Two processes may lead to genetic divergence among populations. One is mediated by geography, whereby physical barriers and geographic distance limit gene flow among populations, resulting in divergence due to drift or mutation. Another is ecological speciation, whereby populations adapt to their local environments via natural selection, and gene flow is impeded by selection against dispersers in favor of adapted residents. I used natural populations of guppies (Poecilia reticulata) to determine the relative influence of these two processes in the structuring of populations. If geography is playing a strong role, I predicted that gene flow would be greatly impeded by physical barriers and geographic distance. If ecology is playing a strong role, I predicted that gene flow would decrease with increasing strength of divergent selection among populations. Specifically, I examined the relative roles of physical barriers, geographic distance, predation, and various other habitat features (e.g. canopy cover, water velocity) on the amount of gene flow among populations. I was thus able to determine whether natural selection or decreased dispersal plays a greater role in the reduction of gene flow. I found that physical barriers and geographic distance played a large role in the regulation of gene flow among populations. Predation and physical habitat features did not play a role in the reduction of gene flow. My research clarifies the mechanisms involved in speciation and the production and maintenance of biodiversity, important issues in conservation and evolutionary biology.

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The colour of guppies (Poecilia reticulata) evolves as a compromise between sexual selection (favouring conspicuousness) and natural selection (favouring crypsis). However, guppies live in a variety of habitats and with a variety of predators and consequently in a variety of selective environments. I investigated how habitat and predator's visual systems affect the evolution of colour. I used regressions to assess the importance of habitat features on the evolution of colour for 29 guppy populations. I then quantified the colour of guppies living in the presence and absence of two predators. The prawn predator is insensitive to orange light while the fish predator is insensitive to ultraviolet light. Habitat explained some variation in colour, but not in a consistent manner. Guppies living with the prawn were more orange and guppies living with the fish had more ultraviolet reflectance, providing evidence for the use of these aspects of colour as private signals.

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This thesis analyzes the role of the press in five political campaigns in Trinidad and Tobago, over a ten year period, from 2000 to 2010. Using framing theory, it seeks to determine if the level of structural and partisan bias in the three daily newspapers in the country was a major factor in the outcome of general elections. This thesis further examines how press coverage of national elections contributed significantly towards development of a healthy democracy in Trinidad and Tobago and this research on media and politics, especially over a defined period of electoral volatility in the country, is the first of its kind in the Caribbean and will complement existing literature written on this subject worldwide. It is also the only comprehensive study on media bias in electoral coverage of political campaigns in Trinidad and Tobago in a context in which there have been public allegations of media bias by political leaders in the country. The two - pronged methodological approach of content analysis, and interviews with media practitioners allow for both qualitative and quantitative analysis of case studies of electoral campaigns using innovative research tools such as a bias scale and coding template, to minimize the margin of error in the analysis. In this thesis the issue of whether the press did have an influential effect on election outcome is also explored. Based on analysis and findings, this thesis proposes a new model of media and politics for countries like Trinidad and Tobago transitioning from a system of authoritarianism to liberalism called an “emerging liberal democratic model”. The evolution of this model is a work in progress which may have implications for other similar societies.

Classified as critically endangered since 1994, the Trinidad Piping guan (Pipile pipile) is an endemic species estimated to number less than 200 individuals. Known to locals of Trinidad as the ‘Pawi’ this bird has been the subject of substantial hunting pressures and much of the species habitat has been destroyed through deforestation. Although officially protected since 1958, occasional recreational hunting of this elusive species still occurs. Due to difficulties locating and capturing the species, no genetic research has previously been performed using samples obtained from Trinidad. All previous research studies have been conducted using biological materials obtained from captive birds outside Trinidad and island data has never been obtained or compared. The genetic diversity of the remaining population was therefore examined through the investigation of mitochondrial haplotypes, pairwise comparison and SNP analysis. With the intention of assisting the protection of this endangered species by the location of remaining areas of habitation, methods of genetic identification were established for the Trinidad Piping guan utilising non-invasive feather samples. Species specific primers were created in the regions of the ND2 and cyt b genes of the mitochondrial genome to identify Pipile pipile. Species detection was further verified with the use of PCR-RFLP of the same gene regions digested with BsaXI, EcoRV and BsrDI. This combined approach allowed the separation of closely related taxa based on single inter-species SNPs. Confirmation of species identification was subsequently performed through the use of forensically informative nucleotide sequencing. The established methodologies were used in the current study to correct the classification of a UK breeding population of Piping guans thought to be Pipile pipile and to identify Trinidad field samples. These detection methods have implications for ecological studies through the location of populations from trace evidence collected in the field. In addition this method could be used to assist Trinidadian police forces in the identification of bushmeats or simply act as a deterrent to hunters. The sequence data obtained in the present study were also used to re-assess the phylogeny of Piping guans. As genetic sequence from a true island bird was previously unstudied, differences between phylogenies created using non-island and island bird data sets were examined. Combined analysis was performed on 1884bp of the ND2 and cyt b genes and placement of Trinidad Piping guan was found to differ from that which has been previously published.

The identity of the Caribbean as a territory is a veritable bricolage of cultural forms. Since Columbus’ mistaken arrival in the West Indies, these islands have become home to Spanish, French, Dutch, British, African, Indian and Chinese immigrants, alongside its Aboriginal inhabitants. Despite the massive diversity that can be seen in these islands, there exists one common cultural expression that has persisted for the past 200 years throughout the Caribbean and Latin America. This celebration is Carnival. Trinidad is the southernmost island in the archipelago that composes the Caribbean. Carnival is celebrated in many of Trinidad’s towns, the biggest celebration being held in its capital city, Port-of-Spain. This research thesis looks at Carnival in Port-of-Spain as a complex urban entity that ritualistically re-energises and reclaims the city’s streets. Through ecstatic celebration, the festival engenders a strong sense of communitas and collective identity, annually reinventing itself and occupying a liminal space between the Ordinary city of day-to-day living and the Extraordinary city of mythological complexity. As the festival moves through the city along its annual Parade Route, it creates an urban narrative which exists invisibly during the year in the city’s collective memory. Through a combination of descriptive text, scholarly research and experiential mapping, A City with Two Faces outlines the transformative qualities of Carnival in the streets of Port-of-Spain from its largest temporary urban forms to its smallest manifestations in syncretic masquerade archetypes.