A rooted phylogeny resolves early bacterial evolution

Abstract

Reconstructing ancestral bacteria The origin of the eubacteria and phylogenetic relationships between subgroups have been difficult to resolve. Applying a phylogenetic analysis and recent computational methods to the expanded diversity of bacterial sequences from metagenomic analyses, Coleman et al. infer the root of the eubacterial tree (see the Perspective by Katz). The root was determined without using the Archaea as an outgroup, to avoid the possibility of a false result due to long branch attraction. This method places the eubacterial root in the neighborhood of Fusobacteriota. Using this information, the authors reconstructed the eubacterial ancestor, identifying that this organism likely had a double-membrane cell envelope, flagellum-mediated motility, antiphage defense mechanisms, and diverse metabolic pathways. Science , this issue p. eabe0511 ; see also p. 574