Researchers at Georgia Tech including James Stroud, assistant professor in the School of Biological Sciences were conducting a study of Cuban brown anoles (Anolis sagrei) at Fairchild Tropical Botanic Garden in Florida when suddenly, a new species appeared on the scene: the Puerto Rican crested anole (Anolis cristatellus).

The subsequent Georgia Tech-led study of the two species and how they adapted to fill different roles, provides some of the clearest evidence to date of evolution in action.

“When two similar species compete for the same resources, like food and territory, they often evolve differences that allow them to coexist,” says Stroud, lead author of the study. "Most of what we know about how animals change in response to this process comes from studying patterns that evolved long ago. This was a rare opportunity where we could watch evolution as it happened.”