Madelyn Purnell

Adapting to Change: Evolutionary History of Extremophile Nematodes in the Great Salt Lake

Graduate, School of Biological Sciences

I am currently a Graduate Student working with Dr. Michael Werner. I am researching past climate change on Great Salt Lake (GSL) and its effect on community structures and gene response in model eukaryotic organisms. I came to the University of Utah after completing an undergraduate degree in Bioinformatics at Brigham Young University. I am passionate about educating about how climate change is affecting our ecosystems and what we can do about it.

Nematodes are microscopic worms that live all over the earth and thrive in some of the most extreme environments. They have an essential role in secondary production, nutrient cycling, and supplying necessary degradation in both marine and terrestrial soil ecosystems. Due to their necessity, many environmental scientists have used nematodes as bioindicators to evaluate environmental stress, and predict taxa habitability and species abundance. With recent findings of nematodes being discovered in saline lakes, we set out to see if nematodes were present in the extreme environment of the Great Salt Lake (GSL). The GSL is one of the largest hypersaline ecosystems in the world, with only brine shrimp, brine flies, and select microbes able to survive its extreme salinity. Recently, my lab obtained the first evidence that nematodes live in the south arm of the GSL. With salinity measuring 13-19% (more than twice the oceanic averages), this makes the GSL the most hypersaline environment in which nematodes have been discovered.

Given the important ecological functions of nematodes and the increase in salinity in lakes across the world, it is imperative to understand the ecology and evolution of nematodes in the GSL. These nematodes display remarkable resilience to the extreme ecosystem variation caused by megadrought and Utah’s ever-growing human population, making them an ideal model for animal evolution under extreme environmental pressure. We will do this by characterizing the new species of nematode and evaluating their environmental impact through fieldwork evaluations of GSL ecological functions and in-lab evaluations of the nematode’s physical and genetic characteristics that allow them to tolerate the harsh environment. All of this information can then be used as bioindicator input for predictive models of the GSL ecosystem which will be able to disclose valuable information about what stressors are most likely to cause ecological collapse and biodiversity decline in the GSL. This information will then be used to better inform policymakers about what practices are most likely to protect the GSL and what else can be done to ensure its continued survival.

Graduate Student Research and Professional Development Fellow