2010 Annual Science Report

Astrobiology Roadmap Objective 4.2 Reports Reporting  |  SEP 2009 – AUG 2010

Project Reports

  • AIRFrame Technical Infrastructure and Visualization Software Evaluation

    The Astrobiology Integrative Research Framework (AIRFrame) analyzes published and unpublished documents to identify and visualize implicit relationships between astrobiology’s diverse constituent fields. The main goal of the AIRFrame project is to allow researchers and the public to discover and navigate across related information from different disciplines.

    ROADMAP OBJECTIVES: 1.1 1.2 2.1 2.2 3.1 3.2 3.3 3.4 4.1 4.2 4.3 5.1 5.2 5.3 6.1 6.2 7.1 7.2
  • Biosignatures in Ancient Rocks

    This team of geologists, geochemists, paleontologists and biologists seeks signs of early life in ancient rocks from Earth. Working mostly on that part of Earth history before the advent of skeletons and other preservable hard parts in organisms, our group focuses on geochemical traces of life and their activities. We also investigate how life has influenced, and has been influenced by changes in the surface environment, including the establishment of an oxygen-rich environment and the initiation of extreme climate states including global glaciations. For this we use a combination of observations from modern analogous environments, studies of ancient rocks, and numerical modeling.

    ROADMAP OBJECTIVES: 1.1 3.2 4.1 4.2 4.3 5.1 5.2 5.3 6.1 6.2 7.1 7.2
  • AbGradCon 2010

    The Astrobiology Graduate Student conference is a conference organized by astrobiology graduate students for astrobiology grad students. It provides a comfortable peer forum in which to communicate and discuss research progress and ideas.

    ROADMAP OBJECTIVES: 1.1 1.2 2.1 2.2 3.1 3.2 3.3 3.4 4.1 4.2 4.3 5.1 5.2 5.3 6.1 6.2 7.1 7.2
  • Biomechanics of the Rangeomorph Fauna

    Some of the oldest, multicellular organisms in the fossil record are enigmatic creatures called rangeomorphs. Although there is much debate as to whether the rangeomorphs are animals, fungi, or something completely unique, recent studies of the fossils suggest that the rangeomorphs used high surface areas to capture dissolved organic matter (DOM) as an energy source. In this project, we attempt to model how nutrients would have flowed over these deep-water organisms, to see how their large size might have helped them compete with bacteria for DOM. Our work suggests that competition with bacteria was a driving force in the evolution of the first complex organisms.

    ROADMAP OBJECTIVES: 4.2 5.2 6.1
  • Environmental Oxygen and the Rise (And Fall) of Metazoans

    The viability of complex animals is intimately linked to the availability of molecular oxygen. This project looks at the environmental signatures of oxygen production and availability on a range of timescales and the connection between the stages of Precambrian oxygenation and biological complexity. Increasingly, it is becoming clear that the major mass extinction events of the Phanerozoic are strongly correlated to episodes of deoxygenation.

    ROADMAP OBJECTIVES: 4.1 4.2
  • Bioastronomy 2007 Meeting Proceedings

    This is the published volume of material from an astrobiology meeting hosted by our lead team in 2007 in San Juan Puerto Riceo. The book includes 60 papers covering the breadth of astrobiology, and developed a new on-line astrobiology glossary.

    ROADMAP OBJECTIVES: 1.1 1.2 2.1 2.2 3.1 3.2 3.3 3.4 4.1 4.2 4.3 5.1 5.2 5.3 6.1 6.2 7.1 7.2
  • Evolution and Development of Sensory and Nervous Systems in the Basal Branches of the Animal Tree

    Animals interact with the world through complex sensory structures (eyes, ears, antennas, etc.), which are coordinated by collections of neurons. While the nervous and sensory systems of animals are incredibly diverse, a growing body of evidence suggests that many of these systems are controlled by similar sets of genes. We are looking at early branching and understudied lineages of the animal family tree (using the jellyfish Aurelia and the worm Neanthes respectively) to see if these animals use similar genes during neurosensory development as the better-studied fruit fly and mouse. This research is critical for determining which structures are shared between animals because of common ancestry (known as homologous structures) and those that evolved independently in different lineages. Ultimately, such research informs how morphologically and behaviorally complex animals evolve.

