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- All Subjects: Health Disparities
- All Subjects: History of Science
- Creators: Lynch, John
explained by natural selection acting on traits that persisted "for the good of the group" prompted a series of debates about group-level selection and the effectiveness with which natural selection could act at or across multiple levels of biological organization. For some this topic remains contentious, while others consider the debate settled, even while disagreeing about when and how resolution occurred, raising the question: "Why have these debates continued?"
Here I explore the biology, history, and philosophy of the possibility of natural selection operating at levels of biological organization other than the organism by focusing on debates about group-level selection that have occurred since the 1960s. In particular, I use experimental, historical, and synthetic methods to review how the debates have changed, and whether different uses of the same words and concepts can lead to different interpretations of the same experimental data.
I begin with the results of a group-selection experiment I conducted using the parasitoid wasp Nasonia, and discuss how the interpretation depends on how one conceives of and defines a "group." Then I review the history of the group selection controversy and argue that this history is best interpreted as multiple, interrelated debates rather than a single continuous debate. Furthermore, I show how the aspects of these debates that have changed the most are related to theoretical content and empirical data, while disputes related to methods remain largely unchanged. Synthesizing this material, I distinguish four different "approaches" to the study of multilevel selection based on the questions and methods used by researchers, and I use the results of the Nasonia experiment to discuss how each approach can lead to different interpretations of the same experimental data. I argue that this realization can help to explain why debates about group and multilevel selection have persisted for nearly sixty years. Finally, the conclusions of this dissertation apply beyond evolutionary biology by providing an illustration of how key concepts can change over time, and how failing to appreciate this fact can lead to ongoing controversy within a scientific field.
There is a higher incidence of asthma, worse outcomes, and a higher burden of disease in Black Americans compared to white Americans. This thesis aims to understand asthma disparities in the Black population by analyzing a variety of social determinants of health and genetic factors that may contribute to these racial health disparities. Based on the evidence collected, a variety of interventions are discussed that explore potential solutions to address the critical issue.
This thesis addresses the global and national health landscape of disparities to provide insight into the social factors such as education, socioeconomic status, and environment that impact marginalized groups. A positive correlation between race, residency, and lower socioeconomic status among global and national landscapes was made with oral health disparities demonstrating poorer health outcomes among these groups. Through a multistep approach this thesis aimed to provide solutions to contribute to the efforts of developing effective policies and interventions that aim to promote oral health equity.
For most women, pregnancy is the period in which they will have more interaction with the healthcare field than any other period in their lives. The quality and accessibility of obstetric care varies greatly throughout the United States, and health disparities in this field have the largest impact on African American women. Black mothers in the U.S. are three to four times more likely than white mothers to die as a result of pregnancy related complications. The increased risk of maternal morbidity and mortality seen in the African American population is largely due to preventable causes. This thesis project includes three case studies which analyze the most prevalent and preventable sources of health disparity affecting Black mothers: preeclampsia, hemorrhage, and cesarean section. Possible solutions to each of these disparities are explored on an individual, institutional, and societal scale.