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 29 for “"Hybrid zone"”.
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Hybridization dynamics and population genomics of a Manacus hybrid zone
Submission published under a 24 month embargo labeled 'U of I Access', the embargo will last until 2025-08-01
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Hybrid zone genetics and within-island diversity of the gecko Tarentola boettgeri
… and negligible gene flow across the contact zone. This led to the hypothesis that reproductive barriers may have formed between populations from different mtDNA lineages. Analyses of seven body dimension and scalation characters revealed that spatial patterns of morphological changes were not …
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Mechanisms for partial reproductive isolation in a Bombina hybrid zone in Romania
… isolation in the case of secondary contact. Hybrid zones are ideal study systems in which to investigate mechanisms for the inhibition of gene flow. This thesis describes a mosaic hybrid zone between the ecologically differentiated fire-bellied toads Bombina bombina and B. variegata. I show …
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Evolutionary genetics and genomics of flower colour loci in an Antirrhinum hybrid zone
… maintenance of diversity between populations. In hybrid zones, loci that establish a barrier to gene flow between populations remain divergent, whereas neutral unlinked loci become mixed. In those instances, fit allelic combinations across several loci can be maintained through selection, but this …
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Genetic introgression and female mate choice within the Calendulauda albescens/C. barlowi hybrid zone
The hybrid zone between Calendulauda albescens and C. barlowi, located near the Orange River, contains a wide range of phenotypically intermediate individuals. This study examines the mitochondrial DNA of some of these individuals to determine if possible introgression is occuring from C. albescens …
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Tufted Titmice, Black-crested Titmice, and their Hybrids Occupy Different Habitats within their Hybrid Zone
… a key role in either facilitating or preventing hybridization between some species. Within a hybrid zone, differences in habitat requirements could spatially separate two species to reduce hybridization. However, hybrid individuals might be best adapted to an intermediate type of habitat also …
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The genetic basis of reproductive isolation in house mice: Studies of a European hybrid zone
… for X-linked loci across a European hybrid zone between two species of house mice, Mus domesticus and M. musculus (Appendix A). Allele frequency patterns at 13 molecular markers with known chromosomal positions identify one region with clearly reduced introgression. This piece of the …
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Morphometric Characterization of a <i>Mercenaria</i> spp. (Bivalvia) Hybrid Zone: Paleontological and Evolutionary Implications
Paleontological documentation of hybridization events has the potential to address a multitude of evolutionary and paleobiological issues unanswerable by purely biological means. However, previous studies of modern hybrids suggest that their morphology is often insufficient for their reliable …
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The Genetic Impacts of Mytilus Galloprovincialis On M. Trossulus In Northern Japan
… on the communities in which they invade. Through hybridization, invasive species also threaten the genetic integrity of the native species by means of genetic pollution. In the marine environment, the Mediterranean mussel Mytilus galloprovincialis is a highly invasive species that has successfully …
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Allozyme Diversity and Hybridization in Castanea Pumila (Section Balanocastanon, Fagaceae)
… for the observed geographic variability is hybridization between two incompletely isolated species. To explore this possibility, the geographic distribution of allozyme variation was examined for patterns indicative of a hybrid zone. Only one of six loci assayed was polymorphic, yielding a …
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Hybridization Between the Watersnakes <i>Nerodia sipedon</i> and <i>Nerodia fasciata,</i> in the Carolinas: A Morphological and Molecular Approach
… and to study the dynamics across their hybrid zone in the Carolinas. Many of the morphological characters exhibited significant interspecific differences, although only the number of dorsally complete crossbands (CBa) was diagnostic by itself. A discriminant function analysis of …
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Evolution in the genus Arum: a comparative analysis of morpohological and genetic variation.
… level, intrageneric level and in a putative hybrid zone. At the intraspecific level, genetic (ISSR) and morphological variation was quantified in populations of the morphologically similar species A. maculatum and A. italicum. Populations of A. maculatum showed evidence of isolation by …
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Morphological Variation and Community Science in Orthoptera
… Gryllus firmus and G. pennsylvanicus and their hybrids. We find that these species differ across their geographic range in key morphological traits, such as body size and ovipositor length, and we directly compare phenotype with genotype for a subset of crickets demonstrating nuclear genetic …
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Patterns of Population Structure and Hybridization within and between Populus trichocarpa and Populus balsamifera
… in temperate latitudes. Populus spp. frequently hybridize where their ranges overlap, and poplar hybrids are the most frequently planted genotypes for fiber production. To better understand the genomics of hybridization in Populus, we sampled and sequenced the genome of 574 poplar trees from six …
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Phylogeographic structure of the Atlantic pupfish, Cyprinodon variegatus (Cyprinodontidae), along the eastern coast of North America: Evidence from mitochondrial nucleotide sequences
… be may be possible to determine if secondary hybrid zones developed as a result of the last retreat of ice from North America during the Pleistocene, about 17,000 years ago. A definitive monophyletic northern clade was found using parsimony, distance, and maximum likelihood phylogenetic …
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Mouse hybrid sterility genes linked to chromosome X
… reproductive isolation mechanism is the Hybrid Sterility (HS). Hybrids between Mus musculus domesticus (Mmd) and Mus musculus musculus (Mmm) create a narrow hybrid zone across central Europe. The PWD wild-derived inbred strain (representing Mmm) and the B6 laboratory inbred strain …
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Hybridization and the genetics of wing colour-pattern diversity in Heliconius butterflies
… drift. However, it is now recognized that hybridization between already divergent populations constitutes another important source of genetic and phenotypic variation, upon which natural and/or sexual selection can operate. Hence, the idea that hybridization can actually promote …
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The role of male-male aggressive signals in reproductive isolation between two hybridizing warblers
… song fails to effectively isolate a species and hybrids are produced, giving an opportunity to investigate the mechanisms of how song might act as a reproductive barrier. The ways in which two hybridizing species respond to and recognize each other’s songs can influence the dynamics of the hybrid …
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Curating Across Interfaces: an Account of a (Hybrid) Expanding Exhibition
… research has been the curation of a series of hybrid exhibitionary spaces. These exhibitionary forms have resulted from creating a series of interfaces under the umbrella of 'that’s contemporary',a non-profit organization that I co-founded and have run since 2011. In this thesis, the practice …
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Evolutionary history and hybridization in Passerina buntings
… importance to evolutionary biology and hybrid zones offer unique natural laboratories in which to investigate the ecological and evolutionary processes important in creating and maintaining biological diversity. By comparing introgression patterns of different loci, researchers can begin …
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