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Bacteria are not usually thought of as having a natural habitat like a mammal or insect, but indirect evidence has suggested that, if anything, most of the early evolution of bacteria was in the marine environment (oceans) and not on land. Surprisingly, NAI researchers from Penn State, Fabia Battistuzzi (now at Arizona State University) and Blair Hedges, found evidence that a large group of bacteria--two-thirds of all ~10,000 described species--trace their ancestry back to a life on land, not in the oceans. These bacteria have many useful adaptations, including the production of oxygen, which now may be tied to their land-loving lifestyle. Their article appeared in the February issue of Molecular Biology and Evolution.
The study involved evolutionary analyses of sequence data from hundreds of complete genomes. Members of the terrestrial group, which they call Terrabacteria, include the Gram positive phyla (Actinobacteria and Firmicutes) and two phyla with cell walls that differ structurally from typical Gram positive and Gram negative phyla: Chloroflexi and Deinococcus-Thermus. The large group of >6,000 species also includes the oxygen-producers, Cyanobacteria. Many members of Terrabacteria produce spores and have other adaptations for resistance to environmental stress. Earlier studies, including some by the same authors, found a similar phylogenetic pattern but community acceptance of any particular tree of prokaryotes has been slow, partly because ribosomal RNA trees have always differed from protein and genome trees. But the Penn State team revealed biases in the ribosomal RNA data, that when accounted for, produce a tree more similar to the genome tree and lending support for Terrabacteria. Their molecular clock estimates place the colonization of land deep in the Precambrian, about three billion years ago.
[Source: NAI Newsletter]
n November 26, 2008, volunteers in programs within the NASA Nationwide Consortium participated in a two-hour, introductory training telecon covering the basic principles of astrobiology, sponsored by NAI's WISC team and JPL. The Consortium includes many of NASA's volunteer-based organizations such as the Solar System Ambassadors, the Night Sky Network, the Aerospace Education Services Project, the Explorer Schools, and the Educator Astronauts. These volunteers reach many thousands of teachers, students, and public audiences every year in assemblies and other presentations.
The speakers were Dr. Max Coleman (JPL), Dr. Margaret Race (SETI Institute), and Jon Rask (ARC). The Astrobiology Primer, a resource document authored from within the NAI/astrobiology community, was used in this training, as were other NAI E/PO resources. Over the next few years, NAI's WISC team will partner with NAI's two new JPL teams to continue to train volunteers from these programs in NAI science and educational materials.
[Source: NAI Newsletter]
The Life in Extreme Environments Educator Conference, hosted by the Jet Propulsion Laboratory Education Office, was held on January 24-25, 2009 in JPL's von Karman auditorium. E/PO Leads from NAI's teams at the University of Wisconsin, Madison, JPL-Titan, and JPL-Icy Worlds participated in producing the event. Eighty-one educators attended. The program included an introduction to astrobiology, as well as more detailed presentations outlining astrobiology research into extrasolar planet habitability, pre-biotic chemistry, spectral "bio"signatures, and planetary protection. NAI educational materials were distributed.
The conference also served as a platform from which to test a remote video connection to educators in Barrow, Alaska, a remote field site for NAI scientists. This test was important, as the NAI-Icy Worlds team will continue to communicate with educators and students in Barrow over the next several years. The connection was made successfully, and several participants joined from Barrow.
For more information: http://astrobiology.nasa.gov/nai/articles/life-in-extreme-environments-educator-conference/
[Source: NAI Newsletter]
The NAI Postdoctoral Fellowship Program provides opportunities for Ph.D. scientists and engineers of unusual promise and ability to perform research on problems largely of their own choosing, yet compatible with the research interests of NASA and the member teams of the NASA Astrobiology Institute. The next award cycle that the NAI will be participating in will be the March 1, 2009 application deadline. For additional information about the program see http://nasa.orau.org/postdoc .
[Source: NAI Newsletter]
Iceland, 29 June to 13 July 2009
Deadline: Applications due March 1, 2009
The NASA Astrobiology Institute and the Nordic Astrobiology Network will conduct a summer school on the role of water in the evolution of life in the cosmos - in Iceland on the above dates. The school is intended for students and post-docs in astrobiology-related subjects (biology, chemistry, physics, astronomy, geosciences etc.)
