The Experts below are selected from a list of 12837 Experts worldwide ranked by ideXlab platform
Kazunori Yoshizawa - One of the best experts on this subject based on the ideXlab platform.
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The Zoraptera problem : evidence for Zoraptera + Embiodea from the wing base
Systematic Entomology, 2020Co-Authors: Kazunori YoshizawaAbstract:The order Zoraptera is one of the most enigmatic insect groups. Its phylogenetic position is far from settled, and more than ten different placements have been discussed since the insects were first discovered. This problem is also difficult to resolve with molecular studies because of the unusual characteristics of zorapteran 18S rDNA sequences, which are the most widely used genetic markers for the estimation of the deep phylogeny of insects. In this study, the wing base structures of Zoraptera and various potential sister taxa were examined. Numbers of unique modifications were detected in the wing base structure of Zoraptera, and six were also observed in the wing base of Embiodea (Embioptera, Embiidina; webspinners). No possible synapomorphies supporting the other relationships were detected. This is the second unambiguous morphological Synapomorphy providing strong evidence for the phylogenetic position of Zoraptera.
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Morphological dissection of behavior: thoracic musculature clarifies independent development of jumping mechanisms between sister groups, planthoppers and leafhoppers (Insecta: Hemiptera: Auchenorrhyncha)
Organisms Diversity & Evolution, 2017Co-Authors: Naoki Ogawa, Kazunori YoshizawaAbstract:Morphological and behavioral characters are frequently examined for comparative studies. Unlike morphology, a single behavioral trait is difficult to subdivide as multiple characters, even when achieved by many evolutionary changes. Therefore, when similar behavioral traits evolved independently among closely related taxa, their distinction is difficult. Almost all members of the suborder Auchenorrhyncha (Insecta: Hemiptera) possess a jumping ability that uses metathoracic muscles, and this behavioral trait has been regarded as a Synapomorphy. In this study, the anatomical observations of metathoracic muscles revealed that highly elaborated jumping ability was gained independently within the suborder, although the evolution of jumping ability might have been initiated at their common ancestor. Our results provide an example of identifying a true evolutionary pathway by dissecting a behavioral character into mechanical elements.
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the zoraptera problem evidence for zoraptera embiodea from the wing base
Systematic Entomology, 2007Co-Authors: Kazunori YoshizawaAbstract:The order Zoraptera is one of the most enigmatic insect groups. Its phylogenetic position is far from settled, and more than ten different placements have been discussed since the insects were first discovered. This problem is also difficult to resolve with molecular studies because of the unusual characteristics of zorapteran 18S rDNA sequences, which are the most widely used genetic markers for the estimation of the deep phylogeny of insects. In this study, the wing base structures of Zoraptera and various potential sister taxa were examined. Numbers of unique modifications were detected in the wing base structure of Zoraptera, and six were also observed in the wing base of Embiodea (Embioptera, Embiidina; webspinners). No possible synapomorphies supporting the other relationships were detected. This is the second unambiguous morphological Synapomorphy providing strong evidence for the phylogenetic position of Zoraptera.
Stefan Richter - One of the best experts on this subject based on the ideXlab platform.
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homology and Synapomorphy symplesiomorphy neither synonymous nor equivalent but different perspectives on the same phenomenon
Cladistics, 2017Co-Authors: Stefan RichterAbstract:In a recent debate, either Synapomorphy and symplesiomorphy or only Synapomorphy have been claimed to be synonymous or equivalent to homology. In my view, exactly the same relationship exists between homology supported by a congruence test on the one hand and Synapomorphy as well as symplesiomorphy on the other hand. Both conditions become established at the same time with the process of rooting of an unrooted topology. I, however, do not consider the concept of homology equal or synonymous to that of Synapomorphy and symplesiomorphy. In my view, they represent different perspectives on the same phenomenon, i.e. correspondence by common origin. Homology has no implication on the direction of transformation, whereas symplesiomorphy as “primitive” condition and Synapomorphy as “derived” condition refer directly to phylogenesis, the real historical evolutionary process of speciation and transformation. In addition, Synapomorphy and symplesiomorphy might also refer to a character state that refers to the absence of a structure/organ, which creates problems with traditional homology concepts. Hennig's terms Synapomorphy and symplesiomorphy are necessary and sufficient for the evolutionary interpretation of character states. For what is corroborated in an unrooted topology as the result of a congruence test, I suggest as a new term “synmorphy” because it can well be applied also to those characters where one state represents the absence of a structure/organ. The place for homology in morphological cladistics, however, is restricted to the characterization of the relationship between different character states of one transformation series (i.e. character).
