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1
Sikora, Martin. "Evolutionary genetics of malaria: genetic susceptibility and natural selection." Doctoral thesis, Universitat Pompeu Fabra, 2010. http://hdl.handle.net/10803/7220.
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Una de les forces selectives més fortes que han afectat a les poblacions humanes en la història més recent és el paràsit de la malària: Plasmodium falciparum, que és la causa de varis exemples d'adaptació induïda per patògens en els éssers humans. Una forma especial de malària és l'associada a l'embaràs, que es caracteritza per l'acumulació d'eritròcits infectats en la placenta, i que pot arribar a causar fins a 200.000 morts maternoinfantils cada any. L'objectiu d'aquest treball és descriure com aquesta forma peculiar de malària ha afectat la variació genètica humana. Amb aquesta finalitat, hem utilitzat mètodes tant de la genètica evolutiva com de l'epidemiologia molecular, resultant en la primera investigació a gran escala de la base genètica de la malària placentària. Els resultats ofereixen una nova visió sobre els gens que modulen el risc d'infecció, ,així com de la selecció natural actuant sobre les vies cel·lulars implicades en la patogènesi de la malaltia. Finalment, també aportem noves dades sobre l'estructura genètica de les poblacions sub-saharianes analitzades.One of the strongest selective forces affecting human populations in recent history is the malaria parasite Plasmodium falciparum, which is the cause of a variety of well-established examples of pathogen-induced adaptation in humans. A special form of malaria is pregnancy-associated malaria, which is characterised by the accumulation of infected erythrocytes in the placenta, and causes up to 200,000 maternal and infant deaths every year. The aim of this work is to characterise how this particular form of malaria has shaped human genetic variation. To that end we use methods of both evolutionary genetics and molecular epidemiology, reporting the first large-scale investigation of the genetic basis of placental infection. Our results provide new insights into genes modulating the risk of infection, as well as natural selection acting on cellular pathways involved in the pathogenesis of the disease. Finally, we also provide new data on the genetic structure of affected populations in Sub-Saharan Africa.
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Ashraf, M. "Evolutionary genetics of salt tolerance." Thesis, University of Liverpool, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.372678.
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Mackinnon, Margaret J. "Evolutionary genetics of malaria parasites." Thesis, University of Edinburgh, 1998. http://hdl.handle.net/1842/15243.
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Two empirical studies on parasite virulence using the laboratory model of the rodent malaria parasite, Plasmodium chabaudi, in inbred mice, were conducted. In the first, the average virulence and transmissibility in eight parasite clones obtained from the wild were measured over four replicate experiments. Large amounts of genetic (between-clone) variation in virulence and transmissibility were observed. Virulence was strongly correlated, both phenotypically and genetically, to population growth rate (parasitaemia) and less strongly correlated to transmissibility. These results provide strong support for the basic tenet of most evolutionary models of parasite virulence, namely, that virulence is a by-product of the parasite's need to replicate fast in order to be transmitted. In the second study, between-host selection for high and low virulence was performed within two parasite clones. Over eleven generations, all the selection lines increased in virulence and transmissibility. Thus, despite artificial between-host selection, parasitic variation within clones coupled with inadvertent within-host selection, allowed the parasite to adapt to a novel host. Together, these studies show that virulence is strongly determined by parasite genetics. A large data set on disease severity from a 3-year longitudinal field study in Sri Lanka was analysed for the effects of host genetic variability, age, immune experience, parasite species (P. falciparum vs. P. vivax), bednet use, sex and other host or environmental factors. The results highlighted the importance of short-term acquired immunity in causing large between-host variation in virulence. This is consistent with the view that parasite variability is responsible for inefficient clinical immunity to malarial disease, although this could not be examined directly and alternative explanations are possible. Two theoretical models incorporating parasite population structure into population genetics were used to predict the probability and rate of evolution of multi-locus drug resistance. All of these studies suggest that parasite genetic variation plays a key role in the evolution of the malaria host-parasite association.
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Wright, Martin Charles. "Studies in evolutionary chemistry." Thesis, University of Oxford, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.335825.
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Nielsen, Johanna Fonss. "Evolutionary genetics of meerkats (Suricata suricatta)." Thesis, University of Edinburgh, 2013. http://hdl.handle.net/1842/7677.
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Cooperative species have long been the focus of much research due to the ‘special difficulty’ cooperation poses to the theory of evolution via natural selection. Despite this long history of scientific interest we actually know relatively little about the evolutionary genetics of cooperative mammalian species, especially in the wild. In this study I use long-term data from the Kalahari Meerkat Project to investigate some aspects of the evolutionary genetics of meerkats (Suricata suricatta). First, I reconstructed a genetically-validated pedigree of the Kalahari meerkat population. 1,494 meerkats (83% of the total known population) were genotyped at a panel of 18 highly variable microsatellite markers. This genetic data, in combination with phenotypic information and two different programs, COLONY2 and MASTERBAYES, was used to infer familial relationships. The resulting pedigree spanned seven generations and included 1,614 individuals of which 1,076 had both parents known. I conclude by discussing the particular merits of using COLONY2 to infer familial relationships for social animals such as meerkats. Second, I investigated the extent of inbreeding and inbreeding depression in early life traits in the Kalahari meerkat population. In the pedigree, 44% of individuals have non-zero (F>0) inbreeding coefficients. Although I found more inbreeding in meerkats than initially expected, there were few cases of inbreeding between very close relatives. Nonetheless, even low to moderate inbreeding appeared to result in inbreeding depression for pup mass at emergence, hind-foot length, growth until independence, and juvenile survival. I also found some tentative evidence for a positive effect of the social environment in ameliorating the effects of inbreeding depression. Third, I conducted a quantitative genetic analysis on mass, skull length, skull width, forearm length, and hind-foot length in up to five key meerkat life stage periods, while accounting for a number of fixed effects, including inbreeding coefficient. By attempting to apportion variance in these traits to a variety of sources I found that birth litter identity often explained much of the variance in morphological traits, although the magnitude of this effect appeared to decline with age. Furthermore, when birth litter was removed from models, the amount of variance explained by additive genetic effects tended to increase. Finally, I conducted a quantitative genetic analysis on two measures of cooperative care and on adult mass. Fixed effects, including inbreeding and relatedness coefficients, were also examined, which revealed that inbred individuals contribute more to pup-feeding, and that helper-recipient relatedness was negatively associated with baby-sitting. I found low heritable variation for baby-sitting (h2 = 0.10) and pup-feeding (h2 = 0.08), and higher heritable variation for adult body mass (h2 = 0.19). I also estimated the magnitude of non-genetic sources of variation in these traits and provide evidence for positive genetic correlations between baby-sitting and pup-feeding, and baby-sitting and adult mass.
