Archives

Paleobiology & Biosignatures: September 2009


November 25-27, 2009 in Frascati, Italy - The NASA Mars Program Office has announced that travel funding will be made available for as many as 5 students who are U.S. citizens or legal residents, with Mars-related interests, to attend the Workshop on Methane on Mars: Current Observations, Interpretation and Future Plans, November 25-27, 2009 in Frascati, Italy. An application must be submitted by September 28, 2009, to be considered for this funding. NASA Headquarters will make the selections and students will be notified no later than October 15, 2009. Reimbursable costs include registration fees, transportation (airfare, mileage to/from airport, parking, rental car) and lodging/per diem. In most cases, actual expenses will exceed the funding provided.

Humans might not be walking on Earth today if not for the ancient fusing of two microscopic, single-celled organisms called prokaryotes, NASA-funded research has found.

By comparing proteins present in more than 3000 different prokaryotes - a type of single-celled organism without a nucleus - molecular biologist James A. Lake from the University of California at Los Angeles' Center for Astrobiology showed that two major classes of relatively simple microbes fused together more than 2.5 billion years ago. Lake's research reveals a new pathway for the evolution of life on Earth. These insights are published in the Aug. 20 online edition of the journal Nature.

This endosymbiosis, or merging of two cells, enabled the evolution of a highly stable and successful organism with the capacity to use energy from sunlight via photosynthesis. Further evolution led to photosynthetic organisms producing oxygen as a byproduct. The resulting oxygenation of Earth's atmosphere profoundly affected the evolution of life, leading to more complex organisms that consumed oxygen, which were the ancestors of modern oxygen-breathing creatures including humans.

May 21 - 23, 2010 Denver, Colorado and Dinosaur Ridge, Cretaceous Dakota Sandstone, Denver

The conference presents an important and novel review on microbial mats and the sedimentary structures they form in siliciclastic settings through Earth times, from the early Archean to the present. The meeting brings together the expertise and knowledge of an international panel of leading researchers to provide a state-of-the art overview of the field. The participants give a timely review of the current and most topical areas of research, essential for all scientists interested in this rapidly growing field. For more information: http://www.sepm.org/activities/researchconferences/microbial/microbial_home.htm Source: NAI Newsletter

AGU Session B14: Early Oxygen

Session Abstract: During most of the geologic past, life and the surface environments on Earth were profoundly different than they are today. In particular, it is generally accepted that the atmosphere was devoid of O2, or nearly so, until the "Great Oxidation Event" approximately 2.4 billion years ago. However, considerable uncertainty remains about the abundances of O2 and other oxidants during the first half of Earth history, as well as processes that constrained these abundances to seemingly trace levels. Emerging data should allow tighter constraints on Archean free oxygen concentrations, the variability of redox conditions at high temporal resolution, and the evolutionary and biogeochemical consequences of oxygenation. At the same time there is a need to refine existing proxies, assess their limitations, and develop new ones. This session will explore these issues. We encourage abstracts from a variety of areas ranging from analytical and theoretical geochemistry to genomics. For more information see
http://www.agu.org/meetings/fm09/program/scientific_session_search.php?show=detail&sessid=219 Source: NAI Newsletter