The school will be organized in three sections:
* An introductory lecture course
* Excursions to several places in Iceland of astrobiological interest (hot springs, glaciers, geysers, Mars-like environments)
* A lab course on the geochemistry and extremophile community of hot springs (no previous experience in microbiological lab work and field research needed)
The school will be able to accept around 40 students. Those accepted from the US and the Nordic countries (including the Baltic States and Northwestern Russia) will be provided lodging, meals, study material and the complete excursion and teaching programme without charge as well as some reimbursement for travel expenses. Some funding is also available for a limited number of participants from other countries. Participants from Europe will be awarded 4 ECTS points for the summer school; formal course credit may also be available for US students.
Further information about the summer school and application instructions are available on-line at http://www.nordicastrobiology.net/iceland2009
[Source: NAI Newsletter]
The Arizona State University Astrobiology Team invites applications for a full-time postdoctoral Research Scientist (non-tenure track) position in Microbial Ecology/Physiology. The successful candidate will have a leading role in the research emphasis "The Stoichiometry of Life" which is aimed at understanding the fundamental relationships between the elemental composition of microbes and their environment, through investigations in the field, the laboratory, and the genomic and geologic records of the history of life. For more information: http://astrobiology.asu.edu/Astrobiology/Opportunities/Entries/2009/1/30_Postdoctoral_Fellowship_in_Microbial_Ecology_Physiology.html
[Source: NAI Newsletter]
Penn State will once again host the Astrobiology Summer Program (ASP), supported by the National Science Foundation and NASA Astrobiology Institute. Undergraduates with an interest in astrobiology and contemplating a career in the sciences are encouraged to apply. Participants receive a stipend, travel, and living expenses, and conduct research for ten weeks at Pennsylvania State University under the guidance of astrobiology faculty mentors. Among the summer activities are field trips to NASA Headquarters, NASA-Goddard Space Flight Center, the Smithsonian's Air and Space Museum and Udvar-Hazy Center. The application deadline is February 15th, 2009. For more information, visit http://evo.bio.psu.edu/asp/ or contact Blair Hedges, sbh1@psu.edu.
[Source: NAI Newsletter]
Please join NAI in congratulating Jim Elser of the new Arizona State University (ASU) Team on his election as Fellow of the American Association for the Advancement of Science (AAAS). He and the other newly elected fellows will be recognized Feb. 14 at the Fellows forum, during the 2009 AAAS annual meeting in Chicago.
Becoming a Fellow is in recognition of efforts toward advancing science applications that are deemed scientifically or socially distinguished. Within that general framework, each awardee is honored for contributions to a specific field.
Elser is cited by AAAS for "pioneering work in developing the theories of ecological and biological stoichiometry to integrate levels of biology from the genome to the biosphere and thereby improve our management of renewable resources." Elser, a professor in the School of Life Sciences at ASU, has built a career asking questions about evolutionary biology and energy and material flows in ecosystems, traveling from Antarctica to alpine lakes of Norway and Colorado to the Mongolian grasslands of China, to find answers. Understanding the balance of carbon, nitrogen and phosphorus in systems forms the backbone of Elser's worldview, known as "stoichiometric theory." He has taught more than 10,000 students and his pioneering studies have shaped young minds and jumpstarted new research approaches, as well as provided insights into nutrient limitation, trophic dynamics, and biogeochemical cycling, evolution and integrated levels of organization from molecules to cells to ecosystems.
