Thesis (Ph. D.)--University of Chicago, Committee on Deveopmental Biology, August 2002. / Includes bibliographical references. Also available on the Internet.

Thesis (Ph. D.)--University of Chicago, Committee on Evolutionary Biology, June 2003. / Includes bibliographical references. Also available on the Internet.

Thesis (Ph. D.)--University of Texas at Austin, 2004. / Supervisor: Tandy Warnow. Vita. Includes bibliographical references.

Thesis (M.F.A.)--Montana State University--Bozeman, 2006. / Typescript. Chairperson, Graduate Committee: David Scheerer. Includes DVD. Includes bibliographical references (leaves 52-56).

The entire thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file; a non-technical public abstract appears in the public.pdf file. Title from PDF of title page (University of Missouri--Columbia, viewed on November 13, 2009). Thesis advisor: Dr. Craig T. Palmer. Includes bibliographical references.

The history of life has involved several major evolutionary transitions that have each led to the emergence of a new individual. Examples of major transitions in individuality include the evolution of the eukaryotic cell, multicellular organisms and eusocial societies. In each of these events, previously independently replicating units (cells, individuals etc.) cooperate to form a new individual, which can then only replicate as a whole. For this to occur, conflict between individuals needs to be minimised, to allow maximising their inclusive fitness to be roughly equivalent to maximising group fitness. It has been predicted that the way in which social groups form should be key for eliminating conflict between individuals and promoting cooperation. In this thesis, I have focused on two major evolutionary transitions; the evolution of multicellularity and the evolution of symbiosis, and show that the mode of group formation (whether groups are parentoffspring associations or not) is crucial for understanding when and why major transitions occur. Firstly, I show that the major transition to obligate multicellularity has only occurred with clonal group formation (where cells remain together after division). Secondly, I use an experimental system to show that predation pressure may be key in promoting the formation of multicellular groups in algae. Finally, I show that the mode of group formation is also important in between-species transitions. I use the evolution of symbiosis to show that transmission route of symbionts and environmental factors, determine how cooperative symbionts will be towards their hosts.

The characteristics of space and the movement of agents are intrinsic elements which are fundamental to any class of biological problems. From the diffusion properties of small and macromolecules in the cytoplasm, to the migration patterns of populations in a macroecological perspective, it is now clear that a full understanding of the different phenomena requires further insights not only on how the different elements interact, but on the different ways they are distributed in space, according to the proper spatial scales for each problem. This work analyzes three different classes of biological problems, focusing on the role played by space in understanding the phenomena from a theoretical perspective. First, we investigate the clustering of mechanosensitive channels on bacterial membranes and how their spatial distribution can lead to collective behaviour, significantly altering their functions. Second, we study protein production, trying to understand how particular properties on ribosomes' diffusion are linked with specific features of the translation process. Finally, on a very different scale, we explore spatial patterns' formation on a coevolutionary problem, where the interaction between two species is site-dependent. We approach these problems with different analytical and numerical techniques, revealing new biological aspects and providing novel views on current discussions in each field. We believe our results reinforce the importance of theoretical approaches to Biology and how space can significantly change many of these models.

No description available.

My study investigates Edith Wharton's engagement with Darwin's evolutionary theory in "The House of Mirth" (1905), "The Custom of the Country" (1913), and "The Age of Innocence" (1920). The value of juxtaposing Wharton's narratives with her scientific knowledge has been recognized by critics since the 1950's. Yet, the few existing discussions of Darwinian allegory that examine these novels do not adequately describe the political dimension of Wharton's fictional sociobiology. My investigation addresses this insufficiency in the criticism. Examining Wharton's fiction in relation to her autobiographical writings, letters, and literary criticism, I demonstrate that her major novels link those laws governing gradual change in the natural world—described by Darwin, and theorists such as Herbert Spencer—with the ideological shifts affecting privileged social groupings. The introductory chapter outlines the critical response to Wharton's sociobiology, and examines specific scientific texts that the author refers to in her extra-literary writing. In chapter two I examine "The House of Mirth's" portrayal of cultural practices that lead to the elimination of unfit individuals such as Lily Bart, and show how Wharton critiques the position that natural selection and other laws theorized in The Origin of Species should apply within human society. The following chapter, on "The Custom of the Country", demonstrates Wharton's interest in representing the effects on existing leisure-class cultural practices of the newly-moneyed socioeconomic elite, whose rise Wharton attributes to social evolution. The novel also describes, I show, an inadequate leisure-class ethics that fails to confront the new elite's biological justification for expansion and dominance. Chapter four investigates "The Age of Innocence", in which Wharton takes aim at leisure-class morality by depicting it as a "negation" ( AI 212) of culturally obscured biological instinct, and by representing the sacrifice of individuals to a "collective interest" ( AI 111) that is portrayed as frivolous. In the concluding chapter, I summarize the ways I have extended existing Wharton scholarship, and describe potential pathways for future research. One key conclusion of my dissertation is that Wharton associates ideological change with natural selection, and sexual selection, in order to articulate the challenges to achieving social equality posed by "primitive" (CC 470) and "instinctive" (CC 355) energies. / Arts, Faculty of / English, Department of / Graduate

Genome-wide neutral diversity levels are shaped by both positive and purifying selection on linked sites. In humans like most species, the relative importance of these types of selection in shaping patterns of neutral diversity remains an open question. We can infer their relative contribution from observed patterns of neutral diversity by using information about recombination rates and targets of natural selection. To this end, I fit a joint model of the effects of positive selection (selective sweeps) and purifying selection (background selection) to genetic polymorphism data from the 1000 Genomes Project. I show that a model of the effects of background selection provides a good fit to patterns in diversity data and that incorporating the effects of selective sweeps does not improve the fit. Using my approach, the effects of background selection explain up to 60% of the variation in neutral diversity levels on the 1Mb scale and account for patterns in the data for which positive selection via selective sweeps had been invoked as explanations. I find that over 80% of the selected regions affecting neutral diversity levels are located outside of exons and that phylogenetic conservation is the best predictor of the source of selection in these regions. My results show that the genome-wide effects of background selection are pervasive, with measurable reductions in neutral diversity throughout almost the entirety of the autosomes. I provide maps of the effects of background selection and software for making similar inferences, which should provide important tools for future research that relies on interpreting patterns in neutral diversity levels.