Eon Billion Evolutionary( Oxygen Metabolic and years ago event level other highlights 0 Extinction of the dinosaurs Phanaerozoic Cambrian 0.5 Early animals Multicellular 20% 1.0 eukaryotes Precambrian 10% Proterozoic .5 First eukaryotes 1% Ozone shield 2.0 Great oxidation 0.1% 2.5 event Cyanobacteria Oxygenic photosynthesis 3.0 (2H20→02+4H) Archaean Major landmarks in biological Purple and green Anoxygenic photosynthesis 3.5 bacteria Anoxic (H2S→S0+2H) evolution,Earth's changing geochemistry,and microbial First cellular Methanogenesis 4.0 life (C02+4H2→CH4+2H2O) metabolic diversification Hadean Formation of crust and ocean 4.5 Formation of Earth Copyright2009 Pearson Education,Inc..publishing as Pearson Benjamin Cummings. 通识教育核心课程 《微生物的世界》16 上海交通大学通识教育核心课程《微生物的世界》 Major landmarks in biological evolution, Earth’s changing geochemistry, and microbial metabolic diversification