Chance vs. Necessity in Mineral Evolution
A New Approach to an Ancient Subject
Earth's mineral kingdom displays many characteristics of an evolving system, including diversification (the number of mineral species increases with time), complexification (the crystal structures of minerals become more complex), congruency (each stage of mineral evolution follows from prior stages), periods of evolutionary punctuation and of stasis, extinction (the rate of mineral evolution varies), and the fascinating interplay of chance and necessity. Recent research exploits large databases of mineral types and localities coupled with statistical methods employed by ecologists to document diversity-distribution relations for minerals. Surprising conclusions are emerging from these new investigations of "mineral ecology": more than half of Earth's ~5000 mineral species are rare; their distribution conforms to a "Large Number of Rare Events" (LNRE) model that mimics the distribution of words in a book. Applying a LNRE model to the analysis of minerals leads to the prediction that there are ~1500 "missing" minerals on Earth--minerals that must exist but have yet to be discovered. Further analysis predicts what some of those minerals might be and where we might find them. A key finding of these investigations, moreover, is that chance and necessity both play roles in Earth's evolving near-surface environment. Were we to visit another "Earth-like" planet and discover thousands of mineral species, it is probable that at least 25% of those minerals—more than 1000 species—would differ from the species known on Earth today.
Robert M. Hazen is Senior Staff Scientist at the Carnegie Institution’s Geophysical Laboratory and Clarence Robinson Professor of Earth Science at George Mason University. He is also Executive Director of the Deep Carbon Observatory, a 10-year project to study the chemical and biological roles of carbon in Earth’s interior.
Bob's recent research focuses on the role of minerals in the origin of life, the co-evolution of the geosphere and the biosphere, and the development of complex systems.
Bob is an author on more than 400 scientific articles and 25 books, including Genesis: The Scientific Quest for Life’s Origin and The Story of Earth.
He is a former President of the Mineralogical Society of America. And he is active in presenting science to nonscientists through writing, radio, TV, public lectures, and video courses.
Bob earned a BS and an SM in Geology at MIT and a PhD at Harvard University in Earth Science.
And he is also retired from a 40-year career as a professional symphonic trumpeter.