A grant has been awarded to Dr. Elizabeth Jockusch and Mr. Jonathan Richmond at the University of Connecticut to investigate how differences in environmental conditions facilitate the formation of new species (a.k.a. ecological speciation). The focal organisms in this study are a group of closely related and geographically widespread North American lizard species known as skinks. Within this group, two distinct forms that inhabit different environments (i.e. ecotypes) occur: a large-bodied, monochrome form in warm, arid habitats and a small-bodied, striped form in cooler, moister areas. In conjunction with DNA evidence indicating that the large-bodied form has originated three times independently, the correlation between body types and habitat association suggests that evolutionary divergence among members of the group is the result of physiological adaptation to alternative environments. Likely as a result of these changes in body morphology, the different ecotypes are reproductively incompatible and have diverged into separate evolutionary lineages that likely represent undescribed species. This project will examine in detail how such processes can occur in natural populations by combining molecular studies using DNA data, behavioral assays of sexual isolation using live animals, and developmental studies that examine evolutionary changes in internal and external anatomy.
Although focused on skinks, this project will serve as a model system for studying the general theoretical predictions of ecological speciation. It will also help identify features of the environment that may be critical for maintaining and promoting biological diversity, and highlight the importance of using an evolutionary perspective in recognizing undescribed species. Furthermore, the multidisciplinary approach of the study will provide a graduate student with training in several fields of organismal biology and will include undergraduates as an integral part of the fieldwork and behavioral studies. Lastly, all specimens, tissues, and DNA data will be made publicly available for further scientific use.