[Source: NAI Newsletter]
Starting on February 23rd, 2009, each of the NAI teams will be giving one hour overview seminars that describe the work they will be performing as members of the NAI. These seminars, which will be broadcast via videoconference and web, will provide an opportunity to find out more about the science, EPO and other activities being performed by the NAI teams. These seminars will take place at 11am Pacific time. The schedule of the talks follows:
Monday, Feb 23: George Cody, Carnegie Institution of Washington
Wednesday, Feb 25: Dave Des Marais, NASA Ames Research Center
Monday, March 9: Isik Kanik, NASA JPL - Icy Worlds
Wednesday, March 11: Mark Allen, NASA JPL - Titan
Monday, March 16: Ariel Anbar, Arizona State University
Wednesday, March 18: Clark Johnson, University of Wisconsin
Monday, March 30: John Peters, Montana State University
Wednesday, April 1: Loren Williams, Georgia Institute of Technology
Monday, April 6: Chris House, Penn State University
Wednesday, April 8: Doug Whittet, Rensselaer Polytechnic Institute
Monday, April 13: Vikki Meadows, VPL at University of Washington
Wednesday, April 15: Mike Mumma, NASA Goddard Space Flight Center
Monday, April 20: Roger Summons, Massachusetts Institute of Technology
Wednesday, April 22: Karen Meech, University of Hawaii
For more information about these seminars and participation information, please visit http://astrobiology.nasa.gov/nai/seminars/
[Source: NAI Newsletter]
At the January NAI Executive Council meeting, each of NAI's Principal Investigators delivered presentations outlining the science of their teams. Those presentations are now available as downloadable podcasts from the NAI website. For more information and to download the podcasts, visit http://astrobiology.nasa.gov/nai/executive-council/january-2009-ec-agenda
[Source: NAI Newsletter]
The NASA Astrobiology Institute (NAI) is accepting proposals to the 2009 NAI Director's Discretionary Fund (DDF). Proposals will be accepted at any time until June 15, 2009. Proposals submitted after that date will be considered for funding as part of the NAI 2010 DDF. For more information: http://astrobiology.nasa.gov/nai/funding/ddf-2009
[Source: NAI Newsletter]
Geological and biological evidence suggests that Earth was warm during most of its early history, despite the fainter young Sun. Upper bounds on the atmospheric CO2 concentration in the Late Archean/Paleoproterozoic (2.8–2.2 Ga) from paleosol data suggest that additional greenhouse gases must have been present.
Methanogenic bacteria, which were arguably extant at that time, may have contributed to a high concentration of atmospheric CH4, and previous calculations had indicated that a CH4-CO2-H2O greenhouse could have produced warm Late Archean surface temperatures while still satisfying the paleosol constraints on pCO2. Here, we revisit this conclusion. Correction of an error in the CH4 absorption coefficients, combined with the predicted early onset of climatically cooling organic haze, suggest that the amount of greenhouse warming by CH4 was more limited and that pCO2 must therefore have been ≥0.03 bar, at or above the upper bound of the value obtained from paleosols.
Enough warming from CH4 remained in the Archean, however, to explain why Earth's climate cooled and became glacial when atmospheric O2 levels rose in the Paleoproterozoic. Our new model also shows that greenhouse warming by higher hydrocarbon gases, especially ethane (C2H6), may have helped to keep the Late Archean Earth warm.
Astrobiology. December 2008, 8(6): 1127-1137.
http://www.liebertonline.com/doi/pdfplus/10.1089/ast.2007.0197
Availability of reduced nitrogen is considered a prerequisite for the genesis of life from prebiotic precursors. Most atmospheric and oceanic models for the Hadean Earth predict a mildly oxidizing environment that is conducive to the formation and stability of only oxidized forms of nitrogen.
A possible environment where reduction of oxidized nitrogen to ammonium has been speculated to occur is aqueous hydrothermal systems. We examined a suite of transition metal oxides and sulfides for their ability to reduce nitrate and nitrite, as well as oxidize ammonia, under hot (300°C) high-pressure (50–500 MPa) aqueous conditions. In general, iron sulfides exhibited the most rapid and complete conversion noted, followed by nickel and copper sulfides to a much lower degree. Of the oxides examined, only magnetite exhibited any ability to reduce NO3− or NO2−. Ammonium was stable or exhibited small losses (<20%) in contact with all the mineral phases and conditions tested.
The results support the idea that hydrothermal systems could have provided significant amounts of reduced nitrogen to their immediate environments. The enhanced availability of reduced nitrogen in hydrothermal systems also has important implications for prebiotic metabolic pathways where nitrogen availability is critical to the production of amino acids and other nitrogenous compounds.
Astrobiology. December 2008, 8(6): 1113-1126.
http://www.liebertonline.com/doi/pdfplus/10.1089/ast.2007.0187
Based on new image data from the High Resolution Imaging Science Experiment (HiRISE) on Mars Reconnaissance Orbiter (MRO), a case can be made that several structures in Vernal Crater, Arabia Terra are ancient springs. This interpretation is based on comprehensive geomorphologic analysis coupled with assessment of multiple hypotheses.
