Portal de Periódicos da CAPES

Sperm Competition and the Evolution of Multiple Mating

1991; University of Chicago Press; Volume: 138; Issue: 1 Linguagem: Inglês

10.1086/285206

1537-5323

James W. Curtsinger,

Evolutionary Psychology and Human Behavior

The "sexy-sperm" hypothesis proposes that multiple-mating females have a selective advantage over single-mating females because the former are fertilized by the most competitive sperm and have sons that produce competitive sperm. A deterministic genetical model of the sexy-sperm process is described here. It assumes one locus that influences sperm competitive ability and a second locus that influences female mating behavior. The conditions for sperm competition to promote the evolution of multiple mating in females are very restrictive: there must be tight linkage between the two loci, positive linkage disequilibrium, and no fitness cost associated with multiple mating. Any trait (even single-mating female behavior) can increase by hitchhiking if it carries no cost and is under the control of a locus that is tightly linked to the positively selected sperm competition locus. When there are costs for multiple mating, the sexy-sperm mechanism fails: the multiple-mating tendency increases initially but is eliminated when linkage disequilibrium decays. Linkage disequilibrium, rather than intergenerational payoff, is the driving force in this model. Under the assumptions of this model, sperm competition plays no special role in the evolution of female mating frequency.