There are currently 0 users and 310 guests online.
Wiley Online Library : Cladistics
Last update1 hour 59 min ago
February 7, 2014
Phylogeny of the family Sialidae (Insecta: Megaloptera) inferred from morphological data, with implications for generic classification and historical biogeography
Sialidae (alderflies) is a family of the holometabolous insect order Megaloptera, with ca. 75 extant species in eight genera distributed worldwide. Alderflies are a group of “living fossils” with a long evolutionary history. The oldest fossil attributed to Sialidae dates back to the Early Jurassic period. Further, the global distribution of modern-day species shows a remarkably disjunctive pattern. However, due to the rareness of most species and scarcity of comprehensive taxonomic revisions, the phylogeny of Sialidae remains largely unexplored, and the present classification system is in great need of renewal. Here we reconstruct the first phylogeny for Sialidae worldwide based on the most comprehensive sampling and broadest morphological data ever presented for this group of insects. All Cenozoic alderflies belong to a monophyletic clade, which may also include the Early Jurassic genus †Dobbertinia, and the Late Jurassic genus †Sharasialis is their putative sister taxon. Two subfamilies of Sialidae are proposed, namely †Sharasialinae subfam. nov. and Sialidinae. Austrosialis is the sister of all other extant genera, an assemblage which comprises three monophyletic lineages: the Stenosialis lineage, the Ilyobius lineage, and the Sialis lineage. The revised classification of Sialidae is composed of 12 valid genera and 87 valid species. Ilyobius and Protosialis are recognized as valid generic names, while Nipponosialis is treated as a synonym of Sialis. Reconstruction of the ancestral area proposes a global distribution of alderflies in Pangaea before their diversification. The generic diversification of alderflies might have occurred before the breakup of Pangaea, but the divergence of some lineages or genera was probably promoted by the splitting of this supercontinent.
February 4, 2014
Evidence for Eurogondwana: the roles of dispersal, extinction and vicariance in the evolution and biogeography of Indo-Pacific Hormuridae (Scorpiones: Scorpionoidea)
Scorpions previously assigned to the genus Liocheles Sundevall, 1883, of the family Hormuridae Laurie, 1896, are widely distributed in the tropical forests of the Indo-Pacific region. Revisionary systematics of these poorly known scorpions has revealed a tremendous diversity of species. As part of an ongoing investigation, the first analysis of Indo-Pacific hormurid scorpion phylogeny based on morphological data scored for all currently recognized species of Hormiops Fage, , Hormurus Thorell, 1876, and Liocheles, is presented. The taxonomy of these scorpions is reassessed and their biogeography reinterpreted in the light of the phylogeny. Phylogenetic, morphological, and distributional data support the revalidation of Hormiops and Hormurus, previously synonymized with Liocheles. The phylogeny indicates that the Australasian hormurids are more closely related to the Afrotropical and Neotropical hormurids than to the Indian hormurids, as previously proposed, refuting the “out-of-India” origin of Asian hormurids. A recent paleogeographical hypothesis, the “Eurogondwana model”, is supported instead. According to this hypothesis, hormurid scorpions colonized Laurasia from Africa via the Apulia microplate (Europa terrane) in the Cretaceous, subsequently colonized the Australo-Papuan archipelago in the early-mid Cenozoic, and then went extinct in the Northern Hemisphere during the second half of the Cenozoic. These results suggest that, contrary to the traditional paradigm, dispersal and extinction may affect spatial and temporal biotic distributions as much as vicariance, even in animals with limited vagility, such as scorpions.
January 29, 2014
The Hymenoptera constitutes one of the largest, and ecologically and economically most important, insect orders. During the past decade, a number of hypotheses on the phylogenetic relationships among hymenopteran families and superfamilies have been presented, based on analyses of molecular and/or morphological data. Nevertheless, many questions still remain, particularly concerning relationships within the hyperdiverse suborder Apocrita, but also when it comes to the evolutionary history of the ancestrally herbivorous “sawfly” lineages that form the basal, paraphyletic grade Symphyta. Because a large part of the uncertainty appears to stem from limited molecular and taxonomic sampling, we set out to investigate the phylogeny of Hymenoptera using nine protein-coding genes, of which five are new to analyses of the order. In addition, we more than tripled the taxon coverage across the symphytan grade, introducing representatives for many previously unsampled lineages. We recover a well supported phylogenetic structure for these early herbivorous hymenopteran clades, with new information regarding the monophyly of Xyelidae, the placement of the superfamily Pamphilioidea as sister to Tenthredinoidea + Unicalcarida, as well as the interrelationships among the tenthredinoid families Tenthredinidae, Cimbicidae, and Diprionidae. Based on the obtained phylogenies, and to prevent paraphyly of Tenthredinidae, we propose erection of the tribe Heptamelini to family status (Heptamelidae). In particular, our results give new insights into subfamilial relationships within the Tenthredinidae and other species-rich sawfly families. The expanded gene set provides a useful toolbox for future detailed analyses of symphytan subgroups, especially within the diverse superfamily Tenthredinoidea.
