I am a combined DVM/PhD candidate in the Zamudio lab in the Department of Ecology & Evolutionary Biology. I am very pumped to integrate my veterinary training in animal health and physiology with research centered on infectious disease ecology and evolution. Broadly, I am interested in how hosts and pathogens interact temporally, how selection and adaptation mediate these relationships, and how we can use this knowledge to inform management decisions. My dissertation investigates amphibian host responses to chytrid fungus over multiple time scales using a combination of field sampling, laboratory infection trials, transcriptomics, and population genomics.

Prior to graduate school, I obtained a B.A. from Scripps College, where I was introduced to field ecology while studying abroad in Kenya and went on to pursue a thesis in spatial ecology. After undergrad, I had the privilege to research the drivers of bushmeat hunting as a Thomas J. Watson fellow.

This site is a work in progress, and mostly an excuse to teach myself some html. Please check back to see how long it takes me to figure out how to align my photos properly.

CV (updated Aug 2019)

1) How do Eastern newts respond to chytrid coinfection?

Eastern newts persist in the wild with high Batrachochytrium dendrobatidis (Bd) prevalence, yet seemingly little population-level effects. Meanwhile, Bsal is not yet present in North America. Given the high prevalence of Bd, if Bsal invades, newts will likely experience coinfection with both pathogens. In collaboration with Ana Longo and the Lips lab, I am using RNA-seq to examine newt immunogenomic responses to Bsal, Bd, and Bsal-Bd coinfection.

2) How does Bsal susceptibility vary across populations?

Understanding intraspecific variation in susceptibility is important for predicting how newts may react to Bsal invasion, how this may influence disease dynamics, and how we should manage an outbreak accordingly. I am particularly interested in how standing genetic variation, historical Bd prevalence, and other biotic and abiotic variables may impact Bsal susceptibility. In order to examine this, I collaborated with the Woodhams lab to sample Eastern newt populations along a latitudinal transect from Georgia to Vermont. I then ran an infection trial, the results of which I will correlate with population genomic diversity, Bd prevalence, and other variables.

1) How do host immune responses change over the course of Bd infection?

Quantifying variation in host immunogenomic responses throughout infection can help distinguish key components of susceptibility and resistance. I am examining Brachycephalus pitanga responses to different Bd lineages to identify disease correlates at early-, mid-, and late-stage infection.

2) How does pathogen-mediated selection shape host responses?

Infectious disease can act as a strong selective pressure on the host, and population persistence may depend on the evolution of resistance. To understand this evolutionary response, I am examining Centrolene prosoblepon adaptation to chytrid fungus following an epizootic event in Panama.

4. B.C. Scheele, F. Pasmans, L.F. Skerratt, L. Berger, A. Martel, W. Beukema, A.A. Acevedo, P.A. Burrowes, T. Carvalho, A. Catenazzi, I. De La Riva, M.C. Fisher, S.V. Flechas, C.N. Foster, P. Frías-Álvarez, T.W.J. Garner, B. Gratwicke, J.M. Guayasamin, M. Hirschfeld, J.E. Kolby, T.A. Kosch, E. La Marca, D.B. Lindenmayer, K.R. Lips, A.V. Longo, R. Maneyro, C. McDonald, J. Mendelson, P. Palacios-Rodriguez, G. Parra-Olea, C.L. Richards-Zawacki, M.O. Rödel, S.M. Rovito, C. Soto-Azat, L.F. Toledo, J. Voyles, C. Weldon, S.M. Whitfield, M. Wilkinson, K.R. Zamudio, S. Canessa. Amphibian fungal panzootic causes catastrophic and ongoing loss of biodiversity. Science, 363: 1459-1463. doi: 10.1126/science.aav0379

Media coverage: New York Times, The Atlantic, Washington Post, National Geographic, Scientific American, Forbes, Wired

3. Bower, D., L. Brannelly, C. McDonald, R. Webb, S. Greenspan, M. Vickers, M. Gardner, M. Greenlees. A review of the role of parasites in the ecology of reptiles and amphibians. Austral Ecology, 44: 433-448. doi: 10.111/aec.12695

