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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
411

Fylogeografie druhového komplexu Pipistrellus pipistrellus / Phylogeography of Pipistrellus pipistrellus species complex

Chudárková, Adéla January 2010 (has links)
(in English) Pipistrellus pipistrellus species complex contains two sympatric species inhabiting Europe and part of West and Central Asia (Pipistrellus pipistrellus s. str, Pipistrellus pygmaeus s. str) and several other lines, isolated in the Mediterranean (North Africa, islands and peninsulas of the Mediterranean Sea). This taxon is a part of the extensive radiation within the genus Pipistrellus, which in today's concept includes about 30 species. Mosaic line of P. pipistrellus complex, located at different stages of diversification and secondary contacts in the Mediterranean biodiversity hotspot, is a suitable model for research on speciation. In this thesis we focused on analyses of distribution, phylogeography, population structure and demography based on mitochondrial data from 323 individuals, representing almost the entire range. Control region of mitochondrial DNA was chosen as a genetic marker. Variability in the 378 pb long fragment acknowledged the existence of several genetically distinct lines whose species status is discussed. Observed fylogeografic pattern confirms the existence of groups of radiation centers in the Mediterranean region. An allopatric speciation was there, two of the lines (P. pipistrellus s. str and P. pygmaeus s. str.) later expanded into Europe and their ranges...
412

Evoluce, systematika a biogeografie vodomilovitých brouků (Coleoptera: Hydrophilidae) jižní polokoule / Evolutionary history, systematics and biogeography of Southern Hemisphere hydrophilid beetles (Coleoptera)

Seidel, Matthias January 2019 (has links)
The research presented in my PhD thesis consists of phylogenetic, biogeographic, taxonomic and ecological research of Southern Hemisphere water scavenger beetles (Coleoptera: Hydrophilidae) with a special emphasis on New Zealand. The introductory chapter provides a brief outline on the break-up of Gondwana and geological processes that shaped New Zealand and its fauna. Furthermore, the diversity of New Zealand Hydrophilidae and worldwide diversity of the hydrophilid subfamily Cylominae and its taxonomic history are illustrated. The scientific part of the thesis contains 4 published papers and 2 manuscripts. The first study recalibrates the Coleoptera time tree, providing new age estimates for the Hydrophiloidea, among others. The new age estimate is implemented in the second study, a phylogenetic study that reconstructs the biogeography of the 'Gondwanan' Cylominae beetles. The Cylominae, whose name was reinstated through nomenclatural priority over Rygmodinae in a separate paper, are found to consist of two tribes, Andotypini and Cylomini. The disjunct distribution of Cylominae is shown to be partly the result of vicariance and partly of long-distance oversea dispersal. The most remarkable long-distance dispersal is that of the only African representative of the subfamily which reached Africa from...
413

PHYLOGENY, CHARACTER EVOLUTION, BIOGEOGRAPHY, AND REDEFINITION OF GENERA IN THE TRIBE EDROTINI LACORDAIRE, 1859 (COLEOPTERA: TENEBRIONIDAE: PIMELIINAE)

