Sexual dimorphism and its effect on the evolutionary potential of infectious disease

From mammals to invertebrates, males and females frequently vary in their susceptibility to diseases or in the severity of infection. While well-studied in the context of host fitness, how sex differences impact on the spread or evolution of disease has been the topic of comparatively little research. This thesis provides some of the first steps towards incorporating the variation represented by host sex into theory on pathogen evolution to varying host environments. Through appreciating the sexes as two distinct environments for an invading pathogen, I address how host sex can affect pathogen fitness, maintain pathogen genetic variation, and direct the nature and pace of host-pathogen coevolution.