The independent evolution of similar forms has interested researchers ever since Darwin. Three pathways--adaptation, exaptation ("preadaptation"), and genetic drift (random factors)--could potentially result in such convergence. The research proposed here aims to tease apart these factors in a well-studied group, the Anolis lizards, using a new estimate of evolutionary history based on DNA sequences and anatomy. At least 17 independent instances of solitary existence in species Anolis afford an extraordinary arena for studies of evolutionary convergence. The PI and his students will study the evolution of convergence in 'solitary species' living on islands. They will test for nonrandom patterns in traits and use established and new comparative methods to distinguish adaptive from exaptive explanations for shared similarities in these species. The researchers will also compare ancient evolutionary colonizations to recent invasions, and describe new species discovered during planned fieldwork.
This research will clarify the evolutionary processes that produce similar traits during evolution. It will also result in the publication of identification keys and descriptions of several new species, thereby facilitating conservation efforts in the regions where Anolis are found (many of which are established biodiversity 'hotspots'). The research will train graduate, undergraduate, and international students in taxonomic and evolutionary studies.
Research funded by our NSF grant resulted in 30 peer-reviewed publications (24 published, 6 in review) with 27 student coauthorships in journals including Nature, Science, Evolution, and Biological Invasions. We published descriptions of five new species and discovered several other undescribed species. We collected over 1500 scientific specimens (mostly lizards and frogs) that were deposited in public museum for use by us and other researchers. We performed field research in nine Latin American countries. Eighteen graduate and undergraduate students (nine from US underrepresented groups or international) were trained in systematic biology and field methods. We hosted two South American students for six-week internships. We produced three short guides to Anolis lizards, for Mexico, Parque Omar Torrijos in Panama, and Rio Palenque field station in Ecuador. We investigated the relationships of Anolis lizards. We established links between ancient species colonizations and recent, human-mediated "invasions" where species are translocated out of their native ranges. We tested whether the same ecological-anatomical types of lizards are found on mainland South and Central America that are found on Caribbean islands and found that mainland species do not fit the island paradigm. We developed a model to characterize invasive lizards and found that invasive species share traits that allow prediction of which species are likely to invade. We rediscovered a fantastic lizard species, Anolis proboscis, that possesses a highly unusual snout anatomy (see attached photo). And we discovered new populations of several interesting species, for example the Mexican Cave Anole (Anolis alvarezdeltoroi) which we observed on the interior walls of limestone caves up to 30 meters from a cave entrance. We examined the causes of declines in frog populations, and we discovered new populations of frogs that had not been collected in decades, including one species that had been declared extinct.
