# Annual Science Report

For Year 1: July 1, 1998 -- June 30, 1999

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# 

# Table of Contents

Preface 3

Introduction 5

#### 

#### Summary of Member Institution Research

Ames Research Center 7

Arizona State University 11

Carnegie Institution of Washington 18

Harvard University 23

Jet Propulsion Laboratory 27

Johnson Space Center 30

Marine Biological Laboratory 35

The Pennsylvania State University 42

Scripps Research Institute 47

University of California, Los Angeles 52

University of Colorado 55

NAI Virtual Collaboration 57

Education and Public Outreach 59

# Preface

The NASA Astrobiology Institute (NAI) was established to further the
interests of NASA, and the science community in general, in research in
astrobiology. In October 1997 a Cooperative Agreement Notice (CAN), that
is, a request for proposals for research, was issued and more than fifty
US research institutions responded. The proposed projects were
investigator-initiated basic science, but within the constraints imposed
by the CAN. Eleven teams were chosen and, along with a single foreign
associated institution (Spain), constitute the NAI. Each of the eleven
teams is designated by the name of the institution (termed the Lead
Institution) of the Principal Investigator, (i.e., Ames Research Center,
Arizona State University, etc.). Members of each of the teams are from
the Lead Institution and from Co-institutions, (i.e., the Harvard
University team includes members from MIT; the Pennsylvania State
University team includes members from the University of Pittsburgh,
etc.).

The mission of astrobiology can be stated as \"The study of the origins,
evolution, distribution, and future of life on Earth and in the
Universe.\" The scientific process used to further this mission is both
inductive and deductive. In the inductive phase, data is collected first
and then hypotheses are formulated; in the deductive phase, the
hypothesis is formulated first and then the data is collected to test
it. These processes go on sequentially often in a seamless progression
but both processes may proceed at the same time in a complex data set
with different hypothesis being formulated and tested at the same time.
The historical sciences -- for example, astronomy, geology, and
paleontology -- are particularly strong on the inductive observation of
events that have already happened, while chemical and biological
sciences rely to a significant extent on the experimental (and
observational) testing of hypothesis. Astrobiology is an amalgam of
these disciplines; it will be interesting to see how the new scientific
discipline of Astrobiology grows and incorporates these complementary
scientific approaches to increasing our knowledge of the natural
universe.

NASA, from its origins has been goal directed and heavily dependent on
the successful completion of missions which, even a few decades ago,
would have been considered miraculous. The mission to the moon was
generated, in part, by the competition with the former Soviet Union to
demonstrate technical and scientific excellence. The goal was
evident---it could be seen on most clear nights---and to achieve it
required outstanding technical and engineering skills. This can be said
for many of the subsequent planetary and outer space missions of NASA
and other space agencies. Instruments for scientific discovery are in
place and more will be in the future. Basic scientific research, with a
major emphasis on astrobiology, is becoming more and more prominent in
the NASA and space endeavor. A primary mission of NAI and astrobiology
in general is to help to develop the basic science required for the
missions. In time, astrobiology will significantly affect the existing
and planned missions and lead to specific missions dedicated to
astrobiology questions.

# The Astrobiology Roadmap (http://astrobiology.arc.nasa.gov/roadmap/index.html) includes 17 objectives. The table below categorizes 137 projects within this scientific report according to these objectives to illustrate how the teams are pursuing the original intent of the NAI. Since the goal of NAI is discovery, that is, to make new observations and formulate and test new hypotheses, new objectives will arise as the program continues. The teams are encouraged to pursue unexpected directions as they are found and, in time, to formulate new objectives that could not have been conceived of at the time the Roadmap's objectives were created.

Baruch S. Blumberg G. Scott Hubbard

Director, NAI Associate Center Director\
for Astrobiology and\
Space Programs

![](media/image2.pct)Table 1: Categorization of NAI Team year 1 projects
by Astrobiology Roadmap   Objectives.

**Introduction**

This report is the summary of the accomplishments of the first year
(July 1, 1998 to June 30, 1999) of research by each of the NAI teams and
planned research for the period July 1, 1999 to June 30, 2000. The data
was derived from the executive summaries supplied by each of the teams,
with minor editorial alterations. Unabridged annual reports from each of
the teams are available from Rho Christensen, Program Co-Ordinator, NASA
Astrobiology Institute, Mail Stop 240-1, Moffett Field, CA 94034, Tel.
650 604 2476. The research programs of each of the 11 institutions are
described below. This report also includes a summary of accomplishments
and planned future activities for the NAI virtual collaboration,
education and public outreach programs.

The eleven member institutions form the core of the partnership. NAI
members and their research goals are described below:

**NASA Ames Research Center** initially will integrate research related
to the contribution of organic matter to planets; the formation and
evolution of habitable planets; the origins of key metabolic pathways in
primitive cells; the structure, function and biological markers of
microbial ecosystems; and the effects of rapid environmental changes on
ecosystem properties.

**Arizona State University** will conduct research into the
cosmochemistry of meteorites and organosynthesis within hydrothermal
systems, the origin of early photosynthetic systems, microbial
fossilization processes, complex ecosystems of extreme environments, and
exploring for habitable environments elsewhere in the Solar System.

**Carnegie Institution of Washington** will investigate aspects of
hydrothermal systems, integrating laboratory studies with observational
analysis of the Solar System and other planetary systems and with
predictive and theoretical models.

**Harvard University** will conduct research on the co-evolution of the
Earth and its biota through time, integrating the stratigraphy,
geochemistry, paleontology, microbiology, and geochronology of major
evolutionary and environmental transitions in our planets' history.

**Jet Propulsion Laboratory** will identify credible biosignatures of
life, and use these biosignatures to study the distribution of life on
Earth, with the goal of detecting life in samples returned from
extraterrestrial environments. These studies will be combined with
studies of planetary geology/geochemistry to further our understanding
of both early and present day environments of Earth and Mars.

**NASA Johnson Space Center** along with US and foreign
Co-Investigators, will concentrate on biomarkers specific properties in
a rock which indicate that biological activity is occurring or has
occurred. The research includes analysis of meteorites from Mars and
some of the oldest rocks on Earth.

**Marine Biological Laboratory** will study microbial biodiversity
through molecular biological techniques, focusing on the evolution of
eukaryotes and of complex systems in simple organisms.

**Pennsylvania State University** will focus on the connection between
the changes in the environment and the changes in Earth's biota,
primarily during the early stages of our planet's evolution.

**Scripps Research Institute** will combine efforts to study the
emergence of self-replicating systems and the nature of pre-biotic
worlds, exploring early precursors to replication on Earth.

**University of California, Los Angeles** will undertake
multidisciplinary research on the paleomicrobiology of Earth's early
life, the metabolic evolution of early ecosystems, and the development
of instruments aimed at detecting life in the galaxy and the solar
system.

**University of Colorado** will address the origin of stars and planets,
the development of habitable planets, the \"RNA world\" and the origins
of life, biological evolution on Earth, the energetics of life on other
planets, and the philosophical aspects of astrobiology and the search
for life elsewhere.

#  

# 

# Ames Research Center

# PI: David Des Marais

### Work and Research Accomplished During Year 1

## Chemical Building Blocks of Life 

We have completed our initial studies verifying the production of
droplets with potential primitive protocell properties under the
extremely cold, harsh conditions in deep interstellar space. We have
also acquired an HPLC with fluorescent detector and started analysis of
this complex, multicomponent material. We have started analysis of this
material in collaboration with two groups, first Professor David
Deamer\'s group at the University of California-Santa Cruz, and with Seb
Gillette of Professor Richard Zare\'s group at Stanford. The former has
shown the production of amphiphyllic compounds and the later that these
are rich in unsaturated organic compounds. We have also written a high
profile paper in Scientific American (July 1999) and our work in this
area was highlighted in July\'s issue of Popular Mechanics!

## Habitable Planets 

\(1\) We are investigating the nature and distribution of water within a
thermally-evolving planetesimal. An existing code for non-isothermal,
multiphase, porous/fractured media flow and transport has been extended
to model water in a three-phase system (vapor, liquid and ice). A
geochemistry code is being developed to model the interactions of
silicates, iron, PAHs, and water. (2) Exchange between crustal and
mantle CO~2~ reservoirs is being explored in a model that includes the
carbonization of ocean basalt as a CO~2~ sink. (3) A one-dimensional
(1-D) radiative-convective numerical code to define the role of CO~2~
ice clouds on the greenhouse effect in a CO~2~ atmosphere has been
developed to understand the effects of CO~2~ clouds upon the outer
boundary of the habitable zone. The first simulations agree well with
known solutions. To permit its incorporation into a 3-D habitable planet
circulation model, the code is being modified to incorporate correlated
k-coefficients for CO~2~ and H~2~O and to optimize accuracy and
computational speed. (4) Laboratory simulations of CO~2~ ice cloud
formation are important to understand cloud microphysics and radiative
properties. Cloud particles did form in the absence of condensation
nuclei when vapor pressure becomes about 30% supersaturation. Once
formed in a CO~2~-rich atmosphere, particles quickly grew and fell
rapidly. This may limit the extent to which CO~2~ clouds can augment the
greenhouse effect on a planet like Mars.

## Evolution of Early Metabolic Pathways and Replication Systems 

1\) For the first time, we have achieved *in vitro* selection of simple
peptide protoenzymes that perform protobiological functions. Our
technique was tested by evolving peptides 80 amino acids long that bind
adenosine triphosphate (ATP). After nine rounds of selection, three
peptides emerged that, in the free form, bind to ATP and AMP but not to
deoxyadenosine triphosphate and guanosine triphosphate. 2) A simple
two-protein system that generates ATP from ADP and inorganic phosphate
in response to light was built into a liposome-forming membrane.
Bacteriorhodopsin (BR) is a photoactivated proton pump and ATP synthase
(ATPase) utilizes the proton gradient generated by BR to synthesize ATP.
The system was shown to make ATP efficiently. 3. A model for the
evolution of biological systems in the absence of a nucleic acid-like
genome was proposed for protocells composed of membrane-encapsulated
peptides. Assuming that the peptides can make and break bonds between
amino acids and that bonds in non-functional peptides are more likely to
be destroyed than in functional peptides, we showed that the catalytic
capabilities of the system as a whole could increase. This increase is
defined to be non-genomic evolution (also, see *New Scientist*, January
16, 1999 p. 37).

## Early Microbial Ecosystems: Modern Analogs 

Group members examined microbial mats in the three principal field areas
at Guerrero Negro, Baja California, Highborne Cay, Bahamas, and
Yellowstone. We examined fluxes of O~2~, dissolved inorganic carbon
(DIC), N species, H~2~, reduced C and S gases, and also microbial
motility in response to light. We obtained samples for genetic and
molecular and isotopic biomarker studies. These will allow correlations
to be made between mat community membership, processes and environments.
Challenges associated with interdisciplinary field work were identified;
and we are working with Ames Information Systems personnel (R. Keller\'s
group) to develop a version of Science Desk that organizes, integrates
and disseminates field research results. High fluxes of O~2~ and DIC
were accompanied by the emission of CH~4~ and other reduced gases.
Subtidal mat cyanobacteria that had, under low UV flux, migrated from
mat depths \>0.5 mm to the surface were, upon reexposure to UV, strongly
inhibited and recovered slowly. Photosynthesis in intertidal mats
recovered rapidly upon rewetting, and even more rapidly without UV. At
Ames, greenhouses were modified to sustain mats returned from the field
and also grown *in situ.* A new DGGE method is being devised to examine
cyanobacterial diversity in Bahamian stromatolites.

## Culture Collection of Microorganisms from Extreme Environments 

We hired a full-time research assistant (Lauren Wingard, M.S.) to
maintain this collection. She went to Florida State University in
February to package and ship under refrigeration the culture collection
(\~600 strains) of Dr. Imre Friedmann. Many of the strains of
cyanobacteria are from the Antarctica and Arctic; others are from warm
deserts (e.g. Gobi, Negev, Sonora, Atacama). In Eugene, these were
established in constant temperature rooms and incubators and are being
tested for contamination. A duplicate set is being housed in a --70^o^C
freezer. These strains join the already-established Castenholz
collection (\>500 strains) of cyanobacteria from hot springs, Antarctic
cold water ponds, and hypersaline marine waters. We have begun to
catalog all strains under a unified system. The CCMEE is now an
affiliate of the United States Federation for Culture Collections.

