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Evaluation of the taxonomic status of Amata wilemani Rothschild, 1911 (Lepidoptera: Erebidae, Arctiinae, Syntomini), a highly variable species, using molecular sequence dataLiu, Yao-Hung 19 July 2011 (has links)
The morphological phenotypic characters involving sexual selection but with highly individual variability are likely to challenge the prezygotic isolating mechanism driven by differentiation of mechanical structures. This kind of characters may also puzzle species identification and taxonomy. Therefore clarifying the correlation between the phenotypic variability and biological/non-biological factors becomes necessary in order to understand the role of this phenomenon under natural selection and sexual selection. The Syntomini represents one of the few lepidopterous groups that exhibit highly individual variability in both wing pattern and reproductive structures. The evolutionary and taxonomic significance of this phenomenon, however, has never been studied using modern methods although it has been documented for long. In order to test several hypotheses relevant to phenotypic variability, the present study focuses the phylogenetic relationship of Amata wilemani Rothschild, 1914, a subalpine moth species with extremely high variability in wing coloration and genitalia. The phylogenetic relationship between the three color morphs of A. wilemani and 38 Syntomini species plus 2 Lithosiinae outgroups was reconstructed using fragments of COI, EF1a and 28S. All color morphs of A. wilemani were recovered to form a monophyletic group under all data partitioning strategies with Amata formosensis (Wileman, 1928) or its closely related species in China as the potential sister group. The result of gene network analysis suggests low divergence between haplotypes of A. wilemani. Because no correlation between color morphs, phenology, geographical distribution, altitudinal gradient, and genitalic morphlogy was detected, it is concluded that A. wilemani should be regarded as a single species with high phenotypic variability, and this may suggest existence of intraspecific competition. The present study also found that Amata karapinensis (Strand, 1915), which was synonymized with A. wilemani by previous authors, should be revived. The incongruence between the phylogenetic relationships based on morphological and molecular characters shows a need of a comprehensive phylogenetic study of this highly diverse group.
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Jag trivs bäst när havet svallar, och måsarna ger skri : En textanalytisk studie av biologisk mångfald i läroböckerGranquist, Anna, Mårdfjäll, Eva January 2007 (has links)
<p>Biological diversity is one out of four dimensions, characterizing the subject of Biology ac-cording to the school curriculum. As a concept, biological diversity had its break through at the UN environmental conference in Rio de Janeiro in 1992, where the convention about bio-logical diversity, named CBD, was signed. According to the convention, almost all the na-tions of the world have engaged themselves to preserve the national diversity of species, in-cluding the diversity of genetics and ecological systems.</p><p>This thesis focuses the biological diversity from the perspective of school books. The aim is to find out how the biological diversity is presented in biology books for students aged 12-15 years.</p><p>In 1994, the current Swedish secondary and high school curriculum called LPO-94 was pre-sented. The biology books used in this study were published between 1994 and 2007, all of them exist in many editions and are published by three different publishers.</p><p>The conclusion of the study is that all the biology books that were examined have reached different levels of the development in the field of biological diversity.</p>
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Jag trivs bäst när havet svallar, och måsarna ger skri : En textanalytisk studie av biologisk mångfald i läroböckerGranquist, Anna, Mårdfjäll, Eva January 2007 (has links)
Biological diversity is one out of four dimensions, characterizing the subject of Biology ac-cording to the school curriculum. As a concept, biological diversity had its break through at the UN environmental conference in Rio de Janeiro in 1992, where the convention about bio-logical diversity, named CBD, was signed. According to the convention, almost all the na-tions of the world have engaged themselves to preserve the national diversity of species, in-cluding the diversity of genetics and ecological systems. This thesis focuses the biological diversity from the perspective of school books. The aim is to find out how the biological diversity is presented in biology books for students aged 12-15 years. In 1994, the current Swedish secondary and high school curriculum called LPO-94 was pre-sented. The biology books used in this study were published between 1994 and 2007, all of them exist in many editions and are published by three different publishers. The conclusion of the study is that all the biology books that were examined have reached different levels of the development in the field of biological diversity.
