细菌在生物进化树中的地仇 An evolutionary tree Bacteria Archaea Eukaryotes Green nonsulphur Animals Methanosarcina bacteria Gram Methano bacterium Haloarchaea Fungi Purple positives Methanococcus bacteria Plants Thermoproteus Pyrodictium Cyanobacteria Flavobacteria Thermotogales Common ancestor of all living organisms细菌在生物进化树中的地位