Two proposed research examines the developmental origins and subsequent evolutionary diversification of one of the most diverse classes of phenotypic traits: horns and horn-like structure in beetles. In particular the proposed research has three major aims: (1) First, it will complete a first characterization of the gene network that patterns horn development in beetles. (2) Secondly, using a comparative approach it will explore how modifications of the regulation of horn development have contributed to the dramatic diversification of horned beetles on three different levels: (i) alternative horned and hornless male morphs within species, (ii) sexual dimorphism, and (iii) interspecific diversity in location, size, and number of horns. (3) Lastly, the proposed research will develop RNA interference approaches for future studies of functional relationships between putative horn patterning mechanisms and horn phenotypes.
INTELLECTUAL MERIT & BROADER IMPACT OF THE PROPOSED RESEARCH: The proposed research directly addresses one of the most significant unresolved questions in evolutionary biology: how do novel complex phenotypes originate and diversify. At the same time the hypotheses framework and experimental design build firmly on 10 years of research by the PI on the behavioral ecology and evolutionary physiology of horn development in beetles. The proposed research will thus make a novel contribution to the field of evolutionary developmental biology, and at the same time facilitate an integration of the evolution of developmental processes with the behavioral, physiological and ecological mechanisms that guide such evolution in nature. Lastly, the proposed research aims to develop working RNAinterference protocols for future studies on the evolution and development of beetle horns. As such the proposed research will contribute a tool previously unavailable to scientists, yet paramount for future functional analyses of developmental evolution in these organisms. The proposed research will be carried out in large part by graduate and undergraduate students and provide additional training and research opportunities to high school students. The PI is strongly committed to use the proposed research as an opportunity to continue and expand his initiative to integrate underrepresented groups into research and training in his new lab at Indiana University. Apart from timely publication in peer-reviewed journals results from this proposal will be used as exemplars in a graduate course on the Evolution and Development of Phenotypic Plasticity as well as an undergraduate course in Insect Biology.
