Photosynthesis is one of the fundamental processes of life on
Earth. The evolutionary transition from anoxygenic (no oxygen
produced) to oxygenic (oxygen-producing) photosynthesis resulted
in the critical development of atmospheric oxygen in amounts
large enough to allow the evolution of organisms that use
oxygen, including plants and mammals. One of the outstanding
questions of the early Earth is how ancient organisms made this
transition. A team of scientists from Arizona State University
has moved us closer to understanding how this occurred, in a
paper recently published in the Proceedings of the National
Academy of Sciences. The paper is titled, "Light-driven oxygen
production from superoxide by manganese-binding bacterial
reaction centers," and is authored by James Allen, JoAnn
Williams, Tien Le Olson, Aaron Tufts, Paul Oyala and Wei-Jen
Lee, all from the Department of Chemistry and Biochemistry in
ASU's College of Liberal Arts and Sciences. One of the
outstanding questions of early Earth biology is how