POLYANDRY FACILITATES POSTCOPULATORY INBREEDING AVOIDANCE IN HOUSE MICE
Version of Record online: 10 DEC 2007
©2007 The Author(s). Journal compilation © 2007 The Society for the Study of Evolution.
Volume 62, Issue 3, pages 603–611, March 2008
How to Cite
Firman, R. C. and Simmons, L. W. (2008), POLYANDRY FACILITATES POSTCOPULATORY INBREEDING AVOIDANCE IN HOUSE MICE. Evolution, 62: 603–611. doi: 10.1111/j.1558-5646.2007.00307.x
- Issue online: 10 DEC 2007
- Version of Record online: 10 DEC 2007
- Received October 14, 2007Accepted November 12, 2007
- multiple mating;
- postcopulatory sexual selection;
- reproductive success;
- selective fertilization
The avoidance of genetic incompatibilities between parental genotypes has been proposed to account for the evolution of polyandry. An extension of this hypothesis suggests polyandry may provide an opportunity for females to avoid the cost of inbreeding by exploiting postcopulatory mechanisms that bias paternity toward unrelated male genotypes. Here we test the inbreeding avoidance hypothesis in house mice by experimentally manipulating genetic compatibility via matings between siblings and nonsiblings. We observed little difference in reproductive success between females mated to two siblings or females mated to two nonsiblings. Females mated to both a sibling and a nonsibling tended to have a lower litter survival, but only when the first male to mate was a sibling. Microsatellite data revealed that paternity was biased toward nonsiblings when a female mated with both a sibling and a nonsibling. Unlike previous studies of invertebrates, paternity bias toward the sibling male was independent of mating sequence. We provide one of the first empirical demonstrations that polyandry facilitates postcopulatory sexual selection in a vertebrate. We discuss this result in relation to the possibility of selective fertilization of ova based on major histocompatibility complex (MHC) haploid expression of sperm.