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dc.contributor.advisorNicholson, Wayne L.en_US
dc.contributor.advisorBirky Jr., C. Williamen_US
dc.contributor.authorMaughan, Heather*
dc.creatorMaughan, Heatheren_US
dc.date.accessioned2011-12-05T22:12:53Z
dc.date.available2011-12-05T22:12:53Z
dc.date.issued2006en_US
dc.identifier.urihttp://hdl.handle.net/10150/193989
dc.description.abstractThe loss of phenotypes, a phenomenon capable of leading to ecological specialization, has been observed to occur readily during evolution and is an important contributor to the phenotypic variation observed in nature. While the loss of phenotypes is often observed, the population genetic processes responsible for phenotypic loss are not well understood. This lack of understanding is due to the complexity of evolutionary process and the intricacy of how information from the genotype develops into the phenotype. The work presented in this dissertation is a first attempt to disentangle the complexity of the population genetics of trait loss in experimental populations of Bacillus subtilis, a bacterium of the low G+C Gram positive group. The experiments described in this dissertation showed that the deletion of two complex phenotypes occurred throughout evolutionary time. While there is evidence suggesting that this phenotypic loss may be due to trade-offs between traits that were lost and those important for fitness, i.e. selection, the contribution of neutral mutation accumulation cannot be ruled out. Genomic studies identified candidate expression changes potentially able to explain the observed phenotypic loss, paving the way for future work linking the observed phenotypic changes with their underlying genetic and developmental cause(s). The results from this dissertation work speak to the complexity of trait loss and the difficulty of explicitly determining whether selective or neutral processes are responsible for trait loss in nature.
dc.language.isoENen_US
dc.publisherThe University of Arizona.en_US
dc.rightsCopyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.en_US
dc.titleEvolution of Sporulation in Bacillus Subtilis: Functional Loss and Evolutionary Consequencesen_US
dc.typetexten_US
dc.typeElectronic Dissertationen_US
dc.contributor.chairBirky Jr., C. Williamen_US
dc.identifier.oclc659746256en_US
thesis.degree.grantorUniversity of Arizonaen_US
thesis.degree.leveldoctoralen_US
dc.contributor.committeememberBirky Jr., C. Williamen_US
dc.contributor.committeememberMoran, Nancy A.en_US
dc.contributor.committeememberNachman, Michael W.en_US
dc.contributor.committeememberPierson III, Leland S.en_US
dc.identifier.proquest1483en_US
thesis.degree.disciplineEcology & Evolutionary Biologyen_US
thesis.degree.disciplineGraduate Collegeen_US
thesis.degree.namePhDen_US
refterms.dateFOA2018-08-24T21:40:40Z
html.description.abstractThe loss of phenotypes, a phenomenon capable of leading to ecological specialization, has been observed to occur readily during evolution and is an important contributor to the phenotypic variation observed in nature. While the loss of phenotypes is often observed, the population genetic processes responsible for phenotypic loss are not well understood. This lack of understanding is due to the complexity of evolutionary process and the intricacy of how information from the genotype develops into the phenotype. The work presented in this dissertation is a first attempt to disentangle the complexity of the population genetics of trait loss in experimental populations of Bacillus subtilis, a bacterium of the low G+C Gram positive group. The experiments described in this dissertation showed that the deletion of two complex phenotypes occurred throughout evolutionary time. While there is evidence suggesting that this phenotypic loss may be due to trade-offs between traits that were lost and those important for fitness, i.e. selection, the contribution of neutral mutation accumulation cannot be ruled out. Genomic studies identified candidate expression changes potentially able to explain the observed phenotypic loss, paving the way for future work linking the observed phenotypic changes with their underlying genetic and developmental cause(s). The results from this dissertation work speak to the complexity of trait loss and the difficulty of explicitly determining whether selective or neutral processes are responsible for trait loss in nature.


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