Early life on the planet joined itself into colonies that resembled the brain, in the sense that it tended to agglomerate into rounded mounds with a crenellated structure. Remains of these cellular co-operatives can be seen at Great Slave Lake in Canada and Shark Bay in Australia, where they are arranged like polka-dots and lava-lamp patterns on the low-lying plain. They resemble small inelegant hummocks of stone, which is in fact what they are, for the living cellular colonies have been replaced by simple minerals.
Fossilization creates a special kind of ‘memory’, which is both literal and superficial. The intricate living structure is exchanged for lithic simplicity but the surface is ‘remembered,’ a hologram in stone. I have seen black and white images of these fossils in a book, but I am unable to find the book in my house. I use the Internet to try to track down a similar image. There is a plethora of information, much of it contradictory, about early bacteria and archaeans, our tiny ancestors. They are by different accounts four billion, or four point five billion, or three point eight billion years old. One source suggests they go back a scant two point five billion years. But among all the learned articles, although there are many images, there is no picture of the particular mounds which I can see clearly in my mind. There our ancestors rise in randomly scattered groups on a great plain, like small heaps of garbage or half-cabbages made of stone.