There was a time in the history of life on earth before predation. Scientists talk about an Ediacaran period in the history of our planet. It is named for the Ediacara hills in Australia, where some of the key fossils were found. Also, for the phonetically curious, the proper pronunciation is Ee-dee-ac-aran. Rhymes with Me - he- wrack -Iran. Anyway, the creatures of the Ediacaran did not eat each other. They were without eyes, claws, or antennae: no means for watching, seizing, or evading each other. Beginning around 635 million years ago, continuing until 542 million, Ediacaran biota had simple lives as they crawled along the sea floor, eating such organic matter ("the mat" as Peter Godfrey-Smith calls it) that had built up there. Eventually dying and contributing to that mat. Ediacaran biota did have nervous systems. The fact itself indicates that nervous systems aren't entirely about sensing and reacting to the outside. The biota didn't have to react to ...