Phylogenetic relationships in Magnoliaceae subfam. Magnolioideae: a morphological cladistic analysis

Relationships within Magnolioideae have been the subject of persistent debate; the main point at issue mostly being the disposition of tribes, genera and sections. A morphological cladistic analysis of the subfamily using Liriodendron as the out-group showed that Magnolioideae consisted of a large basal polytomy, but with five resolved and variously supported clades. Manglietia constituted a clade with sect. Rytidospermum of Magnolia subg. Magnolia. Kmeria and Woonyoungia formed a pair. Pachylarnax, Parakmeria and Manglietiastrum were grouped together, and sect. Splendentes and Dugandiodendron also formed a pair. The largest and best supported clade consisted of Magnolia subg. Magnolia sects. Oyama and Maingola, Magnolia subg. Yulania, Michelia, Aromadendron, Alcimandra, Elmerrillia, Paramichelia and Tsoongiodendron, with sect. Oyama of Magnolia subg. Magnolia is sister to the remainder. Although Magnolia sect. Maingola, Aromadendron, Alcimandra and Elmerrillia constituted a poorly resolved subclade, Aromadendron formed a monophyletic clade with Alcimandra. Within the Michelia/Magnolia subgen. Yulania subclade, Paramichelia was sister to Tsoongiodendron. These results are supported by similar placement of taxa within various molecular analyses of the family, but the low level of resolution indicates that more morphological data are needed to improve phylogenetic signal. Our results support the molecular analyses in suggesting that Magnolia is best considered to be a large and diverse genus, but that the relationships between the taxa within it require more detailed clarification, with more extensive sampling and a combined molecular and morphological approach being needed.     

Relationships of Droseraceae: a cladistic analysis of rbcL sequence and morphological data

Molecular support for the monophyly of Droseraceae and its phylogenetic relationships to other dicot families was investigated using parsimony analysis of nucleotide sequences of the large subunit of ribulose-1,5-bisphosphate carboxylase (rbcL). Analysis of 100 species of plants including families of subclasses Rosidae, Hamamelidae, Dilleniidae, and Caryophyllidae (sensu Cronquist) placed monophyletic Droseraceae in the same clade as Caryophyllidae and Nepenthaceae (Dilleniidae). In a second analysis of 14 species of Droseraceae, 15 caryophyllids, one Nepenthaceae, and three Santalales, a single most-parsimonious tree was found in which Droseraceae are monophyletic, although the position of Drosophyllum as a member of Droseraceae is only weakly supported. The rbcL tree identified four major lineages within genus Drosera: 1) Dionaea; 2) the regia-clade that contains only Drosera regia; 3) the capensis-clade that contains the South African and temperate species outside of Australia; and 4) the peltata-clade that consists of principally Australian endemics. A separate analysis of 14 morphological and phytochemical characters is in general agreement with the rbcL tree except for the placement of Nepenthes, Drosophyllum, and Drosera burmanni. A combined analysis of both data sets places Drosophyllum in a clade with Triphyophyllum (Dioncophyllaceae).     

Phylogenetic relationships of Lecythidaceae: a cladistic analysis using rbcL sequence and morphological data

This study examined in detail the rbcL sequence and morphological support for subfamilial relationships and monophyly of Lecythidaceae. Initially we needed to establish relationships of Lecythidaceae among other dicot families. To complete this we examined 47 rbcL sequences of 25 families along with molecular observations from several large analyses of rbcL data. All analyses strongly support the monophyly of the asterid III grouping. This analysis revealed Lecythidaceae to be paraphyletic and indicated potential outgroup relationships with Sapotaceae. Once relationships had been evaluated using molecular data we then concentrated on analyzing separate and combined morphological and molecular databases. The topology of the morphological data set was similar to the rbcL sequence and combined data sets except for the positioning of Napoleonaeoideae, Grias, Gustavia, and Oubanguia. According to the combined results, Planchonioideae, Lecythidoideae. and Foetidioideae are monophyletic, whereas the subfamily Napoleonaeoideae are paraphyletic. Nested within Napolconaeoideae, we found Asteronthos forms a strongly supported clade with Oubanguia (Scytopetalaceae). Foetidia, the only genus of Foetidioideae, is sister to Planchonioideae, and this clade is sister to Lecythidoideae. The [(Planchonioideae, Foetidioideae) Lecythidoideae are sister to Asteranthos/Oubanguia. Napoleonaeoideae are sister to the rest of Lecythidaceae.     

