DISSERTATION RESEARCH: Genital biomechanics and mating system evolution in leiobunine harvestmen (Opiliones: Sclerosomatidae)

University Of Maryland, College Park, College Park MD

Investigators

Abstract

Reproductive behaviors and structures in animals are extremely diverse, but the functional and evolutionary causes of this diversity remain unclear. Has diversification been driven by conflict between males and females or by female selection for valuable male traits? Recent work by Shultz and colleagues on a promising model system, the eastern North American harvestmen (daddy-long-legs), has identified combinations of features that are consistent with long-term evolutionary effects of mating conflict: a reproductive arms race. The researchers hypothesize that the diversification of reproductive structures in harvestmen is a result of conflict rather than the more widely accepted mechanism of female selection. This hypothesis will be tested using a biomechanical approach to measure key physical variables in males and females of several species. Rigorous statistical and quantitative comparative methods will be used to determine whether significant differences exist between species and whether the mechanical parameters of male and female structures co-vary. If diversification is due to mating conflicts, reproductive structures should be correlated in their abilities to deliver and resist mechanical forces, but this result would not be expected if male traits evolve due to female selection. This study is a novel application of biomechanics for the explanation of an evolutionary process, as well as the use of unusually accurate quantitative data for comparative methods. Opportunities for the continued involvement of undergraduate trainees will be provided. As a biracial minority scientist, the continued research and mentoring of Co-PI Burns serves to increase diversity in science and ensures that previous investments in Co-PI Burns by the NSF will prove to be resources well-allocated.