Tests of turtle phylogeny: molecular, morphological, and paleontological approaches

We present phylogenetic analyses of both molecular and morphological data for the 23 major lineages of living turtles and seven key fossil taxa. Nearly 1 kilobase of cytochrome b sequence, 325 base pairs of 12S ribosomal DNA, and 115 morphological characters contained similar phylogenetic information, although each provided unique information on different nodes of chelonian history. A character-based combinability test (implemented in PAUP*) and a non-parametric test of taxonomic congruence indicated no strong evidence for heterogeneity among data sets, and we used a combined approach to estimate a final phylogeny of the major lineages of living turtles. This approach resulted in a very well-resolved tree, with only a few of the deep branches within the Cryptodira left as an unresolved polytomy. The addition of six relatively complete fossils chosen to help resolve this basal polytomy provided little added resolution to the tree and resulted in a sharp decline in bootstrap proportions for nodes near the fossils. Branch-length analysis and independent dates from the fossil record suggest that these unresolved nodes may represent a rapid radiation of the major cryptodiran lineages 90-120 million years ago.     

Molecules,fossils, and the origin of tetrapods

Summary Since the discovery of the coelacanth, Latimeria chalumnae, more than 50 years ago, paleontologists and comparative morphologists have debated whether coelacanths or lungfishes, two groups of lobe-finned fishes, are the closest living relatives of land vertebrates (Tetrapoda). Previously, Meyer and Wilson (1990) determined partial DNA sequences from two conservative mitochondrial genes and found support for a close relationship of lungfishes to tetrapods. We present additional DNA sequences from the 12S rRNA mitochondria gene for three species of the two lineages of lungfishes that were not represented in the first study: Protopterus annectens and Protopterus aethiopicus from Africa and Neoceratodus forsteri (kindly provided by B. Hedges and L. Maxson) from Australia. This extended data set tends to group the two lepidosirenid lungfish lineages (Lepidosiren and Protopterus) with Neoceratodus as their sister group. All lungfishes seem to be more closely related to tetrapods than the coelacanth is. This result appears to rule out the possibility that the coelacanth lineage gave rise to land vertebrates. The common ancestor of lungfishes and tetrapods might have possessed multiple morphological traits that are shared by lungfishes and tetrapods [Meyer and Wilson (1990) listed 14 such traits]. Those traits that seem to link Latimeria and tetrapods are arguably due to convergent evolution or reversals and not to common descent. In this way, the molecular tree facilitates an evolutionary interpretation of the morphological differences among the living forms. We recommended that the extinct groups of lobe-finned fishes be placed onto the molecular tree that has lungfishes and not the coelacanth more closely related to tetrapods. The placement of fossils would help to further interpret the sequence of morphological events and innovations associated with the origin of tetrapods but appears to be problematic because the quality of fossils is not always high enough, and differences among paleontologists in the interpretation of the fossils have stood in the way of a consensus opinion for the branching order among lobefinned fishes. Marshall and Schultze (1992) criticized the morphological analysis presented by Meyer and Wilson (1990) and suggest that 13 of the 14 morphological traits that support the sister group relationship of lungfishes and tetrapods are not shared derived characters. Here we present further alternative viewpoints to the ones of Marshall and Schultze (1992) from the paleontological literature. We argue that all available information (paleontological, neontological, and molecular data) and rigorous cladistic methodology should be used when relating fossils and extant taxa in a phylogenetic framework. Offprint requests to: Axel Meyer     

Phylogeny and character behavior in the family Lemuridae

A phylogenetic analysis of the family Lemuridae was accomplished using multiple gene partitions and morphological characters. The results of the study suggest that several nodes in the lemurid phylogeny can be robustly resolved; however, the relationships of the species within the genus Eulemur are problematically nonrobust. The genus Varecia is strongly supported as the basal genus in the family. Hapalemur and Lemur catta are strongly supported as sister taxa and together are the sister group to the genus Eulemur. E. mongoz is the most basal species in the genus Eulemur. E. fulvus subspecies form a monophyletic group with three distinct lineages. E. coronatus is strongly supported as the sister taxon to E. macaco. The relationships of E. rubriventer, E. fulvus, and the E. macaco-E. coronatus pair are unresolved. Our combined molecular and morphological analysis demonstrates the lack of influence that morphology has on the simultaneous analysis tree when these two kinds of data are given equal weight. The effects of several extreme weighting schemes (removal of transitions and of third positions in protein-coding regions) and maximum-likelihood analysis were also explored. We suggest that these other forms of inference add little to resolving the problematic relationships of the species in the genus Eulemur.     

