A stepping-stone for oxygen on Earth

For most terrestrial life on Earth, oxygen is necessary for survival. But the planet's atmosphere did not always contain this life-sustaining substance, and one of science's greatest mysteries is how and when oxygenic photosynthesis first began. Now, a team led by geobiologists at the California Institute of Technology has found evidence of a precursor photosystem involving manganese that predates cyanobacteria, the first group of organisms to release oxygen into the environment via photosynthes...

Fuente : http://www.eurekalert.org/pub_releases/2013-06/cio...