## Ecosystem Change

We seek to interpret the spectral signatures of vegetation in normal
conditions and under \"El Niño\" influence in South America. We acquired
existing data from satellites, pollen, radiocarbon analyses, and
tree-rings. We visited potential calibration sites, established GPS
coordinates, and documented local vegetation. Dr. Ellen Metzger (San
Jose State Univ.) joined us to analyze remote sensing data. We initiated
collaborations with M. L. Absy (Manaus; calibrate pollen and remote
sensing data and hind cast paleovegetation indices), J. Marcos and S.
Alvarez (Barcelona; studies in Ecuador), M. L. Absy (Brasilia; the
Planalto and region near Rio de Janeiro), and C. Lasta (INIDEP,
Argentina; linking atmospheric modelling, oceanography, remote sensing
studies of vegetation, archeology, ecology and palynology). We
co-organized the \"Astrobiology Workshop, \'El Niño\' and South American
Ecosystems\" in Mar del Plata, Argentina, April 9-7, 1999; it included
50 scientists from the US, Argentina, Brazil, Ecuador, Venezuela, and
Spain. We made presentations at CSU-Hayward (Geology), SJSU (Geology),
American Assoc. of Microscopy (San Francisco), National Geography
Association, AGU, Univ. of Bamberg (Germany), Museo Etnografico
(Argentina), Univ. of Mar del Plata (Argentina), Brazilian Institute for
the Environment (Brasilia, Brazil), National Inst. for Research of the
Amazon (Manaus, Brazil), NASA Ames, and NASA HQ.

### Work and Research Planned Year 2

## Chemical Building Blocks 

1\) We will make definitive chemical identifications and restrict the
chemical classes of the compounds formed, with emphasis placed on
identifying the biogenically interesting species produced. 2) We will
identify the specific species involved in the droplet (protocell)
forming process. 3) We will expand the photochemcal studies of PAHs in
ices to realistic interstellar and cometary ice analogs. 4) We will
present our current studies at the ISSOL (7/99) and Bioastronomy (8/99)
meetings.

## Habitable Planets 

We will explore the behavior of three-phase systems (water vapor, liquid
water, and ice) during asteroid evolution, without including water-rock
reactions for now. Preliminary modelling of water-rock reactions will be
done separately. Ultimately, these efforts will be merged. The model for
the C cycle on early Earth will be extended to include the role of
impact ejecta as an easily weatherable, easily subductable major sink
unique to the Hadean era on Earth. We anticipate that, during the time
of great impacts, atmospheric CO~2~ is driven to very low levels, thus
minimizing its role in greenhouse warming. The radiative effects of
CO~2~ ice clouds will be assessed with the 1-dimensional
radiative-convective code. Depending both on these results and on the
laboratory simulations of cloud condensation processes which produce
estimates of cloud particle lifetimes, cloud radiative effects will be
incorporated in the habitable planets general circulation model. We will
examine processes that set the inner boundary of the habitable zone by
studying the radiative effects of water clouds on the runaway greenhouse
effect and loss of water from a planet. We will examine conditions
analogous to a runaway greenhouse that are occasionally created by water
clouds over Earth\'s oceans.

## Evolution of Early Metabolic Pathways and Replication Systems 

1) The selected ATP-binding proteins will be improved by successive
rounds of mutagenesis and selection. The most efficient ATP binders will
be expressed in larger quantities in E. coli. This, in turn, would allow
for the accurate determination of their binding constant to ATP and its
analogs. The proteins will be characterized structurally and
phylogenetically. This should address such important questions as: Do
the selected proteins have the ATP binding motifs characteristic of
cellular proteins? Is tight folding necessary for protein functionality?
2) Liposomes containing BR and ATPase will be encapsulated in larger
liposomes whose membranes will be made permeable to ADP, inorganic
phosphate and amino acids. A kinase (which phosphorylates amino acids to
create their chemically active form) will also be encapsulated in these
liposomes. This will enable us to use light for triggering
phosphorylation inside liposomes, thus demonstrating the first step in
the proposed set of protocellular reactions. 3) The model of non-genomic
evolution will be extended to include such functions as generation of
ATP, phosphorylation of amino acids and synthesis of membrane forming
material. The range of conditions under which such a system can evolve
will be investigated.

## Early Microbial Ecosystems: Modern Analogs 

1\) We will expand group-coordinated studies of mats where real-time
process measurements are used to modify field manipulations and
determine acquisition of samples to be returned to Ames for further
study. 2) We will continue the development of the Science Desk
application for field work. We will improve the fidelity of the
greenhouse microbial mat facility, including its interface with
Information Systems-based monitoring and manipulations. 3) We will adapt
microelectrode and flux chamber technology for mineralizing microbial
systems and for continuous *in situ* field measurements. 4) At Guerrero
Negro and Yellowstone: We will continue long-term (several months)
studies of effects of UV screening of mats. Across a range of water
compositions, temperatures and sedimentation regimes, we will
cross-correlate the dynamics of the light regime, the budgets of C, N,
S, and H (including porewaters and lipid biomarkers), the production of
reduced gases, and genetic studies of microbial populations. 5) At
Highborne Cay: We will conduct field sampling and lab (DGGE)
characterization of cyanobacterial diversity within carbonate
stromatolites. We will improve microelectrode and isotopic methods for
stromatolite analysis and also continue ^14^C and ^13^C/^12^C studies of
the microbial mat C budget.

## 

## 

## 

## Culture Collection of Microorganisms from Extreme Environments 

We will continue the routine culture maintenance of the combined (\>1100
strain) collection of cyanobacteria. We will catalog records for all
cyanobacterial strains under a unified system by gathering information
on the cultures such as their strain history, origin, optimal
temperature, etc., and entering it into a data base. When this process
is further developed, the information will be made available both on the
Internet and on the Science Desk application mentioned above for the
Early Microbial Ecosystem project.

## Ecosystem Change 

We will continue to compile a database that incorporates data from
research on pollen and tree rings in the field areas. We will refine our
field studies in potential calibration sites that will demonstrate
relationships between vegetation and climate cycles and change. We will
initiate radiocarbon analyses to calibrate our records of
paleovegetation. Dr. Ellen Metzger will develop a framework for
incorporating remote sensing data into our models. We will further
develop collaborations with our international colleagues to broaden and
deepen our repertoire of field sites, and to develop collaborating
astrobiology programs overseas. We will help to define how astrobiology
can contribute to elucidating relationships between ecosystem and
environmental change.

# Arizona State University

# P.I.: Jack Farmer

# 

### 

### Work and Research Accomplished During Year 1

## Cosmochemistry of Carbonaceous Meteorites

Lead Co-I's: Laurie A. Leshin and John R. Cronin

The goals of this research include investigating prebiotic organic
synthesis and water-rock interaction in carbonaceous meteorites. In Year
1, work by John Cronin followed up on the previous discovery of
enantiomeric excesses in meteoritic amino acids. These new analyses of
amino acids in carbonaceous meteorites required use of the GC-IRMS
instrument at NASA-Ames. This instrument offers great potential for
obtaining C, N, and (it is hoped) H isotope ratios for meteoritic
organic compounds. The new work was accomplished in collaboration with
NASA Ames collaborators Dave Des Marais and George Cooper. Initial
analyses involved derivatives of two amino acids found in the Murchison
meteorite (pyroglutamic acid (the lactam of glutamic acid), N-acetyl
glutamic acid, and N-acetyl alanine). Water-rock interaction is being
investigated through isotopic (O, C, Mn/Cr) analysis of carbonaceous
chondrite carbonates. In Year 1 we have made \~30 new polished thin
sections of CM chondrites from the ASU Meteorite Collection. We are
progressing on the petrographic characterization of the secondary
minerals in a series of CM chondrites with varying degrees of
alteration. This has involved extensive optical and electron microscopy
work by Astrobiology postdoctoral fellow Dr. Gretchen Benedix. Part of
ASU's institutional commitment to Astrobiology involved matching funds
for the establishment of a new "state of the art" ion microprobe
facility. Renovation of lab space is presently underway under the
leadership of Co-I Laurie Leshin and installation of the instrument will
occur in September.

## 

## Experimental Simulations of Planetary Hydrothermal Systems 

Lead Co-I's: John Holloway and Peggy A. O'Day

Goals of this research include investigating the abiotic production of
organic compounds in hydrothermal systems on the early Earth, Mars and
Europa using experimental systems to simulate geochemical conditions in
seafloor hydrothermal systems. Two approaches are being used. The first
involves a whole system approach which simulates an artificial black
smoker by mixing fluid with hot rock to produce a 400°C hydrothermal
fluid. Experiments in Year 1 successfully recreated geologic conditions
found in natural hydrothermal systems. Upon mixing with cold seawater,
simulated hydrothermal fluid precipitates pyrite, chalcopyrite and
amorphous silica. The second approach is a specific system approach that
involves use of a Catalytic Reactor Vessel (CRV). In the CRV, gases and
aqueous solutions are flowed through a reactor containing a selected
mineral or minerals. The CRV allows investigation of specific reactions
and reaction rates using natural catalysts under controlled conditions.
During the first year we have set-up an analytical lab, installed a
state-of-the art gas chromatograph for gases and liquid organics,
designed, built, tested and operated a new type of CRV system, and have
begun to synthesize short-chain alcohols. The first report of the
alcohol synthesis was presented at the American Chemical Society Annual
Meeting in Anheim, CA. (O'Day, et al., 1999). The Astrobiology grant
partially supported the artificial black smoker project and a paper from
that work was submitted on July 2, 1999 (Holloway, et al., submitted).

## Origin And Evolution of Photosynthesis

Lead Co-I: Robert Blankenship

The goals of this research are to understand the origin(s) and early
evolution of photosynthesis. The approach being used combines field
work, lab cultures and molecular phylogenetics. Molecular methods are
being used to understand the role of lateral gene transfers in the
origin of photosynthetic systems. There is an emphasis placed on the
discovery of new organisms. Two specific areas have seen rapid progress
in the first few months of the project. One of these involves isolation
and characterization of iron oxidizing photosynthetic bacteria.
Organisms were isolated from iron-rich springs and are being
characterized both biochemically and genetically. The second area
involves molecular sequence analysis of the evolution of photosynthetic
organisms by examination of the enzymes involved in biosynthesis of
chlorophyll.

## 

## 

## Enhancing Information Retrieval From The Microbial Fossil Record 

Lead Co-I's : Tom Sharp, Paul Knauth and Jack Farmer

The goals of this research include understanding the factors that
control the preservation of microbial biosignatures in rocks over a
range of observational scales through parallel studies of microbial
fossilization processes in modern systems and ancient analog materials.

## Microbial Fossilization Processes in Extreme Environments 

Lead Co-I: Jack Farmer

The goal of this research is to understand the taphonomic processes
governing the fossilization and long-term preservation of biosignatures
in extreme environments. Work during Year 1 involved a collaborative
study of Yellowstone hot-springs by Jack Farmer (ASU), Brad Bebout (NASA
Ames) and Peter Visscher (University of Connecticut). The focus was on
the characterization of mat microenvironments and biogeochemistry in the
field to understand the chemical and biological controls on organic
matter degradation. Field investigations involved the measurement of
microprofiles in oxygen, pH and sulfide within mineralizing subaerial
spring systems. Field measurements revealed the presence of high
concentrations of photosynthetically-produced oxygen within the
mineralized exopolymer matrix of mats which supports high rates of
aerobic degradation and/or the direct oxidation of organic matter
entrapped in sinters. These observations explain the dominance of
morphological over chemofossil signatures in thermal spring
environments, as evidenced by ancient analogs. Results of this work are
being written up and will be submitted for publication at the end of
August.

