Systems paleobiology seeks to interpret the history of life within the framework of Earth's environmental history, using physiology as the conceptual bridge between paleontological and geochemical data sets.
In some cases, physiological performance can be estimated directly and quantitatively from fossils—this is commonly the case for vascular plant remains. In other instances, statistical inferences about physiology can be made on the basis of phylogenetic relationships.
The systems approach also provides a template for evaluating the habitability of other planets, not least of which is the ancient surface of Mars.
Andrew H. Knoll, Dept. of Organismic and Evolutionary Biology, Harvard University, Cambridge, Massachusetts 02138, USA. doi: 10.1130/B30685.1.