Ecological and evolutionary effects of dispersal on freshwater zooplankton

A recent focus on contemporary evolution and the connections between communities has sought to more closely integrate the fields of ecology and evolutionary biology. Studies of coevolutionary dynamics, life history evolution, and rapid local adaptation demonstrate that ecological circumstances can dictate evolutionary trajectories. Thus, variation in species identity, trait distributions, and genetic composition may be maintained among ecologically divergent habitats. New theories and hypotheses (e.g., metacommunity theory and the Monopolization hypothesis) have been developed to understand better the processes occurring in spatially structured environments and how the movement of individuals among habitats contributes to ecology and evolution at broader scales. As few empirical studies of these theories exist, this work seeks to further test these concepts. Spatial and temporal dispersal are the mechanisms that connect habitats to one another. Both processes allow organisms to leave conditions that are suboptimal or unfavorable, and enable colonization and invasion, species range expansion, and gene flow among populations. Freshwater zooplankton are aquatic crustaceans that typically develop resting stages as part of their life cycle. Their dormant propagules allow organisms to disperse both temporally and among habitats. Additionally, because a number of species are cyclically parthenogenetic, they make excellent model organisms for studying evolutionary questions in a controlled environment. Here, I use freshwater zooplankton communities as model systems to explore the mechanisms and consequences of dispersal and to test these nascent theories on the influence of spatial structure in natural systems. In Chapter one, I use field experiments and mathematical models to determine the range of adult zooplankton dispersal over land and what vectors are moving zooplankton. Chapter two focuses on prolonged dormancy of one aquatic zooplankter, Daphnia pulex. Using statistical models with field and mesocosm experiments, I show that variation in Daphnia dormant egg hatching is substantial among populations in nature, and some of that variation can be attributed to genetic differences among the populations. Chapters three and four explore the consequences of dispersal at multiple levels of biological organization. Chapter three seeks to understand the population level consequences of dispersal over evolutionary time on current patterns of population genetic differentiation. Nearby populations of D. pulex often exhibit high population genetic differentiation characteristic of very low dispersal. I explore two alternative hypotheses that seek to explain this pattern. Finally, chapter four is a case study of how dispersal has influenced patterns of variation at the community, trait and genetic levels of biodiversity in a lake metacommunity.

From the human rights-based approach to an ecological approach on how to achieve successful inclusion in international disability education

The barriers that people with disabilities face around the world are not only inherent to the limitations resulting from the disability itself, but, more importantly, these barriers rest with the societal technologies of exclusion. Using a mixed methodology approach, I conduct a quest to revealing several societal factors that limit full participation of people with disabilities in their communities, which will contribute to understanding and developing a more comprehensive framework for full inclusion of people with disabilities into the society. First, I conduct a multiple regression analysis to seek whether there is a statistical relationship between the national level of development, the level of democratization, and the level of education within a country’s population on one hand, and expressed concern for and preparedness to improve the quality of life for people of disabilities on another hand. The results from the quantitative methodology reveal that people without disabilities are more prepared to take care of people with disabilities when the level of development of the country is higher, when the people have more freedom of expression and hold the government accountable for its actions, and when the level of corruption is under control. However, a greater concern for the well-being of people with disabilities is correlated with a high level of country development, a decreased value of political stability and absence of violence, a decreased level of government effectiveness, and a greater level of law enforcement. None of the dependent variables are significantly correlated with the level of education from a given country. Then, I delve into an interpretive analysis to understand multiple factors that contribute to the construction of attitudes and practices towards people with disabilities. In doing this, I build upon the four main principles outlined by the United Nations as strongly recommended to be embedded in all international programmes: (1) identification of claims of human rights and the corresponding obligations of governments, hence, I assess and analyze disability rights in education, looking at United Nation, United States, and European Union Perspectives Educational Rights Provisions for People with Disabilities (Ch. 3); (2) estimated capacity of individuals to claim their rights and of governments to fulfill their obligations, hence, I look at the people with disabilities as rights-holders and duty-bearers and discuss the importance of investing in special capital in the context of global development (Ch. 4); (3) programmes monitor and evaluate the outcomes and the processes under the auspices of human rights standards, hence, I look at the importance of evaluating the UN World Programme of Action Concerning People with Disabilities from multiple perspectives, as an example of why and how to monitor and evaluate educational human rights outcomes and processes (Ch. 5); and (4) programming should reflect the recommendations of international human rights bodies and mechanisms, hence, I focus on programming that fosters development of the capacity of people with disabilities, that is, planning for an ecology of disabilities and ecoducation for people with disabilities (Ch. 6). Results from both methodologies converge to a certain point, and they further complement each other. One common result for the two methodologies employed is that disability is an evolving concept when viewed in a broader context, which integrates the four spaces that the ecological framework incorporates. Another common result is that factors such as economic, social, legal, political, and natural resources and contexts contribute to the health, education and employment opportunities, and to the overall well-being of people with disabilities. The ecological framework sees all these factors from a meta-systemic perspective, where bi-directional interactions are expected and desired, and also from a human rights point of view, where the inherent value of people is upheld at its highest standard.