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Project Reports

• Module 1: The Building Blocks of Life

  Molecular material that may lead to life on planet surfaces has its origin in interstellar space. Using a combination of laboratory spectroscopic measurements and radio astronomical observations, this module has been tracing the life cycle of carbon and phosphorus containing compounds from their formation in outflows around old stars to their arrival on planet surfaces via exogenous delivery. We have been investigating what carbon and phosphorus compounds are found in matter lost from stars, and how the chemical composition changes as this material flows into the interstellar medium and forms dense clouds
  in space. We are following what happens to these compounds as these clouds evolve into solar systems, and how comets, meteorites, and dust particles may have brought interstellar pre-biotic material to Earth and other planets.

  ROADMAP OBJECTIVES: 3.1 3.2 4.2 7.1

• Bowring Project

  ROADMAP OBJECTIVES: 4.2

• Erwin Project

  ROADMAP OBJECTIVES: 4.2 6.1

• 3. Prebiotic Chemical and Isotopic Evolution on Earth

  ROADMAP OBJECTIVES: 3.1 4.1 4.2 7.1

• Origin of Life and Catalysis – Philosophical Considerations

  Our goal is to provide a solid philosophical foundation for the ABRC research program. To achieve this goal, we have several sub-goals like helping the students to develop their position as a group regarding a viable account for the metabolism-first theory, examining some methodological assumptions of the current astrobiological community, and finally propagating the information learned in our group to a larger community by offering courses on the origin of life.

  ROADMAP OBJECTIVES: 3.1 3.2 3.3 3.4 4.2

• Pearson Project

  ROADMAP OBJECTIVES: 3.2 4.2 6.1 7.1

• Modeling Early Earth Environments

  In this project, scientists from different disciplines model the conditions likely to have been found on the Early Earth, prior to 2.3 billion years ago. Specific areas of research include understanding the gases, many biologically produced, and mechanisms that controlled early Earth’s surface temperature, the nature of hazes that shielded the planetary surface from UV and may be responsible for signatures in sulfur isotopes that were left in the rock record, the chemical nature of the Earth’s environment during and after a planet-wide glaciation (a “Snowball event”), the evolution of planetary atmospheres over time due to loss of atmosphere to space, and the use of iron isotopes as a tracer of the oxidative state of the Earth’s ocean over time.

  ROADMAP OBJECTIVES: 1.1 1.2 2.1 4.1 4.2 5.1 5.2 5.3 6.1 7.2

• Carbon Flow Between Organisms in Complex Communities

  ROADMAP OBJECTIVES: 4.2 5.2

• Ferry Report

  The research addresses how anaerobic Archaea cope with oxidative stress, with the long-term view of how anaerobic life evolved to adapt to rising oxygen levels before, during and after the evolution of oxygenic photosynthesis. The research also addresses ancient enzymes involved in metabolic pathways with a focus on energy conservation in methanogenic Archaea.

  ROADMAP OBJECTIVES: 3.3 4.1 4.2 5.1 6.1

• Requirements for the Development and Maintenance of Complex Life

  ROADMAP OBJECTIVES: 3.2 4.2

• 6. Molecular and Isotopic Biosignatures

  ROADMAP OBJECTIVES: 2.1 3.1 4.1 4.2 5.3 6.1 7.1 7.2

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

  Our research involves molecular evolutionary genetics in an effort to better understand the relationship between planetary history and the evolution of life. We continue to update our public database TimeTree (www.timetree.org), which presents divergence times of organisms. Most of the work during the past year involved editing and contributing to a book, The Timetree of Life, which summarizes the current state of knowledge in the field and presents new data, with 81 chapters and 105 authors (Oxford University Press, in production).

  ROADMAP OBJECTIVES: 4.1 4.2 4.3

• Isotopic Signatures of Methane and Higher Hydrocarbon Gases From Precambrian Shield Sites: A Model for Abiogenic Polymerization of Hydrocarbons

  Methane and higher hydrocarbon gases in ancient rocks on Earth originate from both biogenic and abiogenic processes. The measured carbon isotopic compositions of these natural gases are consistent with formation of polymerization of increasing long hydrocarbon chains starting with methane. Integration of carbon isotopic compositions with concentration data is needed to delineate the origin of hydrocarbon gases.

  ROADMAP OBJECTIVES: 1.1 2.1 3.1 4.1 4.2 6.1 7.1 7.2

• A Supertree Analysis of the Metazoan Phylogeny

  Detailed knowledge of the phylogenetic relationships among the extant animal kingdom (Metazoa) and their eukaryotic relatives is critical for understanding the origin of complex life. Recently, the smallest known animal genome and the sole representative species of the phylum Placozoa was released. This genome, Trichoplax adhaerens, has allowed us to get insights into our understanding of how animal life evolved by addressing questions relating to the evolution of the basal metazoans.

