Professor Lawrence Gilbert and his team at the University of Texas at Austin have discovered a population of tropical butterflies that exemplify "evolution in action," and a rare research opportunity. Gilbert says they may be witnessing a species of butterfly splitting into two different species. The stars of this research are the Heliconius butterflies, found in Central and South America. Despite the genetic similarities between the two groups of the butterflies, one group is showing a color preference during mating. With support from the National Science Foundation, Gilbert and his team are working to gain insights about genetics, behavior, ecology, and evolution.