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Origin & Evolution of Life: March 2009


Ames is proud to announce the first lecture in a series on the Evolution of Science and Technology. On Thursday, March 12 at 7:00 PM at the Mountain View Center for the Performing Arts, Dr. James Strick of Franklin & Marshall College will talk about Charles Darwin and his thoughts on the origins of life. Employees and members of the public are invited to attend this free public lecture sponsored by Ames and the NASA Astrobiology Institute. Additional lectures in the series, which honors the 200th anniversary of Charles Darwin's birth among other significant anniversaries, will be announced at a later date.

Evolution of the Modern Nitrogen Cycle

NAI's Deep Time Drilling Project supported the drilling of several pristine cores from ancient rocks in Western Australia in 2004, and a new paper in Science, led by University of Washington astrobiologists, outlines results from the analysis of these cores. The nitrogen isotope values in the core from the 2.5-billion-year-old Mount McRae Shale vary over 30 meters, evidently recording a temporary change from an anaerobic to an aerobic nitrogen cycle, and back again to anaerobic. Other data suggest that nitrification occurred in response to a small increase in surface-ocean oxygenation. The data imply that nitrifying and denitrifying microbes had already evolved by the late Archean and were present before oxygen first began to accumulate in the atmosphere.

[Source: NAI Newsletter]