Christopher Wills's claim has its roots in an insight from Charles Darwin: the interactions between species in an ecosystem are a powerful driver of evolution. In this book Wills describes how, by using the latest genetic techniques, we are probing ecosystems and discovering that even the most apparently barren of them are rich in variety, especially of microbes. Exploring the many ways in which ecosystems have coped with past change, and how rapidly an ecosystem can develop complexity, Wills illuminates a pathway of hope for the natural world that we have so damaged and depleted. Our new genetic knowledge can help these evolutionary cauldrons to continue brewing richness and diversity, the better to heal our living world and to enable our own survival.