So far we have visited many phenomena on Earth and in the universe. However, one geophysical phenomenon was left out, the most complex of all, namely biological life. In the early days ofself-organized criticality, we did not think about biology at all; we had only inert dead matter in mind. However, this situation has radically changed. The story is one in three acts, to be told in the next three chapters, with more to follow. We have constructed some simple mathematical models for evolution of an ecology of interacting species. However, to appreciate the content of the theory that came out at the end, a historical account of the activities seems most suitable.