These bacteria undergo oxygenic and anoxygenic photosynthesis. Dioxygen complexes are the precursors to other families of oxygenic ligands. Organisms in both genera share characteristics in addition to being oxygenic phototrophs. This occurs by oxidation of water in the case of oxygenic photosynthesis. Biochemically, anoxygenic photosynthesis is very different from oxygenic photosynthesis. The algae are photoautotroph organisms which perform oxygenic photosynthesis. They commonly obtain their energy through oxygenic photosynthesis. Photoinhibition occurs in all organisms capable of oxygenic photosynthesis, from vascular plants to cyanobacteria. Microorganisms employ oxygenic and anoxygenic photoautotrophy, as well as chemoautotrophy. This is called "oxygenic photosynthesis". Other evidence indicates that the rise of oxygenic photosynthesis was coincident with the GOE. The symbiosis evolved around 1.5 Ga and enabled eukaryotes to carry out oxygenic photosynthesis. For oxygenic photosynthesis, both photosystems I and II are required. These organisms are the dominant group of bacterioplankton using oxygenic photosynthesis in aquatic ecosystems. These pathways include non-methylotrophic methanogenesis, anoxygenic photosynthesis, and oxygenic photosynthesis.