Molecular systematics of threadfin breams and relatives (Teleostei,Nemipteridae)

Threadfin breams and relatives of the family Nemipteridae comprise 69 currently recognized species in five genera. They are found in the tropical and subtropical Indo‐West Pacific and most are commercially important. Using recently developed molecule‐based approaches exploiting DNA sequence variation among species/specimens, this study reconstructed a comprehensive phylogeny of the Nemipteridae, examined the validity of species and explored the cryptic diversity of the family, and tested previous phylogenetic hypotheses. A combined data set (105 taxa from 41 morphospecies) with newly determined sequences from two nuclear genes (RAG1 and RH) and one mitochondrial gene (COI), and a data set with only COI gene sequences (329 newly obtained plus 328 from public databases from a total of 53 morphospecies) were used in the phylogenetic analysis. The latter was further used for species delimitation analyses with two different tools to explore species diversity. Our phylogenetic results showed that all the currently recognized genera were monophyletic. The monotypic genus Scaevius is the sister group of Pentapodus and they together are sister to Nemipterus. These three genera combined to form the sister group of the clade comprising Parascolopsis and Scolopsis. The validity of most of the examined species was confirmed except in some cases. The combined evidence from the results of different analyses revealed a gap in our existing knowledge of species diversity in the Nemipteridae. We found several currently recognized species contain multiple separately evolving metapopulation lineages within species; some lineages should be considered as new species for further assignment. Finally, some problematic sequences deposited in public databases (probably due to misidentification) were also revised in this study to improve the accuracy for prospective DNA barcoding work on nemipterid fishes.     

The role of diversification in causing the correlates of dioecy

Dioecy is reported to be correlated with a number of ecological traits, including tropical distribution, woody growth form, plain flowers, and fleshy fruits. Previous analyses have concentrated on determining whether dioecy is more likely to evolve in lineages possessing these traits, rather than considering the speciation and extinction rates of dioecious lineages with certain combinations of traits. To address the association between species richness in dioecious lineages as a function of the ecological traits, we compared the evolutionary success (i.e., relative species richness) of dioecious focal lineages with that of their nondioecious sister groups. This test was repeated for the evolutionary success of randomly chosen nondioecious lineages (control lineages) compared with their nondioecious sister groups. If the possession of certain ecological traits enhances the evolutionary success of dioecious lineages, we predict an association between the presence of these traits and relative species richness in the former, but not latter, set of sister-group comparisons. Dioecious focal lineages with a higher number of these traits experienced higher evolutionary success in sister-group comparisons, whereas no trend was found for the control focal lineages. The increase in evolutionary success was especially true for dioecious focal lineages that had a tropical distribution or fleshy fruit. We discuss how these results provide strong support for differential evolutionary success theories for the correlations between dioecy and the ecological traits considered.     

Phylogeographic history of the genus Tropheus,a lineage of rock-dwelling cichlid fishes endemic to Lake Tanganyika

Lake Tanganyika contains the oldest and most complex flock of cichlid fishes counting about 200 endemic species. It is comprised of 16 ecologically, morphologically and genetically highly distinct tribes. Many species are further subdivided into arrays of geographic morphs, each colonizing particular sections of the shore line. The genus Tropheus represents the most spectacular and best studied example for this phenomenon, counting more than 100 distinctly colored populations and sister species, some living in sympatry. Their present distribution and genetic structure was shaped by a series of lake level fluctuations which caused cycles of isolation and secondary admixis. The present study extends previous work on the phylogeography of Tropheus and aims at the fine-scale reconstruction of the origin and spread of lineages in the central and southern basin of the lake. The previously defined mtDNA lineages were evaluated on the basis of statistical parsimony networks. Haplotype networks were created for each lineage and related to their centers of diversity in terms of present distribution. A linearized tree analysis and a mismatch distribution analysis corroborate two of the three radiation waves suggested in earlier works, but the new data suggest a different primary colonization scenario for the southern basin.     