The structures identified extend across several kilometers and are exceptional in that nothing with their detail and scale has been reported from Mars. The deposits are associated with an extensive fracture system that may have facilitated upward flow of warm fluids. Several additional spring-like features occur in Vernal Crater, and it is possible that these are part of a major province of spring activity. Since springs are environments where life could have evolved on Mars, where that life could have found refuge as the climate became colder and drier, and where signatures of that life may be preserved, Vernal Crater may be a site of major astrobiological importance.
Astrobiology. December 2008, 8(6): 1093-1112.
http://www.liebertonline.com/doi/pdfplus/10.1089/ast.2008.0239
Liquid water is essential to life as we know it on Earth; therefore, the search for water on Mars is a critical component of the search for life. Olivine, a mineral identified as present on Mars, has been proposed as an indicator of the duration and characteristics of water because it dissolves quickly, particularly under low-pH conditions. The duration of olivine persistence relative to glass under conditions of aqueous alteration reflects the pH and temperature of the reacting fluids.
In this paper, we investigate the utility of 3 methodologies to detect silicate weathering in a Mars analog environment (Sverrefjell volcano, Svalbard). CheMin, a miniature X-ray diffraction instrument developed for flight on NASA's upcoming Mars Science Laboratory, was deployed on Svalbard and was successful in detecting olivine and weathering products. The persistence of olivine and glass in Svalbard rocks was also investigated via laboratory observations of weathered hand samples as well as an in situ burial experiment. Observations of hand samples are consistent with the inference that olivine persists longer than glass at near-zero temperatures in the presence of solutions at pH 7–9 on Svalbard, whereas in hydrothermally altered zones, glass has persisted longer than olivine in the presence of fluids at similar pH at 50°C.
Analysis of the surfaces of olivine and glass samples, which were buried on Sverrefjell for 1 year and then retrieved, documented only minor incipient weathering, though these results suggest the importance of biological impacts. The 3 types of observations (CheMin, laboratory observations of hand samples, burial experiments) of weathering of olivine and glass at Svalbard show promise for interpretation of weathering on Mars. Furthermore, the weathering relationships observed on Svalbard are consistent with laboratory-measured dissolution rates, which suggests that relative mineral dissolution rates in the laboratory, in concert with field observations, can be used to yield valuable information regarding the pH and temperature of reacting martian fluids.
Astrobiology. December 2008, 8(6): 1079-1092.
http://www.liebertonline.com/doi/pdfplus/10.1089/ast.2007.0195
This study identifies transcriptional regulation of stress response element (STRE) genes in space in the model eukaryotic organism, Saccharomyces cerevisiae. To determine transcription-factor dependence, gene expression changes in space were examined in strains bearing green fluorescent protein–tagged (GFP-tagged) reporters for YIL052C (Sfp1 dependent with stress), YST-2 (Sfp1/Rap1 dependent with stress), or SSA4 (Msn4 dependent with stress), along with strains of SSA4-GFP and YIL052C-GFP with individual deletions of the Msn4 or Sfp1.
When compared to parallel ground controls, spaceflight induces significant gene expression changes in SSA4 (35% decrease) and YIL052C (45% decrease), while expression of YST-2 (0.08% decrease) did not change. In space, deletion of Sfp1 reversed the SSA4 gene expression effect (0.00% change), but Msn4 deletion yielded a similar decrease in SSA4 expression (34% change), which indicates that SSA4 gene expression is dependent on the Sfp1 transcription factor in space, unlike other stresses. For YIL052C, deletion of Sfp1 reversed the effect (0.01% change), and the Msn4 deletion maintained the decrease in expression (30% change), which indicates that expression of YIL052C is also dependent on Sfp1 in space. Spaceflight has selective and specific effects on SSA4 and YIL052C gene expression, indicated by novel dependence on Sfp1.
