My dissertation research is focused on the Angle-headed Agamid lizards, Gonocephalus. This will be the first, comprehensive phylogenetic work on the genus, and aims to explore species boundaries, historical biogeography, and morphological evolution. As with all Southeast Asia taxa, Gonocephalus has evolved in an environment with turbulent geological and climatological histories, making it yet another taxon that is uniquely positioned for studies of factors driving speciation.
The genus is distributed throughout the Thai-Malay Peninsula, islands of the Greater Sundas (Sumatra, Java, and Borneo), and the Philippines. Currently, Gonocephalus is comprised of 17 species (though one of these is likely erroneously included in the genus), with a number of species co-distributed on multiple, major landmasses. One of the most fascinating aspects of this group is their variable adornment of dorsal crests. These range height and extent along the body, with species having a tall crest that extends uniformly from the back of the head to the base of the tail, some with a crest that gradually decreases in height towards the tail, and others with a dorsal crest divided at the base of the neck. There is also sexual dimorphism in the severity of the dorsal crest, opening the door to possible mechanisms of sexual selection. In addition, there is remarkable variability in both iris color and supra-/infraocular scale coloration, characters that again, harbor the potential for sexual selection.
This morphological diversity, coupled with the potential for undocumented diversity, make this a truly fascinating and rewarding group for future study. The application of multi-locus (10+ genes) or Next Generation sequence data, will undoubtedly yield powerful inferences into the evolution and speciation phenomena associated with Gonocephalus.
The genus is distributed throughout the Thai-Malay Peninsula, islands of the Greater Sundas (Sumatra, Java, and Borneo), and the Philippines. Currently, Gonocephalus is comprised of 17 species (though one of these is likely erroneously included in the genus), with a number of species co-distributed on multiple, major landmasses. One of the most fascinating aspects of this group is their variable adornment of dorsal crests. These range height and extent along the body, with species having a tall crest that extends uniformly from the back of the head to the base of the tail, some with a crest that gradually decreases in height towards the tail, and others with a dorsal crest divided at the base of the neck. There is also sexual dimorphism in the severity of the dorsal crest, opening the door to possible mechanisms of sexual selection. In addition, there is remarkable variability in both iris color and supra-/infraocular scale coloration, characters that again, harbor the potential for sexual selection.
This morphological diversity, coupled with the potential for undocumented diversity, make this a truly fascinating and rewarding group for future study. The application of multi-locus (10+ genes) or Next Generation sequence data, will undoubtedly yield powerful inferences into the evolution and speciation phenomena associated with Gonocephalus.