Molecular biogeography of the Mediterranean lizards Podarcis Wagler, 1830 and Teira Gray, 1838 (Reptilia, Lacertidae)

Aim   We discuss biogeographical hypotheses for the Mediterranean lizard species Podarcis and Teira within a phylogenetic framework based on partial mitochondrial DNA sequences.
Methods   We derived the most likely phylogenetic hypothesis from our data set (597 aligned positions from the 12S rDNA and phenyl tRNA) under parsimony, distance and maximum likelihood assumptions.
Results   The species usually included in Teira do not form a strongly monophyletic clade. In contrast, the monophyly of the genus Podarcis is rather well supported. Seven lineages are identified in the genus; in order of appearance within the tree, these are: the Balearic pityusensis and lilfordi pair, the sicula complex, a Tyrrhenian tiliguerta and raffonei pair, muralis , the Siculo-Maltese filfolensis and wagleriana pair, the Balkan group ( erhardi , peloponnesiaca , milensis , melisellensis and taurica ), and the Ibero-Maghrebian group ( bocagei , atrata , hispanica and vaucheri ).
Conclusions   The origin of the three European genera of lacertid assayed ( Lacerta , Teira and Podarcis ) is hypothesized to have occurred in the Oligocene. For Podarcis , a possible scenario of a Miocene diversification is derived from the sequence data, and the zoogeography of the lineages are discussed in relation to the palaeogeography of the Mediterranean. It is hypothesized that in the early history of the genus the main lineages separated by rapid, numerous and close events that produced a starting point very similar to a polytomy, hard to resolve by parsimony analysis of the data set.     

Phylogeny of the Dipsacales s.l. based on chloroplast trnL-F and ndhF sequences

Sequences of the chloroplast trnL-F region and 3(') end ndhF gene were used to elucidate phylogenetic relationships and the delimitation of families within Dipsacales s.l. Parsimony analyses of individual and combined data were conducted using maximum parsimony method. The most parsimonious tree based on combined trnL-F and 3(') end ndhF data set recognizes seven major clades of Dipsacales s.l. with the following relationships: Apiales (Adoxaceae ((Diervillaceae, Caprifoliaceae s.str.) (Linnaeaceae (Morinaceae (Dipsacaceae, Valerianaceae))))). Both Sambucus and Viburnum have close relationships with Adoxaceae, supporting their inclusion in this family. Caprifoliaceae s.l. (excluding Sambucus and Viburnum) is polyphyletic, and comprises three clades or families, i.e., Linnaeaceae (Abelia, Dipelta, Kolkwitzia, and Linnaea), Diervillaceae (Weigela and Diervilla) and Caprifoliaceae s.str. (Heptacodium, Leycesteria, Lonicera, Symphoricarpos, and Triosteum). This study focuses on the systematic position of Heptacodium, Triplostegia, and Morinaceae; and suggests that Heptacodium is closely related to the other Caprifoliaceae s.str.; Triplostegia is a sister to Dipsacaceae; Morinaceae, which has an affinity with Dipsacaceae, is possibly a sister group with Dipsacaceae-Valerianaceae clade. Our results are highly congruent with those of and.     