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Reynolds, Louise. "Evolutionary genetics of adaptation in Lepidoptera." Thesis, University of Liverpool, 2016. http://livrepository.liverpool.ac.uk/3004573/.
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Revolutions in sequencing technology have provided an unprecedented opportunity to uncover the genetic basis of traits of adaptive importance, enabling researchers not only to merely describe the means of inheritance of traits but also to establish the genetic changes under selection. This thesis examines the loci involved in two recent episodes of strong selection, namely the suppression of Wolbachia-induced male-killing in the butterfly Hypolimnas bolina and the evolution of melanism in moths. H. bolina has evolved the ability to suppress the male-killing effects of the heritable endosymbiont Wolbachia. This thesis demonstrates firstly that this results from a single locus trait that doesn't involve genetic variants beyond chromosome 25. This simple genetic basis explains in part the speed of spread of the suppressor in natural populations. The hypothesis that the insect sex determination gene doublesex is the target of selection is then examined. Compatible with this hypothesis, doublesex variants were found to cosegregate with suppression, and that the peak of a selective sweep is located within doublesex region. An unusual pattern of inheritance was uncovered at the doublesex locus, suggestive of a duplication event. These data are consistent with, though not proof of, Wolbachia driving the evolution of this key sex determination gene. The progression of a selective sweep for the suppression, as it travelled in space across Independent Samoa, was then examined. The sweep across Independent Samoa corroborated the genomic region immediately around doublesex as the target of selection. The sweep was very broad but weakened as it progressed across Samoa. The thesis then examines the genetic basis of melanism in Lepidoptera, and compares the genomic region associated with a naturally selected melanistic form to a laboratory mutant. The 'natural' example corresponded to a known genomic hotspot for colour pattern evolution, whereas this region was excluded in the laboratory mutants. These data support the pleiotropic view of convergence - that involvement of a single region is associated with minimized non-target effects. The thesis ends with a discussion of these data and a programme for future research in the area.
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Robertson, Michael Paul. "Engineered regulation of an RNA ligase ribozyme." Access restricted to users with UT Austin EID Full text (PDF) from UMI/Dissertation Abstracts International, 2001. http://wwwlib.umi.com/cr/utexas/fullcit?p3035968.
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Loh, Yong-Hwee Eddie. "Genetic variation in fast-evolving East African cichlid fishes: an evolutionary perspective." Diss., Georgia Institute of Technology, 2011. http://hdl.handle.net/1853/41148.
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Cichlid fishes from the East African Rift lakes Victoria, Tanganyika and Malawi represent a preeminent example of replicated and rapid evolutionary radiation. In this single natural system, numerous morphological (eg. jaw and tooth shape, color patterns, visual sensitivity), behavioral (eg. bower-building) and physiological (eg. development, neural patterning) phenotypes have emerged, much akin to a mutagenic screen. This dissertation encompasses three studies that seek to decipher the underpinnings of such rapid evolutionary diversification, investigated via the genetic variation in East African cichlids.
We generated a valuable cichlid genomic resource of five low-coverage Lake Malawi cichlid genomes, from which the general properties of the genome were characterized. Nucleotide diversity of Malawi cichlids was low at 0.26%, and a sample genotyping study found that biallelic polymorphisms segregate widely throughout the Malawi species flock, making each species a mosaic of ancestrally polymorphic genomes. A second genotyping study expanded our evolutionary analysis to cover the entire East African cichlid radiation, where we found that more than 40% of single nucleotide polymorphisms (SNPs) were ancestral polymorphisms shared across multiple lakes. Bayesian analysis of genetic structure in the data supported the hypothesis that riverine species had contributed significantly to the genomes of Malawi cichlids and that Lake Malawi cichlids are not monophyletic. Both genotyping studies also identified interesting loci involved in important sensory as well as developmental pathways that were well differentiated between species and lineages. We also investigated cichlid genetic variation in relation to the evolution of microRNA regulation, and found that divergent selection on miRNA target sites may have led to differential gene expression, which contributed to the diversification of cichlid species.
Overall, the patterns of cichlid genetic variation seem to be dominated by the phenomena of extensive sharing of ancestral polymorphisms. We thus believe that standing genetic variation in the form of ancestrally inherited polymorphisms, as opposed to variations arising from new mutations, provides much of the genetic diversity on which selection acts, allowing for the rapid and repeated adaptive radiation of East African cichlids.
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Emerson, Kevin James. "Evolutionary and physiological genetics of biological timing /." Connect to title online (Scholars' Bank) Connect to title online (ProQuest), 2009. http://hdl.handle.net/1794/10286.
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Shackelton, Laura A. "The evolutionary genetics of small DNA viruses." Thesis, University of Oxford, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.432409.
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Montgomery, Stephen Hugh. "The primate brain : evolutionary history & genetics." Thesis, University of Cambridge, 2012. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.610157.
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Poetter, Karl. "Molecular population and evolutionary genetics of Rickettsiae /." The Ohio State University, 1989. http://rave.ohiolink.edu/etdc/view?acc_num=osu148767034687517.
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Emerson, Kevin James 1980. "Evolutionary and physiological genetics of biological timing." Thesis, University of Oregon, 2009. http://hdl.handle.net/1794/10286.
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xii, 109 p. : ill. (some col.) A print copy of this thesis is available through the UO Libraries. Search the library catalog for the location and call number.There are two fundamental environmental rhythms that organisms in nature encounter: (1) the daily rhythm of light and dark that is due to the rotation of the earth about its axis and (2) the yearly seasonal rhythm due to the angle of the earth's rotation relative to the plane of its orbit around the sun. All eukaryotes have an endogenous circadian (daily) clock that allows for the timing of biological events within the context of the daily light:dark cycle. A wide diversity of plants and animals in temperate regions use photoperiodic (daylength) cues to time life history events, such as reproduction and diapause (insect dormancy) within the context of the yearly seasonal cycles. This dissertation focuses on the relationship between the circadian clock, photoperiodic time measurement and diapause. Chapter I serves as an introduction to biological timing and briefly summarizes the chapters that follow Chapter II outlines why Drosophila melanogaster , the workhorse of modern insect genetics, is not an appropriate system for the study of photoperiodism. Chapter III defines the Nanda-Hamner response, the circadian phenotype used in this dissertation, and proposes that the NH response is due to a rhythmic level of circadian disorganization in response to environmental cycle length. Chapters IV and V deal primarily with the long-held proposition that the circadian clock forms the causal basis of photoperiodic time measurement. I show that variation in the circadian clock does not covary with photoperiodic phenotypes among natural populations of Wyeomyia smithii , and thus these two processes are evolutionarily independent. Chapter VI describes the first forward genetic screen for candidate genes involved in photoperiodism and diapause termination in any animal. Chapter VII is a discussion of the complexity involved in studies of the genetics of photoperiodism and diapause and how historical inertia of scientific hypothesis acts to confound, rather than clarify, the relationship between genotypes and phenotypes. Chapter VIII is a concluding discussion of the implications of the work presented. This dissertation includes both previously published and co-authored material.