Astrobiology. December 2008, 8(6): 1071-1078.
http://www.liebertonline.com/doi/pdfplus/10.1089/ast.2007.0211
Chirality is an excellent indicator of life, but naturally occurring astrobiological (as well as terrestrial) samples nearly always exhibit massive depolarizing light scattering, which renders conventional polarimeters useless. For astrobiological applications, we instead consider a novel polarimeter originally developed for non-invasive human-glucose measurement. It involves deliberately rotating in time the plane of polarization of a linearly polarized beam and detecting the shift in the plane of the rotating linearly polarized component of the transmitted light from a chiral sample relative to the input polarization plane. We find that this polarimeter can operate in 3 orders of magnitude more depolarizing scattering than conventional polarimeters. Furthermore, it can also be designed to be lightweight, compact, and energy efficient.
Astrobiology. December 2008, 8(6): 1061-1069.
http://www.liebertonline.com/doi/pdfplus/10.1089/ast.2007.0151
Come join an interdisciplinary gathering of scientists, artists and writers as they explore human futures in fact and fiction at the annual CONTACT conference.
WHERE: NASA Ames Research Center, Moffett Field, Calif., Building 943 located at the main gate. To reach NASA Ames, take U.S. Highway 101 to the Moffett Field, NASA Parkway exit and drive east on Moffett Boulevard towards the main gate and bear right into the parking lot. Building 943 is located across the street from the large white dome.
WHEN: Friday, April 3, 2009 to Sunday, April 5, 2009
The CONTACT Conference features
Art exhibits, symposia, social gatherings and presentations from renowned scientists, including:
- Bill Clancey, chief scientist for Human-Centered Computing in the Intelligent Systems Division at NASA Ames Research Center;
- Michael Sims, senior researcher in the Intelligent Systems Division at NASA Ames Research Center, and
- Carol Stoker, a scientist in the Space Sciences Division at the NASA Ames Research Center and a lead scientist on NASA's Phoenix mission.
Fore more information about CONTACT, and to register, visit
http://www.contact-conference.org/
Come hear an interesting exchange of ideas as Lynn Rothschild, evolutionary biologist and astrobiologist at NASA Ames Research Center, and Father George Coyne, Director Emeritus of the Vatican Observatory, astronomer and Jesuit priest, discuss "Are We Alone? The Dance of the Fertile Universe." Ames Center Director, S. Pete Worden will moderate as they consider the fact that while the potential for life was present at the Big Bang, Earth may be the only place that promise was realized. They will also discuss from their different perspectives what niches life may have found since the Big Bang and muse on the significance of the fertile universe.
Ames Research Center, the Commonwealth Club of California and the Yale Club of San Francisco will jointly host this talk.
The event is open to the public; admission is $15 in advance online at Tickets can be purchased in advance at: http://tickets.commonwealthclub.org/auto_choose_ga.asp?area=62 or in cash at the door. Light refreshments will be served prior to the lecture.
WHO:
- Lynn Rothschild, an evolutionary biologist and astrobiologist at NASA Ames;
- Father George Coyne, Director Emeritus of the Vatican Observatory;
- S. Pete Worden, Ames Center Director
WHERE: 500 Severyns Avenue, NASA Ames Research Center, Moffett Field, Calif., 94035. To reach NASA Ames, take U.S. Highway 101 to the Moffett Field, NASA Parkway exit and drive east on Moffett Boulevard towards the main gate. Guards at the main gate will direct reporters to NASA Research Park, directly behind the gate.
WHEN: Thursday, Feb. 19, 2009
- 6:30 p.m. PST: check in begins
- 7 p.m. PST: lecture begins
Editor's note: I just learned that my long time friend Mel Averner died last night. I will write something more lengthy at some point. Suffice it to say there were two people who taught more more than anyone else while I was at NASA - and after I left. Dick Keefe and Mel Averner. Not a thing happened in NASA's space life science programs in the 80's, 90's and recent years that was not directly or indirectly affected by Dick and Mel. Dick passed away several years ago. Mel was full of life and ideas up to the last moments of his life. I had a chance to speak with him last week. The conversation lasted 9 minutes. Long enough for him to say goodbye to me and for me to do so in exchange. Many of his friends had a chance to do the same. In so doing, Mel left little seeds in our minds - seeds that will continue to affect the way that we look at life on Earth and beyond for decades to come. I hope Mel's friends will take the time to post their thoughts below.