单子叶植物高级分类阶元系统演化: matK、rbcL和18S rDNA序列的证据

基于两个叶绿体基因（matK和rbcL）和一个核糖体基因（18S rDNA）的序列分析,对代表了基部被子植物和单子叶植物主要谱系分支的86科126属151种被子植物（单子叶植物58科86属101种）进行了系统演化关系分析。研究结果表明由胡椒目Piperales、樟目Laurales、木兰目Magnoliales和林仙目Canellales构成的真木兰类复合群是单子叶植物的姐妹群。单子叶植物的单系性在3个序列联合分析中得到98％的强烈自展支持。联合分析鉴定出9个单子叶植物主要谱系（广义泽泻目Alismatales、薯蓣目Dioscorcales、露兜树目Pandanales、天门冬目Asparagalcs、百合目Liliales、棕榈目Arecales、禾本目Poales、姜目Zingiberales、鸭跖草目Commelinales）和6个其他被子植物主要谱系（睡莲目Nymphaeales、真双子叶植物、木兰目、樟目、胡椒目、林仙目）。在单子叶植物内,菖蒲目Acorales（菖蒲属Acorus）是单子叶植物最早分化的一个谱系,广义泽泻目（包括天南星科Araceae和岩菖蒲科Toficldiaccae）紧随其后分化出来,二者依次和其余单子叶植物类群构成姐妹群关系。无叶莲科Petrosaviaceac紧随广义的泽泻目之后分化出来,无叶莲科和剩余的单子叶植物类群形成姐妹群关系,并得到了较高的支持率。继无叶莲科之后分化的类群形成两个大的分支：一支是由露兜树目和薯蓣目构成,二者形成姐妹群关系：另一支是由天门冬目、百合目和鸭跖草类复合群组成,三者之间的关系在单个序列分析和联合分析中不稳定,需要进一步扩大取样范围来确定。在鸭跖草类复合群分支内,鸭跖草目和姜目的姐妹群关系在3个序列联合分析和2个序列联合分析的严格一致树中均得到强烈的自展支持,获得的支持率均是100％。但是,对于棕榈目和禾本目在鸭跖草类中的系统位置以及它们和鸭跖草目-姜目之间的关系,有待进一步解决。值得注意的是,无叶莲科与其他单子叶植物类群（除菖蒲目和泽泻目外）的系统关系在本文中获得较高的自展支持率,薯蓣目和天门冬目的单系性在序列联合分析中都得到了较好的自展支持,而这些在以往的研究中通常支持率较低。鉴于菖蒲科和无叶莲科独特的系统演化位置,本文支持将其分别独立成菖蒲目和无叶莲目Petrosavialcs的分类学界定。     

Molecular ecology, speciation, and evolution of the reef fish genus Anisotremus

Grunts (family Haemulidae) in the genus Anisotremus comprise 10 described species which occur predominantly on coral reefs and subtropical rocky reefs in the Neotropics of the Tropical Eastern Pacific the Caribbean and adjacent waters. In this study, the phylogenetic relationships for all described species were examined based on one mitochondrial gene (cytochrome b) and one nuclear marker (the first intron of the ribosomal protein S7). Closely related species of the genus Haemulon and the single representative of the genus Genyatremus, G. luteus were also included in the analysis, following the suggestion, based on morphological data, that they may be closely related to, or possibly placed within, Anisotremus. Two sweetlips, genus Plectorhinchus, which belong to the recognized sister subfamily Plectorhynchinae, were used as outgroups. Two species pairs in the ingroup genus Anisotremus are geminate species, which presumably diverged after the rise of the Isthmus of Panama, thus providing an internal molecular clock calibration. This allowed for a comprehensive evolutionary scenario for the genus. Our data were consistent with two independent allopatric speciation events (geminate species), and one likely sympatric speciation event. Our data were also consistent with the placement of Genyatremus and Haemulon within the genus Anisotremus, thus breaking its monophyletic status. As proposed for other coral reef species, Anisotremus seems to have colonized coral reefs from non-coral reef habitats. In addition, ancestral species seem to have been widespread, since species that are currently found in Brazilian and Pacific waters are basal on the phylogenetic tree. Finally, this study adds to the hypothesis of a secondary evolutionary center in the New World.     

Phylogenetic relationships of the Gomphales based on nuc-25S-rDNA, mit-12S-rDNA, and mit-atp6-DNA combined sequences

Phylogenetic relationships among Geastrales, Gomphales, Hysterangiales, and Phallales were estimated via combined sequences: nuclear large subunit ribosomal DNA (nuc-25S-rDNA), mitochondrial small subunit ribosomal DNA (mit-12S-rDNA), and mitochondrial atp6 DNA (mit-atp6-DNA). Eighty-one taxa comprising 19 genera and 58 species were investigated, including members of the Clathraceae, Gautieriaceae, Geastraceae, Gomphaceae, Hysterangiaceae, Phallaceae, Protophallaceae, and Sphaerobolaceae. Although some nodes deep in the tree could not be fully resolved, some well-supported lineages were recovered, and the interrelationships among Gloeocantharellus, Gomphus, Phaeoclavulina, and Turbinellus, and the placement of Ramaria are better understood. Both Gomphus sensu lato and Ramaria sensu lato comprise paraphyletic lineages within the Gomphaceae. Relationships of the subgenera of Ramaria sensu lato to each other and to other members of the Gomphales were clarified. Within Gomphus sensu lato, Gomphus sensu stricto, Turbinellus, Gloeocantharellus and Phaeoclavulina are separated by the presence/absence of clamp connections, spore ornamentation (echinulate, verrucose, subreticulate or reticulate), and basidiomal morphology (fan-shaped, funnel-shaped or ramarioid). Gautieria, a sequestrate genus in the Gautieriaceae, was recovered as monophyletic and nested with members of Ramaria subgenus Ramaria. This agrees with previous observations of traits shared by these two ectomycorrhizal taxa, such as the presence of fungal mats in the soil. Clavariadelphus was recovered as a sister group to Beenakia, Kavinia, and Lentaria. The results reaffirm relationships between the Geastrales, Gomphales, Hysterangiales, and the Phallales, suggesting extensive convergence in basidiomal morphology among members of these groups. A more extensive sampling that focuses on other loci (protein-coding genes have been shown to be phylogenetically informative) may be useful to answer questions about evolutionary relationships among these fungal groups.     

