Data from: Evolution of female multiple mating: a quantitative model of the "sexually-selected sperm" hypothesis

Explaining the evolution and maintenance of polyandry remains a key
challenge in evolutionary ecology. One appealing explanation is the
sexually-selected sperm (SSS) hypothesis, which proposes that polyandry
evolves due to indirect selection stemming from positive genetic
covariance with male fertilization efficiency, and hence with a
male's success in post-copulatory competition for paternity. However,
the SSS hypothesis relies on verbal analogy with ‘sexy-son’ models
explaining co-evolution of female preferences for male displays, and
explicit models that validate the basic SSS principle are surprisingly
lacking. We developed analogous genetically-explicit individual-based
models describing the SSS and ‘sexy-son’ processes. We show that the
analogy between the two is only partly valid, such that the genetic
correlation arising between polyandry and fertilization efficiency is
generally smaller than that arising between preference and display,
resulting in less reliable co-evolution. Importantly, indirect selection
was too weak to cause polyandry to evolve in the presence of negative
direct selection. Negatively-biased mutations on fertilization efficiency
did not generally rescue runaway evolution of polyandry unless realized
fertilization was highly skewed towards a single male, and co-evolution
was even weaker given random mating-order effects on fertilization. Our
models suggest that the SSS process is, on its own, unlikely to generally
explain the evolution of polyandry.