NAI

  1. Strategies for Evolutionary Success – Sulfolipids


    Researchers from NAI’s University of Rhode Island Team and their colleagues have studied the use of phosphorus vs. sulfur in the membrane lipid sythesis pathways of organisms resident in the ocean’s subtropical gyres. Their data show that the dominant organism in the phytoplankton, a cyanobacterium, has evolved a “sulfur-for-phosphorus” strategy; producing a membrane lipid containing sulfate and sugar instead of phosphate. This adaptation may have been a major event in Earth’s early history when the relative availability of sulfate and phosphate was different than in today’s oceans. Their paper appears in the June 6th issue of ...

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  1. Arctic, Antarctic, Mars


    The city of Hammerfest lies at the northern tip of Norway, well above the Arctic Circle. If you board a ship heading north from there, just before you reach the polar ice cap you run into a group of islands known as the Svalbard archipelago.

    For the past two summers, a group of scientists has traveled to the largest of these islands to study an environment that sheds light on a notorious meteorite, discovered at the opposite end of the Earth, in Antarctica.

    The meteorite, ALH84001, began as a rather unremarkable piece of volcanic rock that formed about 4.5 ...

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  1. Amino Acids Found in Antarctic Meteorites


    Researchers from NAI’s NASA Goddard Space Flight Center Team and their colleagues publish their analysis of two meteorites in the current issue of Meteoritics and Planetary Science. Their study revealed a suite of amino acids present in the meteorites that are not present in the Antarctic ice on which they were found.

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  1. Carbon Isotope Record From ~2.2 Ga Rocks in the Great Lakes Area


    Andrey Bekker of NAI’s Carnegie Institution of Washington Team and his colleagues have an article in press for Precambrian Research which details the carbon isotope record for the carbonate platform in the Great Lakes area. Observed carbon isotope values from the Lake Superior area may correspond to those from Griqualand West Basin, South Africa, supporting the notion of three global glaciations in the Paleoproterozoic Era.

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  1. B-Pictoris Debris Disk Rich in Carbon Gas


    Using NASA’s FUSE spacecraft, scientists from NAI’s Carnegie Institution of Washington Team have discovered abundant amounts of carbon gas in a dusty disk surrounding the young star Beta Pictoris. While planets may have already formed, the prevalence of carbon gas in the disk indicates that the planets could be carbon-rich worlds of graphite and methane, potentially resembling the early conditions of our own Solar System. The authors suggest that either carbon-rich asteroids or comets, unlike any in our own solar system, have vaporized, or that bodies outgassing carbon-bearing species such as methane are responsible for the observation. Their ...

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  1. Earlier Evolution of Oxygenic Photosynthesis – Surviving Snowball Earth


    Roger Buick from NAI’s University of Washington Team and his colleagues report in the current issue of Geology their analysis of oil-bearing fluid inclusions in 2.45 billion year old rocks from Canada. They assert that the oil is derived from an overlying formation, becoming trapped in the host rock before 2.2 billion years ago – prior to the Great Oxidation Event. Abundant biomarkers for cyanobacteria and eukaryotes were identified in the study, suggesting that aqueous environments at the time had become sufficiently oxygenated for sterol biosynthesis to occur, and implying that organisms had the ability to survive “snowball ...

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  1. Biodiversity Rocks the Cover of Nature


    The cover of this week’s Nature belongs to Abigail Allwood of the Australian Centre for Astrobiology, one of NAI’s International Partners. She and her colleagues put forward the latest research on the ancient rocks of the Pilbara Craton in Western Australia, which points to evidence of life on Earth 3.43 billion years ago. Their description of a shallow marine environment, and identification of seven stromatolite morphotypes makes a strong argument for early life. NAI supported Allwood’s work with a 2005 NAI Research Scholarship.

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  1. Super-Earths Around M Dwarf Stars – Competing Theories


    Alan Boss of NAI’s Carnegie Institution of Washington Team published in the current issue of the Astrophysical Journal a new look at the origin of super-Earths orbiting M dwarf stars. The core accretion mechanism of giant planet formation has been used to explain the presence of these planets. Boss’ new work shows they could also have been formed by the disk instability mechanism.

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  1. Chemical Energy for Life on Early Earth and Mars


    Researchers from NAI’s NASA Ames Research Center and University of Colorado, Boulder Teams published in the current issue of Astrobiology their study of the petrology and mineral chemistry of a cold spring in Northern California. They propose that the serpentinization process can provide a source of energy for chemosynthetic organisms, and outline criteria to aid in the identification of serpentinizing terranes on Mars.

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  1. A Deeper Look Into the Watery Plumes of Enceladus


    NASA astrobiologists are hard at work examining the nature of the plumes of water vapor recently discovered on Saturn’s moon Enceladus. If a new geological theory about the plumes, published in this week’s Nature, proves to be correct, it would preclude the existence of a subsurface ocean on the moon. The theory is testable with existing data from NASA’s Cassini mission…

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  1. Abiogenic Explanation for Methane on Mars


    Researchers from NAI’s Indiana Princeton Tennessee Astrobiology Initiative Team published their theory on the origin of the detected atmospheric methane on Mars in the current issue of Astrobiology. Measurements of deep fracture water samples from South Africa led to a model which distinguishes between abiogenic and microbial methane sources based upon their isotopic composition, and couples microbial methane production to molecular hydrogen generation by water radiolysis. The authors also propose an instrument for future missions to Mars which, with measurements over time, could distinguish mechanisms for methane emissions.

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  1. Energy Conservation: Important Now, Important Then?


    An alternative theory for the origin and evolution of life is proposed by scientists from NAI’s Pennsylvania State University Team in the current issue of Molecular Biology and Evolution. The theory, centering on the concept that an energy-conservation pathway was the major force which powered and directed the early evolution of the cell, provides insight into the evolution of the microbial production of methane.

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  1. New Astrobiology TV Documentary Features NAI Scientists


    NAI scientists and their international partners were featured in a new documentary called “Looking for Life” which premiered this week on both PBS and NASA-TV. The program highlights cutting edge field work in the arid Western Australian desert, an acid river in Spain, high altitude lakes in the Bolivian Andes, and the permafrost within an old gold mine in the Canadian Arctic where astrobiologists are characterizing the unique habitats and survival mechanisms of life on Earth, and laying the groundwork for the search for life on other planets.

    For more information about the program, see http://passporttoknowledge.com/life/. Check ...

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  1. Ancient Archea, Novel Protein


    Researchers from *NAI’s Pennsylvania State University Team *published their functional and phylogenetic analysis of protein WrbA function this week in The Journal of Bacteriology. Comparing 30 sequences including that of Archaeoglobus fulgidus, a hyperthermophilic archeabacterium, this study demonstrates the ability for this enzyme to protect against oxidative stress through quinone oxidoreductase activity.

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  1. Biodiversity in Hypersaline Mats


    Researchers at NAI’s University of Colorado, Boulder and Marine Biological Laboratory Team published their analysis of biodiversity in hypersaline microbial mats in a recent issue of Applied and Environmental Microbiology. Bacteria dominated the mat in unprecedented diversity representing 752 species, including 15 novel candidate phyla.

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