## 

## Submicroscopic Study of Microbial Fossils in Precambrian Chert 

Lead Co-I's: Tom Sharp, Paul Knauth and Jack Farmer.

This research seeks improved criteria for biogenicity through the
development of integrated analytical methods for studying ancient
terrestrial and extraterrestrial materials. In Year 1 we completed a
detailed petrographic study of microfossiliferous "black cherts" from
the \~2.0 billion year-old Gunflint Iron Formation, followed by parallel
etching experiments of the same materials using a new fluorine gas
technique, combined with more standard hydrofluoric acid vapor etching.
The results of the two etching techniques are presently being compared
using FESEM. The goal is to correlate petrographic observations of
microfossils and etched morphologies observed under SEM. The next step
will be to prepare the same samples for ATEM to be able to visualize the
materials in cross sectional views and integrate the mineralogy of
samples at high spatial resolution. Petrographic thin sections have been
created using temporary mountant and microfossils will be microdrilled
and remounted on TEM grids for detailed microstructural analysis.

### 

## 

## 

## Chemistry of the Archean Oceans and Environments of Early Biosphere Evolution 

Lead Co-I: Paul Knauth

In this research we are exploring the possibility that the Archean
oceans had substantially higher salinity than the modern oceans. Prior
to the existence of subaerially-exposed continental cratons about 2.5
Ga, all of the salt and brine currently lodged in sedimentary basins on
continents would have resided in the oceans. It is estimated that
Archean ocean salinities would have been 1.5 to 2 X the modern value and
would have declined only as giant salt deposits and associated brines
slowly accumulated through repeated episodes of evaporation in shallow
sedimentary basins on the growing cratons. In Year 1 we published the
basic argument about high salinity in the ancient oceans (Knauth, 1998)
and began developing a strategy for compiling a realistic inventory of
salt and brine on the continents.

## 

## Hydrogeochemical Influences On Ecosystem Evolution: Ancient Desert Springs As Analogues For The Early Development Of Life

Lead Co-I's Jim Elser and Tom Dowling and Carol Tang

This research was not funded by the NAI during Year 1 but was provided
with seed money from ASU's Cost Share to lay the groundwork for a
revised proposal submission to the NAI during the next CAN. In Year 1
the "hydrogeochemical influences on ecosystem evolution" group has
expanded the theoretical and model-based aspects of the proposed field
and molecular evolution studies of simple microbial-grazer-predator
ecosystems in "extreme" lake/stream environments in the Cuatro Cienegas
area of Central Mexico. During Year 1 we completed an initial
reconnaissance of the Cuatro Cienegas field sites lay groundwork for
future studies. The complex permitting process was also completed with
the Mexican government to secure access to field sites. We also
established collaborations with Mexican biologists and have exchanged
site visits. The first integrated team left for the field in mid-June to
begin the initial phase of the work.

## Exploring for Past or Present Habitable Environments on Mars 

Lead Co-I's: Phil Christensen, Jack Farmer and Ron Greeley

This research focuses on the exploration for past Martian life. During
Year 1 data acquired by the Mars Global Surveyor, Thermal Emission
Spectrometer were used to prepare the first mineralogical maps of Mars.
Spectral observations obtained during the aerobraking phase of orbital
insertion indicate the presence of localized patches of
coarsely-crystalline hematite within a region \~300 km across and
positioned near the Martian equator. The data are remarkable because of
the implied high concentration of coarsely-crystalline hematite which
requires processing by liquid water. These are the first mineralogical
data acquired from orbit that suggest aqueous precipitation and imply
the presence of iron-rich fluids in the shallow subsurface to surface
crust of Mars during the past.

## 

A second focus of activity for this research during Year 1 involved site
selection for Mars Surveyor Project landed missions in 2001 and beyond.
Co-Leads Farmer and Greeley conducted a global search for potential
Astrobiology landing sites within the engineering (latitudinal,
elevational) constraints established by JPL for the 2001 mission. This
was accompanied by detailed mapping at several high priority sites,
including 1:2M and 1:500K scale geologic maps of the Terra
Chimera/Elysium region of Mars. This mapping provides the basis for a
detailed analysis of the hydrological history of this region which is an
area of prolonged and varied hydrological activity that holds great
interest for Astrobiology. The global survey of sites falling within the
engineering constraints for the 2001 mission lead to a prioritized list
of potential Astrobiology landing sites. On June 22 and 23 the Co-I's
and collaborators for exploring for past and present habitable
environments on Mars presented candidate Astrobiology landing sites for
the 2001 mission at a NASA-sponsored landing site workshop held in
Buffalo, New York.

A third focus of research involved remote sensing studies of Earth
environments considered good analogs for early Mars. This research
involves a collaboration between Co-I Farmer and Jeff Moersch (NRC
Post-doc and a named collaborator located at NASA Ames). The goal of
these studies is to determine optimal spatial and spectral resolution
required for the identification of aqueous mineral deposits from Mars
orbit. Work in Year 1 focused on the analysis of archived remote sensing
data (representing a broad range of infrared wavelengths) for paleolake
sites at Mono Lake and Death Valley, CA. Analysis of remote sensing data
from AVIRIS (near-IR) and TIMS (mid-IR) data sets was followed by the
development of ground truth using portable field spectrometers at
selected sites in the Mono Basin and Death Valley. We also worked to
develop more streamlined methods of data analysis that can be utilized
for Mars data as it becomes available to the community. Analysis of the
data for sites in the Mono Basin and Death Valley is largely complete
and results are being written up for publication.

## Europa as an Abode for Life

Lead Co-I's: Ron Greeley and Jack Farmer

The goal of this research is to understand the potential for past and
present habitable environments of Europa. Discovery of a fragmented icy
crust on Europa from high resolution Galileo Nominal Mission (1996-1997)
images, led to the Galileo Europa Mission (GEM) which focused on
refining our understanding of Europa\'s geologic and environmental
evolution. During Year 1 the ASU team focused on developing a better
understanding of the surface and interior structure and composition of
Europa as a basis for assessing the potential for Europan life. New
images of Europa combine data from the Solid-State Imaging experiment
(SSI) and the Near Infrared Mapping Spectrometer (NIMS). Spectral
analysis indicates the likely presence of magnesium salts in surface
ices. The spatial association of impure (salt-rich) ice and the ridged
features thought to have formed as crustal plates diverged, suggests
that salts and related (potentially organic) impurities in the ice were
introduced from below. This suggests that surface ices may carry
compositional signatures of the putative subsurface ocean. This has
important information for constraining hypotheses about the nature of a
subcrustal ocean on Europa and its potential for sustaining life. The
presence of cryopreserved organics in surface ices could open up
possibilities for directly sampling the remains of Europan life forms or
pre-biotic chemistry during future landed missions.

### Work and Research Planned Year 2 

Year 1 has seen a rapid ramp-up of the ASU Astrobiology effort. Most of
the projects originally proposed were \"long-term\" in that they took
advantage of the 5-years of funding offered by the NAI. Thus, Year 2
will predominantly consist of continuations of the projects begun in
Year 1. Brief overviews of specific plans for Year 2 are presented
below.

## Cosmochemistry 

In Year 2, activities will be centered around installation, calibration
and validation of the new ion microprobe. Also, ion microprobe isotopic
analyses of the carbonates will consume year 2, as stable isotope
analyses will be some of the first applications developed in the new
laboratory, with application to Astrobiological problems specifically in
mind. GC-IRMS analysis of the soluble organic fraction will continue
with collaborators at NASA Ames.

## Experimental Hydrothermal Systems

In the second year we plan to (1) Continue exploring the abiotic
synthesis of organic molecules in the Catalytic Reactor Vessel on a
variety of mineral substrates, (2) continue the abiotic syntheses
experiments on clay substrates in static reactor systems, and (3) begin
a new series of experiments in the artificial seafloor hydrothermal
system simulating possible chemistries in the Europa ocean.

## Origin and Evolution of Photosynthesis 

Work planned for next year include a range of projects from both ASU
personnel and off campus subcontractors. These include further studies
of the iron oxidizing bacteria, molecular evolution analyses of
additional chlorophyll biosynthetic enzymes, analysis of a unique
chlorophyll d containing bacterium, work on model systems that simulate
some of the very earliest photosynthetic organisms, and study of the ATP
synthesizing.

## Extracting More Information From the Precambrian Fossil Record:

During Year 2 we will begin to focus taphonomic studies on alkaline and
saline lake systems in Baja, California and in the Cuatro Cienegas
Basin, Central Mexico. The Baja work will involve a close collaboration
with the NASA Ames microbial mat group headed by David Des Marais, while
the work at Cuatro Cienegas will involve close collaboration with
Research 4 research being headed by Jim Elser (Biology ASU). The focus
of this work will be the field characterization of mat microenvironments
and biogeochemistry within low temperature mineralizing sedimentary
systems as a framework for understanding basic fossilization processes
and dominant modes of preservation.

In Year 2 we will use TEM to determine mineralogy, microstructure and
composition of the fossilized bacteria and surrounding matrix in modern
and ancient samples. This work will be largely carried out on samples
characterized by light microscopy and SEM during Year 1. In addition, we
will develop correlative evidence (isotopic and trace elemental) for
potential geochemical biomarkers that support morphological and
microstructural evidence for biogenicity. This work will also involve
culture-based lab investigations of living cyanobacteria regarded to be
close morphological analogs for Precambrian microbes that have been
identified in fossil samples.

In Year 2 we will undertake a compilation of salt sequestered as brines
in sedimentary basins and estimates of rate at which salt was removed
from the ocean as continental platforms developed in the Precambrian.

## 

## Hydrogeochemical Influences On Ecosystem Evolution: Ancient Desert Springs As Analogues For The Early Development Of Life

Based on work accomplished under seed-funding from ASU, the Biology
group will prepare a new proposal for submission to the NAI in response
to the second CAN.

## Exploring for Martian Life 

During Year 2 we will continue to explore Martian surface mineralogy
using TES orbital data and feed this information into the site selection
process for future landed missions leading to sample return for
Astrobiology. We will also complete remote sensing analog studies of
paleolake basin and hydrothermal systems to help constrain the optimal
spatial and spectral resolution required for the identification of
surface mineralogy from Mars orbit.

## Exploring for Habitable Environments on Europa 

In Year 2 we will begin to model light penetration into europan surface
ice and the potential for solid state greenhouse that might lead to the
maintenance of liquid water habitats beneath the surface. Models will be
constrained by empirical data obtained from modern analog studies in
Antarctica. We will adapt model-based and empirical studies of black
smoker environments on Earth to conditions on Europa. We will prepare
manuscripts evaluating the potential for habitable environments on
Europa and the possibilities for life.

## The Role of Impacts in the Origin and Evolution of Life

This new research involving an NAI-approved collaboration with the
University of Arizona will be added at the beginning of Year 2. In Year
2 we will begin investigations of the effects of pre-Phanerozoic impacts
on climate and early life, consider the climatic effects of martian
impacts and their implications for life on Mars, and undertake
calculations likelihood and/or extent of hydrothermal systems associated
with large terrestrial impacts.

# Carnegie Institution of Washington

# PI: Sean C. Solomon

### Work and Research Accomplished During Year 1

The six research nodes of Carnegie\'s astrobiology effort pursued an
integrated program of study on physical, chemical, and biological
aspects of hydrothermal systems.

## Hydrothermal Organic Synthesis 

A principal objective of our research program is to determine the nature
and extent of hydrothermal organic synthesis under plausible prebiotic
conditions on Earth and other bodies. Most of this effort was devoted to
the preparation and analysis of experimental runs in which sealed gold
tubes with reactants in the system C-O-H(±N)(±mineral catalysts) were
subjected to controlled high temperature and pressure in a gas-media
apparatus. Four projects used this technique:

Synthesis and stability of amino acids at hydrothermal conditions; we
find that production of alanine in the pyruvic acid-NH~4~Cl-H~2~O system
is strongly dependent on pH, with highest yields under acidic
conditions.

