NSF Postdoctoral Fellowships in Biology combine research and training components to prepare young scientists for careers in biology and provide them an opportunity to establish international collaborations and take advantage of research facilities and opportunities abroad. Forging strong international collaborations is mutually beneficial to the U.S. and the foreign hosts. This fellowship to Dr. Erin McCullough supports research and training on traits that lead to reproductive success that serves as the source of greater biodiversity in future generations in insects. The study animal is the horned dung beetle, a member of the genus Onthophagus which with over 2400 species is the most species-rich genus in the animal kingdom. The host institution is the University of Western Australia under the sponsorship of Dr. Leigh Simmons. Training goals include genetic techniques to establish paternity in insects, multivariate selection analyses, and the estimation and visualization of complex fitness landscapes. The model insect used in this study lends itself to interesting and exciting educational and public outreach activities on animal diversity. The fellowship is supported by both the Directorate for Biological Sciences and the Office of International and Integrative Activities.
Sexual selection is a key driver of the elaborate and diverse morphologies found in the animal kingdom. Sexual selection can occur both before and after mating, but the traits that help males gain access to females are often different from the traits that help sperm compete for the successful fertilization of eggs. Unfortunately, few studies simultaneously measure sexual selection pressures before and after mating. It is therefore unclear how different sexual traits interact to influence a male's overall reproductive success or how these interactions change depending on ecological or environmental conditions. Using the horned dung beetle Onthophagus taurus as a model system, this research investigates how pre- and post-mating sexual selection operates and how these selective pressures vary in response to different density conditions. Understanding how ecological conditions may shift the overall strength and direction of sexual selection is expected to provide key insights regarding the observed diversity in morphology, behavior, and mating strategies.
