THE REPRODUCTIVE EVOLUTION AND ECOLOGY OF DUNG BEETLES IN SINGAPORE AND MALAYSIA

Abstract

The study of sexual selection is an important component in understanding the evolution and diversification of sexually reproducing organisms. Dung beetles are ecologically important organisms and emerging model systems in sexual selection studies. This thesis investigates the dung beetle diversity of Singapore and the role of sexual selection on the reproductive evolution of dung beetles in the region. I first investigated the diversity of dung beetles using both morphological data and molecular information from Next Generation Sequencing barcoding techniques. I then further explored the ecology and evolution of dung beetles in Southeast Asia. I studied the effects of natural selection and niche partitioning on dung beetle diversity in vertical space, the population differentiation of body size and sexual size dimorphism, uncovering cryptic species and possible patterns of divergence using population genomic tools, and investigating the potential co-evolution of possibly reproductively important endosymbiotic nematodes and host dung beetle species.