Data from: Evolutionary lability of sexual selection and its implications for speciation and macroevolution

Sexual selection is widely hypothesized to facilitate speciation and
phenotypic evolution, but evidence from comparative studies has been
mixed. Many previous studies have relied on proxy variables to quantify
the intensity of sexual selection, raising the possibility that
inconclusive results may reflect, in part, the imperfect measurement of
this evolutionary process. Here, we test the relationship between
phylogenetic speciation rates and indices of the opportunity for sexual
selection drawn from populations of 82 vertebrate taxa. These indices
provide a much more direct assessment of sexual selection intensity than
proxy traits and allow straightforward comparisons among distantly related
clades. We find no correlation between the opportunity for sexual
selection and speciation rate, and this result is consistent across many
complementary analyses. In addition, widely used proxy variables – sexual
dimorphism and dichromatism – are not correlated with indices employed
here. Moreover, we find that the opportunity for sexual selection has low
phylogenetic signal and that intraspecific variability in selection
indices for many species approaches the range of variation observed across
all vertebrates as a whole. Our results potentially reconcile a major
paradox in speciation biology at the interface between microevolution and
macroevolution: sexual selection can be important for speciation, yet the
evolutionary lability of the process over deeper timescales restricts its
impact on broad-scale patterns of biodiversity.