Stability and reaction pathways of pyruvic acid under hydrothermal
conditions; we have completed the last of \~300 runs that demonstrate
the rapid decarboxylation of oxaloacetic acid, and the Aldol
condensation of pyruvic acid.

Stability and reaction pathways of citric acid under hydrothermal
conditions; we have completed the last of \~350 runs that define a
complex reaction network, including dehydration, decarboxylation,
hydrogenation, and Aldol condensation. We conclude that under no
plausible conditions of pressure and temperature in the pure C-O-H
system can all requisite reactions of the TCA cycle proceed. Catalysts
are essential.

Mineral-catalyzed hydrothermal carboxylation reactions: Approximately
200 runs with 20 different minerals (primarily sulfides) demonstrate
mineral-enhanced carboxylation of thiols (e.g., CH~3~SH + CO + H~2~O ⇒
CH~3~COOH + H~2~S). We find that yields vary depending on the mineral
used. The nickel sulfide millerite (NiS) results in the highest yields,
while the iron sulfide pyrrhotite (Fe~1-x~S) and mechanical mixtures of
iron and nickel sulfides are much less effective.

## 

## Additional work during the past year involved:

Design and construction of a flow-through, high-pressure hydrothermal
reactor; this device will be operational at Carnegie in summer 1999;

Modifying and testing the high-pressure reactor at Ames; this reactor is
capable of leak-tight operation at temperatures to 350°C and pressures
to 250 bars;

Development of additional analytical capabilities including HPLC for
organic acid analysis and GCMS for gas analysis;

Establishment of a stockpile of more than 60 well-characterized natural
and synthetic minerals for inter-laboratory comparisons;

Initiation of a study of pathways of carboxylation of pyruvic acid in
the presence of mineral catalysts;

Design and construction of a system for *in-situ* spectroscopic study of
reactions using a hydrothermal, diamond-window, high-pressure cell.

## Theoretical Studies of Hydrothermal Synthesis 

Theoretical studies of organic reactions inform experimental studies.

Morowitz has been working on a theoretical foundation for synthesis
experiments by starting with the 3,000,000 compounds in the Beilstein
database and moving by rules and algorithms to the reductive TCA cycle.

Studies by Shock include: (1) Efforts to understand the energetics of
hydrothermal ecosystems and energetic demands of individual thermophilic
microorganisms. (2) Connecting constraints on organic synthesis in
hydrothermal and volcanic systems with those extracted from theoretical
models of planetary evolution. (3) Collaborative theoretical work as a
framework for guiding Carnegie\'s hydrothermal experiments.

## Studies in Planetary Formation and Evolution 

Theoretical studies constrain the circumstances under which planets with
hydrothermal systems form, while planetary observations constrain water
budgets.

Boss studied formation of giant planets by the novel means of
gravitational instability of the gaseous portion of the solar nebula.

Solomon applied new altimetry data to derive improved estimates of ice
volumes in the Martian polar caps and the conditions under which basal
melting would be expected.

Wetherill led an effort to investigate quantitatively the circumstances
under which an initial asteroid belt devoid of planet-size bodies can be
expected to form.

## Studies of Organic Matter in Meteorites 

Organic material in primitive chondritic meteorites retains a record of
prebiotic organic synthesis in the interstellar medium. Our studies
apply a suite of techniques to determine the structures of terrestrial
kerogens to the macromolecule in the Murchison meteorite. Initial
results show the material to be highly aromatic (\>70% of the C and 60%
of the H) and a significant fraction, perhaps 50% of the C, must be in
large PAHs not seen in previous pyrolysis GC-MS studies because of their
refractory nature.

## Biological Studies of Hydrothermal Systems

Studies of microbial communities reveal novel metabolic pathways and
inform attempts to detect biosignatures on other worlds.

Four highlights of Baross\'s work: (1) It was demonstrated that a
subsurface anaerobic hyperthermophile can fix carbon dioxide in addition
to using organic material. (2) Molecular-phylogenetic analyses of
subsurface microbial communities from the 1998 eruption at Axial Volcano
show a wide diversity of Archaea. (3) Actively venting black-smoker
sulfide chimneys were recovered from the Endeavor Segment of the Juan de
Fuca Ridge. (4) High-T, high-P phase separation leads to hypersaline
subsurface fluids associated with submarine hydrothermal vents;
halotolerant microorganisms have been isolated from these fluids.

Emerson has studied prokaryotes in hydrothermal vent habitats,
principally the Loihi Seamount located near Hawaii. Mesophilic,
lithotrophic Fe-oxidizing prokaryotes are prevalent, if not dominant,
members of the microbial community at this site. Initial results suggest
that Fe-reducers are also present, suggesting an active Fe-cycle.

Fogel is developing techniques that use isotopic tracers and
immunological approaches to elucidate biosignatures of life in the solar
system. She employs polyclonal antibodies to detect the presence of the
universal RubisCO enzyme. Further analyses will include the isotopic
composition of the amino acids of the specific proteins isolated and
identified using Western Blotting.

### Work and Research Planned Year 2

## Hydrothermal Organic Synthesis: 

We will continue to study the stability and reaction pathways of
selected organic compounds under controlled hydrothermal conditions. As
in the previous year, much of this effort will focus on the preparation
and analysis of sealed gold tube experimental runs.

In conjunction with new Co-Investigator Jay Brandes (University of
Texas), we will expand our studies of the synthesis and stability of
alanine to leucine and other amino acids. We will also focus on the
formation of peptide bonds under high-pressure hydrothermal conditions.

We will expand our studies of mineral-catalyzed hydrothermal
carboxylation reactions by undertaking a systematic study of the
reactivity of 60 natural samples of transition metal sulfides. We will
characterize these minerals and determine their efficiency in catalyzing
the carboxylation of thiols.

We will synthesize sulfide solid solutions on the Fe-Zn, Fe-Ni, and
Fe-Co joins to evaluate effect of isomorphous substitutions on the rates
and product yields of prebiotic organic reactions. An exploratory
experiment showed that Ni substitution in the pyrrhotite structure
increased its reactivity over that of pure FeS or (FeNi)~9~S~8~.

We will investigate effects of fO~2~ and fS~2~ on prebiotic
organosynthesis using an array of oxygen and sulfur buffers. More
reducing buffers are related to possible organic synthesis in a
Hadean/Archean hydrothermal system, while more oxidizing buffers are
pertinent to some modern terrestrial and ocean ridge hydrothermal
systems.

Metabolic proteins frequently contain iron-sulfur clusters. We will
attempt to synthesize these clusters and characterize their
stoichiometry and oxidation states.

Previous experiments using iron monosulfide have shown that it undergoes
sulfidization, becoming more sulfur rich with the formation of a small
amount of pyrite. We will use isotopically-labeled sulfur to document
this reaction mechanism.

Tungsten and molybdenum may play important roles in enzymes. We will
begin an investigation of the role of WS~2~ and MoS~2~ in prebiotic
organic synthesis.

We will complete the construction phase of the new Carnegie
flow-through, high-pressure hydrothermal reactor, and we will perform a
series of calibration experiments to determine its temperature and
pressure stability.

At the USGS (Menlo Park), Bischoff and Stanford graduate student Kono
Lemke will conduct gold-bag reactor experiments to determine run times
necessary to achieve buffered equilibrium of O, S, and H fugacities -
information that will guide the design of flow-through reactor
experiments.

At NASA-Ames, Chang and postdoctoral scientist Mitch Schulte will
examine amino acid and peptide stability, as well as the ability of
condensing agents (e.g., polyphosphate) to mediate peptide synthesis.
Hydrothermal syntheses of carboxylic acids will also be pursued.

We will use the newly constructed hydrothermal diamond-window cell and
spectroscopic system to study reaction kinetics in the citric acid-H~2~O
system as a function of temperature and pressure. We will also continue
studies on the stability and reaction pathways of pyruvic acid under
hydrothermal conditions.

## Theoretical Studies of Hydrothermal Synthesis Reactions:

Morowitz will continue his evaluation of a minimal reaction network of
organic compounds required to sustain the TCA cycle. This theoretical
approach will inform experimental hydrothermal studies.

Shock will continue to model the energetics of hydrothermal ecosystems
and experimental systems. In particular, he will calculate thermodynamic
properties of various reactions involving formic acid and several
inorganic gases, and he will employ these data in models of stable and
metastable equilibrium states that may be reached in experiments at
Carnegie.

Chang and Schulte will carry out calculations on the stability of simple
thiols under hydrothermal conditions. Insofar as thiols have been
implicated as intermediates in hydrothermal organic chemistry by other
workers (at Carnegie and elsewhere), their thermodynamic behavior
warrants theoretical treatment.

## Studies in Planetary Formation and Evolution: 

Boss will compute three-dimensional models of disk instability processes
that lead to giant planet formation. He will apply varied initial and
boundary conditions, in order to learn how sensitive the instability is
to key parameters such as the size and mass of the nebula and the
thermodynamical behavior of the gas as the instability proceeds.

Wetherill, in collaboration with Postdoctoral Fellow Stephen Kortenkamp,
will continue to identify and quantify circumstances under which an
asteroid belt devoid of planet-size bodies can be expected to form. This
work will be complemented by studies of Boss, who suggests that giant
planets form rapidly by gravitational instability during a late stage in
the accretion of the central star.

Solomon will continue to lead an assessment of the likelihood, timing,
and physical and chemical environments of hydrothermal systems on solar
system objects.

## Studies of Organic Matter in Meteorites: 

Alexander and coworkers will apply an array of analytical techniques,
including ^13^C, ^1^H, and ^15^N NMR, and carbon X-ray absorption
near-edge spectroscopy to study organic compounds isolated from the
Murchison meteorite. Pyrolysis and chemopyrolysis will be used to
provide a perspective on the molecular structural units present.
Finally, ^13^C-labeled compounds will be used to derivatize specific
functional groups in conjunction with ^13^C NMR to determine precisely
the number of these functional groups present.

## Biological Studies of Hydrothermal Systems: 

Baross and Emerson will continue studies of deep-sea thermophiles, with
an emphasis on documenting the range of metabolic strategies present in
microbial ecosystems. Investigations include microbial cultivation, as
well as phylogenetic and phenotypic analysis.

Fogel will continue to study molecular biosignatures in an effort to
develop remote sensing methods for life. Working with Postdoctoral
Fellow Susan Ziegler, she will focus on isotopic and immunological
approaches to detecting life.

Fogel and Emerson will collaborate on the stable isotopic analysis of a
variety of Archaea and other thermophiles to determine if the isotopic
signatures of these organisms are unique.

Most of the proposed research represents an extension of research
activities undertaken during the first year of the NASA Astrobiology
Institute.

# Harvard University

# PI: Andrew Knoll

### Work and Research Accomplished During Year 1

Our research focuses on the coevolution of Earth and life during
critical intervals of biospheric development. We are also developing
novel protocols for biological detection and remote imaging analyses
that can be used in the exploration of Mars and other solar system
bodies. Research directly supported by NAI is included in this summary.

## Laboratory Studies of Biomarker Recognition and Paleoenvironmental Change

Ariel Anbar has made encouraging progress in developing instrument
capabilities and sampling protocols for the study of biological
fractionation of metal isotopes. In particular, Anbar has achieved the
demanding instrument sensitivity required for MC-ICP-MS analyses of Cu
(Anbar and Barling, 1998, Abstr., Goldschmidt Conf.) and Fe (Anbar et
al., 1999, Abstr., Goldschmidt Conf.) isotopic fractionation.

Anbar also completed analyses of iridium and platinum in 3800 million
year old metasediments from Akilia Island, Greenland (Anbar et al.,
Science, in review). Although these rocks were deposited during an
interval thought to be characterized by heavy meteorite bombardment,
they contain low Ir and Pt concentrations. Modeling by Anbar and
colleagues shows how these observations can be reconciled with the
cratering histories used to model secular change in impact rate.

