EFFECTS OF HOST SEXUAL SELECTION ON THE POPULATION BIOLOGY, OF PARASITES

Parasites have been hypothesized to play an important role in sexual s election of their hosts, and a considerable body of evidence supports parasite-mediated sexual selection. However, there has hardly been any emphasis on the effects of host sexual selection on the ecology and e volution of parasites. Coevolution between hosts and parasites may res ult in important differences between parasites exploiting more and les s sexually selected hosts. I suggest that parasites of intensely sexua lly selected hosts should affect a small proportion of hosts with inte nsities being more skewed than among hosts that are less sexually sele cted. Intra- and intersexual interactions among hosts give rise to amp le opportunities for horizontal transmission and hence select for incr eased virulence. Rapid coevolution between parasites and their hosts s hould select for increased host specificity among parasites of highly sexually selected hosts. Sexual selection has been hypothesized to pla y an important role in speciation, and rapid divergence among hosts ma y also result in rapid divergence among host-specific parasites.