Relationships Among the Families and Orders of Marsupials and the Major Mammalian Lineages Based on Recombination Activating Gene-1

Controversies remain over the relationships among several of the marsupial families and between the three major extant lineages of mammals: Eutheria (placentals), Metatheria (marsupials), and Prototheria (monotremes). Two opposing hypotheses place the marsupials as either sister to the placental mammals (Theria hypothesis) or sister to the monotremes (Palimpsest or Marsupionta hypothesis). A nuclear gene that has proved useful for analyzing phylogenies of vertebrates is the recombination activation gene-1 (RAG1). RAG1 is a highly conserved gene in vertebrates and likely entered the genome by horizontal transfer early in the evolution of jawed vertebrates. Phylogenetic analyses were performed on RAG1 sequences from seven placentals, 28 marsupials, and all three living monotreme species. Phylogenetic analyses of RAG1 sequences support many of the traditional relationships among the marsupials and suggest a relationship between bandicoots (order Peramelina) and the marsupial mole (order Notoryctemorphia), two lineages whose position in the phylogenetic tree has been enigmatic. A sister relationship between South American shrew opossums (order Paucituberculata) and all other living marsupial orders is also suggested by RAG1. The relationship between the three major groups of mammals is consistent with the Theria hypothesis, with the monotremes as the sister group to a clade containing marsupials and placentals.     

Macroevolution of perfume signalling in orchid bees

Theory predicts that both stabilising selection and diversifying selection jointly contribute to the evolution of sexual signalling traits by (1) maintaining the integrity of communication signals within species and (2) promoting the diversification of traits among lineages. However, for many important signalling traits, little is known about whether these dynamics translate into predictable macroevolutionary signatures. Here, we test for macroevolutionary patterns consistent with sexual signalling theory in the perfume signals of neotropical orchid bees, a group well studied for their chemical sexual communication. Our results revealed both high species‐specificity and elevated rates of evolution in perfume signals compared to nonsignalling traits. Perfume complexity was correlated with the number of congeners in a species’ range, suggesting that perfume evolution may be tied to the remarkably high number of orchid bee species coexisting together in some neotropical communities. Finally, sister‐pair comparisons were consistent with both rapid divergence at speciation and character displacement upon secondary contact. Together, our results provide new insight into the macroevolution of sexual signalling in insects.     

Diversification in North American arid lands: Niche conservatism, divergence and expansion of habitat explain speciation in the genus Ephedra

A lineage of 12 arid land shrubby species in the gymnosperm genus Ephedra (Gnetales) from North America is used to evaluate the influence of climate on speciation. With a long evolutionary history, and a well documented fossil record this lineage is an ideal model for understanding the process of speciation under a niche conservatism scenario. Using seven DNA molecular markers, Bayesian inference is carried out to uncover sister species and to estimate time of divergence of the lineages. Ecological niche models are generated for four parapatric and sympatric sister species and two analyses of niche evolution are performed, one based on ecological niche models and another using raw data and multivariate analysis. As previous analyses suggest, the diversification of North America Ephedra species may be the result of a recent secondary radiation. Both parapatric and sympatric species diverged mostly in a scenario of climatic niche conservatism. However, we also found strong evidence for niche divergence for one of the sister species pairs (E. californica-E. trifurca). Moreover, the multivariate analysis found environmental differences for some variables between sister species. The estimated divergence time of three pairs of sister species distributed in southwestern North America (E. cutleri-E. aspera, E. californica-E. trifurca and E. torreyana-E. viridis) is inferred to have occurred in the Late Miocene to Pliocene and for the sister species pair E. antisyphilitica-E. coryi distributed in the southern United States and northeastern Mexico, it was inferred from the Pliocene to Pleistocene. The orogenetic and climatic changes documented for these regions related to expansion of arid lands, may have contributed to the diversification in North American Ephedra, rather than adaptations to new climatic conditions.     

