A Generation-Time Effect on the Rate of Molecular Evolution in Bacteria

摘要: Molecular evolutionary rate varies significantly among species and a strict global molecular clock has been rejected across the tree of life. Generation time is one primary life-history trait that influences rate. Theory predicts organisms with shorter generation times evolve faster because accumulation more DNA replication errors per unit time. Although generation-time effect demonstrated consistently in plants animals, evidence its existence bacteria lacking. The bacterial phylum Firmicutes offers an excellent system for testing some members can enter dormant, nonreproductive endospore state response to harsh environmental conditions. It follows spore-forming would--with their longer times--evolve slowly than nonspore-forming relatives. therefore surprising previous study found no Firmicutes. Using phylogenetic comparative approach leveraging on large number genomes, we sporulation reduces genome-wide spontaneous mutation protein Contrary study, our results provide strong rates bacteria, like those are influenced by