Committee in charge: William Cresko, Chairperson, Biology; William Bradshaw, Advisor, Biology; Patrick Phillips, Member, Biology; Eric Johnson, Member, Biology; Stephen Frost, Outside Member, Anthropology
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Hellborg, Linda. "Evolutionary Studies of the Mammalian Y Chromosome." Doctoral thesis, Uppsala : Acta Universitatis Upsaliensis : Univ.-bibl. [distributör], 2004. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-4126.
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Sawyer, Sarah Lynn. "Using SNPs to study complex genetic disease : a population and evolutionary genetics perspective /." Stockholm, 2004. http://diss.kib.ki.se/2004/91-7349-967-6/.
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Westerberg, Ivar. "Deciphering the formation of evolutionary new centromeres in a microchromosome of birds." Thesis, Uppsala universitet, Institutionen för biologisk grundutbildning, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-424933.
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Henning, Frederico [Verfasser]. "Evolutionary Genetics of Coloration in Cichlids / Frederico Henning." Konstanz : Bibliothek der Universität Konstanz, 2015. http://d-nb.info/1099913462/34.
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Patirana, Anoma. "Evolutionary and conservation genetics of kittiwakes ( Rissa spp.)." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape2/PQDD_0020/MQ53020.pdf.
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Clark, Rebecca. "The evolutionary genetics of polymorphic butterfly wing patterns." Thesis, Imperial College London, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.428582.
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Eales, Jacqualyn. "Evolutionary genetics of early colonisation in Caribbean Anolis." Thesis, Bangor University, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.446545.
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Marsden, Clare Diana. "Evolutionary & ecological genetics of African wild dogs." Thesis, University of Glasgow, 2010. http://theses.gla.ac.uk/2412/.
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Loss of adaptive variation arising from population declines and fragmentation is a primary concern in conservation. However, many conservation programmes assess only neutral genetic variation. Whilst assessments of neutral variation are informative about demographic history, inbreeding and genetic structure, they do not provide information on adaptive variation. The Major Histocompatibility Complex (MHC) is a group of genes that has been extensively studied and are known to be important in effective immune responses. Given the threat posed by infectious diseases to wildlife, the MHC is increasingly being assessed in endangered species. African wild dogs (Lycaon pictus, hereafter wild dog) are an endangered canid that has suffered extensive declines in the wild and now persist as small and fragmented populations totalling less than 8,000 individuals. The purpose of this study was to assess how neutral and MHC marker data genetic data can be used to assist conservation of this species. As such, I assessed sequence diversity across ~300bp of mitochondrial DNA, patterns of polymorphism and heterozygosity at 10 neutral microsatellite loci, compared to sequence variation and haplotype diversity at the MHC. Wild dogs were found to be genetically depauperate at the MHC compared to other canids. Patterns of variation indicate a historical loss of variation, followed by more recent diversification. However, it was also shown that evolutionary history contributes to differences in diversity between species. The spatial and temporal structure of MHC diversity was found to be largely correlated with neutral markers, which may suggest that selection is unable to counter strong genetic drift in such small populations. Overall, genetic diversity of both neutral and MHC markers appeared to be largely determined by demographic stability and size of populations. Habitat fragmentation and loss were associated with genetic isolation of wild dog populations, which showed strong structuring. However, the barriers to, or corridors for, dispersal of wild dogs were not always clear. The European captive breeding population was found to have comparable diversity metrics to wild populations, and was found to contain a large proportion of the MHC variation from the Southern African populations from which they were originally sourced. Careful genetic management is now required to correct the severe over- and underrepresentation of some founder lineages in this captive population to reduce inbreeding and loss of genetic variation.
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Elis, Mabon. "Evolutionary genetics of flower colour variation in Antirrhinum." Thesis, University of East Anglia, 2018. https://ueaeprints.uea.ac.uk/69572/.
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Phenotypic differences between species and populations can reveal much about how they have adapted and responded to a complex set of environmental cues. Studies have shown that genetic control of some traits is centralised to single genomic regions, while others are regulated at many unlinked loci dispersed throughout the genome. One trait that shows an enormous degree of variation between plant species is flower colour, and its tractability makes it an ideal trait for studying genetic differences underlying species differentiation. Antirrhinum majus has long been used as a model for studying floral traits, including colour. The 20-30 wild Antirrhinum species use diverse patterns on their flowers, formed by producing and accumulating magenta anthocyanins and yellow aurones in different tissues, to attract pollinators. In this project, I sought to genetically map flower colour phenotypes to the Antirrhinum genome. Several Antirrhinum species were crossed to A. majus to generate segregating populations. I used a combination of bulked segregant analysis, individual genotyping of segregating populations and analysis of genome sequences from wild accessions to test whether genes governing each colour trait were concentrated at particular loci or dispersed across many chromosomes. I found that variation in magenta not previously characterised maps to the known ROSEA-ELUTA (ROS-EL) locus where transcription factors regulating anthocyanin production are encoded. Yellow phenotypes from three species mapped to chromosome 2, where there is reduced recombination between A. majus and many wild species, and where an aurone biosynthetic enzyme is encoded. However, there appear to be some additional modifiers of flower colour in these species, not linked to the ROS-EL and chromosome 2 loci. These results fit neither the central- nor dispersed-control models of genetic control, but rather an intermediate hypothesis - that flower colour can be changed by selection acting on a modest number of loci spread throughout the genome.
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Silva, Martins Walter Fabricio. "Evolutionary genetics of insecticide resistance in Culex quinquefasciatus." Thesis, University of Liverpool, 2015. http://livrepository.liverpool.ac.uk/2047820/.
