This volume focuses on the broad pattern of increasing biodiversity through time, and recurrent events of minor and major ecosphere reorganization. Intense scrutiny is devoted to the pattern of physical (including isotopic), sedimentary and biotic circumstances through the time intervals during which life crises occurred. These events affected terrestrial, lacustrine and estuarine ecosystems, locally and globally, but have affected continental shelf ecosystems and even deep ocean ecosystems. The pattern of these events is the backdrop against which modelling the pattern of future environmental change needs to be evaluated.