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Project Reports

• Adaptation to Salinity in Microbial Communities

  The potential relevance of evaporative lakes as analogs for the late stage hydrosphere of Mars (see results of Manga and collaborators in the UC Berkeley team) is well established (e.g., Benison and Laclair 2003, Astrobiology v.3).

  ROADMAP OBJECTIVES: 2.1 3.2 4.1 5.3 7.2

• Biosignatures in Chemosynthetic and Photosynthetic Systems

  ROADMAP OBJECTIVES: 2.1 4.1 5.1 5.2 6.1 7.1 7.2

• Planetary Biology, Evolution, and Intelligence

  The results of a two and a half day workshop on the topic of the Habitability of Planets Orbiting M Stars was published recently. Thirty scientists from nineteen institutions in the US and UK participated. Thirteen of the participants were from six other NAI Teams

  ROADMAP OBJECTIVES: 1.1 1.2 2.1 2.2 3.1 3.2 4.1 4.2 5.1 5.2 5.3 6.1 6.2 7.1 7.2

• Iron Oxidation – Shaping the Past and Present Environments

   

  ROADMAP OBJECTIVES: 4.1 5.2 5.3 6.1 7.2

• Evolution of Atmospheric O2, Climate, and Biosphere (Ohmoto)

  ROADMAP OBJECTIVES: 1.1 2.1 4.1 4.3 5.1 5.2 6.1 7.1

• Project 3. Prebiotic Chemical and Isotopic Evolution on Earth

   

  ROADMAP OBJECTIVES: 3.1 4.1 4.2 7.1

• Ecosystem to Biosphere Modeling

   

  ROADMAP OBJECTIVES: 4.1 5.3 6.1 7.2

• Project 4. Prebiotic Molecular Selection and Organization

   

  ROADMAP OBJECTIVES: 3.1 3.2 3.4 4.1 7.1

• Habitable Planets

  ROADMAP OBJECTIVES: 1.1 1.2 2.1 4.1 4.3

• Identifying Microbial Life at Crustal Rock-Water Interfaces

  ROADMAP OBJECTIVES: 4.1 5.2 5.3 6.1 7.1

• Genomic Record of the Earth’s Early Biosphere (Hedges)

  ROADMAP OBJECTIVES: 4.1 4.2 4.3

• Project 6. Molecular and Isotopic Biosignatures

  Differences in carbon isotope ratios of co-occurring dolomite, carbonate fluorapatite, and organic matter in Paleoproterozoic stromatolitic phosphorites from the Aravalli Supergroup, India, suggest elevated primary productivity during sedimentation. Postdoctoral Fellow Dominic Papineau’s research provides a basis for the examination of other Paleoproterozoic phosphorites and a contribution to the identification of biosignatures in phosphatic sediments.

  ROADMAP OBJECTIVES: 2.1 3.1 4.1 4.2 5.3 6.1 6.2 7.1 7.2

• Investigations of Modern Analogues of Precambrian Microbial Ecosystems

  ROADMAP OBJECTIVES: 4.1 4.3 6.1

• Molecular Survey of Microbial Diversity in Hypersaline Ecosystems

  ROADMAP OBJECTIVES: 3.4 4.1 4.2 5.1 5.2 5.3 6.1 6.2 7.1

• Iron and Sulfur-Based Biospheres and Their Biosignatures

  This collaborative project involves many members of the UC Berkeley-led NAI team as well as members of other teams and institutions internationally.

  ROADMAP OBJECTIVES: 2.1 4.1 5.1 5.2 5.3 7.2

• Modeling Early Atmospheric Composition and Climate (Kasting)

  ROADMAP OBJECTIVES: 4.1 7.2

• Philosophical Issues in Astrobiology

  ROADMAP OBJECTIVES: 3.2 3.4 4.1 5.1 5.2

• Re-Tracing Steps Towards a Habitable World: The Biogeochemical Evolution of Sulfur on the Early Earth.

  In the last year, we have reported work on the origin of the crust from analysis of rare isotopes in Hadean zircons from Western Australia, established the ages of the oldest and best preserved sediments in Canada at Inukjuak (Quebec) and completed our analysis of multiple sulfur isotopes from the transition from an oxygen-poor to oxygen-rich surface across the Paleoproterozoic.

  ROADMAP OBJECTIVES: 1.1 4.1 4.2 5.1 5.2 6.1

• Rise of Oxygen, Modern Analogs for Anoxic Oceans, and Effect of Early Life on Soil Development

  ROADMAP OBJECTIVES: 1.1 4.1 4.3 6.1 7.1 7.2

• Towards a Cometary Taxonomy Based on Organic Composition

  This research is targeted on building a new taxonomy for comets based on their parent volatile compositions, especially organics. This taxonomy is crucial for understanding the role of each taxonomic group in delivering prebiotic organics and water to early Earth. During this reporting period, we identified the first comet of Kuiper belt origin belonging to the “organics-depleted” class (joining two Oort cloud comets of similar composition).

  ROADMAP OBJECTIVES: 1.1 3.1 4.1 4.3

• Rapid Response to Remotely Detected Seafloor Eruptions

  This project is an on-going study of the microbial and geochemical changes associated with seafloor eruptions at mid-ocean ridges. The intrusion of a magma dike into the neovolcanic zone of a mid-ocean ridge is the “quantum” event in the accretion of the upper ocean crust. Such ridge axis diking/eruptive events are episodic perturbations that trigger a sequence of interrelated and rapidly evolving physical, chemical, and biological processes associated with the formation of ocean crust.

  ROADMAP OBJECTIVES: 4.1 5.3 6.1

• Subseafloor Basement (Basalt) Biosphere Studies

  Low temperature hydrothermal ocean fluids (<100°C), circulate everywhere within the porous and permeable volcanic rocks of the upper ocean basement, providing temperatures and chemical gradients that form plausible habitats for a variety of microbial communities. However, few direct tests have been carried out in buried basement rocks or fluids.

  ROADMAP OBJECTIVES: 1.1 3.3 4.1 5.1 5.2 5.3 6.1 6.2