, analyses strongly support this mutual paraphyly but statistical tests do not reject the null hypotheses of a monophyletic Hexapoda or a monophyletic Crustacea. The dual monophyly of the Hexapoda and Crustacea has rarely been questioned in recent years but the idea of both groups' paraphyly dates back to the nineteenth century. We suggest that the mutual paraphyly of both groups should seriously be considered.     

Evolutionary history and speciation modes in the cyprinid genus Barbus.

Phylogenetic relationships and evolutionary patterns in the genus Barbus were examined through the analysis of the complete sequences of three mitochondrial genes: ATPases 8 and 6, which overlap slightly, and cytochrome b. This complex genus includes diploid as well as tetraploid and hexaploid species that are distributed throughout the Palaearctic, Ethiopian and Asiatic biogeographical regions. Given that genome duplication is an important evolutionary mechanism in eukaryotes, in the present report we attempt to describe its role in the evolution of the genus Barbus, as well as drawing systematic and phylogenetic conclusions. The phylogenetic results indicated the splitting of the current Barbus genus into five main mitochondrial lineages corresponding to (i) the genus Barbus sensu stricto (tetraploid, which is subdivided into the subgenera Barbus and Luciobarbus), (ii) the hexaploid species, (iii) the Ethiopian tetraploid species, (iv) the African diploid species, and (v) the Asian diploid species. The branching of 'foreign' genera as sister groups of some of these monophyletic assemblages (such as Aulopyge is to Barbus sensu stricto or Varicorhinus is to the hexaploid barbels) demonstrates the polyphyly of the group. Moreover, the relationships between the proposed lineages also show that genome duplication may be considered as a homoplasic character since it must have occurred over at least three independent periods and/or in three independent areas. In relation to the possible saltational evolutionary model for the polyploid species examined here, it was found that, although feasible at the nuclear level, the mitochondrial markers looked at do not appear to have undergone this type of evolution. Rather, they seem to have experienced more or less constant change through time.     

Test of the monophyly of Odostomiinae and Turbonilliinae (Gastropoda, Heterobranchia, Pyramidellidae) based on 16S mtDNA sequences

Schander, C., Halanych, K. M., Dahlgren, T. & Sundberg, P. (2003) Test of the monophyly of Odostomiinae and Turbonilliinae (Gastropoda, Heterobranchia, Pyramidellidae) based on 16S mtDNA sequences. — Zoologica Scripta, 32 , 243−254.
While gastropod phylogeny has received much recent attention, relationships within some major gastropod clades have still not been studied. The Pyramidellidae is one such group, comprising more than 6000 named species in more than 350 genera. We sequenced part of the mitochondrial 16S gene from 32 species in an attempt to clarify pyramidellid phylogeny and employed a successive alignment approach that allowed us to maximize the phylogenetic signal of the data. Neighbour-joining, maximum parsimony and likelihood analyses recovered two distinct clades. One clade consisted of Noemiamea which nested within Odostomia ( sensu stricto ) . The inclusion of Brachystomia , Megastomia , Jordaniella and Liostomia within Odostomia is not supported. The second clade comprised Spiralinella , Brachystomia , Boonea , Jordaniella , Liostomia and Parthenina . Our results further suggest that Turbonilla, as interpreted by most authors, is polyphyletic. This study shows that the 16S gene is useful in unravelling pyramidellid phylogeny but needs to be combined with other data (including molecular, morphological and developmental) to fully clarify the evolutionary relationships.     