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Culex quinquefasciatus mosquitoes play an important role in the transmission of vector-borne diseases of public health importance including lymphatic filariasis (LF) as well as many arboviruses. Insecticide-based approaches are one of the most important interventions to mitigate disease burden; nevertheless increased resistance of vectors to insecticides imposes a challenge for the sustainability and effectiveness of both current and future vector control interventions. Hence, understanding the dynamics and likely mechanisms underlying the evolution of resistance will be critical to effective decision-making in insecticide resistance management strategies. The present study was set out to investigate the genetic basis of insecticide resistance in C. quinquefasciatus from Uganda. Two objectives were developed, 1) to investigate patterns of insecticide resistance across the south of the country and how this might reflect local selection and genetic structure and 2) to investigate the basis of the molecular mechanisms underlying resistance to all four classes of insecticides recommended for vector control. The population genetic study compared and contrasted microsatellite markers and two resistance-associated loci (Vgsc-1014F and Ace1-119S). While no significant difference in genetic diversity across populations were detected by microsatellites, higher frequency of Vgsc-1014F compared to the Ace1-119S mutations was observed in all populations suggesting that the Ugandan Eastern – Southwest populations are under a heterogeneous selection pressure, which created a pattern of local adaptation in these populations. Additionally, the copy number (CN) assay developed in this study indicated the presence of CN variation in the voltage gated sodium channel (Vgsc) gene in about 10% of the individuals assayed from these populations. Genotypic/phenotypic association tests conducted on bendiocarb resistant-individuals suggested that this resistant phenotype was not underlying solely by the 119S target-site mutation in the Ace-1 gene. Indeed, synergist bioassays show an increase of mortality of around 25% in mosquitoes pre-exposed to either TTP or PBO, indicating a possible resistance mediated by detoxification enzymes. Using a novel whole-transcriptome microarray we profiled the bendiocarb-resistant phenotype and implicated two P450s (Cyp-Cx1 and Cyp6n23) with the highest up-regulation expression compared to a susceptible strain. Remarkably, the predicted Cyp-Cx1 is closely related to two P450s from the family Cyp6, which were already validated in vitro as insecticide metabolizers in A. gambiae and A. aegypti, which corroborates a likely association of metabolic resistance in the investigated bendiocarb-resistant phenotype. Taken together the results yielded by genomic and transcriptomic experiments provide evidence that Ugandan C. quinquefasciatus mosquitoes are under heterogeneous selection pressure imposed by insecticides from distinct classes, and that the evolution of insecticide resistance is mediated by at least two main genetic mechanisms; target-site mutations (Vgsc-1014F and Ace1-119S) as well as over-expression of detoxification enzymes.
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Xu, Yiyang. "Topics in population genetics and mathematical evolutionary biology." Thesis, University of Bristol, 2015. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.682366.
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Part A studies the optimal strategies of seed germination problems where the population has a class structure under a fluctuating environment . In particular, a multidimensional age-class model is studied using a dynamical programming method. Numerical results about the so-called optimal stochastic strategy which consists of information about previous environmental states are computed. Comparing the optimal stochastic strategy with the optimal population-based strategy shows that the optimal stochastic strategy is highly effective in genera.l. A potentially useful diffusion approximation for the seed germination problem is also derived with numerical results. For part B, a multi-dimensional Moran model is studied using a diffusion approximation approach. The scaling limit and corresponding governing stochastic partial differential equations (SDEs) are derived. An expansion method is used to approximate the stationary distribution of the SDEs. An approximation formula for the effective migration rate is then derived.
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McGuigan, Katrina Louise. "Evolutionary genetics of rainbowfish : phylogeny, adaptation and constraint /." St. Lucia, Qld, 2001. http://www.library.uq.edu.au/pdfserve.php?image=thesisabs/absthe16397.pdf.
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Flowers, Jonathan M. "Evolutionary genetics of the tidepool copepod Tigriopus californicus /." Diss., Connect to a 24 p. preview or request complete full text in PDF format. Access restricted to UC campuses, 2005. http://wwwlib.umi.com/cr/ucsd/fullcit?p3171114.
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Jackson, Hazel Anne. "Evolutionary conservation genetics of invasive and endemic parrots." Thesis, University of Kent, 2015. https://kar.kent.ac.uk/50698/.
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The world is now thought to have entered into a sixth mass extinction event, which unlike previous mass extinctions, is entirely driven by human impacts. The early colonisation of humans has led to as many as a thousand endemic bird species becoming extinct, while increasing human mediated transport of species around the world has led to invasive species becoming one of the largest global conservation challenges of today. Studies in molecular ecology can help us to unravel how evolutionary processes are important for informing conservation and invasion biology by understanding genetic mechanisms that enable populations to grow and adapt in a changing world. As genetic diversity is essential for the persistence of populations, this thesis aims to understand how species respond, at a genetic level, to human-driven events such as the reduction of a population to a small size, or the introduction of a species into a novel environment. The findings demonstrate the important use of genetic markers for phylogenetic reconstruction and understanding population structure. These phylogenetic reconstructions examine taxonomic distinctiveness and patterns of evolution, and allow the identification of ancestral origins for invasive ring-necked parakeets. Evidence from genetic phylogroups, trade data and drivers of population growth, highlight how multiple introductions and patterns of climate matching between the native and invasive ranges of ring-necked parakeets, are mechanisms for invasion success. In contrast to mild genetic bottleneck effects, high levels of diversity and the avoidance of problems associated with small population size within populations of invasive ring-necked parakeet, the endemic Seychelles black parrot exhibited a reduction in population size and reduced levels of genetic diversity over time. Moreover, the inclusion of new genetic data for a number of extinct parrot species enabled an examination of the loss of broader scale phylogenetic diversity, important for ecosystem function, as a result of extinctions of endemic species and invasions of ring-necked parakeets. The findings from this thesis have already been applied to conservation and invasion biology by contributing to the reclassification of the endemic Seychelles black parrot, and to improving the ability of ecological niche models to predict areas suitable for future invasions of ring-necked parakeets. Furthermore they provide a novel approach to identifying potential candidates as ecological replacements to restore ecosystem function and lost phylogenetic diversity.
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Twyman, Hanlu. "Evolutionary genetics of CYP2J19 in red carotenoid pigmentation." Thesis, University of Cambridge, 2018. https://www.repository.cam.ac.uk/handle/1810/271129.
