Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 129 for “"geographic range"”.
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Geographic range dynamics of South Africa's bird species
… in species conservation is a knowledge of the geographic ranges of species, and how these are changing through time. For birds there is a special opportunity to undertake studies of range changes, making use of the data collected by the First and Second Southern African Bird Atlas Projects …
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Tertiary marine prosobranchs: larval dispersal and geographic range
… marine invertebrate species to establish great geographic ranges; several studies along a single margin of an ocean basin have supported this proposal (Shuto, 1975; Hansen, 1978). This study makes use of the fossil record to examine larval dispersal patterns on a larger geographic scale: across …
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Increased phenotypic plasticity linked to broader geographic range size in sunflower (Helianthus) species
… five Helianthus species representing different geographic ranges. Locally restricted H. longifolius and H. verticillatus showed less plasticity in growth and allocation traits than widespread H. angustifolius and H. maximiliani. Rare species with narrower ranges also displayed less …
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The Population Genetics Of The Wood Frog, Rana Sylvatica, Across Its Geographic Range
… of genetic variation across the continental-wide range of the wood frog, Rana sylvatica. Levels of genetic differentiation between sampled populations were investigated as was the possible locations of glacial refugia for this species. DNA microsatellites were used as the genetic marker. This …
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The relationship between niche breadth and geographic range size in African Horseshoe bats (Rhinolophidae, Chiroptera)
… of environmental conditions resulting in large geographic range sizes. Conversely, specialists have low niche breadth and small range sizes. I tested this hypothesis using African Horseshoe bats to determine if differences in niche breadth can explain variation in geographic range size.
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Major histocompatibility complex diversity in an urban Chacma baboon (Papio ursinus) population: Implications for conservation
… restriction and fragmentation of the historic geographic range of the peninsula's Chacma baboon (Papio ursinus) population.
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Revision of Xanthomicrogaster Cameron, 1911 (Hymenoptera: Braconidae: Microgastrinae)
… in order to understand the variation and geographic range of the genus. Previous descriptions of the genus and the recognized species are examined and placed into context using the material from across the geographic range. Seven species are newly described here from the ACG project, …
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Celiac Test Assay Comparison: Bio-Rad Autoimmune EIA Anti-Tissue Transglutaminase (tTG) IgA and IgG Tests on the Inova Quanta-Lyser 240 vs. BioPlex 2200 Celiac IgA and IgG Kits for Use at a Large Reference Laboratory
… by this change due to their coverage of broad geographic range and diverse patient populations. For this reason, traditional Celiac testing methods have given way to new technologies that offer greater flexibility and performance. A comprehension of the pathogenesis of this disease helps to …
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Host Plant and Spatial Influences on the Natural Enemy Community Structure of a Host Specific Insect Herbivore
… of its host plants across the gall former's geographic range while controlling for spatial autocorrelation among sample sites. Belonocnema treatae exhibits regional host plant specialization across the southern US on three live oak species, Quercus fusiformis (Qf), Quercus virginiana (Qv), …
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Population and migratory dynamics of blacklegged ticks and the Lyme bacterium, Borrelia burgdorferi
Geographic range expansion and population growth of vector-borne pathogens are regulated by the migration of their arthropod vectors. Recent climate and land-use changes have produced alterations in the geographic range and population size of blacklegged ticks (Ixodes scapularis) and the pathogens …
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Habitat Ecology, Trophic Interactions, and Distribution of Endangered Himalayan Musk Deer in the Nepal Himalaya
… and vegetational attributes within the home range. It also assesses the impacts of livestock presence in habitat selection of musk deer. Logistic regression of musk deer’s presence/absence with binomial error structure and logit link function was employed to determine the physical and …
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Pheromones in Heliconius butterflies: Chemical ecology, genetics, and behaviour
… in pheromone components across the broad geographic range of several species. I show that this provides a useful approach to identify biologically active components, which we expect to be species-specific over a large geographic range. There is also considerable interest in understanding …
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A Global Conservation Assessment of Temperate Forests: Status and Protection
… of temperate forests across naturally occurring geographic and elevational ranges. My results indicate that protected temperate forests do not represent the full geographic and elevational range of naturally occurring temperate forests. Bias in location, elevation and slope of protected areas are …
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Genetic Structure of Amblyomma Cajennense (Acari: Ixodidae) Populations Based on Mitochondrial Gene Sequences
… is a common tick species that has a large geographic distribution from the southern regions of the United States (Texas), to the Caribbean Islands, Central, and South America. This tick is a vector of the agent of Brazilian spotted fever, an often fatal disease in South America. Throughout …
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Morphological Variation and Community Science in Orthoptera
… of morphological divergence across species’ ranges provide insight into local adaptation and speciation. Here, we compare phenotypic divergence among 4,221 crickets from 337 populations of two related species of field cricket, Gryllus firmus and G. pennsylvanicus and their hybrids. We find …
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Population differentiation, dispersal limitation, and local adaptation in the gametophytic fern Vittaria appalachiana
… One response is the shifting of the species' geographic range to higher latitudes and elevations, which will be unlikely for those species that have limited dispersal potential. Alternatively, organisms may tolerate the change, which will be unlikely for those organisms that are not …
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Physiological and Ecological Constraints on the Evolution of Viviparity in Sceloporine Lizards
… that simulated retention in the oviduct under a range of oxygen partial pressures. In Chapter one, I tested the hypothesis that embryos of the oviparous lizard Sceloporus undulatus from a high-latitude population are laid at more advanced developmental stages and have a higher developmental rate …
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Phylogeography and Diversification of the Greenish Blue Butterfly (Plebejus Saepiolus) in Western North America
… processes. Often large-scale climatic or geographic events, like climate cycling of the Pleistocene, can influence dispersal patterns and create a disjunct and complex distribution in a species range. The Greenish Blue Butterfly, Plebejus saepiolus (Lycaenidae, Polyomattini), is a species …
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Phylogeography and Diversification of the Greenish Blue Butterfly (Plebejus Saepiolus) in Western North America
… processes. Often large-scale climatic or geographic events, like climate cycling of the Pleistocene, can influence dispersal patterns and create a disjunct and complex distribution in a species range. The Greenish Blue Butterfly, Plebejus saepiolus (Lycaenidae, Polyomattini), is a species …
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Do villages still matter?
… Three case studies were chosen that cover a wide geographic range, selecting two contemporary cases in areas with some of the highest rates of urbanization. The historic case broadens the geographic scope of the study, but also provides historical insights into how each variable influenced success …
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