The story of Earth is a 4.5-billion-year saga of dramatic transformations driven by physical, chemical and biological processes. The co-evolution of life and rocks unfolded in an irreversible sequence of evolutionary stages. Each stage re-sculpted our planet’s surface; introduced new planetary processes and phenomena; and inexorably paved the way for the next.
Robert M. Hazen is Staff Scientist at the Carnegie Institution of Washington and Clarence Robinson Professor of Earth Sciences at George Mason University. With degrees from MIT and Harvard, he studies mineral evolution and the coevolution of the geosphere and biosphere.