Speciation in Hawaiian angiosperm lineages: cause, consequence, and mode

The biota of Hawaiian Islands is derived entirely from long distance dispersal, often followed by in situ speciation. Species descended from each colonist constitute monophyletic lineages that have diverged to varying degrees under similar spatial and temporal constraints. We partitioned the Hawaiian angiosperm flora into lineages and assessed morphological, ecological, and biogeographic characteristics to examine their relationships to variation in species number (S). Lineages with external bird dispersal (through adhesion) were significantly more species-rich than those with abiotic dispersal, but only weakly more species-rich than lineages with internal bird dispersal (involving fleshy fruits). Pollination mode and growth form (woody vs. herbaceous) had no significant effect on S, in contrast to studies of angiosperm families. S relates positively to the geographic and ecological range size of whole lineages, but negatively to local abundance and mean range sizes of constituent species. Species-rich lineages represent a large proportion of major adaptive shifts, although this appears to be an artifact of having more species. Examination of 52 sister species pairs in numerous lineages provides evidence for allopatric (including peripheral isolates) and parapatric (ecological) modes, with 15 cases of each. Although postspeciational dispersal may obscure these modes in many of the remaining cases, instances of sympatric and hybrid speciation are also discussed. Because speciation is both a consequence and a cause of ecological and biogeographic traits, speciation mode may be integral to relationships between traits. We discuss the role of speciation in shaping the regional species pool.     

Influence of the geography of speciation on current patterns of coral reef fish biodiversity across the Indo‐Pacific

The role of speciation processes in shaping current biodiversity patterns represents a major scientific question for ecologists and biogeographers. Hence, numerous methods have been developed to determine the geography of speciation based on co‐occurrence between sister‐species. Most of these methods rely on the correlation between divergence time and several metrics based on the geographic ranges of sister‐taxa (i.e. overlap, asymmetry). The relationship between divergence time and these metrics has scarcely been examined in a spatial context beyond regression curves. Mapping this relationship across spatial grids, however, may unravel how speciation processes have shaped current biodiversity patterns through space and time. This can be particularly relevant for coral reef fishes of the Indo‐Pacific since the origin of the exceptional concentration of biodiversity in the Indo‐Australian Archipelago (IAA) has been actively debated, with several alternative hypotheses involving species diversification and dispersal. We reconstructed the phylogenetic relationships between three species‐rich families of coral reef fish (Chaetodontidae, Labridae, Pomacentridae) and calculated co‐occurrence metrics between closely related lineages of those families. We demonstrated that repeated biogeographic processes can be identified in present‐day species distribution by projecting co‐occurrence metrics between related lineages in a geographical context. Our study also evidence that sister‐species do not co‐occur randomly across the Indo‐Pacific, but tend to overlap their range within the IAA. We identified the imprint of two important biogeographic processes that caused this pattern in 48% of the sister‐taxa considered: speciation events within the IAA and repeated divergence between the Indian and Pacific Ocean, with subsequent secondary contact in the IAA.     

Phylogenetic relationships of butterflies of the tribe Acraeini (Lepidoptera, Nymphalidae, Heliconiinae) and the evolution of host plant use

