Professor Siva-Jothy is a lecturer in the Department of Animal and Plant Sciences, University of Sheffield. This talk was given on Thursday 20th March 2014. "The males of many species harm the female during mating. In this talk I will examine these traits and explain their function and outcome. On first sight this type of behaviour seems evolutionarily intractable - why would a male be selected to harm his mate, the individual that will produce offspring? The answer lies in understanding that male and female organisms have different interests. I will look at examples from gonochorists (species with separate sexes) as well as hermaphrodites - where individuals carry both genders’ interests - to illustrate the variety of bizarre mating forms and how they are easily accommodated by current evolutionary theory." Professor Siva-Jothy’s research focuses on understanding the causal mechanisms underpinning sexually selected and life history traits. There are currently two major strands to the research in his laboratory. First, the determination of patterns of life-history investment in immune function, and the coordination of immune effector systems to provide immune function. Second, understanding the nature of sexual conflict in the bed bug Cimex lectularius. Inspiration & Co interview: https://soundcloud.com/inspirationandco/pokemon-sumo-wrestling-and This talk was given on Thursday 20th March 2014.