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Molekulární variabilita a rozšíření druhového komplexu Frustulia rhomboides (Bacillariophyceae) / Molecular variability and distribution of the Frustulia rhomboides species complex (Bacillariophyceae)Urbánková, Pavla January 2011 (has links)
Recent use of molecular methods to revisit taxonomically problematic diatom species revealed severe limitations of morphological species concept. Characterization of diatom species which was based solely on the morphology of their frustules often generated too broad species boundaries which inevitably lead to wrong conclusions about their ecology and distribution. Widespread opinion that many diatom species are cosmopolitan generalists resulted in a theory that dispersal of diatoms is not limited by geographical distance. However, a number of recent studies showed that dispersal of diatoms is governed by the same rules which matter for macroorganisms. Proposed master thesis addresses the topic of diversity and dispersal in diatom species complex Frustulia rhomboides sensu lato in Europe and New Zealand. Results suggest that: (1) although revealed molecular variability in this complex shows clear ecological and biogeographical signal, it is not correlated in morphology. This is another support to general need for adoption of different species concept in diatoms. (2) A considerably uneven ratio in species diversity of genus Frustulia found in ecological similar habitats in Europe and New Zealand supports the idea that diatom dispersal is limited and stressed the need for studies dealing with biogeography.
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Dissection of fertility barriers among lineages of Gibberella zeaeFuentes-Bueno, Irazema January 1900 (has links)
Master of Science / Department of Plant Pathology / Robert L. Bowden / John F. Leslie / Fusarium graminearum Schwabe sensu lato (teleomorph: Gibberella zeae (Schwein.) Petch), a homothallic ascomycete fungus, is the causal agent of Fusarium head blight (FHB) of wheat (Triticum aestivum L.), barley (Hordeum vulgare L.), and other small grains. FHB occurs worldwide and serious outbreaks have been reported in North America, South America, Asia, and Europe. According to the phylogenetic species concept (PSC), F. graminearum is composed of at least 15 phylogenetic lineages known as the Fusarium graminearum species complex.
Although F. graminearum is homothallic, some members of different phylogenetic lineages are known to intercross in the laboratory. It has been suggested that F. graminearum sensu lato fits the biological species concept (BSC). According to the BSC, “species are groups of actually or potentially interbreeding natural populations, which are reproductively isolated from other such groups”. Previous reports of intercrossing were qualitative, so the degree of reproductive isolation, if any, is not clear. Since intrinsic reproductive isolation is the key criterion to identify species by the BSC, more detailed quantitative information is needed.
Chromosome rearrangements between fungal strains may reduce fertility in sexual crosses through the production of genetically inviable recombinant progeny. As such, rearrangements can be important postzygotic reproductive barriers between species. Following methods used in Neurospora crassa, ascospore tetrads were analyzed for patterns of ascospore viability. Crosses were made with three lineage 7 (F. graminearum sensu stricto according to PSC) strains as female. Each female was a MAT1-2 knockout mutant that rendered it obligately heterothallic. Males were several members of lineages 6 (F. asiaticum according to PSC) and lineage 7. Crosses with lineage 7 males formed complete asci with 8 ascospores indicating that their genomes are isosequential with the testers. Crosses with one strain from lineage 6 with two known inversions produced asci containing 8, 6, and 4 ascospores, consistent with it not being isosequential. However, three other strains of lineage 6 appeared to be isosequential with the testers. Therefore, chromosome rearrangements did not appear to be common to strains of lineage 6 and probably do not contribute significantly to reproductive isolation of lineage 6 and lineage 7.
Interlineage fertility studies with the three lineage 7 tester strains were performed to quantify interlineage fertility parameters including the total number of ascospores produced, perithecial density, and perithecium internal development scores. All lineage 7 female testers successfully crossed to all 23 male strains from lineages 1 to 9. For total ascospore production, one female tester crossed equally well with all lineages and the other two testers showed statistically significant differences for a few lineages. For perithecial density, there was a significantly lower density with all three testers when crossed with lineage 6, but the other lineages were not statistically different from lineage 7. For perithecial development, there was large variation for every lineage. Therefore, in the crosses with reduced fertility, the reduction can be attributed to a postzygotic effect since mature perithecia and asci developed.
All of the tested lineages of the Fusarium graminearum species complex can produce viable progeny with F. graminearum lineage 7, which was the taxonomic type of the original species before it was split into phylogenetic species. There are a few examples of reduced fertility with two lineage 7 testers, the remaining tester crossed equally well with all lineages. Therefore members of lineages 1-9 all should be considered members of Fusarium graminearum according to the BSC. The existing female testers could be used to identify members of the F. graminearum clade by performing test crosses in the laboratory.
