DISSERTATION RESEARCH: The Genomic Nature of Adaptation in Anolis lizards

Most of the biological diversity on Earth is thought to result from adaptive radiation, an evolutionary phenomenon where many new species are rapidly formed through colonization of and adaptation to new environments. The work of many researchers over the last fifty years has resulted in an emerging understanding of the broad-scale evolutionary patterns associated with adaptive radiation. Despite these advances, we have little understanding of the genetic processes that take place during adaptive radiation. For instance, it is not known how often new mutations are uniquely favored in one environment alone versus being beneficial to multiple species living in different habitats. This proposal addresses this gap in our knowledge using one of the most iconic examples of adaptive radiation, Anolis lizards from the West Indies. This research will focus on two Anolis species that reside on tree trunks?one living in a hot, dry environment, the other in a moist, cool forest. In a small area of the Dominican Republic, these different habitats are immediately adjacent to one another. Here, the two species interbreed and form hybrid offspring. These unique circumstances provide an opportunity to identify what gene variants are associated with adaptation to the two distinct environments and what variants are beneficial to both species.

To address the genomic nature of adaptation in Anolis lizards, the co-investigators will use next-generation sequencing technologies to collect transcriptome data from individuals of each species as well as hybrids. The genotypes derived from this sequencing will be used to perform genomic cline analyses, which identify parental alleles that are over- and underrepresented among hybrids. The results of genomic cline analyses will be combined with population genomic analyses to identify the frequency of global and local adaptations and provide a first insight into the microevolutionary processes associated with adaptive radiation.