QUOTE : However it formed, this little cluster of manganese atoms opened up a new world, not only for the bacteria that first trapped it, but for all life on our planet. Once it formed, this little cluster of atoms started to split water, the four oxidised manganese atoms combining their natural avidity to yank electrons from water, thereby releasing oxygen as waste. Stimulated by the steady oxidation of manganese by ultraviolet radiation, the splitting of water would have been slow at first. But as soon as the cluster became coupled to chlorophyll, electrons would have started to flow. Getting faster as chlorophyll became adapted to its task, water was sucked in, split open, its electrons drawn out, oxygen discarded. Once a trickle, ultimately a flood, this life-giving flow of electrons from water is behind all the exuberance of life on earth. We must thank it twice–once for being the ultimate source of all our food, and then again for all the oxygen we need to burn up that food to stay alive.