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.
Results
Showing 1 to 20 of 61 for “"Convergent Evolution"”.
-
Convergent evolution of betalains in Caryophyllales
In this thesis, I investigate the evolution of betalains in Caryophyllales. Betalains are a group of red and yellow pigments, which in plants occur only in the order Caryophyllales. Here, betalains replace the otherwise ubiquitous anthocyanin pigments, and the two pigment types appear mutually …
-
The mechanisms underlying convergent evolution in the plumage patterns of birds
Convergent evolution is a central theme in biology. Birds are an ideal system to examine the mechanisms underlying convergent evolution. Although bird patterning is diverse, within-feather patterns have repeatedly converged on the same four types: mottled patterns, scales, bars and spots. Other …
-
From Micro to Macro: Investigating mechanisms involved in the convergent evolution of feather lice ecomorphs
… will evolve similar traits, in a process called convergent evolution. These occurrences provide opportunities to investigate the mechanisms that drive species diversification and adaptation and whether different mechanisms can lead to similar evolutionary outcomes. Under what conditions is …
-
Convergent Evolution of Biochemical Innovations in Polychaetes: Characterizing the Molecular Basis of Bioluminescence and Venom Production
<p>The convergent evolution of phenotypic traits is a widespread phenomenon across the tree of life and is explained as the outcome of different taxa facing similar selective forces or environmental conditions. A longstanding question in evolutionary biology is whether the evolution of convergent …
-
ΔΟΜΙΚΗ ΑΝΑΛΥΣΗ ΤΗΣ ΣΚΛΗΡΟΦΥΛΛΙΑΣ ΣΕ ΑΕΙΦΥΛΛΑ ΕΙΔΗ ΤΗΣ "ΜΑΚΚΙΑΣ" ΒΛΑΣΤΗΣΗΣ
… INVESTIGATION OF THE HARD LEAL CORRELATED TO CONVERGENT EVOLUTION. ELEVEN SPECIES OF THE GREEK CHAPARRAL WERE STUDIED CONCERNING THE ANATOMICAL EXPRESSION OF THEIR ADAPTIVE STRATEGIES.
-
The reproductive biology and ecology of Colchicum (Colchicaceae) in southern Africa
… syndromes. These syndromes reflect patterns of convergent evolution and serve to generate hypotheses about potential pollinators based on a plant's morphological characteristics (Faegri and van der Pijl, 1979; Johnson and Steiner, 2000).
-
The Reproductive biology of Erica pudens
… whether E. pudens is another example of convergent evolution in Erica by establishing its phylogenetic position. E. pudens possesses floral characteristics that are consistent with the rodent-pollination syndrome. These characteristics include tightly-packed, pendulous inflorescences with …
-
Adaptation and niche construction by Pseudomonas fluorescens SBW25
The mechanisms underlying adaptive radiation or evolution have been extensively investigated using experimental bacterial populations in liquid cultures, referred to as microcosms. Evolving populations of <i>Pseudomonas fluorescens</i> SBW25 in static microcosms reproducibly lead to the emergence …
-
Plant water relations along a rainfall gradient, between the succulent Karoo and Mesic Mountain Fynbos, in the Cedarberg Mountains, near Clanwilliam, South Africa
… ecosystems is thought to be the result of convergent evolution. In the Mediterranean, California, and Chile the length of the summer drought and the cold winter temperatures are hypothesized to be the primary selective pressures. In Australia and South Africa low soil nutrients are thought …
-
Some observations on the life history of Strophitus edentulus
… form, it is possible that we have here a case of convergent evolution, the investigation of which may throw some light on the nature of this most interesting adaptation of the fresh water mussels. In the following paper I have presented a review of the observations and experiments from which the …
-
Phylogenetics and biogeography of Australian subterranean Parabathynellidae.
… their diversity, some aspects of character evolution and their biogeographic history within Australia. In addition, taxonomic descriptions are provided for the first parabathynellid species from South Australia. For the first data chapter molecular sequence data from the mitochondrial …
-
Problems in Pedigrees and Phylogenies
… familial relationships between individuals and evolutionary relationships between species. The former can be depicted by a pedigree, whereas the latter can be depicted by a phylogeny. These two distinct objects can be viewed as analogous, in the sense that they both describe a correlation …
-
Convergence of Life History Phenotypes in Two Species of Topminnows, <i>Fundulus notatus</i> and <i>Fundulus olivaceus</i>
<p>Convergent evolution is the independent evolution of similar characteristics by means of natural selection. Convergence is a well-known phenomenon, but convergence resulting from equivalent environmental gradients has only been pursued in a few cases. The main purpose of this study was to look …
-
The cellular and molecular basis of the Nef requirement for HIV-1 infectivity
… These examples of functional conservation and convergent evolution emphasize the fundamental importance of SERINC5 in the interaction of the host with retroviral pathogens. Remarkably, SERINC5 potently inhibits HIV-1 even in the presence of Nef in a dose-dependent manner, suggesting that this …
-
Ontogeny and evolutionary morphology of the skeleton in frogs
… in exploring questions of morphological evolution. Here, two projects illuminate the relationship between ontogeny and the evolution of skeletal morphology in frogs. In the first part of this dissertation, I examine the evolution of skull development in pipoid frogs, a group that is …
-
Osteology of Calluella guttulata (Blyth 1855) and Associated Commentary on Evolution in the Family Microhylidae (Anura)
… is a morass of unusual structures and repetitive convergent evolution. The available phylogenetic information is limited, and the osteological information barely scratches the surface of the diversity present in the group, but even this much is enough to begin to identify certain patterns and …
-
Evolution of the Neckeraceae (Bryopsida)
… characters is artificial and based on convergent evolution. According to the latest phylogenetic studies of pleurocarpous mosses, based on molecular data, the Neckeraceae belong to the order Hypnales and share a sister group relationship with the Lembophyllaceae. In the most recent …
-
Evolutionary and functional study of plant cell wall polysaccharide glucomannan
… mannan; I investigated the function, evolution, and mutant phenotypes of its synthase. The main chapter consists of three independent parts. Chapter2 addresses the question, “In which group of evolutionary stages does β-GGM (β-galactoglucomannan) exist?”. The results suggest that β-GGM …
-
Hidden Diversity of Madagascan Freshwater Crabs (Brachyura: Potamoidea) Revealed by Morphological and Molecular Studies
… freshwater crabs to better understand character evolution in these crabs. Character states of the mandibular palp, the ambulatory legs, and the gonopods were mapped onto the molecular phylogeny for all 24 species of Malagasy freshwater crabs. Patterns were interpreted in the context of …
-
Virulence of Drosophila C virus increased after a host shift and serial passage in Drosophila hosts
… its native host, and the pathogen experiences convergent evolution. This study tests the first two generalities using complex hosts (Drosophila sp) and the highly virulent Drosophila C virus (DCV). The fitness of DCV was utilized as a proxy for virulence (pathogen’s harm to host) and …
Page 1 of 4