Data from: Genetic variation for outcrossing among Caenorhabditis elegans isolates

The evolution of breeding systems results from the existence of genetic
variation and selective forces favoring different outcrossing rates. In
this study we determine the extent of genetic variation for characters
directly related to outcrossing, such as male frequency, male mating
ability, and male reproductive success, in several wild isolates of the
nematode Caenorhabditis elegans. This species is characterized by an
androdioecious breeding system in which males occur with hermaphrodites
that can either self-fertilize or outcross with males. We find genetic
variation for all characters measured, but also find that environmental
variation is a large fraction of the total phenotypic variance. We further
determine the existence of substantial genetic variation for population
competitive performance in several laboratory environments. However, these
measures are uncorrelated with outcrossing characters. The data presented
here contribute to an understanding of male maintenance in natural
populations through their role in outcrossing.