title: Evolution. When did photosynthesis emerge on Earth?
abstract: Life began early in Earth's history, but it was the emergence of photosynthesis that allowed its proliferation across the planet, because it freed life from its sole dependence on abiotic chemical sources of reducing power. Des Marais discusses recent geological and molecular biological evidence, such as the paper by Xiong et al., that photosynthesis emerged at least 2,800 million years ago.
authors.affiliation: NASA Ames Research Center,Moffett Field, CA 94035, USA. ddesmarais@mail.arc.nasa.gov
authors.forename: D J
authors.initials: DJ
authors.lastname: De Marais
mesh_terms: D001419:Bacteria / Q000235:genetics* / Q000378:metabolism*; D000458:Cyanobacteria / Q000235:genetics* / Q000378:metabolism; D019143:Evolution, Molecular; D005580:Fossils; D019015:Geologic Sediments; D010100:Oxygen / Q000378:metabolism; D010788:Photosynthesis; D010802:Phylogeny
chemical_list: D010100:Oxygen