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 23 for “"population divergence"”.
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The role of cultural divergence in reproductive isolation in a tropical bird, the rufous-collared sparrow (Zonotrichia capensis)
… preference. I investigated the role of cultural divergence in reproductive isolation in a widespread Neotropical passerine the rufous-collared sparrow (Zonotrichia capensis). In Chapter II, I investigated, the role of female preference for and male territorial response towards, local and …
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Variation in shoaling behavior in lake Mývatn threespine stickleback in relation to temperature and origin
Behavioral variation within populations has the potential to facilitate local adaptation and population divergence. The threespine stickleback (Gasterosteus aculeatus) in Lake Mývatn is an ideal candidate to study such local adaptations. Threespine stickleback diverge in their morphology and …
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Diversification of beaked redfish, Sebastes mentella, along a depth gradient in the central North Atlantic
… relatively little is known about their impact on population diversification,adaptation and speciation. The pelagic beaked redfish, Sebastes mentella, exhibits depthassociatedpatterns of population genetic substructure in the central North Atlantic, with awidely distributed population inhabiting …
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Population genetics of wood frogs (Lithobates sylvaticus) in a forested ridge-top wetland ecosystem
… Genetic data can be used to address current population status, probability of persistence, and population connectivity. The objective of this study was to determine the amount and distribution of population genetic diversity of wood frogs in natural ridge-top wetlands and what factors …
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Evolutionary and conservation genetics of the Seychelles warbler (Acrocephalus sechellensis)
… and adaptive genetic variation within and among populations. To accomplish this, I studied an island species, the Seychelles warbler (Acrocephalus sechellensis), with microsatellite markers and major histocompatibility complex (MHC) genes as measures of neutral and adaptive variation …
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Adaptation and differentiation across island populations of Berthelot’s pipit (Anthus berthelotii)
… shape patterns of genetic diversity across populations of Berthelot’s pipit (Anthus berthelotii), a passerine bird endemic to the Canary Islands, Selvagens and Madeira archipelagos. To achieve this, I examined variation in pathogen infection, neutral microsatellites and functional major …
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Life History Divergence & Tidal Salt Marsh Adaptations of the Coastal Plain Swamp Sparrow
… natural selection is a powerful mechanism for population divergence and likely one of the primary causes of speciation. To understand how specific habitats shape local adaptation, it is helpful to study closely-related populations from widely differing ecosystems that have not had sufficient …
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Geographic variation in the phenotypes of two sibling horseshoe bats Rhinolophus simulator and R.swinnyi
… of adaptive and neutral mechanisms to population divergence in African horseshoe bats (genus Rhinolophus). The two species were sampled from their distributional ranges within southern Africa and several morphometric and echolocation parameters were taken. The relative contributions of …
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Evolutionary dynamics of bird populations in Southeast Asia
… during the LGM coincided with deeper inter-population genetic divergences. The distinctiveness of the northeastern Borneo populations of some species may be underlain by a combination of factors that included riverine barriers, LGM expansion of montane forests and regional physiography. (3) …
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Phylogeny and phylogeography of four southern ocean petrels
… philopatry. They may thus be expected to show population divergence, but published studies show that this is not always the case. Most studies to date have concentrated on northern hemisphere species, with mostly albatrosses studied within the southern oceans. White-chinned (Procel/aria …
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Introgression, Population Structure, and Systematics of the Sphagnum capillifolium complex
… and historical events affect patterns of population divergence and gene flow is an important question in evolution and biogeography. Sphagnum subgenus Acutifolia is one of the four major subgenera of Sphagnum peatmoss comprising numerous species with broad geographic ranges and diverse …
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The individual and collective behavior of social organisms across environments
… there is limited research exploring population differences in collective behavior and its role in phenotypic divergence. Addressing these gaps could help us predict the effects of environmental changes on behavioral evolution. In this thesis, I address these questions through the use …
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Speciation Genomics in Australian Meliphagoid Birds
… through a continuum of increasing genomic divergence and decreasing gene flow between populations. While sampling across hybrid zones provide insight for an intermediate stage of speciation, comparative studies of multiple contact zones between populations at different stages of speciation …
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Speciation Genomics in Australian Meliphagoid Birds
… through a continuum of increasing genomic divergence and decreasing gene flow between populations. While sampling across hybrid zones provide insight for an intermediate stage of speciation, comparative studies of multiple contact zones between populations at different stages of speciation …
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The movement ecology of common bream Abramis brama in a highly connected wetland using acoustic telemetry.
… highly diverse in well-connected systems. Intra-population divergence in spatial and temporal resource-use is an important component of fish distribution patterns and population structure, which can affect population viability and adaptive potential. The common bream Abramis brama (µbUHaP¶) is a …
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Dispersal, gene flow, niche divergence and local adaptation in the hyper-diverse ruschioid Aizoaceae: testing alternative modes of speciation in the Knersvlakte quartz field flora of the Succulent Karoo, South Africa
… diversification may have been facilitated by divergence of populations isolated on these 'environmental islands' in a similar fashion to serpentine systems such as those in California - and continues from previous work on the Knersvlakte-endemic ruschioid genus Argyroderma which supported an …
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Evolutionary Assembly of the Neotropical Montane Avifauna
… and clade age influence lineage diversity (population differentiation). In particular, species that are old, poor dispersers, and specialized to narrow elevational zones, accumulate greater lineage diversity with time. These results are consistent with predictions of the time-for-speciation …
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Plasticidad fenotípica y diferenciación genética inter- e intrapoblacional en Quercus Suber l.: evaluación mediante caracteres fisiológicos y marcadores moleculares
… by a xerothermic index) suggesting that population differences were likely due to local adaptation processes. Nine-year old plants were phenotypically characterized. This analysis showed that individuals originated from the wettest populations exhibited the higher specific leaf area …
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Mate choice in the Polychaete nereis acuminata : the role of aggression and parental experience
… levels exhibited. Aggression between the populations maintained in the laboratory, Reish (R), Newport (N), San Gabriel (SG), Connecticut (C) and the wild population Los Angeles (LA) were examined. Although there were significant differences in male aggression between the R, N, SG and C …
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Habitat modification and gene flow in Saimiri oerstedii: Landscape genetics, intraspecific molecular systematics, and conservation
Habitat modification, when it results in population fragmentation, often results in the loss of genetic diversity due to reduced gene flow, inbreeding, and genetic drift. However, the severity of these effects depends on how diminished dispersal and gene flow become between patches of suitable …
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