Microbial Burst Accompanying Earth's Greatest Extinction
When: May 19, 2014 11AM PDT
Roughly 252 million years ago, the end-Permian extinction resulted in the greatest loss of life in the fossil record. The cause remains mysterious, but decades of research indicate that a strong perturbation of the global carbon cycle occurs at the extinction’s peak. This talk addresses three aspects of this disruption. First,
we show that geochemical signals indicate super-exponential growth of the marine inorganic carbon reservoir, coincident with the extinction and consistent with the expansion of a new microbial metabolic pathway.
Second, we show that the efficient pathway via which members of the microbial genus Methanosarcina convert acetate to methane emerged at a time statistically indistinguishable from the extinction. Finally, we show that nickel concentrations in South China sediments increased sharply at the extinction, probably as a consequence of massive Siberian volcanism, enabling a methanogenic expansion by removal of nickel limitation. Collectively, these results are consistent with the instigation of Earth’s greatest mass extinction by a specific microbial innovation.
To join using a videoconferencing system:
Please RSVP to Mike Toillion (firstname.lastname@example.org) if you will be joining by Polycom.
To view the slides, connect to http://connect.arc.nasa.gov/nai_directors_seminar/
To join using a web browser:
The slides and audio/video for this meeting will be presented using Adobe Connect. To join the meeting, connect to:
If you are having problems connecting, you can try joining http://connect.arc.nasa.gov/nai_directors_seminar/?launcher=false, or rebooting your computer, or try joining from another network.