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Carotenoids are responsible for much of the bright yellow to red colours in animals and have been extensively studied as condition dependent signals in sexual selection. In addition to their function in coloration, carotenoids also play a crucial role in colour vision within certain lineages. Despite this, little is known about the genetic mechanisms underlying carotenoid based pigmentation. Recently, the gene CYP2J19 was strongly implicated in red ketocarotenoid pigmentation for coloration and colour vision within two lineages of song birds (the zebra finch and the red factor canary). Here, I extend the investigation of the function of CYP2J19 in colour vision and red coloration amongst reptiles. I suggest that the original function of CYP2J19 was in colour vision and that it has been independently co-opted for red coloration within certain red lineages. Using a combination of phylogenetic and expression analysis, I study the role of CYP2J19 as the avian ketolase involved in red ketocarotenoid generation within a clade of well-studied seed-eating passerines, the weaverbirds, and demonstrate a direct association between levels of CYP2J19 expression and red ketocarotenoid-based coloration. Next, I consider the evolution of CYP2J19 across multiple avian lineages. I find evidence for positive selection acting on the gene coding sequence despite its conserved function in colour vision. This finding, though surprising, appears to be common across avian CYP loci in general. Finally, by considering the genomic organisation of CYP2J19 in the zebra finch, I find that the gene underwent a duplication event near the base of the estrildid lineage, which was followed by significant gene conversion post-duplication. Overall, the findings provide strong support for the role of CYP2J19 in red ketocarotenoid pigmentation and demonstrate how an understanding of evolutionary genetics benefit the study of the evolution of adaptive phenotypes.
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Parahitiyawa, Nipuna Bandara. "Phylogenetic aspects of oral bacterial microbiome." Thesis, Click to view the E-thesis via HKUTO, 2009. http://sunzi.lib.hku.hk/hkuto/record/B43278486.
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Douglass, Nicola Jennifer. "Molecular and evolutionary analysis of a gene conserved in most Orthopoxviruses." Doctoral thesis, University of Cape Town, 1993. http://hdl.handle.net/11427/25663.
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Evidence is presented to show that variola and monkeypox viruses evolved independently from a common ancestor. An open reading frame (ORF), potentially coding for a protein of 341 amino acid residues, was found to be conserved in two strains of variola virus (Harvey and Somalia), but degenerate in the Denmark strain of monkeypox virus. Monkeypox virus had a deletion of 391 bp, two 24bp deletions and a single base pair deletion within the coding region of this single copy ORF. The ORF corresponds to the E5R ORF in the published sequence of the Copenhagen strain of vaccinia virus, and the DNA sequence was determined for an additional strain of vaccinia virus, Dairen. A number of other Orthopoxviruses were found to contain this ORF, strengthening confidence in its presence in an ancestral Orthopoxvirus. The equivalent DNA sequence was determined for a number of monkeypox virus strains from West and Central Africa. The Denmark strain was identical to one from Liberia, indicating that this virus probably originated from West Africa. A third virus from West Africa, Benin, was found to have >99% base similarity and the same pattern of deletions as the other two monkeypox viruses. The Zaire strains were identical to one another and different from the West African strains. Like the West African strains, they contained the two 24bp deletions and single base pair deletion. In place of the large deletion they had three smaller deletions of 5-, 9- and 127-bp as well as a single base pair insertion. They also had additional deletions of land 2-bp and an insertion of 3bp. The West African strains have the potential to code for a truncated gene product of 107 amino acid residues, whereas the Zaire strains have no significant ORF. This clearly shows that monkeypox virus has diverged into two geographically isolated groups (Zaire and West Africa). There was >99% base similarity between the two groups, suggesting that the divergence occurred recently. Phylogenetic analysis, by the neighbour-joining method, was undertaken on the corresponding DNA sequences from variola (2 strains), monkeypox (6 strains), vaccinia (1 strain + 2 published sequences), cowpox (2 strains), taterapox, camel pox and ectromelia viruses. For every species gerbilpox virus was the nearest neighbour, suggesting that taterapox virus may be the species most closely related to the common ancestral Orthopoxvirus. Within the variola and cowpox virus species there was >99% DNA sequence conservation. Between species, camelpox virus was the most closely related species to gerbilpox virus, with variola virus, and, more distantly, vaccinia virus, falling into the same group. Cowpox virus was the most diverged species examined. Ectromelia virus shared a branch with cowpox virus. A comparison was made of the intergenic DNA sequence between this ORF and the adjacent downstream ORF. Variation was found, both within and between species, in the form of insertions and deletions. The interrelationships between the different Orthopoxvirus species more or less parallels that of the E5R-equivalent comparison. Some of the viruses had clusters of direct repeats. A pentameric repeated unit was found in 2, 10 and 17 copies in camelpox, gerbilpox and ectromelia viruses respectively. Raccoon poxvirus had a 7bp unit in 13 adjacent copies. The two cowpox viruses had a more complex arrangement of repeated sequences. It was thought that the ESR ORF may prove to be nonessential for virus replication. This was tested by interruption of the E5R gene in vaccinia virus; this did not affect the ability of the virus to form plaques in cell culture, but appeared to reduce the pathogenicity of the 'virus for rabbits. The deduced amino acid sequences were analysed for conserved and variable regions within the gene, to which no specific function has yet been assigned.
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Cheng, George. "Uncovering the genetic organisation of Claroideoglomus candidum." Thesis, Uppsala universitet, Institutionen för biologisk grundutbildning, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-392016.
Full textAbstract:
Arbuscular mycorrhizal (AM) fungi are hypothesized to have been key players in facilitating thetransition from aquatic to terrestrial plants and continue to benefit plants through their symbioticassociation after 450 million years. These fungi form mycelia that can contain hundreds of nucleiwithin one aseptate cytoplasm, which leads to the ongoing debate on whether thesemultinucleated fungi are homokaryotic or heterokaryotic. Not only is there evidence to supportthe hypothesis of the nuclei as genetically identical, but also the other hypothesis of divergentnuclei within a single strain. There has been no evidence of sexual reproduction, howeverspecialized genomic regions specific to meiosis and a putative mating-type (MAT) locus haverecently been identified and may help answer the ongoing debate between homokaryosis andheterokaryosis. In this study I applied de novo genome assembly and annotation of 24 individual nuclei from asingle spore of Claroideoglomus candidum. The full length of the de novo genome assembly was87.6 Mb with 17,542 genes. Estimated polymorphism between the nuclei was very low. Iidentified the MAT locus in C. candidum, using a previously sequenced MAT locus fromanother congeneric species. Only one of the MAT locus alleles was found in the examined spore.The evidence points towards homokaryosis as the genetic organization of Claroideoglomuscandidum.
