Fig 5.

Schematic tree of life with Bacteria in green, Archaea in purple, and Eukaryota in pink—emerging from the merger of an alphaproteobacterial symbiont with an asgardarchaeotal host. Horizontal gene transfer, which can complicate the phylogenetic analysis, is indicated by interconnecting lines. The light-shaded boxes indicate enzymes of likely archaeal (purple), bacterial (green), or unknown (gray) origin. Question marks indicate putative origins that are less clear.