Electron transfer in protein results from quantum tunnelling between reduction- oxidation (redox) centres. "There's a widely accepted idea that electrons get from one redox centre to another in a protein by travelling down a series of molecular bonds that describe a best pathway," said Christopher Moser, one of the team. "What we've found is that there is nothing special about that pathway. Instead, evolution ignores the structure of the protein medium between the two points and uses only proximity to ensure that the electron transfer rates are fast enough to satisfy the needs of biology."