I consider myself to be both an evolutionary biologist and an amphibian biologist because I’m interested in studying the genetics of amphibians and the factors that influence their geographic ranges. For example, one big question is how changes in temperature and precipitation over the last 100,000 years have caused amphibian species ranges to expand, contract, and/or move. Learning more about how amphibian species have responded to climate changes in the past can help us predict how they will respond to future climate change. We can use this knowledge to design effective strategies for protecting species from decline and extinction.

In my research, I use DNA sequencing and geographic information systems (GIS) spatial analysis to answer questions about phylogenetics (how species are related) and phylogeography (how genetic variation within a species is organized in geographic space, or on a map). My dissertation research has led to some unexpected and very interesting discoveries.

I was surprised to learn that the southern redback salamanders in the Kisatchie National Forest in Louisiana are actually more closely related to salamanders in the Ouachitas in Arkansas and Oklahoma than they are to salamanders at the other Louisiana site at the Sicily Island Wildlife Management Area. In its lifetime, a southern redback salamander doesn’t travel much farther than the extent of a single log, so we would expect that nearby populations would be more closely related than populations spread much farther apart.

This surprising relationship is at least partially explained by my second discovery from climate analyses using GIS modeling: the range of the southern redback salamander was much broader and contiguous across the Southeast during the cooler climate of the Last Glacial Maximum (LGM), 21,000 years ago. So at some point in history, it is likely that Louisiana and the Ouachitas were connected by habitat suitable for this species instead of the geographic isolation we see today.

In addition to genetics lab work, my research also involves collecting salamanders in the field. The southern redback salamander is protected in Louisiana because of its small range in the state, so I cannot collect whole animals to study. Instead, I take a small part of the tail from a few salamanders at each site. This does not kill the animal or cause it any long-term harm, and we are able to extract high-quality DNA from these small tissue samples.

My project has not required extensive fieldwork, but any amount of scientific collection of protected species requires a special permit from the Louisiana Department of Wildlife and Fisheries. A typical collecting trip for me involves making sure I have a copy of my permits, gathering my gear (razor blades, alcohol for sterilization, small tubes with alcohol to store the tail tips, notebook, GPS), driving about 2.5 hours to the field site, spending a few hours searching for salamanders and collecting tissue samples, and driving home.