By Georgia Jackson, College of Arts and Sciences
Rey Cohen is treated to a chorus of frog song each morning as he makes his way through the subterranean halls of the 哔咔漫画 Science Center.
鈥淕eneral knowledge is the basis of all knowledge. You never know what you鈥檙e going to discover.鈥� 鈥� Rey Cohen, lab manager
Cohen is a USF alumnus and lab manager for , where Assistant Professor Yu-San Yang of the Department of Integrative Biology is studying the mating behaviors and sexual ornaments of poison dart frogs.
The closer Cohen gets to the lab, the louder the frogs become. He likens their music to the sound of a bell.
Stepping into Yang Lab is like stepping into a sauna, thanks to the many temperature-controlled terrariums that line the walls. Inside, frogs glitter like gemstones 鈥� ruby, emerald, sapphire 鈥� on mossy beds.
The frogs' vibrant and diverse colors are what drew Yang to study them in the first place.
鈥淭hey are a great system for the type of questions we are interested in,鈥� Yang said. 鈥淭hey have high diversity both within and among species, and their coloration is used for so many purposes 鈥� warning predators away, attracting a potential mate, signaling when competing for territories, etcetera. They also have so many unique mating behaviors, parental care behaviors and social behaviors.鈥�
The poison dart frogs have, so far, proven to be the perfect species for Yang, whose research investigates the role mating behaviors play in sexual selection, speciation and diversification.
Yang and two undergraduate researchers, Quarohn Holliday and Jacinta Richardson, check on the frogs. [Photo credit: Corey Lepak.]
Yang鈥檚 curiosity has resulted in a number of scholarly insights and publications, in which Yang and her co-authors demonstrate that sexual imprinting 鈥� a phenomenon in which offspring model their mate preferences after parental traits 鈥� not only mediates female mate preferences, but can also shape biases in male-on-male aggression.
Their findings build on research Yang completed in graduate school, where she paired tadpoles with foster parents of different colors.
鈥淐ross-fostered females prefer to court mates of the same color as their foster mother, and cross-fostered males are more aggressive toward rivals that share the color of their foster mother,鈥� Yang explained.
The team found that when male aggression biases and female mate preferences are formed through parental imprinting, sexual selection can lead to behavioral reproductive isolation and set the stage for speciation. In other words, learned aggression biases prevent, say, red poison dart frogs from dominating the population, allowing frogs of different colors to persist stably within the same population. At the same time, learned mate preferences that lead female frogs to choose like-colored mates, drive, say, red frogs and blue frogs to become distinct species.
Before she filled her lab with frogs, Yang studied Trinidadian guppies, mangrove killifish and invertebrates, including fiddler crabs.
鈥淎ll species that I鈥檝e studied have interesting and highly flexible social behaviors,鈥� said Yang. 鈥淭his is a young lab, and we are just getting started on all the exciting things that we can study in the poison frog species we have."
Like the terrariums that line its walls, Yang Lab is, itself, a kind of ecosystem. The only animal behavior lab on the USF Tampa campus, it sustains research at the undergraduate, graduate and postdoctoral levels. Undergraduates who work in Yang Lab learn to practice lab safety and to care for the frogs. Some present their research at university symposiums and larger conferences. At the graduate level, Yang鈥檚 goal is to inspire independent research.
"They take the lead in developing their thesis topic, and I help them refine the questions and develop protocols,鈥� Yang said. 鈥淭hey also mentor undergraduate students for research and go to conferences to present their research and network.鈥�
The lab also supports Cohen, whose responsibility it is to train the lab team, care for the frogs and ensure the lab operations run smoothly.
鈥淕eneral knowledge is the basis of all knowledge,鈥� said Cohen. 鈥淵ou never know what you鈥檙e going to discover.鈥