Christopher Charles Wirth (12469815) 27 April 2022 (has links)
<p>The tribe Edrotini is the largest component group of the largest tenebrionid subfamily, Pimeliinae, in the Americas, with 427 described species/subspecies in 55 genera. However, the group is taxonomically impeded, with the last comprehensive revision published nearly 115 years ago. This is particularly regrettable since members of this tribe are ubiquitous in arid regions throughout the Americas and are exceptionally diverse in their morphology and behaviors. To provide phylogenetic context and a foundation for taxonomic work, in Chapter 1 I sample a majority of genera and reconstruct the first phylogeny of the Edrotini, using targeted enrichment sequencing. My results indicate major changes are required to both edrotine tribal composition and generic concepts. In combination with a suite of eight morphological characters I use this phylogeny to reconstruct ancestral states and test for characters correlated with stridulation the tribe. I find stridulation is strongly correlated with two morphological characters and propose a defensive function for these structures</p> <p>In Chapter 2, I use the molecular phylogeny in combination with 100 morphological characters to evaluate all Edrotini genera and members of five related tribes with constrained parsimony analyses. Based on the results thirteen genera are transferred from the Edrotini and the tribal classification is revised, with 35 genera recognized and description of a further five recommended. One neotype and seven lectotypes are designated for type species. A dichotomous key to genera is provided. Thirty-one current genera are redescribed; two species described; and four genera described, including four species. One subgenus is elevated to genus and three genera are placed as subgenera pending a species-level revision of the clade. Six genera, four subgenera, and one species are synonymized. Eleven species are transferred to the correct genus and one replacement name proposed. </p> <p>And in Chapter 3, I revise the genus <em>Edrotes</em> LeConte to include eight species distributed across arid southwestern North America. All species are redescribed, of which three are brought out of synonymy. A neotype for <em>E. rotundus</em> (Say) is designated. The synonymic position of five species is amended. An illustrated key to <em>Edrotes</em> species is included. A molecular phylogeny of all species is generated and used to infer divergences dates and historical biogeography for the genus. The most recent common ancestor of <em>Edrotes</em> is dated to the late Miocene or early Pliocene and inferred to have inhabited the Sonoran Desert. </p>
414

Genetic And Phenotypic Evolution In The Ornate Chorus Frog (pseudacris Ornata): Testing The Relative Roles Of Natural Selection,

Degner, Jacob 01 January 2007 (has links)
Understanding how migration, genetic drift, and natural selection interact to maintain the genetic and phenotypic variation we observe in natural populations is a central goal of population genetics. Amphibians provide excellent model organisms for investigating the interplay between these evolutionary forces because amphibians are generally characterized by limited dispersal abilities, high philopatry, and are obligately associated with the areas around suitable habitats (e.g. breeding ponds). Thus, on relatively small geographic scales, the relative effects of all of these evolutionary forces can be studied together. Here, we study the interaction of migration, genetic drift, natural selection, and historical process in the ornate chorus frog (Pseudacris ornata). We report the development and characterization of 10 polymorphic microsatellite genetic markers. Number of alleles per locus ranged from 2 to 21 averaging 9.2 and expected heterozygosities ranged from 0.10 to 0.97 averaging 0.52. However, in an analysis of two populations, three locus-by-population comparisons exhibited significant heterozygote deficiencies and indicated that null alleles may be present some loci. Furthermore, we characterized genetic structure and historical biogeographic patterns in P. ornata using these microsatellite markers along with mitochondrial DNA sequence data. Our data indicate that in these frogs, migration may play a large role in determining population structure as pairwise estimates of FST were relatively small ranging from 0.04 to 0.12 (global FST = 0.083). Additionally, we observed an overall pattern of isolation-by-distance in neutral genetic markers across the species range. Moreover, our data suggest that the Apalachicola River basin does not impede gene flow in P. ornata as it does in many vertebrate taxa. Interestingly, we identified significant genetic structure between populations separated by only 6 km. However, this fine scale genetic structure was only present in the more urbanized of two widespread sampling localities. Finally, in this study, we demonstrated that there was a significant correlation between the frequency of green frogs and latitude. There was a higher frequency of green frogs in southern samples and a lower frequency of green frogs in northern samples. However, when we interpreted this phenotypic cline in light of the overall pattern of isolation-by-distance, it was apparent that the neutral evolutionary forces of genetic drift and migration could explain the cline, and the invocation of natural selection was not necessary.
415

<b>Phylogenomics and species distribution models to infer evolutionary relationships, delimit species, and better understand lichen-host interactions in tiger moths</b>

