Thesis (Ph. D.)--Rutgers University, 2007. / "Graduate Program in Ecology and Evolution." Includes bibliographical references.

Thesis (Ph. D.)--Rutgers University, 2008. / "Graduate Program in Ecology and Evolution." Includes bibliographical references (p. 138-149).

Thesis (Ph.D.)--University of Wollongong, 2006. / Typescript. Includes bibliographical references: p. 351-382.

In this thesis, I investigated the role of parental care in evolution. Parents provide the environment in which offspring develop and therefore have a large influence on their offspring's phenotypes, and so are in prime position to influence evolutionary processes. I used an experimental approach, and focused on the burying beetle, Nicrophorus vespilloides. The burying beetle is a perfect system for this question: they exhibit elaborate biparental care which is correlated with rapid speciation in the Nicrophorus genus. I started with a thorough exploration of burying beetle ecology and how the guild structure and interspecific competition in local populations can shape phenotypic evolution of my focal species, N. vespilloides. Interspecific competition shapes how the carrion niche is partitioned, which feeds back onto the evolution of body size within Nicrophorus reducing competition. The evolution of parental care in this genus likely facilitated its adaptive radiation, as parental care is linked with body size, both within and across species. But to what extent does the ecology shape the production and maintenance of phenotypic and genetic variation? I then use a quantitative genetic approach to show that body size and development time of N. vespilloides shows no additive genetic variation. Evolution of these fitness related traits can only occur through maternal effects or sibling effects. I tested this prediction by mimicking the radiation of the burying beetles by imposing my own selection on body size when parents could care for their offspring and when they could not. The presence of post-hatching parental care dramatically changed how populations responded to selection, through a combination of cooperation between parents and offspring, and cooperation between offspring. As well as shaping the evolutionary potential of populations, an experimental change in parental care can induce new selective forces, favouring adaptive novelties for the new social environment. Larvae evolving without parental care evolved disproportionately larger mandibles when small to better adapt them to a life without care. Much is known about the evolution of parental care across the animal kingdom, but what happens next: are the burying beetles a "one-off"? I compiled data across the arthropods comparing clades that exhibit post-hatching parental care with their sister clades and show that clades with care are more species rich. While the mechanism may not be the same as with Nicrophorus, I discussed other potential mechanisms that may be at play in the role of parents in evolution.

Understanding dispersal is a central aim of evolutionary ecology. Theoretical analyses of dispersal have been crucial in identifying key variables which contribute to its evolution and maintenance, but the supporting empirical data remains elusive. Microbes offer a powerful model system on which ecological and evolutionary theory can be experimentally tested with controlled and replicated experiments, and with the convenient malleability of selective pressures and bacterial genomics. Pseudomonas aeruginosa is an ubiquitous, opportunistic pathogen that is able to induce acute or chronic infections in a broad array of hosts. As well as in vivo environments, P. aeruginosa can be found in a range of ecological habitats, from solid to aqueous, and as such requires a variety of dispersal mechanisms (including swimming, gliding on a surfactant and ‘crawling’) for effective colonisation and infectivity. In this thesis, I present a collection of papers which outline empirical ecological and evolutionary experiments to identify the abiotic and biotic forces that shape the evolution of these different dispersal mechanisms, with particular focus on the theoretically important role of kin competition and the structure of the abiotic environment.

In this thesis, I explore four different ways in which relatedness affects sexual interactions in the red junglefowl Gallus gallus ssp., and the fruit fly Drosophila melanogaster. First, I show that in both species, inbreeding depression is sex-specific and modulated by parental age and gametic age. However, the sex that suffers higher inbreeding depression was trait- and species-dependent. Second, I examined patterns of inbreeding avoidance. I found no evidence of inbreeding avoidance in the fruit fly, but in the red junglefowl both males and females avoided mating with relatives, independently from sex-ratio of the social group. Third, I investigated whether relatedness amongst members of one sex affects mate choice in members of the opposite sex. Male fruit flies preferentially courted females unrelated to females with whom they had previously mated, while female flies displayed a weak preference for males related to their previous mates. In the red junglefowl, females exposed to male trios of two males related to each other and one unrelated male, displayed a marked preference for mating with the male unrelated to the other two males, and might also bias postcopulatory sperm utilization in favour of the unrelated male. Fourth, I explored the implications of male relatedness on the intensity of male-male competition. Male red junglefowl were less aggressive towards related competitors, but invested more sperm in females that had previously mated with a related male rather than with an unrelated male. In fruit flies, male relatedness had a strong impact on female life-history and offspring viability, although I found no evidence that these effects were modulated by changes in male-male competition. Collectively, the findings of these studies demonstrate the complex relationship between relatedness and other important biological phenomena as such senescence and sexual conflict.

