This is a five year study of the systematics of Iguanian lizards. Both morphological and molecular characters will be used to address the relationships within the Tropiduridae, Polychrotidae, Chamaeleonidae, and basal agamines. Three mitochondrial genes (16S rRNA, cytochrome c oxidase subunit I, and cytochrome c oxidase subunit III) will be sequenced in a effort to investigate more recent divergences. Relationships involving older lineage divergences will be determined using nucleotide sequences from nuclear single-copy genes. Detailed comparative morphological studies will be conducted on the same taxa used in the molecular study, and the intrinsic qualities and information of each kind of data will be evaluated using several analytical approaches. %%% Iguanian lizards represent a biologically diverse group of vertebrates, with the New World families (occurring primarily in South America) being considerably more diverse than their Old World counterparts (represented by taxa in Madagascar). The results from this multidisciplinary approach to understanding the diversity of this group of vertebrates will provide a framework for understanding molecular and morphological change in a related group of taxa located in different regions of the World. The overall pattern of variation obtained from this study can also provide a basis for understanding the ecology, physiology, and behavior of this important component of the World's biota.
