The Evolution of Photosynthesis

When the first single-celled organisms appeared on Earth, more than 3 billion years ago, they fed upon carbohydrates—sugars—dissolved in the sea. The sugars had their origin in chance chemical reactions. Life, however, multiplied exponentially; one cell made two, two made four, four made eight, and so on. Self replication is the essence of life. It was inevitable that burgeoning organisms in the sea would outstrip their catch-as-catch-can food supply It would seem that life was doomed to a de...

 Perspectives on Gaia

TREVIZE WAS surrounded by the tameness of Gaia. The temperature, as always, was comfortable, and the air moved pleasantly, refreshing but not chilling. Clouds drifted across the sky, interrupting the sunlight now and then, and, no doubt, if the water vapor level per meter of open land surface dropped sufficiently in this place or that, there would be enough rain to restore it. The trees grew in regular spacings, like an orchard, and did so, no doubt, all over the world. The land and sea were...