Résumé
Information transmission is intrinsic to life, and noise is intrinsic to information transmission. Biological noise during development is essential for the flexibility and plasticity of individual organisms, but also underlies some diseases. Biological noise during reproduction is the fuel for evolution, including the evolution of therapy resistance in pathogenic microbes and in cancer. Recent technological advances in our ability to characterize many sources of biological noise have demonstrated that its amount is often heritable. Here, we frame the population genetics of loci that influence the amount of any source of biological noise. While analogous theory for heritable changes in mean trait values has been established for nearly a century, to our knowledge this is the first general approach for studying the evolution of heritable changes in their statistical distributions. This represents a critical theoretical contribution to an important and rapidly growing domain of intellectual inquiry. It also sheds light on the hypothesis that natural selection can increase evolvability, and generalizes modifier theory used in the tradition of Feldman and colleagues.