The quiet evolutionary response to cellular challenges

Abstract

Like many evolutionary geneticists, I am fascinated by genes underlying potentially adaptive traits that differentiate populations. While such traits are obviously important, I have, in part through my own work on adaptation to whole-genome duplication, become interested in traits that do not differ in obvious ways between populations. There is good evidence that such traits are also important and can leave signatures of selection in genomes. This idea is not a new revelation—in the vast literature on protein biophysics there is keen awareness that evolutionary adjustments are often needed to keep essential proteins functioning in new conditions. However, this concept has not been employed extensively outside that field to, for example, interpret genome scans for selection. Things written off as false positives in genome scans may actually be critical for adaptation; evolutionary adjustment of proteins underlying conserved traits may explain otherwise puzzling footprints of selection and may help explain why adaptation is often multigenic. The general conclusion that selection can act on trait maintenance rather than change, is likely broadly relevant.