January 27, 2014
The thorax of Mantophasmatodea, the morphology of flightlessness, and the evolution of the neopteran insects
Mantophasmatodea was described as a new insect order in 2002. Since then, this small group of wingless insects has developed into one of the best investigated insect taxa. Nevertheless, many aspects of mantophasmatodean morphology as well as their evolutionary relationships remain ambiguous. To determine the phylogenetic relationships of Mantophasmatodea based on an extended character set and to elucidate possible morphological adaptions towards flightlessness, we investigated the thoracic morphology of two species, Austrophasma caledonensis and Mantophasma sp. The morphological similarity between these two species is striking and no differences in musculature were found. The mantophasmatodean thorax strongly resembles that of ice crawlers (Grylloblattodea), especially with respect to the presence of pleural processes in the meso- and metathorax, branched furcae in all segments, and similar muscle equipment. In a cladistic analysis containing all major lineages of Neoptera, the monophyly of Polyneoptera is supported by the presence of an anal fan and several modifications of the wing joint. Within Polyneoptera, a sister-group relationship between stoneflies and the remaining Polyneoptera is supported. A clade comprising Mantophasmatodea and the Grylloblattodea gains strong support from thoracic morphology and can be considered assured. Potential thoracic apomorphies include prothoracic paracoxal invaginations, pterothoracic pleural arms that originate from the epimeron, and a unique metathoracic sterno-coxal musculature. The monophyly of Orthoptera and Dictyoptera is further supported while the deeper polyneopteran nodes remain unresolved. Among the wingless taxa investigated we found few general morphological adaptations whereas, in other aspects, especially in the musculature, strong differences could be observed. However, much more research on the strongly neglected topic of flightlessness is required to make reliable statements.
Hennig () recognized symplesiomorphies as homologies, and that view is logically correct under the concept of homology (homogeny) prevalent among evolutionists since 1870. Nelson and Platnick () instead wanted homology to exclude symplesiomorphies for reasons that they never made clear but which certainly included opposition to Hennig. They and some of their followers, most recently Platnick () and Brower and de Pinna (), have continued to advocate that anti-Hennigian position, often under the slogan “homology equals synapomorphy,” while ironically passing themselves off as cladists and often using ambiguous or falsified citations to pretend that legitimate phylogeneticists think likewise. Such authors have seldom shown much concern for accuracy or logic, with the result that a great deal of print has been wasted. Those problems can be avoided simply by maintaining a Hennigian view and so discarding the purported equivalence of homology and synapomorphy.
January 1, 2014
Phylogeny of harvestmen family Gonyleptidae inferred from a multilocus approach (Arachnida: Opiliones)
Gonyleptidae is the second most diverse harvestmen family and the most studied in terms of morphology, behaviour, and ecology. Despite this, few phylogenetic studies have focused on gonyleptids, and those are based on a very limited number of taxa. We addressed this gap by constructing a phylogenetic hypothesis of the family using 101 taxa from all 16 gonyleptid subfamilies and four mitochondrial and nuclear loci (COI, 28S rRNA, 12S rRNA, and 16S rRNA). These were analysed under parsimony and likelihood optimality criteria (and using direct optimization for the former). Relationships among Gonyleptoidea and within each subfamily of Gonyleptidae were largely congruent between parsimony and maximum-likelihood approaches. Taxonomic actions from our phylogeny include the following: Tricommatidae, new status, is restored as a family; Metasarcidae, new status, is recognized as a family and considered sister to the Cosmetidae; and Cranainae and Manaosbiinae are suggested as members of Gonyleptidae, restoring Roewer's concept of the family. Within Gonyleptidae, the “K92” group—composed of Sodreaninae, Caelopyginae, Hernandariinae, Progonyleptoidellinae, and Gonyleptinae—forms a clade, although the latter two subfamilies are not monophyletic. The genus Parampheres is here transferred to Caelopyginae, and “Multumbo” dimorphicus to Gonyleptinae. Gonyleptidae is characterized by the presence of a ventral process on the penis glans and a bifid apophysis on the male coxa IV. The long-legged Mitobatinae can be considered monophyletic only if some short-legged pachylines are included, or if we assume that elongate legs arose twice independently (in the true mitobatine genera and in Longiperna). Pachylinae, the most diverse gonyleptid subfamily, represents several distinct lineages. We further conclude that the traditional use of a small set of morphological characters in the systematics of Gonyleptidae is unable to explain the complex evolution of the family.
December 19, 2013
Relationships among the major branches of moss phylogeny are understudied compared with other major land-plant groups. We addressed this by surveying 14–17 plastid genes from taxa representing the major lineages, using different phylogenetic methods (parsimony, likelihood) and codon- and gene-based data partitioning schemes (likelihood). Our phylogenetic inferences generally corroborated the best supported clades across multiple recent studies, with comparable or higher levels of clade support here. We resolved persistent ambiguities with strong to moderate support across analyses, including several early nodes in subclass Dicranidae, and relationships among other subclasses of peristomate mosses. In particular, we resolved a sister-group relationship between Bryidae and Dicranidae, between these subclasses and Timiidae, and between this entire clade and Funariidae. We consistently recovered Tetraphidopsida (a nematodontous class) as the sister group of arthrodontous mosses (Bryopsida), although with only weak support. Strongly conflicting arrangements at the base of moss phylogeny concerning Takakiopsida and Sphagnopsida, two non-peristomate moss lineages, were inferred in parsimony and likelihood analysis, but this depended on how base-frequency parameters were estimated and how data were partitioned in likelihood analysis. Relationships inferred for the remaining peristomate and non-peristomate moss clades, and their associated support values, were otherwise broadly congruent across analyses.
The Barcode of Life
The Genealogical World of Phylogenetic Networks
BMC Evolutionary Biology
Molecular Biology and Evolution