Mosquitoes in a warming world : climate adaptation and its consequences for disease transmission
- Vector-borne diseases cause over one sixth of all illness worldwide and are emerging and expanding at an increasing rate, due largely to rampant anthropogenic change. Of all human diseases, vector-borne disease systems are uniquely sensitive to environmental change as their transmission involves interactions between multiple species, including ectothermic arthropods. Recognizing this, the potential impacts of climate warming on vector-borne disease transmission have been extensively studied, leading to a general expectation that warming may shift disease burdens towards higher latitudes and altitudes. However, the potential responses of pathogen vectors to warming remain poorly understood -- a knowledge gap my dissertation seeks to fill. In chapter 1, I apply a theoretical framework from conservation biology to synthesize prior information on the potential for mosquito thermal adaptation. Finding that a lack of information on within-species variation in mosquito thermal tolerance currently hinders our understanding of this process, I helped establish Aedes sierrensis as a model system to investigate this empirically in chapter 2. I conduct a common garden experiment measuring Ae. sierrensis thermal tolerance across the species' range—the largest such experiment to date—finding clear, but limited, evidence of current thermal adaptation. Despite this evidence, I find that evolutionary adaptation alone will likely be insufficient to enable persistence under ongoing warming, as the thermal limits of Ae. sierrensis are already frequently exceeded across their distribution. Following on this finding, I investigate the thermal vulnerability of major vector species across their ranges in chapter 3. I find that, when accounting for the ability to access cooler microclimates, most vector species are currently 'thermally safe.' Contrary to the expectation that tropical species are the most vulnerable to climate warming, I find that thermal safety was high around the equator and lowest in the subtropics given the high thermal extremes experienced there. Overall, this dissertation draws on concepts from conservation biology, and combines laboratory experiments with mathematical and statistical modeling, to improve our understanding of the eco-evolutionary responses of mosquito species to warming.
|Type of resource
|electronic resource; remote; computer; online resource
|1 online resource.
|Couper, Lisa Isabel
|Degree committee member
|Degree committee member
|Stanford University, School of Humanities and Sciences
|Stanford University, Department of Biology
|Statement of responsibility
|Submitted to the Department of Biology.
|Thesis Ph.D. Stanford University 2023.
- © 2023 by Lisa Isabel Couper
- This work is licensed under a Creative Commons Attribution Non Commercial 3.0 Unported license (CC BY-NC).
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