Does shape matter? The evolution of the penis bone

Sexual selection is accepted as being responsible for the evolutionary divergence of genital morphology, however empirical studies are lacking, and those available have focused exclusively on male morphology. Extreme variability in the mammalian penis bone (baculum) is one of the most puzzling enigmas of mammalian morphology. Using the house mouse, I investigated the selective mechanism acting on the baculum, considering female mediated processes as possible drivers for male genital evolution. This thesis provides support for the role of post copulatory sexual selection in the coevolution of mammalian genitalia and, novel insight into the stimulatory role of the mammalian baculum.