John Hayes has combined stable isotopes and molecular biomarkers in the
investigation of ancient and modern ecosystems. NAI-supported highlights
include the discovery of novel methane-consuming archaeans in modern
marine sediments (Hinrichs et al., 1999, Nature 398: 802-805); a
detailed biogeochemical dissection of terminal Proterozoic, mid-shelf
bacterial mats that corroborates and extends inferences of major
environmental reorganization near the Proterozoic-Cambrian boundary
(Logan et al., in press, Geochim. Cosmochim. Acta); and the
demonstration of hydrogen isotopic fractionation during lipid synthesis,
opening up new paths of analysis for the lipids preserved in Precambrian
sedimentary rocks (Sessions et al., in press, Organic Geochem.)

Heinrich Holland completed new analyses of iron distribution in 2750
million year old paleosols from Western Australia, confirming that these
weathering horizons developed beneath an oxygen-poor atmosphere. Holland
also developed new models for the rise of atmospheric oxygen 2300-2200
million years ago and for the large variation in the abundance of
dolomite in carbonate sediments deposited over the past 800 million
years. The latter hinges on the recognition of dolomite as a
\"CO2-bank,\" which is drawn down when the rate of CO2 consumption in
weathering exceeds the rate of CO2 supply by volcanism. This provides a
significant buffer against fluctuations in atmospheric CO2 content
associated with CO2-chemical weathering feedbacks (Holland, 1999,
Abstr., Goldschmidt Conf.).

## Field-Based Investigations

In our original proposal, we stressed multidisciplinary, field-based
studies of coevolving life and environments, and in year 1, several new
efforts got underway. Andrew Knoll initiated studies of terminal
Proterozoic successions in West Africa, collecting nearly 200 samples of
carbonate, phosphorite, chert, and shale deposited above a ca. 600
million year old glacial horizon. Carbon and strontium isotopic studies
have already been completed, and radiometric analyses are underway.
Notably, phosphorite samples display superb textural preservation, and
includewell-preserved fossils.

Paul Hoffman has initiated coupled sequence stratigraphic and isotopic
studies of Neoproterozoic successions in Svalbard. These thick,
fossiliferous sections provided the first proving ground for studies of
linked Neoproterozoic climate and biogeochemical change. Hoffman\'s new
research will allow tests of his novel Snowball Earth model (Hoffman et
al., 1998, Science 281: 1342-1348). Hoffman is also collecting closely
spaced paleontological samples that will provide a better understanding
of the biological consequences of Neoproterozoic environmental events.

John Grotzinger is focusing on terminal Proterozoic carbonate platforms
from Namibia that contain the earliest known record of diverse,
skeletonized animals (Grotzinger et al., 1998, GSA Abstr. Progr., 30:
A147, and in prep.). Grotzinger\'s discoveries overturn much accumulated
dogma about the role of biomineralization in early animal
diversification, showing that biomineralization was an important element
of earliest animal diversification.

Grotzinger is also developing novel imaging capabilities that work in a
virtual environment, providing new tools that facilitate field research
on Mars.

## Integrating Comparative Biology and the Geological Record

Insights into the evolution of biological diversity require that the
historical data provided by paleontology and geochemistry be integrated
with molecular perspectives on phylogeny and development. Harvard team
members have played a prominent role in developing the emerging
interdisciplinary view of early animal evolution, showing how genetic
possibility and environmental opportunity have combined to determine the
pattern of animal diversification reconstructed from the fossil record
(Valentine et al., 1999, Development 126: 851-859; Erwin, in press,
American Zoologist; Knoll and Carroll, 1999, Science, in press). Team
members have also integrated precise radiometric age determinations with
stratigraphic data on fossil distributions to constrain the timing of
both early animal diversification and end-Permian mass extinction
(Bowring and Erwin, 1998, GSA Today 8(9): 1-8; Bowring et al., 1999,
Proc. Nat. Acad. Sci., in press). Among other things, these results show
that end-Permian extinction resulted from abrupt (less than 100,000
years) environmental perturbation and does not reflect ecosystem decay
over long intervals of time.

## Collaboration with other NAI Teams and Education

Anbar\'s research in analytical geochemistry is a collaborative effort
involving members of the JPL and NASA Ames NAI teams. In a new
collaboration, Knoll is joining with geochemists from the Carnegie team
to develop novel analytical tools for paleontology, focusing on
elemental and isotopic mapping of anatomically preserved plant fossils.
For example, the interannual variation in C-isotopic composition of late
Devonian woods has been shown to match the variation seen today in trees
from comparable environments. Isotopic mapping is enabling us to ask
about the physiological evolution of life on land, especially the
evolution of lignin-containing tissues.

New courses for students ranging from freshmen to graduate students have
been initiated at Harvard, MIT, and Rochester. We have also initiated a
weekly group meeting and (a true fruit of NAI) monthly joint seminars
with astronomers at the Harvard-Smithsonian Astrophysical Observatory. A
public lecture series was successfully launched, with well-attended
lectures on astrobiology by K. Nealson, B. Jakosky, and S. Squyres. Team
members delivered about 100 outside lectures in year 1, many of them in
public venues. Members will also participate in the MBL summer
teacher\'s course in Astrobiology.

### Work and Research Planned Year 2

In the second year of funding, we plan to build on efforts begun in year
1.

Anbar will continue to develop tools for the isotopic analysis of
biologically interesting metals. He anticipates that the biological
fractionation of Cu isotopes will be demonstrated in experimental
systems and applied to geological materials in the coming year.

Anbar and Holland will produce ICP-MS analyses of redox-sensitive metal
elements (U,V, Re, Mo) in Archean and Proterozoic black shales. The
expectation is that these analyses will further constrain our
understanding of oxygen availability on the early Earth. Holland will
concentrate on samples collected from southern Africa, whereas Anbar
will focus on a excellent suite of Paleoproterozoic shales collected by
A.H.Knoll from drill cores in northern Australia. This latter sample set
will provide an important test of the Proterozoic ocean model proposed
last year by Donald Canfield and will be carried out in conjunction with
paleontological and molecular biomarker analyses underway at Harvard and
the Australian Geological Survey Organization.

Knoll, Hoffman, and Grotzinger will continue field projects in West
Africa, Svalbard, and Namibia. Collectively, these efforts are expected
to provide important tests of hypotheses that relate biological and
environmental evolution near the Proterozoic-Cambrian boundary. In all
three projects, substantial progress in sample analysis is expected in
year 2. Note that in all cases, analyses of collected samples will be
carried out by a wider set of team members with expertise in
paleontology (Knoll, Erwin), trace element geochemistry (Anbar),
isotopic geochemistry (Schrag,Bowring), geochronology (Bowring), organic
geochemistry (Hayes), and sedimentology (Grotzinger, Hoffman).

Erwin, Bowring, and Knoll expect to conduct field work focussed on
terminal Proterozoic and Permian-Triassic sections in southern China.
Target sections represent key exposures of rocks expected to provide
insights into the timing of evolutionary diversification and extinction,
the environmental context of critical biological events, the pattern of
early evolution in multicellular organisms (Proterozoic sections), and
the nature of recovery from mass extinction (Permo-Triassic sections).
As above, collections made in the field will be distributed among team
members for laboratory analysis.

The Harvard-Carnegie project will be expanded to include NMR analyses of
organic constituents in fossil plants, improving our ability to derive
physiologically useful data from fossils.

New team member Dan Schrag will initiate a project on the Ca and Si
isotopic composition of modern and ancient minerals precipitated in the
oceans. Both elements are fractionated isotopically during skeleton
formation. Thus, it is expected that analyses of Proterozoic and
Paleozoic samples will illuminate the growing participation of biology
in the marine carbonate and silica cycles through time.

New team member Charles Marshall will contribute to the integration of
paleontological and molecular data, concentrating on sequencing,
phylogenetic analysis and developmental interpretation of even-skip
genes and the linking of data from fossils and phylogenies.

Our public lecture program will be doubled in size in year 2 and
expanded to include lectures at the Smithsonian as well as in Boston.

# Jet Propulsion Laboratory

# PI: Kenneth Nealson

### Work and Research Accomplished During Year 1

Start up administrative problems associated with timely receipt of
funding, incorporation of the agreement into the JPL contract and
changes in internal accounting systems has limited the extent of
research planned during the first year. For that reason the progress
report is very JPL-centric. Notwithstanding the delays in start up, our
own group and several of our colleagues have made significant progress.

I have outlined the major accomplishments made by these workers below,
and I note that despite adminstrative start-up problems, there is still
immense excitement among our members.

The Astrobiology Research Element at JPL has in the past year begun
studies of several extreme environments on Earth that may serve as
analogs for extraterrestrial environments of astrobiological interest. A
major focus of research is Mono Lake, an alkaline hypersaline lake in
northern California that may be similar in many respects to open bodies
of water on Mars during the latter stages of that planet\'s \"warmer,
wetter\" early history. Also being studied are samples of permafrost
from Siberia and Antarctica, including samples dated at up to 10-20
million years old. In both cases, an integrated strategy is being
employed which examines the microbial biodiversity and ecology of the
environment using microbiological and molecular biological techniques,
and also explores the organic geochemistry and biogeochemistry of the
sample matrices using analytical chemistry techniques. Preliminary
findings have yielded very exciting results, including the isolation of
species of cyanobacteria from various endolithic habitats around Mono
Lake, and the isolation of unusual alkalophilic actinomycetes from these
same endolithic environments.

Dr. Nealson, Drs. Clark Johnson and Brian Beard of the University of
Wisconsin, and postdoctoral researchers Henry Sun and Lea Cox of Caltech
and JPL have also begun investigations of the isotopic fractionation of
iron by environmental microorganisms. These organisms metabolize iron
and other metals, and appear to induce a fractionation of iron isotopes
that is not seen in abiotic processes. This work has resulted in the
submission of a paper to the journal [Science]{.underline} that was
recently accepted for publication. This is the first demonstration of
biological fractionation of iron, and has attracted much attention in
the community.

Dr. Marilyn Fogel of the Carnegie Institution of Washington has been
working in the area of biosignature development, and in collaboration
with the Nealson laboratory has finished work on fractionation of carbon
by heterotrophic bacteria, and how this differs between organisms grown
aerobically and anaerobically. This has resulted in a publication that
is now in press in the Journal *Organic Geochemistry.*

Drs. Gene McDonald, Sasha Tsapin, Michael Storrie-Lombardi have been
working on the development of a deep UV Raman spectrometer system for
the study of extreme environments on Earth, and eventually for in situ
life detection. The development and preliminary data collection using
this new instrument were described in two abstracts presented at the
annual meeting of the American Society for Microbiology.

Drs. Brian Tonner, Lea Cox, and Ken Nealson, with colleagues from the
Argonne National Laboratories (Ken Kemner) and Lawrence Berkeley Labs
(Werner Meyer-Ilse and Pupa DeStasio) have been working on the
development of Synchrotron Radiation Techniques for life detection. This
work has resulted in a series of abstracts, and preliminary data
suggesting that these methods may offer powerful methods for life
detection in opaque matrices.

Dr. Yuk Yung and Dr. K. Nealson received NASA support for the study of
gas emission in bacterial mat environments, and this work has been
initiated by Dr. Lisa Stein along with others from the JPL consortium.
This work is funded outside of our NAI program, but interfaces with it
very nicely.

# 

### Work and Research Planned Year 2

For the upcoming year, we expect to have a full program in Astrobiology,
as originally planned, and to have a great deal of activity in the
following areas. This activity has already begun as the guarantee of
funding from JPL has allowed many of our members to initiate activity
full scale in an effort to "catch up" with other members of NAI.

## Environmental Microbiology

# 

The group at JPL will continue its efforts in environmental
characterizations (organismal, geochemical, mineralogical, and physical)
of alkaline lakes, cold and dry deserts, and permafrost environments.
This work will include molecular characterization of the populations
based on analyses of DNA and RNA sequences and patterns, as well as
isolation of new organisms, and the study of these organisms in the
environments, and in the laboratory.