Makani L Fisher (17656290) 16 December 2023 (has links)
<p dir="ltr">The lichen-feeding tiger moth tribe Lithosiini (Erebidae: Arctiinae) represent the largest radiation of invertebrate lichenivory. Caterpillars feed on lichen and as they feed, also sequester lichen polyphenolics, a behavior unique to these insects. The role of these compounds is believed to defend lithosiines against predators as larvae have been found to be protected against predators such as ants and moths to predators such as birds and bats. Experimental testing with controlled diets is necessary to fully make this connection, however little is known about host specifics for lithosiines. Furthermore, although lithosiines are monophyletic, the lack of a fully resolved phylogeny hampers investigation into many of the shallower level relationships, e.g. those among genera and species, within the group.</p><p dir="ltr">I addressed these knowledge gaps using the subtribe Cisthenina. Members of this group have been used to investigate predator-prey interactions and been included in morphological and molecular studies. Thus, while the group still needs attention, there is an ample amount of legacy loci data available for its members. I used these data to investigate the evolutionary relationships at the genus level, but to increase resolution in my analyses I additionally sampled taxa throughout the group with a recently developed anchored hybrid enrichment (AHE) probe set. I combined it with the legacy loci to both increase taxon sampling and resolution. I confirmed that trees made strictly from the legacy loci were unsuccessful and resulted in poorly supported relationships that made little sense. The addition of the AHE data greatly helped resolve relationships, however, there remained areas that were poorly supported and they appear to be genera with only a few loci. Thus, there is still room for improvement, but this offers a way for moving forward in lithosiine research, particularly to involve others who may have limited funding, equipment, and/or personnel and may only be able to afford legacy loci in diverse collaborations.</p><p dir="ltr">As the AHE probe set worked well with genus-level relationships I further attempted to use it in species delimitation of the notorious <i>Hypoprepia fucosa</i>-<i>miniata </i>species complex. Members of this group are varying shades of yellows, oranges and reds and have a convoluted taxonomic history. I gathered and organized over 4,000 specimens and using the AHE probe set found support for five distinct species. Interestingly, I used other morphological characters such as genitalia, but found no differences between species and a large amount of intraspecific variation. This suggests other courtship behaviors may be present and external morphology, i.e., color patterns, remain the best way to identify species. As part of this I am describing a new species and raising one from subspecies and as species are now readily distinguishable, they can be used for further investigations into lithosiines.</p><p dir="ltr">I used a member of this complex, <i>H</i>. <i>fucosa</i> to then evaluate the use of species distribution models (SDMs) to better understand their niche and how it relates to plausible lichen hosts. I evaluated 17 lichen species from two lichen genera, <i>Physcia </i>(13 species) and <i>Myelochro</i><i>a </i>(4 species)<i>. </i>These genera were selected based on previous feeding assays and the metabolites found in them have also been found in <i>H</i>. <i>fucosa </i>further suggesting caterpillars may feed on them. SDMs typically only use environmental factors to define and predict species niches. I compared the niches described by traditional SDMs to assess how similar they were, but I also investigated the use of lichens as biotic factors in the models. I assessed the influence each lichen had on the moth’s distribution found the niche of every lichen to be significantly different than that of the moth and their inclusion in SDMs of <i>H</i>. <i>fucosa </i>to improve model performance. This suggests <i>H</i>. <i>fucosa </i>caterpillars to be polyphagous, but to have some connection with these lichens. Further investigation with live specimens is needed, but these results support this as an effective way to describe lithosiine niches to better understand lichen feeding.</p>
416

Conservation Biology of the Gammarus pecos Species Complex: Ecological Patterns across Aquatic Habitats in an Arid Ecosystem

Seidel, Richard Alan 31 August 2009 (has links)
No description available.
417

Investigation of Inter- and Intraspecific Genetic Variability of <i>Euhrychiopsis lecontei</i>, a Biological Control Agent for the Management of Eurasian Watermilfoil.