  ROADMAP OBJECTIVES: 4.2

• Origin of Multicellularity and Complex Land-Based Ecosystem

  80-90% of all land plants have mutualistic symbiotic associations with fungi where the fungal symbionts provide increased access to essential minerals and the fungal symbionts gain fixed carbon. We are characterizing the fungal symbionts in early lineages of land plants (over 300 million years old) that have a life cycle where one phase is above ground and photosynthetic and another phase is completely underground for as long as fifteen years. This subterranean phase in these poorly understood plants is completely dependant on a set of fungal symbionts to provide a source of fixed carbon. Establishing the identity of the fungal symbionts in these diverse underground plants is fundamental to understanding the broader co-evolutionary and ecological history of plant-fungal associations across the almost 500 million year history of land plants.

  ROADMAP OBJECTIVES: 4.2 5.2

• Philosophical Problems in Astrobiology; Issues on the Origin of Life,

  My project is exploring philosophical issues in astrobiology. My central focus this year was on the origin of life: what is the proper level of analysis for a successful theory of the origin of life? Among other things, I compared and contrasted contemporary scientific theories of the origin of life in light of what philosophers of science have learned about the structure and justification of scientific theories.

  ROADMAP OBJECTIVES: 3.1 3.2 3.3 3.4 4.1 4.2

• Diversity and Biogeography of the Unique Tropical Phylum Placozoa

  The following project employed molecular techniques, along with supplemental bioinformatics to: 1) Test whether placozoans are occupying the water column 2) Describe the diversity of placozoans found within sea tables at Kewalo Marine Lab as well as samples from an open water site off Isla Magueyes, Puerto Rico and test whether there is haplotype/clade overlap and 3) Determine if it is possible to capture more of the diversity than previous work by analyzing a more variable region on the mitochondrion

  ROADMAP OBJECTIVES: 4.2 5.1

• Sulfur Biogeochemistry of the Early Earth

  Sulfur is widespread in surface geochemical systems and is abundant in many rock types. It is present in volcanic gases and marine waters, and has served a key role in geobiological processes since the origin of life. Like other low atomic number elements, sulfur isotope ratios in various compounds usually follow predictable mass-dependent fractionation laws; these different mass-dependent isotope fractionations serve as powerful tracers for igneous, metamorphic, sedimentary, hydrothermal and biological processes. Mass-independent sulfur isotope fractionation is a short-wavelength photolytic effect that occurs in space, as well as in gas-phase reactions in atmospheres transparent to deep penetration by ultraviolet light. Crucial aspects of the chemical evolution of the early atmosphere — and the surface zone as a whole — can be followed by mass-independent sulfur isotopes in Archean metasedimentary rocks. Metabolic styles of organisms in response to global changes in surface redox over geologic time can also be traced with multiple S isotopes.

  We have concluded from our various studies over the last year and before to the very inception of the NAI node at Colorado, that all Archean sulfur minerals previously documented for their 34S/32S compositions warrant a comprehensive re-examination of their 32S, 33S, 34S (and 36S), sulfur isotope systematics.

  ROADMAP OBJECTIVES: 1.1 1.2 4.1 4.2 5.1 5.2 5.3 6.1 7.1 7.2

• The Diversity of the Original Prebiotic Soup: Re-Analyzing the Original Miller-Urey Spark Discharge Experiments

  Recently obtained samples from some of the original Stanley Miller spark discharge experiments have been reanalyzed using High Pressure Liquid Chromatography-Flame Detection and Liquid Chromatography-Flame Detection/Time of Flight-Mass Spectrometry in order to identify lesser constituents that would have been undetectable by analytical techniques 50 years ago. Results show the presence of several isoforms of aminobutyric acid, as well as several serine species, isomers of threonine, isovaline, valine, phenylalanine, ornithine, adipic acid, ethanolamine and other methylated and hydroxylated amino acids. Diversity and yield increased in experiments utilizing an aspirating device to increase the gas flow rates; this could be applied as a simulation of prebiotic chemistry during a volcanic eruption. The variety of products formed in these experiments is significantly greater than previously published and mimic the assortment of compounds detected in Murchison and CM meteorites.

  ROADMAP OBJECTIVES: 2.1 3.1 3.2 3.4 4.1 4.2 5.1 6.2 7.1 7.2