The PSC and BSC species concepts do not agree for this group of fungi. This disagreement indicates that the F. graminearum species complex is in the early stages of speciation. The lack of intrinsic reproductive barriers supports the hypothesis that these lineages have developed in geographic isolation. As the lineages have apparently been brought together through global trade, interlineage hybrids have been reported in the field. The discrepancy between PSC and BSC will eventually be resolved by whether the lineages fuse or remain separate in nature. Even if the lineages remain separate, this study demonstrates the potential for gene flow between lineage 7 and lineages 1 through 9.
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Definice druhů u rodu Trentepohlia (Ulvophyceae, Chlorophyta) pomocí kombinace molekulárních a morfologických přístupů / Species concept in the genus Trentepohlia (Ulvophyceae, Chlorophyta): a combination of molecular and morphological approachesŠafránková, Michala January 2016 (has links)
In this Master's thesis I engage in the problematics of the species concept of green subaerial alga Trentepohlia (Ulvophyceae, Chlorophyta). This genus has been studied intensively since the 18th century. For more than 200 years, Trentepohlia species have been delimited using various morphological criteria. However, recent molecular studies showed inadequacies in this approach Therefore, my goal was a precise morphological study of the European Trentepohlia species and the re-evaluation of their phylogenetic position using rbcL gene sequencing. During the period 2013-2015, I carried out a detailed study of the oldest references of Trentepohlia species and compiled a delimitation key of the European species. Based on this research I concluded that it would be desirable to synonymize T. odorata with T. jolithus, as well as T. uncinata with T. arborum. I also sampled Trentepohlia species within Europe and carefully studied and described their morphology. Fresh Trentepohlia thalli were molecularly characterized by cloning, which revealed a common mixture of Trentepohlia species in what on a first sight appears to be a homogenous crust. Phylogenetic analyses based on the rbcL confirmed the ongoing inconsistencies among morphologically and molecularly delimited species and also the existence of cryptic...
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Approaches to Species Delineation in Anamorphic (mitosporic) Fungi: A Study on Two Extreme CasesVinnere, Olga January 2004 (has links)
<p>Since the beginning of mycology, studies of species concept in fungi have been mainly based on morphology, partially due to the history of mycology as part of botany. Current advances in biochemical and molecular research have provided mycologists with powerful tools that can be used for delineation of fungal taxa. Recently, an integrated approach to fungal taxonomy involving both morphological and molecular traits has found a wide application for identification of species, especially in anamorphic (mitosporic) fungi.</p><p>In this thesis, I have tried to use this approach for identification of species units in two rather unrelated groups of organisms. One of the case studies concerned <i>Colletotrichum acutatum</i> – a worldwide economically important plant pathogenic anamorphic fungus, which is exhibiting a high level of variation in both morphological and molecular features. This fungus has been intensively studied during the past decades, and several attempts have been made to find reliable markers to separate it from other closely related species of <i>Colletotrichum</i>. The second case studied in this thesis was <i>Mycelia Sterilia</i> – an artificial group of fungi, which are deficient in production of spores of any kind, therefore lacking the main morphological feature used for assigning them to any certain fungal taxon below class level. Due to this peculiarity, <i>Mycelia Sterilia</i> have usually been neglected, and currently there is no working species concept applicable to these fungi. </p><p>In this work, I have tried to clarify the relationships among <i>C. acutatum</i> and several other anamorphic (<i>C. gloeosporioides</i> and <i>C. fructigenum</i>) and teleomorphic (<i>Glomerella acutata</i>, <i>G. cingulata</i> and <i>G. miyabeana</i>) taxa that are closely related to each other. For this purpose, examination of morphological traits was employed in combination with comparison of DNA sequencing data from three loci and subsequent phylogenetic analysis. As a result, re-description of <i>C. acutatum</i> and separation of (at least) two new species was proposed.</p><p>For studies of <i>Mycelia Sterilia</i>, a large collection of sterile strains was screened in search for biologically interesting organisms. One novel pathogen has been found, and two plant growth promoting strains with antifungal properties were selected. Attempt for tentative identification of those fungi was made based on their morphological, physiological and molecular features. Sequencing of several genes and spacers of the ribosomal DNA array revealed that the plant pathogenic strain is closely related to the teleomorphic basidiomycete genus <i>Campanella</i>, and plant growth-promoting isolates were identified as belonging to the anamorphic ascomycete genus <i>Phoma</i>. However, assigning the sterile strains to any existing species was not possible.</p><p>The main conclusion of the thesis is that species in anamorphic fungi should be defined based on a combination of morphological and molecular methods, both equally important, involving as many aspects of fungal biology as is possible at our current state of knowledge. </p>
