Phylogenomics and the Developmental Genetics and Evolution of Butterfly Colour Patterns

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A goal of evolutionary developmental biology is to understand developmental mechanisms responsible for species differences. Butterfly color patterns are an attractive model system for developmental genetics and evolution because they are variable, consist of simple well-defined 2-dimensional subunits, and undergo selection. The butterfly genus Junonia is an important model system for colour pattern development, but nearly all data comes from one species, J. coenia without considering the variation and evolutionary context of the rest of the genus. The long-term goals of this research program are (1) to understand how genomic changes create new phenotypic variation using the 42+ species of the genus Junonia as a model system. Rampant hybridization occurs in portions of the genus, so (2) we will also use Junonia to examine the role of hybridization and introgression in diversification and adaptation, contrasting the causes and effects of different frequencies of hybridization. Finally (3) we will examine the roles of hybridization, introgression, and adaptation in diversification and adaptive evolution, using butterflies and high elevation insect mitochondria as case studies. Short-term objectives include: (1) Conducting a phylogenomic analysis of Junonia to create a comprehensive species-level phylogenetic tree to reconstruct phenotypic evolution among members of this genus. (2) Comparing biogeographic patterns of genetic variation in New and Old World Junonia species, focused on poorly studied Old World clades showing preliminary evidence of hybridization reminiscent of that observed in the New World. (3) Reconstructing the time course and routes of invasion, dispersal, hybridization, and introgression of the J. villida lineage (as well as possibly other Junonia lineages) into the New World. (4) Evaluating mitogenomes and complete nuclear rRNA repeats as candidates for next generation DNA barcodes. (5) Characterizing patterns of mitochondrial adaptation to high elevation in butterfly, moth, and caddisfly clades including both high and low elevation species. (6) Testing a prediction of mesoevolutionary theory, that taxa with seasonal polyphenism will have elevated speciation rates and increased phenotypic diversity, by conducting phylogenomic reconstruction of butterfly clades containing species both with and without seasonal polyphenism and comparing rates between lineages. Significance: This program unifies the genomics and developmental genetics of butterfly colour patterns with their ecological and evolutionary context, providing insights into the genetic basis of evolutionary novelties and the contributions of these processes to generating biodiversity. Broader impacts: This program trains HQP in evo-devo, genomics, and evolutionary biology, and entomology. Developing new techniques and providing exciting results in these fields, HQP are equipped with essential skills for careers in basic and applied research, healthcare, and education.