    ROADMAP OBJECTIVES: 4.1 4.2
  • Genomic Relationships Among Basal Metazoans

    Understanding the origins of animals (“Metazoa”) and the advent of metazoan complexity requires a proper understanding of the interrelationships among the living forms. To properly place animals like sponges and jellyfish into the tree of life, we have taken a multi-faceted approach using two different kinds of molecular data: traditional sequence-based molecular phylogenetics, and a new type of binary data, the presence or absence of specific microRNAs (short ~22 nucleotide non-coding RNA genes). Both data sets suggest that sponges are paraphyletic: some sponges are more closely related to jellyfish and humans than they are to other sponges (e.g., bath sponges). These results suggest that the last common ancestor of all living animals was organized like a true sponge, and thus our origins as complex animals lies within sponge biology.

    ROADMAP OBJECTIVES: 4.2
  • Geochemical Signatures of Multicellular Life

    This project aims to identify geochemical fossils (biomarkers) in sediments that reflect the transition from microbial life forms to their multicellular animal descendants.

    ROADMAP OBJECTIVES: 3.2 4.2
  • Computational Astrobiology Summer School

    The Computational Astrobiology Summer School (CASS) is an excellent opportunity for graduate students in computer science and related areas to learn about astrobiology, and to carry out substantial projects related to the field.

    The two-week on-site part of the program is an intensive introduction to the field of astrobiology. NASA Astrobiology Institute scientists present their work, and the group discusses ways in which computational tools (e.g. models, simulations, data processing applications, sensor networks, etc.) could improve astrobiology research. Also during this time, participants define their projects, with the help of the participating NAI researchers. On returning to their home institutions, participants work on their projects, under the supervision of a mentor, with the goal of presenting their completed projects at an astrobiology-related conference the following year.

    ROADMAP OBJECTIVES: 1.1 1.2 2.1 2.2 3.1 3.2 3.3 3.4 4.1 4.2 4.3 5.1 5.2 5.3 6.1 6.2 7.1 7.2
  • PHL 278: A Gateway Course for a Minor in Astrobiology

    We have recently developed obtained Montana Board of Regents for an undergraduate minor in Astrobiology at Montana State University. The Minor includes courses in Earth Sciences, Physics, Astronomy, Microbiology, Ecology, Chemistry, and Philosophy. Two new courses have been developed as part of the minor, one of which is a gateway or introductory course examines the defining characteristics of life on earth as well as the challenges of a science that studies life and its origin. The other course which will be offered fall 2011 is the capstone course for the minor which will delved into the science of Astrobiology in more detail and targeted for Juniors and Seniors that have fulfilled the majority of the requisite course requirements for the curriculum.

    ROADMAP OBJECTIVES: 1.1 1.2 2.1 2.2 3.1 3.2 3.3 3.4 4.1 4.2 4.3 5.1 5.2 5.3 6.1 6.2 7.1 7.2
  • Metabolic Networks From Single Cells to Ecosystems

    We use mathematical and computational approaches to study the dynamics and evolution of metabolism in individual microbes and in microbial ecosystems. In particular, we take advantage of sequenced genomes to study the complete network of biochemical reactions present in an organism. We have been extending these approaches from single genomes to multiple genomes, generating ecosystem-level models of metabolism, which can help us understand some of the key transitions in the history of life on our planet.

    ROADMAP OBJECTIVES: 4.1 4.2 5.1 5.2 6.1
  • Modelling Planetary Albedo & Biomarkers in Rocky Planets’/moons Spectra

    The recent discovery of several potentially habitable Super-Earths (planets up to about 10x the mass of our own Earth that could be rocky) and the first nearby super-Earth planets around the habitable Zone of Gl581, has proven that we can already detect potentially habitable planets and makes this research extremely relevant. We model atmospheric spectral signatures, including biosignatures, of known and hypothetical exoplanets that are potentially habitable.
    The atmospheric characterization of such Super-Earths and potentially habitable Moons, will allow us to explore the condition on the first detectable rocky exoplanets and potentially characterize the first detectable Habitable Exoplanet.