Phylogeny of the Celastraceae inferred from 26S nuclear ribosomal DNA, phytochrome B, rbcL, atpB, and morphology

Phylogenetic relationships within Celastraceae (spindle-tree family) were inferred from nucleotide sequence characters from the 5' end of 26S nuclear ribosomal DNA (including expansion segments D1-D3; 84 species sampled), phytochrome B (58 species), rbcL (31 species), atpB (23 species), and morphology (94 species). Among taxa of questionable affinity, Forsellesia is a member of Crossosomataceae, and Goupia is excluded from Celastraceae. However, Brexia, Canotia, Lepuropetalon, Parnassia, Siphonodon, and Stackhousiaceae are supported as members of Celastraceae. Gymnosporia and Tricerma are distinct from Maytenus, Cassine is supported as distinct from Elaeodendron, and Dicarpellum is distinct from Salacia. Catha, Maytenus, and Pristimera are not resolved as natural genera. Hippocrateaceae (including Plagiopteron and Lophopetalum) are a clade nested within a paraphyletic Celastraceae. These data also suggest that the Loesener's classification of Celastraceae sensu stricto and Hallé's classification of Hippocrateaceae are artificial. The diversification of the fruit and aril within Celastraceae appears to be complex, with multiple origins of most fruit and aril forms.     

Molecular phylogeny, historical biogeography, and divergence time estimates for swallowtail butterflies of the genus Papilio (Lepidoptera: Papilionidae)

Swallowtail butterflies are recognized as model organisms in ecology, evolutionary biology, genetics, and conservation biology but present numerous unresolved phylogenetic problems. We inferred phylogenetic relationships for 51 of about 205 species of the genus Papilio (sensu lato) from 3.3-Kilobase (kb) sequences of mitochondrial and nuclear DNA (2.3 kb of cytochrome oxidases I and II and 1.0 kb of elongation factor 1 alpha). Congruent phylogenetic trees were recovered within Papilio from analyses of combined data using maximum likelihood, Bayesian analysis, and maximum parsimony bootstrap consensus. Several disagreements with the traditional classification of Papilio were found. Five major previously hypothesized subdivisions within Papilio were well supported: Heraclides, Pterourus, Chilasa, Papilio (sensu stricto), and Eleppone. Further studies are required to clarify relationships within traditional "Princeps," which was paraphyletic. Several biologically interesting characteristics of Papilio appear to have polyphyletic origins, including mimetic adults, larval host associations, and larval morphology. Early diversification within Papilio is estimated at 55-65 million years ago based on a combination of biogeographic time constraints rather than fossils. This divergence time suggests that Papilio has slower apparent substitution rates than do Drosophila and fig-pollinating wasps and/or divergences corrected using best-fit substitution models are still being consistently underestimated. The amount of sequence divergence between Papilio subdivisions is equivalent to divergences between genera in other tribes of the Papilionidae, and between genera of moths of the noctuid subfamily Heliothinae.     

PHYLOGENETIC RELATIONSHIPS OF THE BROWN ALGAL ORDERS ECTOCARPALES, CHORDARIALES, DICTYOSIPHONALES, AND TILOPTERIDALES (PHAEOPHYCEAE) BASED ON RUBISCO LARGE SUBUNIT AND SPACER SEQUENCES

Phylogenetic relationships among 23 species of morphologically simple brown algae belonging to the Ectocarpales sensu stricto , Chordariales, Dictyosiphonales, and Tilopteridales sensu stricto , Phaeophyceae (Fucophyceae), were analyzed using chloroplast-encoded RUBISCO large subunit gene sequences ( rbc L) and the associated RUBISCO spacer sequences. Comparison of the observed and expected sequence divergence at the three codon positions of rbc L showed that the level of mutational saturation within the brown algae is minor. Thus, rbc L is well suited for phylogenetic studies in this group. Unweighted parsimony analyses and a neighbor-joining distance analysis were performed using unambiguously aligned rbc L sequences from the above four orders, one marine raphidophyte and two Tribophyceae (Xantophyceae). Polyphyly of Tilopteridales sensu lato (i.e. including Dictyosiphonales) is verified; we therefore recommend the use of Tilopteridales in the strict sense. The Ectocarpales, Chordariales, and Dictyosiphonales are paraphyletic with respect to each other, forming a highly interwoven clade. A separate parsimony analysis of the RUBISCO spacer as well as a combined rbc L and spacer analysis supported the close relationship among the latter three orders, adding to the evidence that they should be subsumed into the Ectocarpales sensu lato.