Study Finds No Lower Mutation Rates in Essential Genes

Overview

• The peer‑reviewed paper by University of Bath researchers, published in PLOS Biology on Thursday, reports no evidence that essential genes have lower spontaneous mutation rates in E. coli or baker’s yeast.
• The team assembled what they call the largest and cleanest mutation‑accumulation dataset to date and used experiments designed to reduce natural selection so spontaneous mutations could be observed directly.
• Earlier signals that important genes mutate less often are explained by natural selection removing harmful changes before detection, a process the authors call “ghost mutations.”
• The researchers found non‑adaptive genomic factors, such as genes copied later during DNA replication, predict higher mutation rates, showing physical genome processes shape variation.
• The paper concludes there is no basis to revise the standard two‑step Darwinian model for the species studied and notes further work is needed to test whether the result holds beyond microbes.