Richard Glor, graduate evolutionary biology student in Arts & Sciences at Washington University in St. Louis, has found extensive genetic differentiation among populations of numerous Anolis lizard species inhabiting single Caribbean islands. While to the naked eye the lizards appear to be uniform, these lizards from the islands of Cuba, Puerto Rico, Hispaniola and Jamaica all show a surprising amount of genetic diversity. Glor goes to the islands and collects lizard samples to study morphology, or body features, and color patterns and then sequences DNA from the different species.
"The levels of differentiation we're seeing genetically with anoles completely blows away any kind of variation in humans," Glor said. "We've found an unanticipated dimension of biodiversity, far greater than ever thought to exist. If you look at DNA in any widespread species, it suggests that several species may actually be present."
The variation that Glor has found startles evolutionary biologists and challenges researchers to understand what is causing the DNA evolution, said Jonathan Losos, Ph.D., Washington University professor of biology, and Glor's co-adviser.
"What's so exciting about the variation Rich has discovered is that it's completely unexpected," said Losos, who has studied Caribbean lizards for more than 15 years. "These lizards have been a model system for understanding evolutionary diversification for 30-plus years,including by a number of famous scientists, yet Rich was the first to discover this. He's uncovered a whole different layer of speciation and diversification in these species. It's possible that one group is not just one species but represents maybe six or eight spec
Contact: Tony Fitzpatrick
Washington University in St. Louis