The Song Laboratory of Insect Systematics and Evolution

Among animals with internal fertilization, many species have species-specific male genitalia with morphological divergence among closely related species that is often dramatic and complex. This pattern is especially evident in insects, and male genitalia are considered one of the most important and useful species-diagnostic characters in insect systematics. Recent theoretical developments in genital evolution show that male genitalia are under sexual selection and evolve very rapidly.

My research on insect male genitalia began from a taxonomic framework, but it soon transformed into an integrative research program covering a broad spectrum in evolutionary biology including developmental biology, functional and comparative morphology, ecology and systematics.

Recently, I became very interested in studying the role of sexual selection in shaping genital diversity, and therefore species diversity. For instance, if a lineage with high genital diversity amongst its members has high rates of diversification, inferred from a phylogeny, sexual selection may explain the genital evolution in that lineage. Many lineages within grasshoppers exhibit acoustic or visual pre-mating courtship behaviors, which are presumably also under sexual selection, but it is not clear whether male genitalia are still under sexual selection in these lineages. My current research aims at testing whether sexual selection is a major factor in the diversification of grasshoppers by quantifying the amount of shape variation in genital morphology from many lineages with different mating strategies in a robust phylogenetic framework.