    ROADMAP OBJECTIVES: 1.1 1.2 4.1 4.2 6.2 7.2
  • Deep (Sediment-Buried Basement) Biosphere

    The ocean crust comprises the largest aquifer on earth and there is increasing evidence that supports the presence of actively growing microbial communities within basaltic porewaters.

    Advanced Integrated Ocean Drilling Program (IODP) circulation obviation retrofit kit (CORK) observatories provide a unique opportunity to sample these otherwise inaccessible deep subseafloor habitats at the basalt-sediment transition zone. Aging porewaters remain isolated within this sediment-buried upper oceanic basement, subjected to increasing temperatures and pressures as plates move away from spreading ridges.

    ROADMAP OBJECTIVES: 4.1 4.2 5.2 5.3 6.1 6.2 7.1 7.2
  • Origins of Multicellularity

    By comparing animal genomes with genomes from their closest living relatives, the choanoflagellates, we can reconstruct the genome composition of the last common ancestor of animals.

    ROADMAP OBJECTIVES: 4.2
  • Paleoecology of the Mistaken Point Biota

    The Ediacara biota represent an enigmatic group of soft-bodied organisms that flourished in the late Precambrian oceans some 578-542 million years ago. These exquisite fossils have a worldwide distribution, however some of the most remarkable specimens are found all along the southeastern coast of Newfoundland, Canada, known worldwide as the Mistaken Point Ecological Reserve. Here, Ediacaran fossils are preserved as complete census populations allowing scientists to investigate these ancestral organisms using modern ecological analyses. Our work used ecological and morphometric studies to investigate the likelihood that some of these enigmatic organisms actually represent some of the oldest examples of sponges. Furthermore, our work highlights the necessity of a non-uniformitarian mechanism to deliver bio-accessible (labile) dissolved organic carbon to the Mistaken Point seafloor, which formed the primary food source for these deep-water organisms.

    ROADMAP OBJECTIVES: 4.2
  • Paleontological Investigations of the Advent and Maintenance of Multicellular Life

    This years research has targeted several areas associated with the origin and early diversification of multicellular life. Team member Knoll and colleagues (Harvard) have investigated the molecular basis of complex multicellularity, which developed in a variety of different groups. They have also continued work on the evolution of biomineralization in early eukaryotes. Team member Erwin has continued work on the evolution of developmental gene regulatory networks in early metazoans and, with Jim Valentine (UC Berkeley) completed the manuscript on the Ediacaran-Cambrian diversification of animals.

    ROADMAP OBJECTIVES: 4.2
  • Stromatolites in the Desert: Analogs to Other Worlds

    In this task biologists go to field sites in Mexico to better understand the environmental effects on growth rates for freshwater stromatolites. Stromatolites are microbial mat communities that have the ability to calcify under certain conditions. They are believed to be an ancient form of life, that may have dominated the planet’s biosphere more than 2 billion years ago. Our work focuses on understanding these communities as a means of characterizing their metabolisms and gas outputs, for use in planetary models of ancient environments.

    ROADMAP OBJECTIVES: 4.1 4.2 5.2 5.3 6.1 6.2
  • Project 3E: In Situ Sulfur Isotope Studies in in Archean-Proterozoic Sulfides

    Sulfur is an essential element for life on Earth, and it participates in a diverse array of chemical reactions as it moves through the lithosphere, atmosphere, hydrosphere and biosphere. The sulfur isotopic composition of sulfide minerals integrates these processes and thus provides useful information about changing Earth systems. Sulfur isotope studies are vital components of current knowledge about the evolution of habitable environments on early Earth, the antiquity of microbial metabolisms, the evolution of photosynthesis, the oxygenation of the atmosphere, and the mass extinctions of the Phanerozoic, and they are likely to play just as critical a role in the discovery and detection of biosignatures in extraterrestrial materials. Recent developments have made it possible to measure sulfur isotope ratios in situ with analytical precision and accuracy approaching that of “conventional” bulk techniques which are more destructive, remove samples from their petrologic context, and mask variability on small spatial scales. Using the CAMECA ims-1280 at the WiscSIMS laboratory, we have explored the limiting factors for precision and accuracy of SIMS sulfur isotope measurements in various sulfide minerals, used the findings to develop techniques that optimize precision and accuracy, and applied these techniques in several contexts relevant to astrobiology. In the near future, these developments will support paired, in situ sulfur, carbon and iron isotope analyses on the same samples in an effort to understand the co-evolution of microbial communities and biogeochemical cycles in early Earth environments.