## Instrument Development

The JPL group will continue the development of the UV-Raman system,
finishing the design of the instrument, lab and field testing it, and
working on the miniaturization.

In addition, we have applied for funds to develop a laser ablation
subsurface analysis system through the HEDS program, and if this is
funded, it will represent a second major effort.

Finally, a number of members of our NAI consortium (Fogel from the
Carnegie, Tonner from Florida, and colleagues from ANL and BNL) will
work together on synchrotron radiation methods for sample analysis.

## Minerals as Biosignatures

# 

Dr. Joe Kirschvink has a very active program in progress in the
mineralogy of magnetite, and the proof that magnetite is a viable
biomineral. He will continue this work with support from the NAI.

Dr. Jillian Banfield, from the Univ. of Wisconsin in Madison, will be
working in the areas of mineral structure and mineral weathering,
looking at specific weathering features that can be identified as
peculiar to biology.

Dr. Nealson's laboratory is directed at the processes that lead to
mineral dissolution, and understanding whether any of the mineral
remains left behind can be identified as biological. This work is (and
will continue to be) primarily focused on iron and manganese oxides, and
the products they produce as metal reduction proceeds. It includes an
element of the isotopic fractionation work described below, as
fractionation of iron can be seen during the metal dissolution process
catalyzed by bacteria.

## Stable Isotope Fractionation

Dr. Clark Johnson and Dr. Brian Beard, from the Univ. of Wisconsin in
Madison, will be continuing work (in collaboration with the JPL group)
on the fractionation of iron isotopes. This work will include
investigation of natural samples as well as samples from a variety of
metal oxidizing and reducing bacteria.

Dr. Ariel Anbar of the Univ. of Rochester will continue his work with
fractionation of transition metals, focusing on several key metals
including Fe, Mo, and Cu.

Drs. Yuk Yung and Geoffry Blake from Caltech will be involved with the
study of fractionation of N during production of N-oxides by bacteria.
This work is in collaboration with the Astrobiology group from JPL.

## Mars Properties

Major events that will occur in the next couple of years will involve
analysis of Mars Global Surveyor data for site selection. The USGS group
at Flagstaff, along with several members of the NAI from JPL are
actively involved with this aspect of work, characterizing sites, and
correlating these data with other properties of Mars, and data from
other missions.

Tom Ahrens is initiating work with several aspects of Mars geology and
geochemistry, and in particular has begun a set of experiments with
members of the astrobiology to look at the survival of organic matter
and even organisms under conditions of simulated impact shock.

## Involvement with Missions

Members of the NAI Consortium are actively involved with several ongoing
missions, and this will constitute an exciting part of our efforts in
the coming year, and hopefully, will unite us with many members from
other NAI sites. Some of these are listed below:

+----------------+-------------------+---------------------------------+
| Mars '98       | Polar Orbiter     | K. Nealson/Co-I on Themis       |
+----------------+-------------------+---------------------------------+
| Mars '01       | Orbiter           | D. McCleese/PI on IR Camera     |
+----------------+-------------------+---------------------------------+
| Mars03         | Lander            | K. Nealson/Project Scientist    |
|                |                   |                                 |
|                | Lander            | P. Conrad, et al./Instrument    |
|                |                   | design                          |
+----------------+-------------------+---------------------------------+
| Mars '05       | Lander            | K. Nealson/Project Scienctist   |
|                |                   |                                 |
|                | Lander            | P. Conrad, et al./Instrument    |
|                |                   | design                          |
+----------------+-------------------+---------------------------------+

In summary, we expect the NAI Consortium from JPL to be fully mobilized
and very active in '99-00, and we expect to make major contributions in
the above areas, and probably many others. We are in a lag phase just
now, as explained in the executive summary, but we expect that the Co-Is
of our group will be active and contributing members and very visible.
We hope that our ability to connect with missions will be a way for the
NAI to become involved with mission science in a positive way.

# NASA Johnson Space Center

# PI: David McKay 

### Work and Research Accomplished During Year 1

## Terrestrial Rocks

The importance of terrestrial analogs cannot be overestimated. Only by
understanding the evidence for life on Earth can we assess indications
of possible life elsewhere in the universe. We are studying the life
forms and biomarkers in samples from deep aquifers, thermal springs, and
some of the most ancient rocks on Earth. We are also conducting shock
experiments on terrestrial rocks to understand the temperature and
pressure histories encountered by meteorites from Mars.

Analyses of the Columbia River basalts (Thomas-Keprta et al., 1998c)
have shown that rod and oval-shaped organisms with and without
appendages grow in microcosms that simulate environments in the deep
terrestrial subsurface. Minerals encrust these organisms and their
biofilms in as little as eight weeks. The microbes become mineralized
without retaining their cell walls or membranes. This study shows that
cellular appendages, in addition to the mineralized cell bodies, can
also be preserved by mineralization. The mineralized appendages are
nearly identical in size and morphology to the structures in martian
meteorites ALH84001, Nakhla, and Shergotty which are interpreted as
possibly biogenic (see Extraterrestrial Samples below).

Precipitates of carbonates and/or silica from four neutral pH carbonate
thermal springs support diverse microbial communities within the water
and in biofilms (Allen et al, 1998, 1999). Filamentous microbes are
engulfed in precipitating aragonite and may be rapidly destroyed but
sometime leave distinctive mineral fabrics. Other species of microbes
coexist with mineral deposits in endolithic communities. Thermal spring
microbes produce abundant organic mucus and extensive biofilms.
Populations of submicrometer spheres are composed of calcium fluoride,
calcium phosphate, or silica. In each case the sphere formation is
biologically mediated but the spheres themselves are apparently neither
living organisms nor fossils.

Large spheroidal features up to 30 μm in diameter from the Warrawoona, a
3.5 Ga old carbonaceous chert, may be among the oldest terrestrial
microbial fossils (Morris et al. 1998, 1999). These spheres have unique
surface textures and chemical compositions that indicate they are
biogenic. This is the first report describing Warrawoona Archean
microfossils using scanning electron microscopy.

A comprehensive review article by Westall et al. (1999) describes the
ways in which fossil bacteria are preserved. Many types of fossilized
bacteria from the Early Archean to present day are described to
illustrate the various modes of preservation and the morphology of
fossil bacteria. Comparisons are made to putative martian microfossils.
Additional work (Westall et al. 1999) establishes criteria for
differentiating spherical bacteria from inorganic spheroidal
precipitates.

Experimental impact studies by Bell et al. have determined the stability
of carbonates under shock conditions reportedly experienced by the
ALH84001 meteorite. This work shows that carbonate is stable up to 60
Gpa. No evidence of shock pressures greater than 40-45 Gpa exist in
ALH84001.

## Extraterrestrial Rocks 

## 

Features in the Martian meteorites and ALH84001 (\~4.0 GA
crystallization age), Nakhla (\~1.3 GA crystallization age), and
Shergotty (180 MA crystallization age) are strikingly similar to
mineralized bacterial organisms from the Columbia River basalts (McKay
et al., 1999). Features in Nakhla and Shergotty include spheroid-shaped
features that occur in rare patches in regions rich in Martian clay
minerals. The fact that they occur in distinct regions is important and
highly suggestive of biological activity. The meteorites also contain
elongated forms, which are nearly identical to rod-shaped mineralized
organisms in the Columbia River basalts.

A series of reports by Thomas-Keprta et al. (1998a-b, 1999a-c) describe
fine-grained magnetite crystals that we have proposed as mineralogical
indicators of primitive Martian organisms. Magnetite is found in a wide
variety of terrestrial rock types and in meteorites, but none has been
reported with the specific and unique characteristics of magnetites
produced by magnetotactic bacteria. We suggest that the several
varieties of magnetite in ALH84001 carbonate globules might be explained
by a combination of inorganic and biogenic processes at low temperature.
A significant fraction of the magnetite has a pure chemical composition,
unique morphology, and length-to-width ratio that are indistinguishable
from a variety of terrestrial biogenic magnetite but distinct from all
known inorganic forms of magnetite. Unless an inorganic analog for these
crystals is found, the presence of elongated prismatic magnetite
crystals associated with the carbonate globules in Martian meteorite
ALH84001 must be considered as strong evidence for primitive life on
early Mars.

Microscopic regions of silica glasses in ALH84001 described by Bell et
al (1999a-b) are interpreted as possibly biogenic deposits of opal-A.
This silica is composed of tiny spheres, 2 to 5 nm in diameter and is
essentially pure, amorphous, SiO~2~. Terrestrial forms of opal,
including high temperature, low temperature inorganic, and low
temperature biogenic, have been examined using transmission electron
microscopy. The best terrestrial analog for the silica in ALH84001 is
biogenic opal-A, which has identical morphology and chemistry to silica
in the Martian meteorite.

Flynn et al. (1999) have presented data using XANES (X-ray absorption
near edge structure) techniques to measure the presence of reduced
carbon compounds at a spatial resolution of one micrometer within
individual ALH84001 carbonate globules and in alteration veins of
Nakhla. They found indigenous reduced organic carbon components in both
Martian meteorites. The data on their own do not specifically confirm
that the reduced carbon is of biologic origin, but indicates that this
carbon is likely Martian.

## Education / Public Outreach 

We have developed a large-format display and a series of public
information handouts covering the key concepts of Astrobiology and the
search for life in extraterrestrial samples. We presented these at the
Lunar and Planetary Science Conference (Allen et al. 1999) and the
national conferences of the Geological Society of America and the
National Science Teachers' Association. We have assembled a group of
master teachers and scientists to design Astrobiology education products
for upper elementary through high school classrooms.

## 

### 

### 

### 

### 

### Work and Research Planned Year 2

## Terrestrial Rocks

Complete survey of biomarkers in carbonate thermal springs

Complete survey of microbial fossils in Archean samples

Initiate bacteria fossilization experiments

Initiate studies of samples from submarine caves and deep mines

## Extraterrestrial Rocks

Investigate possible microfossils and alteration products in Nakhla and
Shergotty

Initiate search for additional biomarkers in Nakhla and Shergotty

Initiate search for evidence of life in other Martian meteorites

Document occurrences of terrestrial biological contamination in Martian
meteorites

## Biomarkers Database

Construct a comprehensive, interactive database of biomarkers and false
positives

## Education / Public Outreach

Produce Astrobiology education products for upper elementary to high
school

Present Astrobiology concepts at teacher workshops and national
education conferences

Place education products on NASA Astrobiology Institute and JSC web
sites

## Iowa State University

Grow bacteria which synthesize nanometer-scale iron oxides

Document features in iron oxides unique to a bacterial origin

## University of Houston

Document biomarkers in silica and carbonate hot spring deposits

Document biomarkers in carbonate mud deposits

## State University of New York, Plattsburgh

Study the organic component associated with mineral biomarkers in
Martian meteorite ALH84001 using advanced x-ray and infrared analytical
techniques

## Los Alamos National Laboratory

Study fossilized macromolecules on mineral surfaces using atomic force
microscopy

Investigate sensitive and site specific fluorescence staining for DNA,
proteins and lipids

## University of Montana

Determine temperature of formation of minerals using nuclear magnetic
resonance techniques

Investigate the interaction of iron and oxygen in the presence of
microbial surfaces

## Marshall Spaceflight Center

Investigate morphological biomarkers in ancient rocks and deep ice

Coordinate collaboration with Russian colleagues

## New Mexico Tech

Investigate biomarkers in extreme terrestrial environments, including
acid hot springs and deep mines

## University of Houston -- Downtown

Document morphological and chemical evidence for life in the oldest
Earth rocks

## University of New Mexico

Document hydrogen, carbon, sulfur and nitrogen isotope fractionation
associated with life in terrestrial rocks

## Florida State University

Produce minerals similar to those found in ALH84001 in a Mars-like
environment using sulfate reducing bacteria

## University of Georgia

Document features of iron carbonate minerals unique to a bacterial
origin

## Lunar and Planetary Institute

Characterize differences between biogenic and non-biogenic oxide,
sulfate, carbonate, and phosphate minerals

## Marine Biological Laboratory

Develop tracer techniques for detecting individual cells or cell
components in geologic materials

# Marine Biological Laboratory

# PI: Mitchell Sogin

Our initial research efforts are centered on studies of microbial
diversity in anaerobic environments, detection and phylogenetic analysis
of ribosomal RNAs from nonculturable micro organisms, evolution of alpha
tubulins, isolation of symbiosis-specific genes and the evolution of
bacterial chromosomes as represented by *E. coli.* The following are
statements of progress made during the past few months. All of these
projects are at very early stages of development. We anticipate
submitting manuscripts describing several new protist species and
corresponding phylogenies inferred from comparisons of actin and
ribosomal RNA genes by December of this year.