Metallothionein primary structure in amphibians: Insights from comparative evolutionary analysis in vertebrates

Metallothioneins are cysteine-rich, low-molecular weight metal-binding proteins ubiquitously expressed in living organisms. In the last past years, the increasing amount of vertebrate non-mammalian metallothionein sequences available have disclosed for these proteins differences in the primary structure that have not been supposed before. To provide a more up-to-date view of the metallothioneins in non-mammalian tetrapods, we decided to increase the still scarce knowledge concerning the primary structure and the evolution of metallothioneins in amphibians. Our data demonstrate an unexpected diversity of metallothionein sequences among amphibians, accompanied by remarkable features in their phylogeny. Phylogenetic analysis also reveals the complexity of vertebrate metallothionein evolution, made by both ancient and more recent events of gene duplication and loss.     

Phylogeny of New Zealand hepialid moths (Lepidoptera: Hepialidae) inferred from a cladistic analysis of morphological data

The phylogeny of the New Zealand hepialid moths was estimated from a cladistic analysis of sixty‐three morphological characters, from all life cycle stages. One hundred and sixteen maximum parsimony trees were produced. The phylogenetic reconstruction indicated that the currently recognized generic concepts, and the four informal lineages hypothesized in a previous morphological taxonomic revision, were monophyletic. The relationships of species within genus Wiseana were not fully resolved. Analysis of a data set of thirty‐nine adult male characters from the New Zealand taxa and the Australian genera Jeana, Oxycanus and Trictena supported the monophyly of the New Zealand ‘Oxycanus’ s.s lineage.     

Constraints and selection: insights from microsporogenesis in Asparagales

Developmental constraints have been proposed to interfere with natural selection in limiting the available set of potential adaptations. Whereas this concept has long been debated on theoretical grounds, it has been investigated empirically only in a few studies. In this article, we evaluate the importance of developmental constraints during microsporogenesis (male meiosis in plants), with an emphasis on phylogenetic patterns in Asparagales. Different developmental constraints were tested by character reshuffling or by simulated distributions. Among the different characteristics of microsporogenesis, only cell wall formation appeared as constrained. We show that constraints may also result from biases in the correlated occurrence of developmental steps (e.g., lack of successive cytokinesis when wall formation is centripetal). We document such biases and their potential outcomes, notably the establishment of intermediate stages, which allow development to bypass such constraints. These insights are discussed with regard to potential selection on pollen morphology.     

Generic interrelationships of theCardueae (Compositae): A cladistic analysis of morphological data

A cladistic analysis of 45 genera ofCardueae for 75 characters is presented, taking into account characters of bracts, corolla, stamens, styles and cypselas. Forty-six binary characters completeBremer's (1994) work. Some of the characters considered byBremer are criticised. The traditionalCarlininae is a paraphyletic group, the ten genera studied sharing no common derived character. A new classification of theCardueae is proposed and the distribution of the tribe is presented. Several new combinations are proposed. The nomenclature ofCentaurea is discussed and the status of the genusSerratula is analysed.     

Homo floresiensis: a cladistic analysis

The announcement of a new species, Homo floresiensis, a primitive hominin that survived until relatively recent times is an enormous challenge to paradigms of human evolution. Until this announcement, the dominant paradigm stipulated that: 1) only more derived hominins had emerged from Africa, and 2) H. sapiens was the only hominin since the demise of Homo erectus and Homo neanderthalensis. Resistance to H. floresiensis has been intense, and debate centers on two sets of competing hypotheses: 1) that it is a primitive hominin, and 2) that it is a modern human, either a pygmoid form or a pathological individual. Despite a range of analytical techniques having been applied to the question, no resolution has been reached. Here, we use cladistic analysis, a tool that has not, until now, been applied to the problem, to establish the phylogenetic position of the species. Our results produce two equally parsimonious phylogenetic trees. The first suggests that H. floresiensis is an early hominin that emerged after Homo rudolfensis (1.86 Ma) but before H. habilis (1.66 Ma, or after 1.9 Ma if the earlier chronology for H. habilis is retained). The second tree indicates H. floresiensis branched after Homo habilis.     