    ROADMAP OBJECTIVES: 1.1 4.1 4.2 7.1
  • Thermodynamic Efficiency of Electron-Transfer Reactions in the Chlorophyll D-Containing Cyanobacterium, Acharyochloris Marina

    Photosynthesis produces planetary-scale biosignatures – atmospheric oxygen and the color of photosynthetic pigments. It is expected to be successful on habitable extrasolar planets as well, due to the ubiquity of starlight as an energy source. How might photosynthetic pigments adapt to alternative environments? Could oxygenic photosynthesis occur at much longer wavelengths than the red? This project is approaching these questions by using a laser technique to study the recently discovered cyanobacterium, Acaryochloris marina, which uses the chlorophyll d pigment to perform its photosynthesis at wavelengths longer than those used by the much more prevalent chlorophyll a. Whether A. marina is operating more efficiently or less than Chl a-utilizing organisms will indicate what wavelengths are the ultimate limit for oxygenic photosynthesis.

    ROADMAP OBJECTIVES: 3.2 4.2 5.1 5.3 6.2 7.2
  • Understanding Past Earth Environments

    We study the chemical and climate evolution of the Earth as the best available proxy for what other inhabited planets might be like. A particular focus is on the “Early Earth” (formation through to the 1.6 billion years ago) which is poorly represented in the geological record but comprises half of Earth’s history. We have studied the total pressure of the Archean atmosphere (prior to 2.5 billion years ago), developed constraints on CO2 concentration, studied the oxygen and nitrogen cycles, the fractionation of sulfur isotopes and explored the effect of hazes on early Earth climate.

    ROADMAP OBJECTIVES: 1.1 1.2 4.1 4.2 5.1 5.2 6.1
  • Stoichiometry of Life, Task 3a: Ancient Records – Geologic

    We are analyzing, at high resolution, Mid-Proterozoic drill core and outcrop samples in an effort to fingerprint the evolving redox state of the atmosphere and ocean at critical intervals in Earth history. This refined view of biospheric oxygenation provides the key backdrop for measuring and inferring abundances of diverse bioessential elements. Within this context we can better understand the distribution and evolution of early eukaryotic organisms at a variety of spatial and temporal scales.

    ROADMAP OBJECTIVES: 4.1 4.2
  • Stoichiometry of Life, Task 4: Biogeochemical Impacts on Planetary Atmospheres

    Oxygenation of Earth’s early atmosphere must have involved an efficient mode of carbon burial. In the modern ocean, carbon export of primary production is dominated by fecal pellets and aggregates produced by the animal grazer community. But during most of Earth history the oceans were dominated by unicellular, bacteria-like organisms (prokaryotes) causing a substantially altered biogeochemistry. The NASA Ocean Biogechemical Model (NOBM) is applied using cyanobacteria (blue-green algae) as the only photosynthetic group in the oceans. The analyses showed that the early Earth ocean had 19% less primary production and 35% more nitrate due to slower growth by the cyanobacteria, and reduced nutrient uptake efficiency relative to modern phytoplankton Additionally there was 8% more total carbon in the oceans as a result of higher atmospheric pCO2. We plan to optimize this early Proterozoic ocean model in combination with a 1 D model to account for changes in aggregate formation and sinking speed in response to varying nutrients.

    ROADMAP OBJECTIVES: 1.1 4.1 4.2 5.2 6.1 7.2
  • Quantification of the Disciplinary Roots of Astrobiology

    While astrobiology is clearly an interdisciplinary science, this project seeks to address the question of how interdisciplinary it is. We are reviewing published works across a broad range of scholarly databases, comparing disciplinary indicators such as subject terms, journal titles and author affiliations, and creating a computational model to identify and compare the makeup of astrobiological research literature in terms of the proportion of work that come from constituent fields.

    ROADMAP OBJECTIVES: 1.1 1.2 2.1 2.2 3.1 3.2 3.3 3.4 4.1 4.2 4.3 5.1 5.2 5.3 6.1 6.2 7.1 7.2