Our bodies contain a vast number and diversity of microbes. These microbes interact, and these interactions can define how microbes affect us. Microbial ecology and evolution, therefore, are important for both microbiology and human health. However, our understanding of microbial communities remains limited. There is a need for theory that dissects the complexity and identifies the key factors and processes affecting microbial groups. Here I develop realistic computer simulations and population models of microbial communities. My first project seeks to explain microbial communication (quorum sensing) and argues that quorum sensing is a way to infer when competing genotypes are no longer a threat. The second project proposes an evolutionary explanation for another major microbial trait: adhesion. I argue that adhesion is a weapon allowing cells to compete within microbial groups and push competitors out, particularly when growing on a host epithelium. The third project moves from microbes to the host and asks whether a host can control which microbes grow and persist inside it. I develop a model of the human gut epithelium and show that the gut architecture amplifies the ability of hosts to select helpful microbes over harmful ones using nutrient secretion. In addition to selecting particular microbial strains, a host will also benefit from stable symbiotic communities that behave in a predictable manner. But what determines whether host-associated communities are ecologically stable? My final project uses ecological network theory to show that ecological stability is likely to be a problem for gut communities that are diverse and contain species that cooperate with each other. However, I argue that the host should function as an ecosystem engineer that increases ecological stability by weakening the strong dependence of cooperating species upon one another. While host-associated communities are complex ecological systems, my thesis identifies key factors that affect their form and function.

The ecological importance of introduced mammalian predators is well acknowledged in New Zealand, however, little research has focused on the ecology of native avian predators and their role in communities. This study investigated the ecology of moreporks (Ninox novaeseelandiae) on Ponui Island, Hauraki Gulf, New Zealand between August 2007 and April 2008. The primary aim was to investigate the functional response of moreporks to availability of their prey. The contents of regurgitated morepork pellets were compared with relative abundance of prey taxa (invertebrates, small birds and rodents) over the study period. The diet consisted primarily of a range of invertebrate prey, particularly weta (Anostostomatidae and Raphidophoridae) and beetles (Coleoptera). Small numbers of vertebrate prey were recorded including rodents and birds. A positive relationship between the percentage contribution to pellet samples of certain taxa and their relative availability was found, and there were peaks in the occurrence of seasonally abundant taxa including cicadas (Cicadidae), and huhu beetles (Prionoplus reticularis). The tendency of moreporks to prey on abundant taxa indicates that they are unlikely to depress prey populations to low levels, and may have some degree of stabilising influence. A significant increase in the rodent component of the diet in April indicated that the risk to moreporks of secondary poisoning during mammalian pest control operations may vary considerably with the time of year. The secondary aims were to collect data on roost site characteristics and breeding success. Moreporks roosted at a mean height of 4m, and foliar cover at the 4-6m height tier appeared to be the most important characteristic of roost sites when compared with control sites. These findings suggested that moreporks were selecting roost sites with high overhead cover. Possible reasons for this include predator avoidance, avoidance of mobbing passerines, and the microclimate provided. None of three established pairs and two other birds were observed to establish a nest or breed successfully. Additionally, only three juvenile moreporks were sighted or heard across the 90ha study area suggesting low breeding success in 2007-08. This may have been influenced by a range of factors including 1), predation by the high densities of ship rats on Ponui, or other predators 2), a lack of suitable nest sites such as tree hollows in some areas or 3), competition for invertebrate prey with high densities of ship rats and North Island brown kiwi (Apteryx mantelli).

