Fig S13. Alternative scenarios that might explain the evolution transition of Archaeoglobi from methanogen.

In scenario a, the methanogen LCA encodes a different type of both Mcr and Mtr from Ca. Methanomixophus and has lost them in the early stage, which demonstrates the least gene loss events of Mcr/Mtr during evolution; in scenario b, substantial gene loss events of methanogenic components occurred during evolution, however, the Ca. Methanomixophus retains the relics of Mcr/Mtr from the LCA.