THE GREAT OXIDATION EVENT AND THE END-PERMIAN MASS EXTINCTION

Astrobiology is the study of life in a universal context. Guided by a community-written roadmap, astrobiology endeavors to answer some of the most basic questions: How does life begin and evolve? Does life exist elsewhere? What is the future of life on Earth and beyond? In 2009 and 2010, we celebrate the 50^th anniversary of the Exobiology Program, the progenitor of Astrobiology. At the core of both Exobiology and Astrobiology is the study of the interactions, and co-evolution, of life and its planetary host. In this talk I will review recent NASA-funded research on two extreme interactions: the Great Oxidation Event and the end-Permian mass extinction.

The Great Oxidation Event profoundly altered the Earth, disrupting geochemical cycling and laying the foundation for the explosive radiation of multi-cellular creatures. Thought to have been driven by the evolution of oxygenic photosynthesis, the precise timing and dynamics of this transition are under close study. Recent research has revealed the possibility of a “nickel famine” in the Archaean ocean. There have also been tantalizing clues of “whiffs” of oxygen present well before the level of atmospheric oxygen grew.

The end-Permian mass extinction was the most far-reaching mass extinction known; fully 90% of known marine species and 70% of land species were wiped out. Many causes have been posited but no definitive result has been obtained. Recent research, however, has begun to rule out some causes. Other research has elucidated the conditions in the oceans just before the great extinction.

Dr. Michael New is the Astrobiology Discipline Scientist at NASA Headquarters. He manages the Astrobiology: Exobiology and Evolutionary Biology grants program and the ASTID instrument development program. Before coming to NASA HQ, he was a Deputy Branch Chief (Acting) and a researcher at NASA Ames Research Center. His research interests are modeling early life systems at the molecular level and the use of supervised (computer) learning approaches to problems in the origin of life. He holds a PhD in Chemical Physics from Columbia University and a BS (summa cum laude) in Chemistry from Yale University.