Complementing Cois Coiribe’s Spring Edition focus on Earth, Ocean, and Natural Sciences, this spotlight feature on Dr Christina P. Tadiri explores her unique research and motivations. Read on to find out more about both her academic insight and her vision for the years to come.
Title and name
Dr Christina P. Tadiri
College and/or department
College of Science and Engineering
Introduction…
My name is Christina and I’m a Lecturer in Environmental Sciences at University of Galway. I completed my Bachelor’s degree and PhD at McGill University in Montréal, Canada, in Environment and Biology, respectively. I am generally interested in how the environment shapes infectious disease dynamics. During my undergrad, I conducted a small risk assessment for Lyme Disease in a local park at a time when Lyme was emerging in Québec, and for my honours research, I used guppies and their ectoparasite Gyrodactylus to study how environmental food availability interacted with host condition to shape the spread of disease.
For my PhD, which was funded by the Canadian National Science and Engineering Research Council, I expanded on this work to study how various environmental variables and population-level characteristics – including host resistance and tolerance to infection, connectivity, and distribution – interacted with each other to influence epidemic dynamics in metapopulations.
After my PhD, I spent one year at the Research Institute of the McGill University Health Centre studying how the social environment, particularly gender and culture, shape human disease epidemics, including Covid-19. I also spent one year in Biology studying how nutrient enrichment – a common consequence of agricultural and urban runoff – may destabilise aquatic ecosystems. I investigated how that destabilisation may be propagated downstream across metacommunities. I then moved to Basel, Switzerland, on a Marie Curie Fellowship and the University of Basel’s Research Fund for Excellent Junior Researchers. While there, I spent three years studying how various environmental variables, including temperature, predation, and bioturbation, influence host–parasite interactions using water fleas (Daphnia) and their parasite Pasteuria ramosa as a model system.
I joined University of Galway last year to start my own research lab, where I continue to explore these types of questions using a combination of field-observational, lab-experimental, and theoretical work.
Can you describe the main focus of your current research? What problem or question are you trying to solve?
I am currently focused on deepening our understanding of the biodiversity–disease relationship. There are two main hypotheses about how biodiversity may influence disease. The ‘dilution effect’ suggests that higher species diversity can reduce disease transmission by decreasing the abundance of highly competent disease hosts. The ‘amplification effect’, on the other hand, posits that diverse communities could harbour more disease vectors or reservoirs, leading to increased disease transmission and potential for spillover. To what degree either of these occur in nature or in what contexts remains an open question in disease ecology. At the same time, what is often overlooked in this question is that disease can influence biodiversity, either through contributing to species loss, or by mediating inter-species competition through supressing the more dominant host.
I am currently exploring this feedback loop, as well as how abiotic environmental variables – such as temperature, nutrients, and other pollutants – may shift the balance of its outcomes, using Daphnia and their parasites as a model through a combination of field and experimental work. In the near future, I plan to scale this work up both spatially and temporally to study how dispersal among increasingly fragmented communities – a process that could benefit biodiversity but could also contribute to the spread of disease – may influence host–parasite co-evolution, and how other environmental variables may modulate these effects.