2. Fitak, R., J.D. Antonides, E.J. Baitchman, E. Bonaccorso, J. Braun, S. Kubiski, A.C. Fagre, R.B. Gagne, J.S. Lee, J.L. Malmberg, M.D. Stenglein, R.J. Dusek, D. Forgacs, N.M. Fountain-Jones, M.L.J. Gilbertson, K.E.L. Worsley-Tonks, W.C. Funk, D.R. Trumbo, B.M. Ghersi, W. Grimaldi, S.E. Heisel, C.M. Jardine, P.L. Kamath, D. Karmacharya, C.P. Kozakiewicz, S. Kraberger, D.A. Loisel, C. McDonald, S. Miller, D. O’Rourke, C.N. Ott-Conn, M. Páez-Vacas, A.J. Peel, W.C. Turner, M.C. VanAcker, S. VandeWoude, J. Pecon-Slattery. The expectations and challenges of wildlife disease research in the era of genomics: forecasting with a horizon scan-like exercise. Journal of Heredity,110(3): 261-274. doi: 10.1093/jhered/esz001

1. Ellison, A, G. DiRenzo, C. McDonald, K. Lips, K. Zamudio. First in vivo Batrachochytrium dendrobatidis transcriptomes reveal mechanisms of host exploitation, host-specific gene expression, and expressed genotype shifts. G3: Genes| Genomes| Genetics, 7(1): 269-278. doi: 10.1534/g3.116.035873

1. McDonald, C., A. Ellison, T. James, F. Toledo, K. Zamudio. Gene expression varies within and between enzootic and epizootic lineages of Batrachochytrium dendrobatidis in the Americas. Revised and resubmitted to Fungal Biology (July 2019).

1. McDonald, C., A.V. Longo, K.R. Lips, K.R. Zamudio. Incapacitating effects of coinfection in a novel pathogen system. In prep for Molecular Ecology (July 2019).

Teaching philosophy

My overarching teaching philosophy is that purely didactic approaches are counterproductive to instilling students with respect and enthusiasm for the natural world. While foundational concepts should be conveyed, memorizing the Tree of Life is much less effective than exploring it. Whether teaching a first-year writing seminar or TAing laboratory-based classes, I encourage enthusiasm in my students by placing value on their individual experiences and perspectives. In my classes, learning is an engaged process, and thinking critically is imperative. I find that respect given to students is returned proportionally. I place emphasis on valuing each student’s unique background and the exciting power they wield in being able to contribute—through the sheer product of their lived experience—completely original and thus compelling perspectives on any subject they encounter.

Instructor of record:

  • BIOEE1640: Socially Responsible Wildlife Conservation in a Postcolonial World

I designed and taught an original, semester-long writing course for 17 students that focused on better understanding biodiversity conservation within a broader postcolonial, sociocultural, and scientific discourse. You can check out the website I developed for the course here (note: it is largely password-protected, but if you are interested in my syllabus or materials, please contact me).

Graduate TA experience:

  • BIOEE4701: Herpetology
  • BIOEE1780: An Introduction to Evolutionary Biology and Diversity
  • BIOEE2700: The Vertebrates: Comparative Anatomy, Function, and Evolution

As with any subject in the academy, biology can be jeopardized by its own self-reference. I try to think critically about biology within a larger societal context. We cannot fully understand science without acknowledging its history and grounding it in a cultural framework that recognizes implicit belief structures. Biology is one way to explain our world; it is not the only way, and recognizing a diversity of theories and disciplines always augments our comprehension.

One of the ways we can improve our science is by understanding who has access, who has been systematically barred from participating, and remedying this imbalance. In 2016 I co-founded Cornell’s Diversity Preview Weekend, a student-run program that invites underrepresented minority students to visit Cornell prior to applying and provides them with guidance about the application process (check out a synopsis of our first event here!). We have since expanded this program to include several departments, and we look forward to welcoming a fourth cohort this spring.

I think a lot about race, gender (p.s. I prefer they/them pronouns), sexuality, privilege, and allyship, and I'm excited to continue to collaboratively make biological research more inclusive and more accountable.


Corson Hall, Cornell University, Ithaca NY


(76O) 92O-3163