The tribe Acraeini (Nymphalidae, Heliconiinae) is believed to comprise between one and seven genera, with the greatest diversity in Africa. The genera Abananote, Altinote, and Actinote (s. str.) are distributed in the Neotropics, while the genera Acraea, Bematistes, Miyana, and Pardopsis have a Palaeotropical distribution. The monotypic Pardopsis use herbaceous plants of the family Violaceae, Acraea and Bematistes feed selectively on plants with cyanoglycosides belonging to many plant families, but preferentially to Passifloraceae, and all Neotropical species with a known life cycle feed on Asteraceae only. Here, a molecular phylogeny is proposed for the butterflies of the tribe Acraeini based on sequences of COI, EF-1alpha and wgl. Both Maximum Parsimony and Bayesian analyses showed that the tribe is monophyletic, once the genus Pardopsis is excluded, since it appears to be related to Argynnini. The existing genus Acraea is a paraphyletic group with regard to the South American genera, and the species of Acraea belonging to the group of "Old World Actinote" is the sister group of the Neotropical genera. The monophyly of South American clade is strongly supported, suggesting a single colonization event of South America. The New World Actinote (s. str.) is monophyletic, and sister to Abananote+Altinote (polyphyletic). Based on the present results it was possible to propose a scenario for the evolution in host plant use within Acraeini, mainly concerning the use of Asteraceae by the South American genera.     

The mitochondrial DNA molecule of the aardvark, Orycteropus afer, and the position of the Tubulidentata in the eutherian tree

An outstanding problem in mammal phylogeny is the relationship of the aardvark (Orycteropus afer), the only living species of the order Tubulidentata, to the extant eutherian lineages. In order to examine this problem the complete mitochondrial DNA (mtDNA) molecule of the aardvark was sequenced and analysed. The aardvark tRNA-Ser (UCN) differs from that of other mammalian mtDNAs reported and appears to have reversed to the ancestral secondary structure of non-mammalian vertebrates and mitochondrial tRNAs in general. Phylogenetic analysis of 12 concatenated protein-coding genes (3325 amino acids) included the aardvark and 15 additional eutherians, two marsupials and a monotreme. The most strongly supported tree identified the aardvark as a sister group of a clade including the armadillo (Xenarthra) and the Cetferungulata (carnivores, perissodactyls, artiodactyls and cetaceans). By applying three molecular calibration points the divergence between the aardvark and armadillo-cetferungulates was estimated at ca. 90 million years before present.     

Benthic Community Structure and Invertebrate Drift in a Pacific Island Stream,Kosrae, Micronesia1

Tropical Pacific island streams have poorly understood communities that deserve scientific attention. We examined benthic macroinvertebrates and fishes of the Inem River on Kosrae, Federated States of Micronesia. Larval chironomids, lepidopterans, odonates, and freshwater shrimps dominated the benthos and drift. Diel periodicity in drift was not evident. Nine fishes, two shrimps, and one snail species were identified. Kosrae's stream fauna appears even more depauperate than other Pacific high islands, possible due to its extreme isolation.     

Phylogeny of Hypselodoris (Nudibranchia: Chromodorididae) with a review of the monophyletic clade of Indo-Pacific species, including descriptions of twelve new species

This work provides an account of the systematics and phylogeny of Hypselodoris . Aspects of the morphology of 42 species are described and the systematic status of an additional 11 species is discussed. Twelve new species are described: Hypselodoris alboterminata, H. bertschi, H. bollandi, H. fucata, H. iacula, H. insulana, H. krakatoa, H. paulinae, H. reidi, H. rudmani, H. violabranchia and H. zephyra. A phylogenetic analysis supports the monophyly of Hypselodoris and Risbecia . Two distinct clades of Hypselodoris are present. One contains species from the Atlantic and eastern Pacific while the other contains species limited to the Indo-Pacific tropics and adjacent temperate regions. Species from the Atlantic and eastern Pacific are bluish in body colour and have a plesiomorphically large receptaculum seminis while Indo-Pacific taxa are variably coloured and all have a minute receptaculum seminis. The distribution and size of mantle glands provides a wealth of morphological characters. With few exceptions, mantle glands vary in closely related species and are important for distinguishing members of smaller clades. Mantle gland distribution is therefore useful in identifying preserved material that is difficult to identify to species in the absence of the pigment of living specimens. Similar colour patterns found in sympatric species of Hypselodoris appear to be a result of both common descent and convergence between less closely related lineages. Biogeographic distributions of sister taxa provide several examples of vicariance. Examination of these cases shows that no single vicariant pattern is present, but vicariance appears to occur at the margins of the Indo-Pacific rather than centrally. Some vicariance occurs even within archipelagos such as the Hawaiian Islands. These cases largely refute the generality of the hypothesis of Springer (1982), that Pacific Plate and Australasian Plate endemic sister taxa should predominate.