Dr. Deby Cassill, associate professor in the USF College of Arts and Sciences Department of Integrative Biology, has focused her academic research career on better understanding the “secrets” of animal behavior and how it can tell us more about our own human nature.
Cassill credits her insatiable sense of “curiosity” and a love of “studying in a closet” as she marched her way through a variety of academic degrees. She holds a bachelor’s, master’s, and doctoral degree in biology from Florida State University, in addition to an MPA degree from University of West Florida, a teaching certificate in special education from Rollins College, and a bachelor's in psychology from the University of Iowa.
“In the 70s and 80s, I worked at Tallahassee headquarters on community mental health programs and then shifted to containing the cost of health care by bringing in the HMOs. One evening while watching a David Attenborough documentary on TV with my family, I announced, ‘I wanted to be doing biology, not just watching it.’ So, I consigned myself to nine years of hard labor from classroom to closet to classroom as I retooled my skill set to become a research biologist,” she explained.
Based on the USF St. Petersburg campus, she’s focused her research on two key areas: first, understanding the “triggers” of animal and insect behavior including cooperation, sharing, altruism, competition, stealing, murder, and predation; and second, developing a theory of maternal investments. Why do sea turtle mothers abandon their eggs? Why do sharks abandon their pups after birth? Why do elephants feed and protect their calves until they are adults, able to survive on their own?
![Cluster of fire ants on leaves](/arts-sciences/chronicles/images/2024/august/deby-cassill-feature-440x300.jpg)
(Photo source: Adobe Stock)
“My maternal investment model poses an answer. Stay tuned!” she said.
“Animal behavior has always been my passion,” she explains. “Especially the behavior of social animals. I chose to work with ants because I could set up life and death situations with impunity to determine who survived and who did not. As kids, my brothers hunted birds, rabbits and squirrels. I watched ants until the sun set or I got hungry. In the 6th grade, I won a purple ribbon on an ant project. Ants were always fascinating creatures. I never dreamed that one day I would find a job that paid me to study them and discover their many secrets. How lucky I am I? I won’t stop studying ants until they reveal to me why they are such a contradiction of fighting to the death with neighbors and yet they help the wounded?”
For two decades, Cassill has published research that has added “bricks to the foundation” to answer questions “about the origin of altruism.”
“My theory on the origin of cooperative societies is already published. But a few bricks were missing to extend that theory to explain altruism—why we are kind to strangers? Over the next few years, I will publish the ‘big reveal on altruism.’”
Her other projects include the maternal investments in sharks, whales (cetaceans), sea turtles, snakes, crocodiles, fish, coral and more.
Cassill added that in Charles Darwin’s theory of evolution, he provides “an elegant explanation for the fission of populations into diverse species. Females produce more offspring than can survive. Most offspring starve. Only a few of the ‘fittest’ survive to sexual maturity. Darwin did not address the fusion of parent and offspring into family units, or the fusion of family units into societies. My maternal investment model predicts the risk factors that favor the evolution of family units and societies. Next on my plate is the big reveal on the origin of altruism.”
![Student studying ants in field](/arts-sciences/chronicles/images/2024/august/deby-cassill-feature-440x400.jpg)
Alexis Masnjak, a graduate student who studied parental care among fire ant males, female queens, and female worker-siblings with Cassill. (Photo courtesy of Cassill)
Once that is published, Cassill hopes to give talks to business leaders on what it takes for the long-term survival of high-function, hierarchical companies.
“Long-term survival requires transparent, non-lethal competition for resources during the springtime glut. Those that gain more must share with those in need during the winter paucity. Communication is transparent up, down, and sideways within the hierarchy. This is what high-function hierarchical organizations must do to survive long-term. This is an idea worth sharing, is it not?” she adds.
Cassill’s research has led to numerous community invites including community clubs at the Villages, the Dali Museum, and ‘Nerd Nights’ in downtown St. Petersburg.
“All animals must find food. All animals reproduce. I am lucky enough to have compelling stories to tell about food and sex,” she said.
While her passion for animal behavior has driven her academic career, she’s thankful for the career she’s been able to lead while at USF and the impact she also is able to have on students.
In addition to being a repeat donor for graduate student scholarships, she’s also served as a faculty representative of the USF St. Petersburg Support, Outreach, and Care Action Team (SOCAT) Team for 15 years, an organization formed to help students cope with anxieties, depression, and other stressors that are “all a part of their transitions from life within their family to a productive life within their community.”
“Working as a faculty member within the USF system has been a privileged career for me. Our custodial staff keep our spaces clean. Our facilities staff keep our building safe. Our police persons keep our campus safe. Our administrators keep our whole organization functioning. But it is our students who are the reason that we all have a great place to work. They are the VIPs of our campus,” she said.
Learn more about Cassil’s research and the Department of Integrative Biology.