reference to full recent article "Early Evolution of Photosynthesis" http://www.plantphysiol.org/content/154/2/434.full Early Evolution of Photosynthesis "Early Evolution of Photosynthesis" "Early Evolution of Photosynthesis" Early Evolution of Photosynthesis "Early Evolution of Photosynthesis" "Early Evolution of Photosynthesis" "Early Evolution of Photosynthesis" "Early Evolution of Photosynthesis" "Early Evolution of Photosynthesis" http://www.plantphysiol.org/content/154/2/434.full ref