We hope that these examples will convince that reader that the history of the evolution of life and the Earth can only be appreciated by deciphering their interdependencies. Molecular and cell biologists have tremendous potential to contribute to our understanding of the evolution of the Earth's near-surface environment by making concrete links between biomarker structure and biochemical function. Similarly, geologists have much to offer evolutionary biology by helping constrain the time period and physical context of the appearance of new life forms. 2006 Elsevier Ltd. All rights reserved.