Roketenetz, Lara Diane 26 May 2015 (has links)
No description available.
418

Population Genetic Structure and Biogeographic Patterns in the Yellow Perch <i>Perca flavescens</i>: An Analysis of Mitochondrial and Nuclear DNA Markers

Sepulveda Villet, Osvaldo Jhonatan January 2011 (has links)
No description available.
419

The Population Ecology, Molecular Ecology, and Phylogeography of the Diamondback Terrapin (Malaclemys terrapin)

Converse, Paul E. 19 September 2016 (has links)
No description available.
420

Systematics and Evolution of the Californian Trapdoor Spider Genus Aptostichus Simon (Araneae: Mygalomorphae: Euctenizidae)

Bond, Jason E. 28 September 1999 (has links)
Chapter One: Raven's 1985 phylogenetic analysis of the Mygalomorphae placed a number of previously unrelated genera into the rastelloid family Cyrtaucheniidae. Although Goloboff's 1993 reanalysis of mygalomorph relationships retained the familial composition of the Rastelloidina it di not support cyrtaucheniid monophyly. This study resolves the issue of cyrtaucheniid monophyly within the context of the Rastelloidina. Using 71 morphological characters scored for 29 mygalomorph taxa we find that the Cyrtaucheniidae is polyphyletic and propose the following families in its place: Cyrtaucheniidae, Kiamidae (new family), Aporoptychidae (new rank), Ancylotrypidae (new family) and Euctenizidae (new rank). We also propose two new euctenizid genera, Apachella and Sinepedica, revise the taxonomy of the euctenizids of the Southwestern United States, and present a key for these six genera. In addition to the morphologically based phylogeny we test and refine the euctenizid intergeneric phylogeny using molecular data (mitochondrial 16S rRNA and COI genes and 28S rRNA nuclear genes). The results of the combined morphological and molecular analysis are used to construct a composite rastelloid phylogeny that is used to investigate biogeographical relationships, burrow entrance evolution, and homoplasy. Chapter Two: This systematic study of the predominately Californian trapdoor spider genus Aptostichus Simon, 1890 describes 28 species, 25 of which are newly described: A. atomus, A. improbulus, A. insulanus, A. icenoglei, A. ebriosus, A. muiri, A. cahuillus, A. luiseni, A. serranos, A. calientus, A. chemehuevi, A. shoshonei, A. pauitei, A. tipai, A. cochesensis, A. indegina, A. gertschi, A. kristenae, A. fornax, A. spinaserratus, A. brevifolius, A. brevispinus, A. agracilapandus, A. tenuis, and A. gracilapandus. Aptostichus stanfordianus Smith, 1908 is considered to be a junior synonym of A. atomarius Simon 1890. Using 72 quantitative and qualitative morphological characters we propose a preliminary phylogeny for this group. Based on the results of this phylogenetic analysis, we recognize the Atomarius, Simus, Hesperus and Pandus species groups. Additionally, our phylogenetic analysis indicates that adaptations favoring the invasion of the very arid desert habitats of southern California have evolved multiple times in the Aptostichus clade. The existence of both desert and non - desert species in three of the four species groups makes this genus an ideal candidate for the study of the evolutionary ecology of desert arthropods. Chapter Three: Aptostichus simus is a trapdoor spider that is endemic to the coastal dunes of southern California and is recognized as a single species on morphological grounds. Mitochondrial DNA 16S rRNA sequences demonstrate that populations from San Diego County, Los Angeles County, Santa Rosa Island, and Monterey County are extremely divergent (6 - 12%). These results are comparable to, or higher than recent reports of species - level differences in other invertebrate taxa. A molecular clock hypothesis shows that these four populations have been separated for 2 - 6 million years. A statistical cluster analysis of morphological features demonstrates that this genetic divergence is not reflected in anatomical features that might signify ecological differentiation among these lineages. The species status of these divergent populations of A. simus depends upon the species concept utilized. The time - limited genealogical perspective that is employed separates A. simus into two genetically distinct species. This study suggests that a species concept based on morphological distinctiveness in spider groups with limited dispersal capabilities probably underestimate taxonomic diversity. / Ph. D.

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