Date of Award


Publication Type

Master Thesis

Degree Name



Great Lakes Institute for Environmental Research

First Advisor

Cristescu, Melania (Great Lakes Institute for Environmental Research)


Environmental science.



Creative Commons License

Creative Commons Attribution-Noncommercial-No Derivative Works 4.0 License
This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 4.0 License.


Freshwater organisms are constantly under pressure from an array of stressors with complex affects. In this thesis I first review the interactive effects on Daphnia pulex of three prevalent anthropogenic stressors: climate change, calcium decline, and toxic metal exposure. Then, I examine gene expression levels of five Daphnia genes related to carapace building and calcium homeostasis to understand the effects and interaction of low calcium and predator presence. Finally, I use phylogenetic reconstruction to explore the evolutionary history of one of the tested genes, the Sarco(endo)plasmic Calcium ATPase. My results indicate that both stressors tested and their interaction affects the expression patterns of all the tested genes, often in surprising ways. The results from the phylogenetic reconstruction suggest that many ancient and recent gene duplication events have shaped the evolution of this gene.