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Approaches to Species Delineation in Anamorphic (mitosporic) Fungi : A Study on Two Extreme CasesVinnere, Olga January 2004 (has links)
Since the beginning of mycology, studies of species concept in fungi have been mainly based on morphology, partially due to the history of mycology as part of botany. Current advances in biochemical and molecular research have provided mycologists with powerful tools that can be used for delineation of fungal taxa. Recently, an integrated approach to fungal taxonomy involving both morphological and molecular traits has found a wide application for identification of species, especially in anamorphic (mitosporic) fungi. In this thesis, I have tried to use this approach for identification of species units in two rather unrelated groups of organisms. One of the case studies concerned Colletotrichum acutatum – a worldwide economically important plant pathogenic anamorphic fungus, which is exhibiting a high level of variation in both morphological and molecular features. This fungus has been intensively studied during the past decades, and several attempts have been made to find reliable markers to separate it from other closely related species of Colletotrichum. The second case studied in this thesis was Mycelia Sterilia – an artificial group of fungi, which are deficient in production of spores of any kind, therefore lacking the main morphological feature used for assigning them to any certain fungal taxon below class level. Due to this peculiarity, Mycelia Sterilia have usually been neglected, and currently there is no working species concept applicable to these fungi. In this work, I have tried to clarify the relationships among C. acutatum and several other anamorphic (C. gloeosporioides and C. fructigenum) and teleomorphic (Glomerella acutata, G. cingulata and G. miyabeana) taxa that are closely related to each other. For this purpose, examination of morphological traits was employed in combination with comparison of DNA sequencing data from three loci and subsequent phylogenetic analysis. As a result, re-description of C. acutatum and separation of (at least) two new species was proposed. For studies of Mycelia Sterilia, a large collection of sterile strains was screened in search for biologically interesting organisms. One novel pathogen has been found, and two plant growth promoting strains with antifungal properties were selected. Attempt for tentative identification of those fungi was made based on their morphological, physiological and molecular features. Sequencing of several genes and spacers of the ribosomal DNA array revealed that the plant pathogenic strain is closely related to the teleomorphic basidiomycete genus Campanella, and plant growth-promoting isolates were identified as belonging to the anamorphic ascomycete genus Phoma. However, assigning the sterile strains to any existing species was not possible. The main conclusion of the thesis is that species in anamorphic fungi should be defined based on a combination of morphological and molecular methods, both equally important, involving as many aspects of fungal biology as is possible at our current state of knowledge.
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Systematic and Ecological Studies of the Viola subsinuata Species ComplexHastings, Jennifer Lynn 01 October 2018 (has links)
No description available.
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Morphometric analysis of Cambrian fossils and its evolutionary significanceJackson, Illiam January 2017 (has links)
The Extended Evolutionary Synthesis (EES) is currently emerging as a theoretical alternative to the Modern Synthesis (MS) in which to frame evolutionary observations and interpretations. These alternative frameworks differ fundamentally in their understanding of the relative roles of the genotype, phenotype, development and environment in evolutionary processes and patterns. While the MS represents a gene-centred view of evolution, the EES instead emphasizes the interactions between organism, development and environment. This novel theoretical framework has generated a number of evolutionary predictions that are mutually incompatible with the equivalent of the MS. While research and empirical testing has begun on a number of these in a neontological context, the field of palaeontology has yet to contribute meaningfully to this endeavour. One of the reasons for this is a lack of methodological approaches capable of investigating relevant evolutionary patterns in the fossil record. In this thesis morphometric methods capable of providing relevant data are developed and employed in the analysis of Cambrian fossils. Results of these analyses provide empirical support for the process of evolution through phenotypic plasticity and genetic assimilation hypothesized by the EES. Furthermore, theoretical revision to the species concept in a palaeontological context is suggested. Finally, predictions of the EES specific to the fossil record are made explicit and promising directions of future research are outlined.
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