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Homology and Synapomorphy‐symplesiomorphy—neither synonymous nor equivalent but different perspectives on the same phenomenon
Cladistics, 2016Co-Authors: Stefan RichterAbstract:In a recent debate, either Synapomorphy and symplesiomorphy or only Synapomorphy have been claimed to be synonymous or equivalent to homology. In my view, exactly the same relationship exists between homology supported by a congruence test on the one hand and Synapomorphy as well as symplesiomorphy on the other hand. Both conditions become established at the same time with the process of rooting of an unrooted topology. I, however, do not consider the concept of homology equal or synonymous to that of Synapomorphy and symplesiomorphy. In my view, they represent different perspectives on the same phenomenon, i.e. correspondence by common origin. Homology has no implication on the direction of transformation, whereas symplesiomorphy as “primitive” condition and Synapomorphy as “derived” condition refer directly to phylogenesis, the real historical evolutionary process of speciation and transformation. In addition, Synapomorphy and symplesiomorphy might also refer to a character state that refers to the absence of a structure/organ, which creates problems with traditional homology concepts. Hennig's terms Synapomorphy and symplesiomorphy are necessary and sufficient for the evolutionary interpretation of character states. For what is corroborated in an unrooted topology as the result of a congruence test, I suggest as a new term “synmorphy” because it can well be applied also to those characters where one state represents the absence of a structure/organ. The place for homology in morphological cladistics, however, is restricted to the characterization of the relationship between different character states of one transformation series (i.e. character).
Robin J Tausch - One of the best experts on this subject based on the ideXlab platform.
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relative apparent Synapomorphy analysis rasa i the statistical measurement of phylogenetic signal
Molecular Biology and Evolution, 1996Co-Authors: James Lyonsweiler, Guy A Hoelzer, Robin J TauschAbstract:: We have developed a new approach to the measurement of phylogenetic signal in character state matrices called relative apparent Synapomorphy analysis (RASA). RASA provides a deterministic, statistical measure of natural cladistic hierarchy (phylogenetic signal) in character state matrices. The method works by determining whether a measure of the rate of increase of cladistic similarity among pairs of taxa as a function of phenetic similarity is greater than a null equiprobable rate of increase. Our investigation of the utility and limitations of RASA using simulated and bacteriophage T7 data sets indicates that the method has numerous advantages over existing measures of signal. A first advantage is computational efficiency. A second advantage is that RASA employs known methods of statistical inference, providing measurable sensitivity and power. The performance of RASA is examined under various conditions of branching evolution as the number of characters, character states per character, and mutations per branch length are varied. RASA appears to provide an unbiased and reliable measure of phylogenetic signal, and the general approach promises to be useful in the development of new techniques that should increase the rigor and reliability of phylogenetic estimates.
François-xavier Gauffre - One of the best experts on this subject based on the ideXlab platform.
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The prosauropod dinosaur Azendohsaurus laaroussii from the Upper Triassic of Morocco
Palaeontology, 1993Co-Authors: François-xavier GauffreAbstract:Azendohsaurus laaroussii was described by Dutuit as an ornithischian dinosaur on the basis of a dentary fragment and two isolated teeth from the Upper Triassic Argana Formation of Morocco. It was subsequently suggested to be a mixture of ornithischian and saurischian remains. Study of further material demonstrates that all the A. laaroussii material represents a single valid taxon within the Prosauropoda. A. laaroussii derives from the Paleorhinusbiochron and is hence Carnian in age. Some apomorphic characters attributed to the Ornithischia by Sereno and to the Sauropodomorpha by Gauthier are shown to be invalid. A new Synapomorphy of the Prosauropoda is proposed, based on the construction of the maxillary. -from Author
Samuel S Bowser - One of the best experts on this subject based on the ideXlab platform.
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predicted secondary structure of the foraminiferal ssu 3 major domain reveals a molecular Synapomorphy for granuloreticulosean protists
Journal of Eukaryotic Microbiology, 2004Co-Authors: Andrea Habura, Daniel R Rosen, Samuel S BowserAbstract:The small subunit ribosomal RNA genes of foraminiferal protists are the largest and most divergent of any eukaryote. We demonstrate that this foraminiferal sequence alteration represents a substantial modification to the small subunit ribosomal RNA structure, including a large (up to 350 nt) novel helix in a very well-conserved portion of the head domain. This modification dates from the beginning of the foraminiferal radiation and, within modern orders, is partially conserved at the sequence level, suggesting that it is a functional part of the ribosome. The pattern of conservation makes it particularly useful for determining lower-taxon relationships in morphologically ambiguous allogromiid foraminifera.
