THE CONTEXT-DEPENDENT EFFECT OF MULTIPLE PATERNITY ON EFFECTIVE POPULATION SIZE

Authors


  • This article was published online on March 8, 2011. An error in the author's name was subsequently identified. This notice is included in the online version to indicate that it has been corrected September 16, 2011.

Abstract

Effective population size (Ne) is important because it describes how evolutionary forces will affect a population. The effect of multiple sires per female on Ne has been the subject of some debate, at the crux of which is the effects of monandry and multiple-paternity (MP) on male variance in reproductive success. In both mating systems, females mate with several males over their lifetimes, but sire offspring with one male at a time in the former and have several sires per clutch in the latter. First, I theoretically show that whether the annual male variance in reproductive success in an MP population is greater or less than that of a monandrous population depends on the distributions of within-clutch paternity. Then, I simulated different distributions of within-clutch paternity under a range of parameters that characterize natural populations to show that an MP population can have an Ne smaller or larger than that of a monandrous population with otherwise equal dynamics. The Ne(MP):Ne(Monandry) ratio increased with mating frequency and female variance in reproductive success, was equalized by long generation times, and was affected by the distribution of within-clutch paternities. The results of this model provide a unifying framework for the debate.

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