## Eukaryotic Diversity in Anoxic Environments.

Microorganisms represented the only form of life during the initial
three billion years of our evolutionary history. The earliest organisms
prospered under anaerobic conditions and even the first eukaryotes must
have evolved in anoxic environments. The primary objective of our
microbial studies is explore microbial diversity in several anoxic
environments using a combination of culturing and molecular techniques.

We have isolated microorganisms from unusual habitats that might be
'refuges' for 'evolutionary relicts', such as, mangroves, saltmarshes,
bogs, mudflats and environments proximate to deep ocean thermal vents
and seeps. A preliminary survey of several anaerobic habitats revealed a
wide diversity of flagellated eukaryotic microorganisms of which over
25% could not be assigned to any established eukaryotic lineage. We have
established monoprotist cultures for several isolates and have been
using molecular techniques based upon comparisons of rRNAs and tubulins
to determine their phylogenetic affinities.

To construct a global view of eukaryotic phylogeny we are gathering DNA
sequence data for a variety of coding genes from anaerobic taxa rarely
studied in molecular laboratories. These taxa are likely to represent
early diverging eukaryotes and are the subject of detailed
ultrastructural study by the laboratory of David J. Patterson. We have
concentrated our efforts on six groups of protists (comprising a total
of 15 distinct species ) that encompass the broadest spectrum of
eukaryotic diversity. We have recently completed the first phase of this
study by isolating, subcloning and sequencing a total of 11 -tubulin
genes, 12 -tubulin genes and 14 small subunit ribosomal DNA from
various taxa. We are particularly interested in completing analysies for
the 'core jakobids' *(Reclinomonas*, *Jakoba), Malawimonas*,
*Trimastix*. and *Carpediemonas.* These organisms cannot be assigned to
any of the well-known eukaryotic group by morphology but they share
intriguing structural features, most notably a ventral feeding groove,
with early diverging diplomonads, retortamonads, and the heterolobosea.
These similarities suggest a relationship between all of these groups
termed the "excavate hypothesis". The "excavate" taxa encompass both
mitochondria-containing core jakobids, heterolobosea and the
amitochondrial diplomonads, retortamonads, *Trimastix*. and
*Carpediemonas*. In addition to excavates, pelobionts, such as
*Mastigamoeba simplex*, may be primitive as evidenced by the lack of
mitochondria and presence of simple flagellar apparatus and endomembrane
systems. The parabasalids represent the third major group with free
living representatives which are potentially primitively
amitochondriate.

We have amplified and sequenced SSU rDNA and alpha tubulin genes from
several excavate taxa and the pelobiont *Mastigamoeba simplex.*
Phylogenetic trees based upon analyses of 16S-like rRNAs and tubulins
(Figs. 1 and 2) show the "excavate taxa" (core jakobids, diplomonads,
Heterolobosea, *Trimastix*, *Malawimonas*, *Carpediemonas*) are not
monophyletic. Furthermore the core jakobids, *Trimastix* and pelobionts
are not deep lineages in the rDNA tree. In rDNA trees, pelobionts show
an affinity to *Entamoeba* , but in rDNA and alpha tubulin phylogenies
they are not specifically allied with other amitochondriate flagellates.

Our trees imply that *Trimastix* and pelobionts at least, have a
mitochondriate ancestry and have secondarily lost them (independently of
each other). The discrepancies between the branching order of the major
groups in rDNA and tubulin trees are puzzling and may result from true
differences in the histories of these genes (that is, lateral gene
transfer between organismal lineages could have occurred) or from
artifacts in phylogenetic reconstruction. In any case, these differences
underscore the difficulty in recovering deep phylogenetic relationships
in single gene analyses; to resolve these discrepancies, additional
phylogenetic markers are needed. To this end, we are pursuing beta
tubulin and elongation factor homologs from the excavate taxa and
pelobionts to test groupings observed in our alpha-tubulin and rDNA
trees.

## Prokaryotic diversity in Anoxic Environments. 

With respect to prokaryotes, we have begun the analysis of sampled
sediment cores, microbial mats, and chimney rock from the 1998
ATLANTIS/ALVIN cruise to the Guaymas Basin and East Pacific Rise (EPR)
21°N hydrothermal vent sites (April 25 - May 5, 1998; H. W. Jannasch,
chief scientist). Our goal is to establish a combined molecular and
cultivation survey of microbial biodiversity and habitat range within
the extreme temperature and redox gradients of these vent sites.
Temperature gradients of Guaymas Basin sediments were determined
in-situ; they defined the shipboard incubation temperatures for the
corresponding sediment samples in selective anaerobic media.
Quantifications by serial dilution yielded the highest positives (106
cells ml-1) from relatively cool areas (75°C) close to the sediment
surface; the lowest population densities (101 cells ml-1) occurred in
hot samples (105°C) deeper in the sediment. Pure culture isolations from
these highest positive dilutions are underway. Isolations initiated
aboard ship from undiluted enrichment samples of Guaymas Basin and EPR
21°N have yielded 15 pure culture isolates of fermentative and
sulfur-reducing hyperthermophilic archaea. After screening by Denaturing
Gradient Gel Electrophoresis (DGGE) of PCR-amplified 16S rDNA, the
isolates fell into three distinct groups: Five high temperature strains
(up to 100°C) from Guaymas sediments, eight 90°C isolates from diverse
Guaymas sediments and 21°N EPR chimneys, and two 90°C isolates from only
a single coring location at Guaymas. Heterotrophic growth, sulfur
reduction, and 16S rDNA sequence analysis identified these three types
as members of the archaeal genus *Thermococcus*. The isolates of the
first DGGE group were not specifically related to previously described
*Thermococcus* species. The isolates of the second DGGE group formed a
well-supported monophyletic clade with *Tc. fumicolans* and *Tc.
mexicalis*, the latter species also from the Guaymas site. The isolates
of the third DGGE group formed a well-supported clade with two
*Thermococcus* species grown with organic substrates, *Tc.
peptonophilus* and *Tc. chitinophagus.*

We are complementing the cultivations with molecular diversity
assessments; specifically developed DNA and rRNA isolation procedures
for the Guaymas sediments form the basis for specific DGGE-PCR assays
for bacteria, archaea, and eukaryotes. Currently, the non-cultured
microbial community is compared to the cultured isolates by DGGE, and
several uncultured microbial community components are being identified
by DGGE and sequencing. These include especially the conspicuous
filamentous sulfur oxidizers of the genus *Beggiatoa*, which form
extensive mats on the surface of the Guaymas sediments and belong to the
largest prokaryotes on earth. Initial 16S rDNA sequence data corroborate
our previous identification (by fluorescent in-situ hybridization) that
the Guaymas *Beggiatoa spp*. are members of the gamma-Proteobacterial
*Thioploca-Thiomargarita* lineage. The members of this monophyletic,
sulfur-oxidizing lineage apparently share a unique nitrate-accumulating
physiology which may have evolved as a response to frequently shifting
redox gradients and irregular oxidant supply.

## Evolution of Endosymbioses genes.

Work on the isolation of symbiosis-specific genes has focused on
optimizing the methods for obtaining RNA from natural samples and for
inducing symbioses in the laboratory. We have been testing different
protocols for the extraction of RNA from our cultured symbionts in order
to determine which one is most efficient and yields RNA that is
amplifiable through RT-PCR. The inducible host, *Trichosphaerium*, has
been successfully used to establish two symbioses in the laboratory. We
will reisolate the symbionts from these associations and extract their
RNA using the method that we have chosen. Our goal for 1999 is to
utilize the PCR-based subtractive hybridization method, called
suppression subtractive hybridization (SSH), on RNA isolated from our
induced and free-living symbionts to begin isolating symbiotically
expressed sequences.

## Evolution of Bacterial Chromosomes: delineation of ancestral proteins

We have started our work with the premise that groups of
sequence-related proteins in any one organism descended from common
ancestor proteins. Some of these protein ancestors were recent and the
descendant proteins are shared only by closely related organisms. Other
protein ancestors go back to earliest times and are present in most
living organisms. These are the families of proteins we are
concentrating on, families that trace back to ancient times and
developed diversity by duplication and divergence before the last common
ancestor came into existence.

In the bacterium *Escherichia coli* we have delineated families of
related proteins that seem likely to have descended from common
ancestors. To the extent that the proteins are ones shared by all living
things, the ancestors should be very old. Many of *E. coli* proteins are
present in most living things, thus ancestors will trace back to
earliest times.

One may try to count how many early, undifferentiated proteins were
present in a very ancient ancestral cell. We have found in *E. coli*
525sequence-related groups of proteins. A few are large sets of around
100 proteins, and these are the regulators and transporters of the cell.
Many other groups are small. The smaller the group size, the greater the
number of that size. Many are simply pairs of two related proteins that
have no other partner in the genome (by our criteria for sequence
similarity). Most of the smaller groups and pairs are enzymes.

It appears that many enzymes have diverged so far from each other that
we can no longer see primary sequence similarities between them. In
other words, we do not believe there were 475 ancestors of 1025 enzymes.
It seems much more likely that there were fewer ancestors, perhaps one
ancestor for each general type of enzyme, and over long periods of time
the products of duplication and divergence have so stretched the
differences in the progeny of that family that we cannot see the
relationships by primary amino acid sequence alone.

We are using new tools of sequence analysis such as PSI BLAST to
identify strictly conserved amino acid positions within groups of
faintly related proteins, thus allowing us to see similarities between
groups that are superficially different. The pattern of conserved sites
develops a profile of sites likely to have been present in a common
ancestor. This allows us to group together some of the sets of NAD-type
dehydrogenases as being likely descendants of a common ancestor. Table
2. The same is true for some families of kinases, some families of
peptidases and the like. Table 3.Over one-third of all *E. coli*
proteins are orphans in that they have no sequence-related partner in
the *E. coli* genome. Our work aims to continue finding similarities
between small groups and orphan sequences to the point that we will be
able to list the kinds and numbers of ancestral proteins that are
realistically sufficient to generate a free-living cell.

We are also looking at molecular mechanisms of divergence during
evolution. One mechanism has been gene fusion. We have identified 82 of
*E. coli* genes that are composed of at least two genes that are found
singly in other organisms. Another mechanism of evolution has been
generation of new function with very little alteration in primary
sequence. We have found an example in *E.coli*. One of the groups of
sequence-similar proteins in E. coli has 25 members. Fourteen are
regulator proteins (repressors) and 4 are transport proteins of the
periplasmic binding protein type. The remainder are of unknown function.
This group is unusual in having two entirely different functions in one
sequence-related group. The repressors act as homodimers,the periplasmic
binding proteins as monomers. The repressors shut of transcription of a
specific operon in the DNA. The periplasmic binding proteins carry a
molecule to be transported across the periplasmic space and hands the
molecule over to a permease spanning the inner membrane. Yet they are in
the same sequence-related group. Both types of protein have the property
of changing conformation when they bind a specific small molecule. This
seems to be a case of visible evolution. Multiple alignment shows that
the main difference between the sequences in the group is the presence
or absence of a DNA-binding motif at the N-terminus of the proteins. The
rest of the alignments show similar conserved amino acids for both
repressors and transporters. Table 4. We can imagine, then, that an
ancestral binding protein, already capable of conformational change upon
binding a small molecule, somehow recombined with another protein or
underwent multiple mutational events and gained a DNA binding site at
the N-terminal end. Not many other changes were required to generate a
regulatory protein. Both transport and regulation are necessary to life,
and here we can see how closely related some are to a common ancestor.