O paradigma neoinstitucional assumiu, no fim do século XX e no começo do XXI, um papel de preponderância na Ciência Política, ditando as epistemologias e os métodos de se produzir conhecimento na disciplina. Suas duas principais correntes – institucionalismo da escolha racional e institucionalismo histórico – constituem marcos distintos de explicação dos fenômenos políticos, sendo os principais referenciais teóricos nas análises políticas institucionais. Porém, ambas correntes apresentam diversos problemas epistemológicos, fundados principalmente no caráter estático de suas abordagens sobre a fenomenologia política. Embora tal postura teórica fosse outrora suficiente para explicar a política, no mundo dinâmico atual, uma nova teoria que capte o dinamismo dos fenômenos políticos faz-se necessária. Neste sentido, o objetivo deste trabalho é apresentar uma proposta heurística para a análise das mudanças institucionais, denominada institucionalismo evolucionário. Esse modelo heurístico dialoga com a teoria evolucionária, o neoinstitucionalismo e a teoria dos jogos. Além da proposição desse modelo, este trabalho exemplifica sua aplicação por meio da análise da evolução das dinâmicas de segurança nas relações entre Polônia e Rússia no pós-Guerra Fria. / At the end of the 20th century and the beginning of the 21st century, the neoinstitutionalist paradigm assumed a preponderant role in Political Science, dictating the epistemologies and methods for producing knowledge in the discipline. Its two main theoretical streams – rational choice institutionalism and historical institutionalism – constitute distinct approaches to explaining political phenomena, and are the main theories for analysing politics under the framework of the paradigm. Nevertheless, both theories present many epistemological problems, based mainly in their static approach to political phenomenology. Although these theories have once managed to explain reality, our current dynamic world demands a new theory capable of analysing the dynamics of political phenomena. Therefore, this work aims to present a heuristics capable of understanding institutional change, known as evolutionary institutionalism. This heuristics dialogues with evolutionary theory, neoinstitutionalism and game theory. Other than this theoretical model, this work applies it in the analysis of security dynamics in the context of Polish-Russian relations in the post-Cold War period.

O paradigma neoinstitucional assumiu, no fim do século XX e no começo do XXI, um papel de preponderância na Ciência Política, ditando as epistemologias e os métodos de se produzir conhecimento na disciplina. Suas duas principais correntes – institucionalismo da escolha racional e institucionalismo histórico – constituem marcos distintos de explicação dos fenômenos políticos, sendo os principais referenciais teóricos nas análises políticas institucionais. Porém, ambas correntes apresentam diversos problemas epistemológicos, fundados principalmente no caráter estático de suas abordagens sobre a fenomenologia política. Embora tal postura teórica fosse outrora suficiente para explicar a política, no mundo dinâmico atual, uma nova teoria que capte o dinamismo dos fenômenos políticos faz-se necessária. Neste sentido, o objetivo deste trabalho é apresentar uma proposta heurística para a análise das mudanças institucionais, denominada institucionalismo evolucionário. Esse modelo heurístico dialoga com a teoria evolucionária, o neoinstitucionalismo e a teoria dos jogos. Além da proposição desse modelo, este trabalho exemplifica sua aplicação por meio da análise da evolução das dinâmicas de segurança nas relações entre Polônia e Rússia no pós-Guerra Fria. / At the end of the 20th century and the beginning of the 21st century, the neoinstitutionalist paradigm assumed a preponderant role in Political Science, dictating the epistemologies and methods for producing knowledge in the discipline. Its two main theoretical streams – rational choice institutionalism and historical institutionalism – constitute distinct approaches to explaining political phenomena, and are the main theories for analysing politics under the framework of the paradigm. Nevertheless, both theories present many epistemological problems, based mainly in their static approach to political phenomenology. Although these theories have once managed to explain reality, our current dynamic world demands a new theory capable of analysing the dynamics of political phenomena. Therefore, this work aims to present a heuristics capable of understanding institutional change, known as evolutionary institutionalism. This heuristics dialogues with evolutionary theory, neoinstitutionalism and game theory. Other than this theoretical model, this work applies it in the analysis of security dynamics in the context of Polish-Russian relations in the post-Cold War period.