2013-2014
2012-2013
2011-2012
2010-2011
2009-2010
2008-2009
2007-2008
2006-2007
2005-2006
2004-2005
OI Colloquium
Roger Summons
 Massachusetts Institute of Technology, Department of Earth and Planetary Sciences
Title Oxygen, Geostable Molecules, and the Cloud Paradigm
Date07 / 11 / 2011
Time 2:30 pm (Coffee served at 2:15pm)
PlaceMDCL-1110
Linkhttp://www-eaps.mit.edu/geobiology/people.html
Abstract Over the past fifty years geoscientists have struggled to understand how and when Earth’s surface became habitable to complex, intelligent life. One of the prevailing scenarios, first articulated by Cloud, Holland, and Walker, proposes that there was an initial anoxic, or very low O2, atmosphere. Although photosystem II appeared relatively early, there was an extended period of imbalance between sources and sinks of O2, through pervasive feedback between biosphere, atmosphere, hydrosphere, and lithosphere. Ultimately, O2 accumulated in the atmosphere to near its present level, at about 540Ma. Life evolved concurrently. This talk examines some of the evidence for and against this idea, based on the distributions of isotopic and molecular fossils and what these can tell us about the antiquity of oxygen-dependent biochemical pathways.

HOST: Dr. Lori Ziolkowski

   Back to 2012 talk listing

Origins Institute at McMaster University, 2004-2009
Contact information can be found here
If you have questions, comments or concerns about the content of this website, please contact the OI webmaster.