The vertebrate social behavior network: evolutionary themes and variations

Based on a wide variety of data, it is now clear that birds and teleost (bony) fish possess a core "social behavior network" within the basal forebrain and midbrain that is homologous to the social behavior network of mammals. The nodes of this network are reciprocally connected, contain receptors for sex steroid hormones, and are involved in multiple forms of social behavior. Other hodological features and neuropeptide distributions are likewise very similar across taxa. This evolutionary conservation represents a boon for experiments on phenotypic behavioral variation, as the extraordinary social diversity of teleost fish and songbirds can now be used to generate broadly relevant insights into issues of brain function that are not particularly tractable in other vertebrate groups. Two such lines of research are presented here, each of which addresses functional variation within the network as it relates to divergent patterns of social behavior. In the first set of experiments, we have used a sexually polymorphic fish to demonstrate that natural selection can operate independently on hypothalamic neuroendocrine functions that are relevant for (1) gonadal regulation and (2) sex-typical behavioral modulation. In the second set of experiments, we have exploited the diversity of avian social organizations and ecologies to isolate species-typical group size as a quasi-independent variable. These experiments have shown that specific areas and peptidergic components of the social behavior network possess functional properties that evolve in parallel with divergence and convergence in sociality.     

The nature of the ancestral red alga: inferences from a cladistic analysis

A cladistic analysis of the orders of Rhodophyta is presented. Sixteen taxa and 34 characters comprise the data matrix. Included in the analysis are biochemical and ultrastructural features of pigments, cell walls, cell organelles, mitosis and pit connections as well as vegetative and reproductive characters. The traditional recognition of two classes or subclasses, Bangiophycidae and Florideophycidae, is not supported regardless of whether Porphyridiales, Rhodochaetales or Bangiales is designated the outgroup. Florideophycidae, however, appears to be monophyletic with Bangiales as its sister group. Relationships among taxa with one or two plug cap layers, i.e. Acrochaetiales, Palmariales, Corallinales, Nemaliales, Batrachospermales, Gelidiales and Hildenbrandiales are unresolved. Rhodochaetales, Bangiales and possibly Erythropeltidales are monophyletic, but Porphyridiales is polyphyletic. The class Cyanidiophyceae is not recognized and the included genera are considered to be unicellular red algae belonging to Porphyridiales. Taxa that have been proposed as sister groups for red algae, including Cyanobacteria, Cryptophyta, Glaucophyta and Chlorophyta, and Ascomycetes and Basidiomycetes are discussed in relation to the proposed phylogeny of Rhodophyta.     

Unique and conserved features of floral evocation in legumes

Legumes, with their unique ability to fix atmospheric nitrogen, play a vital role in ensuring future food security and mitigating the effects of climate change because they use less fossil energy and produce less greenhouse gases compared with N-fertilized systems. Grain legumes are second only to cereal crops as a source of human and animal food, and they contribute approximately one third of the protein consumed by the human population. The productivity of seed crops, such as grain legumes, is dependent on flowering. Despite the genetic variation and importance of flowering in legume production, studies of the molecular pathways that control flowering in legumes are limited.Recent advances in genomics have revealed that legume flowering pathways are divergent from those of such model species as Arabidopsis thaliana. Here, we discuss the current understanding of flowering time regulation in legumes and highlight the unique and conserved features of floral evocation in legumes.     

Staminodes: Their morphological and evolutionary significance

Different approaches to circumscribe staminodial structures in the angiosperms are reviewed. The need for a morphological distinction between “true staminodes” (derived from stamens or homologous to stamens) and “pseudostaminodes” (nonhomologous to stamens) is emphasized. In phylogenetic studies the term “staminode” is often used uncritically, without knowledge of the true homology of these structures. Staminodes are either whole organs (outer tiers or whorls, namely petals, intermediate tiers, or organs within a tier), or partial organs. This article aims to discuss the shortcomings of the past and current approach of staminodes and proposes definitions of staminode types for use as characters in phylogenetic analyses. Staminodial structures should be classified according to their position and function in the flower. Both aspects are intricately linked and make the identification of staminodes sometimes problematic. Shifts in time (heterochrony) and space (heterotopy or homeosis) make that a regressing organ either aborts completely or becomes remodeled into something new. Petals are included in the definition of staminodes as they combine function and heterotopy. A hierarchical ordering of staminodial types is given and discussed. Three interdependent but possibly complementary functions are attached to the occurrence of staminodes: an attractive, nutritional, and structural function. The importance of staminodes for the evolution of the androecium and flower is demonstrated. The difficulty in unmasking pseudostaminodes, comprising receptacular disks, is demonstrated. The value and shortcomings of molecular-based interpretations of staminodes are discussed. It is shown that the decision to recognize a staminode from receptacular emergences often relies on unstable grounds and remains largely dependent on the acceptance of a given phylogenetic background.     

