Sperm competition and the evolution of male reproductive anatomy in rodents.

ABSTRACT: Sperm competition is a pervasive selective force in evolution, shaping reproductive anatomy, physiology and behaviour. Here, we present comparative evidence that varying sperm competition levels account for variation in the male reproductive anatomy of rodents, the largest and most diverse mammalian order. We focus on the sperm-producing testes and the accessory reproductive glands, which produce the seminal fluid fraction of the ejaculate. We demonstrate a positive association between relative testis size and the prevalence of within-litter multiple paternity, consistent with previous analyses in which relative testis size has been found to correlate with sperm competition levels inferred from social organization and mating systems. We further demonstrate an association between sperm comp

SUBMITTER: Ramm SA 

PROVIDER: S-EPMC1564092 | biostudies-literature | 2005 May

REPOSITORIES: biostudies-literature