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Pennell, Tanya Marie. "The evolutionary dynamics of intralocus sexual conflict." Thesis, University of Sussex, 2016. http://sro.sussex.ac.uk/id/eprint/60057/.
Full textAbstract:
Males and females often have divergent evolutionary interests, sparking two forms of sexual conflict: 1) interlocus sexual conflict (IRSC), an antagonistic interaction between the sexes that is mediated by different loci in each sex; 2) intralocus sexual conflict (IASC), where genes have opposite fitness consequences depending on the sex expressing them. Both forms of conflict appear to be common, yet there are large gaps in our understanding of their evolutionary dynamics. I focus on IASC and begin by synthesising theoretical concepts and empirical findings to better understand its evolutionary dynamics in a critical review of the topic (Chapter 1). I take a multifaceted approach by considering the maintenance, resolution, and consequences of this evolutionary feud. I then explore the extent of sexually antagonistic genetic variation for fitness in a large-scale study of Drosophila melanogaster, using hemiclonal analysis (Chapter 2). I compare results to data collected from the same population five years previously and show that the strength of the conflict has declined over time. Next, I show that subtle changes in temperature during the adult life-stage can dramatically affect sex-specific fitness and alter the direction of the conflict, which could contribute to the maintenance of IASC in natural populations (Chapter 3). I also present a new theoretical model that incorporates IASC into traits that are involved in IRSC arms races (Chapter 4). Surprisingly, IASC can have dramatic and contrasting effects on sexually antagonistic coevolution: stabilising arms races or drawing the sexes into repeated bouts of arms race escalation and stasis. Finally, I extend IASC theory to explore an analogous conflict between castes in social animal societies (Chapter 5) and suggest unique research opportunities to be capitalised upon in species with a division of labour. I summarise the work in this thesis by highlighting the broad and varied biological consequences of such a pervasive conflict (Chapter 6).
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O'Connor, Timothy. "Detecting evolutionary dynamics of genotype-phenotype associations." Thesis, University of Cambridge, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.609119.
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Rice, Sean Hill. "The influence of development on evolutionary dynamics: A theoretical investigation." Diss., The University of Arizona, 1991. http://hdl.handle.net/10150/185631.
Full textAbstract:
Development is the process by which genes build organisms. It thus determines how genetic variation is translated into phenotypic variation. The dynamics of evolution are therefore determined not only by the action of selection and drift, but also by the processes by which organisms are built. I present a general model with which to study how selection acts on a developmental program. This model explains, and clarifies, the trend towards conservatism in early development. Furthermore, it predicts that this conservatism will be reduced under certain environmental conditions, namely when fitness functions are fluctuating. This leads to the prediction of the pattern of nearshore innovation seen in the fossil record. A more careful test of the theory requires a system in which we have some understanding of the details of development. I provide this in the form of a model of shell growth in mollusks. This model predicts shell form as a function of the interactions between shell producing tissues during growth. Using this system, I test the prediction of the general model that characters that are not correlated with, but not independent of, many other characters should evolve slowly. This prediction is upheld by data gathered from 8 genera of marine gastropods.
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Bryant, Josephine Maria. "Evolutionary genomics of pathogenic mycobacteria." Thesis, University of Cambridge, 2015. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.708462.
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McHenry, Michael Lyon. "Genomic and Co-Evolutionary Determinants of Clinical Severity in Active Tuberculosis Patients." Case Western Reserve University School of Graduate Studies / OhioLINK, 2021. http://rave.ohiolink.edu/etdc/view?acc_num=case1623754259445275.
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Shi, Ying. "Molecular studies of the evolutionary relationships of Brachypodium (Poaceae)." Thesis, University of Leicester, 1991. http://hdl.handle.net/2381/35347.
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The evolutionary relationships of the isolated genus Brachypodium (Poaceae) with genera in the Triticeae and with Festuca and Bromus have been investigated at different DNA levels, i.e. repetitive DNA, both nuclear and chloroplast RFLPs, 5S ribosomal DNA spacer, and ribosomal DNA repeat units. Brachypodium was found to have one of the smallest genomes known, with a very small amount of repetitive DNA and a largely undermethylated genome. A group of cloned repeated DNA probes was found to be genus-specific. The low/single copy DNA probes isolated from Brachypodium hybridised to a wide range of grass genera, and detected RFLPs among them. The RFLPs appeared mostly to be derived from deletion/insertion events. A chloroplast DNA probe was highly polymorphic both between species in Brachypodium and between different genera. The presence of a single copy of rpsl5 gene in Brachypodium was observed. Two 5S gene families were amplified via PCR. The smallest 5S spacer was only 150bp, which is the smallest one identified so far in the Poaceae. The ribosomal DNA in the genus was analysed and four restriction maps of rDNA were constructed. The degree of length variation of rDNA in Brachypodium was found to be low. The genome organisation and the structure of 5S DNA and rDNA are different from those of Triticeae. The evolutionary position of Brachypodium in relation to Triticeae, Festuca and Bromus was analysed by parsimony method using RFLP data and 5S spacer sequences. The most parsimonious trees showed that Brachypodium is well separated from Triticeae, Festuca and Bromus. The evidence from the work reported in this thesis is in favour of placing Brachypodium in a separate tribe instead of combining it within Triticeae or any other tribe. In addition, the structure and the distribution of 5S gene families and of rDNA has a clear taxonomic value within the genus Brachypodium. Finally, the relative taxonomic value of various components of DNA at different taxonomic levels using a range of molecular techniques is discussed.
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Tomkins, Janine. "Molecular and evolutionary investigation of the phosphoglucomutase gene family." Thesis, University College London (University of London), 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.362936.
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Denny, Paul William. "The apicomplexan plastid DNA : an evolutionary and molecular study." Thesis, University College London (University of London), 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.264810.
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Osborn, Andrew Mark. "Evolutionary analysis of bacterial mercury resistance in natural environments." Thesis, University of Liverpool, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.262489.
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Huebinger, Ryan Michael. "Genetic relationships and evolutionary history of extant Bowhead whale populations, Balaena mysticetus." [College Station, Tex. : Texas A&M University, 2007. http://hdl.handle.net/1969.1/ETD-TAMU-1514.
