While mammals generally have 30 to 50 vertebrae divided into distinct regions, snakes can have between 100 and more than 400 body vertebrae, and between five and more than 200 tail vertebrae. Her goal is to understand biological diversity in the context of evolutionary history. 

“Since this variation of vertebral count is such a cool thing that we don’t understand, I hope to quantify it and to see how this trait functions evolutionarily,” said Folds, who is concentrating in biology and astronomy at Brown. “One of the questions our lab is asking is, ‘How does this variation in vertebrae count affect how snakes’ bodies work?’ My project will help create a foundation of data to help provide answers.”

To research the specimens — which are usually stored in glass jars filled with a liquid preservative that sustains the specimens’ lifelike appearance — Folds counts special scales on a snake’s belly that directly correlate to its number of vertebrae.

As she carefully counts the scales, she marks every group of 10 with a metal pin. Because the specimens are wet, she uses a pen and paper to document her observations and later adds the data into the computer back in the laboratory at Brown.

“It's great to have this incredible way to preserve data that we couldn't otherwise get,” Folds said. “Because of these carefully preserved specimens, I can look back and see what a snake looked like in, say 1930s Wyoming — that information is no longer lost to history.”

Hands-on summer research, from California to Connecticut

Folds is engaging in her summer research project with the support of Brown University’s Maria L. Caleel Fellowship for seniors and rising seniors in Brown’s undergraduate biology program conducting summer research as the foundation for their honors thesis.

As a Caleel fellow, Folds received a competitive stipend, additional funding for research expenses and professional development opportunities, which has supported her hands-on research in different U.S. locations, including the California Academy of Sciences in San Francisco, where she studied snakes that were more than 100 years old.

A native Californian, Folds is particularly drawn to rattlesnakes, which are iconic in her home state. While also native to the Northeast, rattlesnakes are now scarce in the wild — but are still in plentiful supply in museum collections.

During summer research trips to the Yale Peabody Museum in New Haven, Connecticut, with her Brown University labmates, Folds has been examining timber rattlesnakes, her study specimen of choice.

Since childhood, Folds has been passionate about studying animals and their distinctive characteristics, “from the uncountable specialties fine-tuned to each niche, to the seemingly incongruent features, to the layered meshes of ecological interactions, to the intricacies of every individual motion,” she wrote in her application for the Caleel fellowship. With this project, she’s able to quantify some of those “uncountable specialties.”

Folds hopes to return to museums after summer ends, including the American Museum of Natural History in New York where she would like to collect data from additional specimens. After graduation, she intends to pursue an advanced degree in evolutionary biology and conduct research in a museum setting.

“This is a pretty cool gateway to that goal,” she said.

Folds will present her findings at the University’s Summer Research Symposium in early August and plans to turn her project into an honors thesis.