Fig. 3: Gene origination events of Nitrospirota and Nitrospinota for gene clusters enriched in basal and later-branching clades (as shown in Fig. 1).

The size of the circles represents the percentage of the enriched gene clusters subset (basal enriched or later-branching enriched) that had its initial origination event at the given node. Gene clusters enriched in basal clades of both phyla show overlap with gene clusters of the Last Common Ancestor (LCA) identified by Ancestral State Reconstruction and have their originations at the root or in basal nodes close to the root (purple, both sides). Gene clusters enriched in later-branching clades do not overlap with LCA gene clusters and have most of their originations at the base of classes Nitrospiria and Nitrospinia, respectively (green, both sides).