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Vasemägi, Anti. "Evolutionary genetics of Atlantic salmon (Salmo salar L.) : molecular markers and applications /." Umeå : Dept. of Aquaculture, Swedish Univ. of Agricultural Sciences, 2004. http://epsilon.slu.se/s324.pdf.
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com, cmarshall@tobob, and Carina Rynn Ecremen Marshall. "Evolutionary Genetics of Barramundi (Lates Calcarifer)in the Australian Region." Murdoch University, 2005. http://wwwlib.murdoch.edu.au/adt/browse/view/adt-MU20050421.134447.
Full textAbstract:
Barramundi (Lates calcarifer) is a centropomid teleost with a wide distribution across the
Indo Pacific. In Australia, barramundi are native to the tropical zone from Exmouth Gulf
in Western Australia, across the northern part of the continent, to the Mary River in
Queensland. Barramundi are protandrous hermaphrodites, and are euryhaline, with a
catadromous life history. Barramundi are a valuable Australian resource, with important
commercial and recreational fisheries and aquaculture production to the value of $11
million dollars per year. Recent declines in the availability of the fish in some rivers has led
to an interest in the possibility of restocking rivers with barramundi from other areas.
Determining the genetic structure of barramundi populations in Australia is important for
understanding biogeographic history, and appropriate management practices for both
aquaculture and recreational and commercial fishing. Previous studies have concentrated
on the east coast of Australia, and have largely ignored the western populations. In this
study, I obtained DNA data from barramundi populations across the Australian range of
the species, as well as populations from Papua New Guinea and Indonesia. The aims of
this study were to use the genetic data to determine: 1. if populations in Western Australia
show genetic differences between geographic regions 2. if these populations show an
ancestral split from populations in the east of Australia and 3. the ancestral origins of
Australian barramundi.
Previous studies of DNA data from barramundi have discovered an east/west split
occurring at the Torres Strait that was assumed to be caused by the closing of the strait
during lowered sea levels. However, these studies suffered from a bias in sampling area,
concentrating either on the eastern half of the range of barramundi, or on the western tip
of the range. Data from these studies were combined and reanalyzed. Two major clades
were discovered, with considerable biogeographic structuring, but their geographic
locations did not coincide with the reported vicariance event at the Torres Strait. Instead,
historical divisions among freshwater drainage systems appeared to have driven the
evolutionary history of barramundi in Australia.
In order to investigate these historical divisions further, a 290 bp section of the
mitochondrial DNA control region was sequenced in 284 barramundi from seven
populations across the Australian geographic range of the species and from one population
in Papua New Guinea and one population in Indonesia. Analyses of molecular variance
within and among populations showed significant geographic structuring, based on
biogeographical provinces and drainage divisions. Nested clade analyses indicated that
these geographical associations were the result of restricted gene flow, range expansion,
and past fragmentation events. I hypothesise that the Ord River area in the west of the
continent was the ancestral source population for the rest of the species range across
Australia, with Indonesia being the most likely origin of this source. Populations of
barramundi from the Pilbara region are genetically distinct and geographically isolated, with
strong evidence of an ancestral divide along geographical barriers to dispersal. There is a
strong association between Papua New Guinea and Australia, although further investigations using the cytochrome b region of mitochondrial DNA indicated a more
ancestral divide between the two than is currently evident, which could reflect an ancient
geographical divide between the two, or could be evidence of a secondary migration route
to Australia.
For a more detailed study of evolutionary processes acting on populations of barramundi in
Western Australia, allelic diversity was examined at five microsatellite loci. All loci were
polymorphic and genotypic frequencies conformed to Hardy-Weinberg expectations, with
no significant linkage between loci evident in any population. Measures of within
population diversity were significantly related to latitude, suggesting southerly migration
from a northern source population. The Ord River was the most genetically diverse
population, and the most likely ancestral migration source to the area, with diversity
decreasing down the west coast. Although there were significant differences among
populations, the nuclear microsatellite data do not indicate the same degree of genetic
structuring as is evident in the mitochondrial data. This may be a consequence of rapid
evolutionary change at microsatellite loci, with past separations or population differences
masked by recombination and back mutation of the microsatellite alleles. However, the
nature of nuclear and mitochondrial inheritance may also indicate life history differences
between the sexes, where significant genetic contribution to gene flow by males and limited
female gene flow may lead to preservation of maternally inherited population substructure.
The principal findings from this study are:
There is no genetic evidence for an east/west division of barramundi populations
in Australia, as suggested by previous research.
Despite barramundis catadromous life history, and ability to disperse through
marine waters, the present genetic structure indicates a division principally among
river drainages. From a population genetic viewpoint, the species can be regarded
as freshwater, rather than marine.
The most likely origin of barramundi in Australia is the Ord River region, with
Indonesia as the route of migration.
Differences in the population structure demonstrated by nuclear and mitochondrial
data indicate possible life history differences between the sexes.
Barramundi populations in different biogeographical provinces may have been
substantially isolated over a long period of time, and may therefore represent
independently evolving populations. This has important implications for fishery
management and translocation issues for restocking rivers.
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Viljakainen, L. (Lumi). "Evolutionary genetics of immunity and infection in social insects." Doctoral thesis, University of Oulu, 2008. http://urn.fi/urn:isbn:9789514289286.
