Data from: The evolution of genetic architectures underlying quantitative traits

In the classic view introduced by R. A. Fisher, a quantitative trait is
encoded by many loci with small, additive effects. Recent advances in
quantitative trait loci mapping have begun to elucidate the genetic
architectures underlying vast numbers of phenotypes across diverse taxa,
producing observations that sometimes contrast with Fisher's
blueprint. Despite these considerable empirical efforts to map the genetic
determinants of traits, it remains poorly understood how the genetic
architecture of a trait should evolve, or how it depends on the selection
pressures on the trait. Here, we develop a simple, population-genetic
model for the evolution of genetic architectures. Our model predicts that
traits under moderate selection should be encoded by many loci with highly
variable effects, whereas traits under either weak or strong selection
should be encoded by relatively few loci. We compare these theoretical
predictions with qualitative trends in the genetics of human traits, and
with systematic data on the genetics of gene expression levels in yeast.
Our analysis provides an evolutionary explanation for broad empirical
patterns in the genetic basis for traits, and it introduces a single
framework that unifies the diversity of observed genetic architectures,
ranging from Mendelian to Fisherian.