title: Sexually transmitted infection and the evolution of serial monogamy.
abstract: The selective forces shaping mating systems have long been of interest to biologists. One particular selective pressure that has received comparatively little attention is sexually transmitted infections (STIs). While it has been hypothesized that STIs could drive the evolutionary emergence of monogamy, there is little theoretical support. Here we use an evolutionary invasion analysis to determine what aspects of pathogen virulence and transmission are necessary for serial monogamy to evolve in a promiscuous population. We derive a biologically intuitive invasion condition in terms of population-specific quantities. From this condition, we obtain two main results. First, when pathogen virulence causes mortality rather than sterility, monogamy is more likely to evolve. Second, we find that at intermediate pathogen transmission rates, monogamy is the most selectively advantageous, whereas at high- and low-transmission rates, monogamy is generally selected against. As a result, it is possible for a pathogen to be highly virulent, yet for promiscuity to persist.
authors.affiliation: Department of Mathematics and Statistics, Queen's University, 99 University Ave Kingston, Ontario, Canada K7L 3N6 13dm38@queensu.ca.
authors.forename: David V
authors.initials: DV
authors.lastname: McLeod
authors.affiliation: Department of Mathematics and Statistics, Queen's University, 99 University Ave Kingston, Ontario, Canada K7L 3N6.
authors.forename: Troy
authors.initials: T
authors.lastname: Day
mesh_terms: D000818:Animals; D005075:Biological Evolution; D005298:Fertility; D008954:Models, Biological; D011157:Population Dynamics; D012098:Reproduction; D012726:Sexual Behavior, Animal; D012749:Sexually Transmitted Diseases / Q000635:transmission*; D014774:Virulence
keywords: infectious disease; mating system evolution; promiscuity; sociality