The Cambrian evolutionary 'explosion': decoupling cladogenesis from morphological disparity

The origin and differentiation of major clades is often assumed to have occurred in tandem with the 'explosion' of fossil evidence of diverse morphologies ('disparity') at the base of the Cambrian. Evidence is presented that this was not the case. Biogeographical and morphological differentiation among the earliest trilobites reveals incompleteness in the known early Cambrian record; similar evidence can be accrued for other major groups. Phylogenetic analysis proves the likelihood of 'ghost' lineages extending into the Precambrian. The important events in the generation of clades were earlier than the Cambrian 'explosion', at which time the groups become manifest in the fossil record. It is likely that the important phylogenetic changes happened in animals of small size; sister taxa of major groups are shown to be small animals. Decoupling cladogenesis from the Cambrian 'explosion' removes the necessity of invoking unknown evolutionary mechanisms at the base of the Phanerozoic. Genes controlling development may have played a role in generating new morphologies, through heterochrony for example, in the early differentiation of metazoan body plans.     

Spermatozoa of murid rodents from Africa: morphological diversity and evolutionary trends

The diversity of the structural organization of the spermatozoa of African murid rodents is described at the light and transmission electron microscopical level of resolution. In most species the sperm head is falciform in shape but it varies somewhat in overall breadth, width, and length. A typical perforatorium is present and the acrosome splits into a large head cap over the convex surface and a smaller ventral segment similar to the sperm head of most Asian and Australasian murids. In a few species, however, the morphology is very different. In Acomys and Uranomys spermatozoa, the apical hook is more bilaterally flattened, has a large apical acrosomal region, and no separate ventral segment. Two species of Aethomys have, in addition to an apical hook, a 4μ long extension of the cytoskeletal material that projects from the concave surface of the sperm head, whereas in Dasymys two large ventral processes extend from the upper concave region which contain nuclear material basally and a huge extension of cytoskeleton apically. In Aethomys chrysophilus type B, the sperm nucleus is unique in form and often has a central region in which threads of chromatin can be seen; it is capped by a massive acrosome whose apical segment is complex and convoluted in structure. Stochomys longicaudatus appears to have a conical sperm head, and in all three Lophuromys species the sperm head is spatulate in shape with the flat, plate-like nucleus capped by a thin acrosome. The evolutionary trends in changes of sperm head shape and design of these rodents are discussed. It is suggested that some of the differences in morphology may relate to the variation in structural organization of the coats around the egg through which the spermatozoon has to pass in order for fertilization to occur.     

A new genus of Paramacronychiinae (Diptera: Sarcophagidae), argued from a genus-level cladistic analysis

Primorya gen.n. is described as a new genus of the flesh fly subfamily Paramacronychiinae, including the type species and sole member Primorya ussuriensis sp.n. from the Russian Far East. Arguments for erecting a new genus are obtained from a phylogenetic analysis of all paramacronychiine genera. Goniophyto suenagai (Kurahashi), comb.n. is transferred from Wohlfahrtiodes Villeneuve and included in a broadened concept of Goniophyto Townsend, and Agria cicadina (Kato) , comb.n. is transferred from Angiometopa Brauer & Bergenstamm. A key to all paramacronychiine genera is provided.     

Visualization of elusive structures using intracardiac echocardiography: Insights from electrophysiology

Echocardiography has the ability to noninvasively explore hemodynamic variables during pharmacologic or exercise stress test in patients with heart failure. In this review, we detail some important potential applications of stress echocardiography in patients with heart failure. In patients with coronary artery disease and chronic LV dysfunction, dobutamine stress echocardiography is able to distinguish between viable and fibrotic tissue to make adequate clinical decisions. Exercise testing, in combination with echocardiographic monitoring, is a method of obtaining accurate information in the assessment of functional capacity and prognosis. Functional mitral regurgitation is a common finding in patients with dilated and ischaemic cardiomyopathy and stress echocardiography in the form of exercise or pharmacologic protocols can be useful to evaluate the behaviour of mitral regurgitation. It is clinical useful to search the presence of contractile reserve in non ischemic dilated cardiomyopathy such as to screen or monitor the presence of latent myocardial dysfunction in patients who had exposure to cardiotoxic agents. Moreover, in patients with suspected diastolic heart failure and normal systolic function, exercise echocardiography could be able to demonstrate the existence of such dysfunction and determine that it is sufficient to limit exercise tolerance. Finally, in the aortic stenosis dobutamine echocardiography can distinguish severe from non-severe stenosis in patients with low transvalvular gradients and depressed left ventricular function.