The Eon in which we live is called the Phanerozoic, which comes from the ancient Greek word for visible life. The eon starts with the Cambrian, which began 541 million years ago. But in recent decades it has become increasingly clear from the fossil record that there was visible life before the Cambrian, and complex life at that. So what caused it to emerge then, and what caused it to proliferate and diversify so vigorously in the early Cambrian?

Rachel Wood is Professor of Carbonate Geoscience at the University of Edinburgh. She and her team have uncovered fossils that suggest that the fuse of the so called Cambrian explosion was lit in the Ediacaran – the geological period that preceded the Cambrian.

Go to geologybites.com for illustrations that include pictures of the Ediacaran fossils Rachel Wood discusses in the podcast and of some of the locations in Siberia and Namibia where she found them, as well as to learn more about Geology Bites.