Holly Gaff

Holly Gaff

University of Tennessee
Graduate Research Associate

Taylor University
BS Mathematics/Environmental Science

University of Tennessee
PhD Mathematics with an emphasis in Ecology in progress

When I first started college, I was in a Math Education program, but by the end of my first year, I knew that education was not for me. However, I wasn't sure where to turn. I didn't enjoy math for the beauty of it so I knew that pure math wasn't my calling. I was much more interested in how math could be used to solve real world problems. I started taking biology classes since biology had been my second favorite class in high school after math. In an ecology class, the professor told me about an entirely new area of math that I never knew existed-Mathematical Ecology. After completing my B.S. in Math/Environmental Science, a degree program I created at Taylor University, I found the Mathematical Ecology graduate program at the University of Tennessee and was accepted. I am currently in my fifth year. I am hoping to complete my PhD sometime during my sixth year. I was a teaching assistant for one semester for each of my first four years in graduate school. I have spent the rest of my time in graduate school as a research assistant for a project called ATLSS.

ATLSS stands for Across Trophic Level System Simulation. This project creates a computer simulation of the South Florida Everglades ecosystem. ATLSS is currently part of the Central and Southern Florida Comprehensive Study Review with the goal of aiding plans for major changes to the hydrologic control systems over the next 30 years. This project demonstrates one of the newer areas of math ecology. It is a multi-model, i.e., a series of models linked together. Each model represents a different trophic level in the Everglades, e.g., hydrology, macroinvertebrates and fish, or particular species, e.g., the endangered Florida panther and Cape Sable Sea Side Sparrow. Each level uses an appropriate type of model, e.g., a coupled ordinary differential equation model, an age/size structured model or an individual-based model. These models are combined to give the best possible simulation of the entire ecosystem.

My specific job is to work on the fish model. I am responsible for writing and running the computer code for the model. I am also responsible for developing tools to visualize the output. The model itself is an age/size structured model and is run over the entire South Florida study area. The area is subdivided into 500m square cells. The fish in each cell grow, reproduce and move both within the cell and among neighboring cells. I use my math skills in both model development and computer programming.

Mathematical ecology and mathematical biology are growing fields. If you have any interest in applied math, I would encourage you to look into these fields. You need a strong background in applied math; in addition, computer programming and some knowledge of biology are very helpful. Six years in graduate school may seem like a long time, but it isn't considering that while I am here I don't just take classes, I gain experience both in teaching and research. When I graduate I can get a job teaching at a university, working for the government or working in industry.