A biology professor from Cal State Northridge discussed his research surrounding small, cold-climate lizards that break the rules of plant-based diets in McCarthy Hall on Wednesday afternoon.
Robert Espinoza, Ph.D., discussed his research findings that explain how certain southern South American lizards do not fit the rules of what scientists have typically considered herbivores to be.
“Even though herbivory is rare, it does evolve from time to time and it usually evolves in large body lizards and in lizards that live in warm places,” Espinoza said.
He described the specific lizards he was researching in Argentina as plant eaters with small body types from cool places.
“Herbivores have a suite of morphological, physiological, ecological and behavioral adaptations that help them in procuring, digesting and assembling plants,” he said.
Espinoza described how unusual it is for a lizard to be a herbivore and how unusual their warm body temperatures can be as well.
According to Espinoza, some reptiles eat insects or other small animals and less than 1 percent of them eat plant matter.
Espinoza said the goals behind his research ultimately stem from the mystery as to why plant eating lizards are so rare.
“We are looking for a better understanding of the conditions that support the evolution of plant eating,” Espinoza said. “There are challenges to being a plant eater, so one of the questions is why would it even evolve at all if there are so many advantages to being a carnivore or omnivore.”
Espinoza said there are about 6,000 species of lizards alive today and that just 72 species are known to be herbivorous.
He explained that herbivores prefer and live in warm climates, because the gut microbes that do most of the work digesting plant matter require warm temperatures to operate.
“Herbivores have longer torsos and wider torsos so they can pack in more gut matter,” Espinoza said.
Espinoza said that in addition to herbivores being large lizards that carry big guts, knowing how they chew plants also helps to understand how they function as reptiles.
“Typical specializations for herbivores include these cusps or gibbets in the teeth with occasional serrations like a knife, to help slice,” Espinoza said. “It’s really not that these lizards are chewing, but they have to crop.”
He said that in order for herbivores to tear off a piece of a leaf to consume, they have to slice into it with the serrations on their teeth.
Espinoza said he hopes students that attended the presentation, grasped a sense of the fascination for doing original research and making discoveries.
“It’s really all about the fun of discovery, and I hope to impart that sense of wonderment that I still get when I make a new discovery,” Espinoza said. “Something that I know that no one else knows yet and i can contribute that to the fabric of science.”
Katie Blashford, 18, a business major, said she was unaware of the many species of lizards in the world.
“I found it interesting that lizards evolve,” Blashford said. “When you talk about evolution, they are hardy ever talking about lizards and that was interesting to learn.”