Full textAbstract:
Abstract In social insects a major cost of social life is the high number of pathogens found in large societies and the greater likelihood of transmission of pathogens among closely related individuals. The aim of this thesis was to investigate the effect of high pathogen pressure on the molecular evolution of genes involved in the innate immune system in social insects. In addition, the transmission dynamics of the intracellular bacteria Wolbachia in wood ants was examined. By comparing DNA sequences from diverse species of ants and honeybees it was shown that the immune genes in hymenopteran social insects have evolved rapidly. However, by using codon-based likelihood models of evolution positive selection was detected in only two ant genes. This may reflect behaviourally based colony-level defences that can reduce selective pressure on the immune genes. The transmission modes of Wolbachia were studied by comparing DNA sequence variation of the bacteria with that of the host ants. First, it was found that all the studied ants carry Wolbachia. Second, Wolbachia have been transmitted both vertically from mother to offspring and horizontally between individuals of the same as well as of different speciesTiivistelmä Yhteiskuntahyönteisten (muurahaiset, ampiaiset, mehiläiset ja termiitit) ekologisen menestyksen kääntöpuolena on ollut jatkuva riesa taudinaiheuttajista, joita suurissa yhteisöissä tavataan runsaammin kuin yksittäin elävissä eliöissä. Taudinaiheuttajien tuoman paineen myötä yhteiskuntahyönteisille on kehittynyt käyttäytymiseen perustuvia puolustusmekanismeja täydentämään kaikille monisoluisille eliöille yhteistä synnynnäistä, fysiologista immuniteettia. Nämä puolustusmekanismit ovat todiste siitä, että taudeilla on ollut suuri merkitys yhteiskuntahyönteisten käyttäytymisen evoluutiossa. Toisaalta taudinaiheuttajien vaikutuksista synnynnäiseen immuunipuolustukseen tiedetään hyvin vähän. Väitöstutkimuksen ensisijainen kohde oli taudinaiheuttajien merkitys yhteiskuntahyönteisten synnynnäisen immuunipuolustuksen evoluutiossa. Tutkimuksessa tarkasteltiin, miten immuunijärjestelmän geenit ovat ajan mittaan muuttuneet. Tulokset osoittivat että muutoksia, jotka johtavat proteiinien aminohappojen vaihtumiseen on tapahtunut tiuhempaan tahtiin muurahaisilla ja mehiläisillä kuin yksittäin elävällä banaanikärpäsellä. Merkkejä erityisen voimakkaasta luonnonvalinnasta löydettiin kuitenkin yllättävän pienestä määrästä geenejä. Tämä voi johtua siitä, että käyttäytymiseen perustuvat puolustusmekanismit lieventävät taudinaiheuttajien vaikutusta synnynnäiseen immuunipuolustukseen. Väitöstutkimukseen sisältyi myös hyönteisten solunsisäisen bakteerin, Wolbachian, siirtymismekanismien kartoitus kekomuurahaisilla. Wolbachia on loinen, joka siirtyy yleensä äidiltä jälkeläisille munasolussa. Leviäminen voi tapahtua myös horisontaalisesti lajitoverien ja jopa eri lajien edustajien kesken. Geenisekvensseihin perustuvassa tutkimuksessa kaikista muurahaisista löytyi Wolbachia-bakteereja, ja samasta yksilöstä saattoi löytyä useaa eri bakteerikantaa. Koska muurahaislajien väliset geneettiset erot olivat paljon suurempia kuin erot niissä elävien bakteerien välillä, voitiin päätellä että bakteerien pääasiallinen leviämistapa tutkituilla muurahaisilla on ollut horisontaalinen
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Affenzeller, Michael. "Population genetics and evolutionary computation : theoretical and practical aspects /." Linz : Trauner, 2005. http://www.gbv.de/dms/ilmenau/toc/490631479affen.PDF.
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Lewin, Paul Dominic. "Embryology and the evolutionary synthesis : Waddington, development and genetics." Thesis, University of Leeds, 1998. http://etheses.whiterose.ac.uk/1455/.
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The role of embryology, genetics and morphology within mid twentieth century evolution theory, is discussed in the context of the growth to dominance of natural selection as the orthodox mechanism of adaptive evolution. The unification of neo-Mendelian heredity and neo-Darwinian selection theory, is descnbed as the core of modern synthetic neo-Darwinism as it emerged in 1930s mathematical population genetics. As selectionism strengthened within synthetic neo-Darwinism, embryological development was excluded from its traditional causal role in adaptive evolution within the "old synthesis" of Haeckelian recapitulation and neo-Lamarckian inheritance. A two-tier embryology was created, as embryology was understood to deal separately with the experimental analysis of ontogenetic development, and the historical descriptive analysis of phylogenetic lineages. Neither tier informed the other, or played any direct causal role in the mechanism of the creation of adaptive evolutionary novelty. That adaptive evolutionary mechanism was entirely the preside of natural selection. However, as the selectionist synthesis hardened in the 1940s, late nineteenth century Darwinists' concerns over the hereditary fixation of highly specific adaptive somatic modifications resurfaced. Consequently, the strategic defence of the synthetic theory against any resurgence of neo-Lamarckian heredity, involved an appeal to the principles of modem synthesis developmentalism; namely, the developmentalist syntheses of Waddington and Schmalhausen. The unforeseen implication of these moves by founding supporters of the synthetic theory, was that the disciplines upon which 1940s developmentalism rested--namely, Western chemical embryology and Soviet evolutionary morphology--did after all playa central and causal role in the mechanism of adaptive evolution. Attempts to characterise the alternative and developmentalist syntheses of Waddington and Schmalhausen as the "missing links" to an otherwise incomplete modem synthesis, are historically evaluated. These attempts are thought to embody either a mistaken understanding of the essential nature of synthetic neo-Darwinism, or an obfuscation of the continuing issue of its synthetic adequacy.
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Davies, Neil. "Origins of diversity : the evolutionary genetics of Caribbean butterflies." Thesis, University College London (University of London), 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.309290.
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Majerus, Tamsin Mary Olivier. "The evolutionary genetics of male-killing in the Coccinellidae." Thesis, University of Cambridge, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.620427.
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Paape, Timothy. "Evolutionary genetics of self-incompatibility in solanaceae and papaveraceae." Diss., [La Jolla] : University of California, San Diego, 2009. http://wwwlib.umi.com/cr/ucsd/fullcit?p3372555.
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Thesis (Ph. D.)--University of California, San Diego, 2009.Title from first page of PDF file (viewed Oct. 6, 2009). Available via ProQuest Digital Dissertations. Vita. Includes bibliographical references.
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Goudie, Frances. "The Evolutionary Genetics of Thelytokous Parthenogenesis in Eusocial Hymenoptera." Thesis, The University of Sydney, 2014. http://hdl.handle.net/2123/13632.
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The phenomenon of thelytoky, the asexual production of diploid female offspring, is being increasingly uncovered among the eusocial Hymenoptera. Thelytoky is associated with a number of fascinating and novel reproductive systems. In this thesis I investigate the evolutionary and genetic consequences of thelytokous parthenogenesis, with particular focus on the Cape honey bee Apis mellifera capensis (hereafter Capensis). In Capensis thelytoky is associated with loss of heterozygosity, which can only be curtailed by ongoing selection against homozygous offspring. This selective cost is one factor that drives the distribution of thelytokous reproduction within the Capensis population, as different castes differ in their ability to endure the costs, and capitalise on the benefits of thelytoky. Considering these costs and benefits in a broader context, I show that the distribution of thelytokous parthenogenesis across the eusocial Hymenoptera can be accounted for by the constraints imposed by caste conflict within an insect colony.