A goal we are working on is to identify descendants of very ancient
proteins that are present in many contemporary organisms. We have
identified sequence-related sets of proteins in *Escherichia coli* that
seem likely to have arisen by gene duplication and subsequent
divergence. Some of these sequence-related sets we know are also present
in many other organisms, such as the ATP-binding subunit and the
membrane binding subunit of ABC transporter complexes and also the
sensor-regulator pairs of signal transduction proteins. These proteins
are likely to be descended from the very ancient proteins that formed
early in the process of evolution of cellular life. Identification and
analysis of these ancestrally-related proteins should tell us more about
the processes of the origin of life**.** We have carried out analysis of
the sequence-related sets of *E. coli.* Some sets are large, some small.
The proteins of the large sets remain detectably related presumably
because the proteins have not diverged very far from their ancestors
over millions of years. In *E. coli* generally speaking these large-set
proteins are the regulators and transporters. The smaller sets, as small
as simple pairs, are the consequence of so much divergence from the
starting point that we cannot see the sequence similarities of
descendants from their common ancestor proteins. These proteins we find
are largely enzymes in *E. coli.* Thus it is the transporters and
regulators that may be most informative in reconstructing early events
in protein evolution.

![](media/image3.pct){width="5.570833333333334in"
height="7.397222222222222in"}

Figure 1. Phylogeny of eukaryotes inferred from rDNA sequences inferred
using the minimum evolution/Kimura two-parameter corrected distance
method (PAUP\* 4.0). Divergence between sequences is indicated by
horizontal branchlengths (scale bar). Percentage bootstrap support (the
degree to which the groupings are supported by the data) is shown near
the branches. Genus and species names are shown for organisms whose
sequences were obtained in this study. All other organisms are indicated
by a higher taxonomic name in bold.

![](media/image4.pct){width="5.9944444444444445in"
height="7.715277777777778in"}

Figure 2. Phylogeny of eukaryotes inferred from alpha-tubulin sequences
inferred by the protein maximum likelihood method (PROTML). Bootstrap
values are shown near branches.

# The Pennsylvania State University

# PI: Hiroshi Ohmoto

The main goal of research at Penn State Astrobiology Research (PSARC) is
to increase our understanding of the connection (interplay) between the
environment and the biota on Earth, especially during the early stage of
its evolution. Attainment of this goal will greatly enhance our ability
to predict and identify life elsewhere in the solar system. Here we are
mainly concerned with the origin of life and the evolution and
extinction of important organisms (e.g., methanogenic bacteria,
cyanobacteria, eukaryotes, terrestrial organisms, and early animals).
The term "environment" refers specifically to the chemistry of the
atmosphere (especially, the concentration of CO~2~, CH~4~, CO, and O~2~)
the chemical and thermal structures of oceans and climate.

The above goal has been pursued primarily from multidisciplinary and
multidimensional research focused on the following five major problems:

The environment of prebiotic Earth and the origin of life: theoretical
and experimental approach. J. Kasting (Leader), M. Schoonen, R. Mionard,
and H. Ohmoto.

Roles of metals in the origins and evolution of life: Microbiological
and biochemical approach. J. Ferry (Leader), J. Brenchley, and S.
Brantley.

Timescale for early evolution of life on Earth: molecular evolutionary
approach. B. Hedges (Leader) and M. Nei.

Evolution of atmospheric O2, climate, and the terrestrial biosphere:
approaches from field-oriented geochemical investigations. L Kump
(Leader), H. Ohmoto, K. Freeman, M. Arthur, R. Capo, and B. Stewart.

Causes and consequences of the diversification and extinction of
metazoans: field, geochemical and paleontological investigations. M
Arthus (Leader), M. Patzrowsky, K. Freeman, L. Kump, H. Ohmoto, R. Capo,
and B. Stewart.

### Work and Research Accomplished During Year 1

Excellent progress has been made in all phases of our research projects.

Task I

Quantifying the effect of methane on climate on early Earth and Mars.
Quantifying the effects of zodiacal dust on planetary environments.
Structural analyses of hydrogen cyanide polymer. Experimental
investigation of the kinetics of CO-hydration. Hydrothermal experiments
on N~2~ reduction.

Evaluation of the catalytic effects of Ni-Fe-S clusters on the
transformation of CO to acetate. Hydrothermal experiments on reduction
of CO~2~ by the pyrite-pyrrhotite-magnetite assemblage.

Task II.

Structural analysis and synthesis of enzymes involved in ancient
metabolic pathways. Characterization of carbonic anhydrase in the Archea
and Bacteria. Isolation and characterization of novel psychrophilic
microorganisms from ice cores. Experimental investigation on reactions
between *Methanobacterium thermoautotrophicum* and Fe-Ni sulfide
minerals.

Task III.

Theoretical evaluation of statistical methods used in constructing
phylogenetic trees from molecular data. Compliation of genes useful to
studying the phylogenetic relationships of archae, eubacteria, protists,
plants, fungi, and animals and their evolutionary times. Establishing
the timescale for plants, animals, and fungi. Molecular evidence for the
early history of living vertebrates. Calibration of molecular clocks.

Task IV.

Geochemical modeling of oceanic anoxia. Ocean stagnation and the
end-Permian extinction. Search for new clues for the early rise of
atmoshperic oxygen. In-situ oxygen and lead isotope studies on
uraninites from \~2.4 Ga uraniferous conglomerates. Ce anomalies in
ancient sedimentary tocks. Discovery of the 2.6 Ga terrestrial biomats.
Provenance of 2.6 Ga paleosol carbonate from the Eastern Transvaal
district, South Africa. Paleosols and evolution of life on land.

Task V.

Oceanic oxic/anoxic interfaces and the Proterozoic sulfur cycle. The
modern oxic/anoxic interface. Sulfur isotope geochemistry of
Neoproterozoic strata in Mamibia. Constraints on the timing and cause of
the Cambrian explosion. Geochemistry of mesoproterozoic carbonates,
evaporites, and black shales. Chemostratigraphy of the Duitschland
Formation, South Africa.

## Education and Outreach Programs 

During the period of September 1998 to June 1999, PSARC organized 27
seminars on a variety of topics related to Astrobiology. Most of the
seminars were given by scientists from other institutions.

Three new graduate courses in Astrobiology were given in during the
first year. They are Geosc. 597B/Biol. 597B (2 credits): Astrobiology in
the Fall Semester of 1998, Geosc. 502 (3 cr.): Evolution of Biosphere in
the Spring Semester of 1999, and Geosc. 597F (1 cr.): Field
Investigations in Astrobiology in the Summer Semester of 1999.

Four biology courses were modified to meet the goal of PSARC. They are
Biol. 427 (3 cr.): Evolution, Biol. 405 (3 cr.): Molecular Evolution,
Biol. 514 (2 cr.): Topics in Evolution, and Biol. 505 (3 cr.):
Statistical Methods in Evolutionary Genetics.

For undergraduate education, two new undergraduate courses in
Astrobiology, one a general education course and the other a higher
level course, are scheduled to begin in the second year. Four freshman
women are currently mentored by three faculty members of PSARC under the
WISER (Women in Science and Engineering Research) program.

PSARC will hold Astrobiology Workshop for high school science teachers
(June 28-July 2, 1999) and participate in WISE Week for high school
students (July 19 -- July 23).

Other outreach activities by PSARC members include several presentations
on "Astrobiology" to elementary school children in the State College
Area School District. Plans are also being made for a large-scale
exhibition on Astrobiology at Carnegie Museum of Natural History in
Pittsburgh.

Martin Schoonen (SUNY) presented a lecture as part of the Geology Open
Night series at Stony Brook titled \"Prebiotic Soup is out, Minerals are
in!\"

### Work and Research Planned Year 2

Task I.

Alex Pavlov is currently updating the climate code by including new,
exponential sum absorption coefficients for CO~2~ and H~2~O, by changing
the flux calculation to a δ 2-stream method, and by changing the
convergence scheme from Newton's method to a time-stepping algorithm.
Once completed, the updated code will produce more accurate
stratospheric temperatures. This will allow us to generate realistic
synthetic spectra of O~3~- and CH~4~-rich atmospheres, which will
eventually be useful for NASA's proposed TPF (Terrestrial Planet Finder)
mission. The code will also be useful for calculating surface
temperatures in smog-covered early Earth atmospheres and in early
Martian atmospheres filled with IR-scattering CO~2~ clouds.

Work has been initiated on flow injection electrospray MS analysis to
study the base-catalyzed HCN polymerization in real time providing
structural information on the initially formed products. A refined
understanding of these initial oligomerization steps provides insight
into the structure of HCN polymer.

In the second year we will continue the CO-hydration kinetics study and
explore the role of minerals and dissolved metal ions. Post Doc Yong Xu
will work on the ammonia formation reaction and test the idea that
mineral surfaces may catalyze that reaction.

Future experiments will explore higher CO~2~ pressure, utilize QFM or
Fe-FeO redox buffers, and explore interactions between PPM and
CO-saturated solutions.

Task II.

Other enzymes involved in sulfur metabolism will be purified from the
methanoarchaea to verify and further document the pathways for sulfur
fixation and cysteine synthesis in the Archaea domain. Crystallization
trials will commence to identify conditions for obtaining crystals of CO
dehydrogenase/acetyl-CoA synthase suitable for structure determination.
Finally, the isolation of compounds from *M. thermoautotrophicum*
required for acquisition of nickel from pentlandite will be attempted.

Psychrophilic aerobes and anaerobes will be isolated from ice cores.
Phylogenetic analysis of these isolates is expected to place their
evolutionary origins.

We will be pursuing investigation of the extraction of Ni from
pentlandite by two well- characterized methanogens, and by a consortium
of methanogens isolated from a swamp in the southeastern U.S. This
latter consortium has been shown to be capable of extracting Ni from
pentlandite when grown in medium devoid of dissolved Ni. During this
year, we anticipate documenting that all these organisms can extract Ni
from minerals, and we hope to begin characterization of the mechanisms
of extraction.

We have also begun pursuing an investigation of bacterial mobilization
of Mo from silicate and sulfide minerals. As a test organism, we are
going to use Azotobacter vinelandii, a well-characterized soil microbe.
Azotobacter has a well-known need for Mo, but little is known about how
the organism extracts Mo from Mo-poor soils. We are setting up these
experiments in collaboration with Dr. Ariel Anbar, of the Univ. of
Rochester (Dr. Anbar is a participant in the NAI). Dr. Anbar has agreed
to measure the isotope signature of the Mo released during bacterial
growth so that we can ascertain if there is an isotopic shift for the
biologically released Mo as compared to abiotically released Mo. Dr.
Anbar is also working on the measurement of Ni isotopes and during this
year it may become possible to measure Ni isotopic shifts in our
experiments.

Task III.

During the second year, we plan to continue the theoretical studies and
computer simulations to refine statistical methods for estimating
divergence time. Particular emphasis will be placed on studying
duplicate genes that are common to all three domains of life, such as
tRNA synthetase genes. The laboratory studies of animal phyla will
continue and some initial results from those studies will be submitted
for publication. Special emphasis will be placed on those phyla not
currently being sequenced by the medical and genetic research community,
with the goal of being able to better test the Cambrian Explosion model
with a diversity of animal phyla. In collaboration with Hidemi Watanabe,
work will continue on estimating divergence times for Bacteria, Archaea,
and Eukaryota with sequences from the genome projects. Our baseline
study on vertebrate divergence times (Kumar and Hedges, 1998, A
molecular timescale for vertebrate evolution, Nature 392:917-920) will
be revisited during Year II now that considerably more sequence data are
available in the databases. Also, a web database of all evolutionary
divergence times (timescale database) will be initiated during Year II.

Task IV.

In the coming months we will be adding a complete treatment of the
carbon cycle (including inorganic carbon chemistry) and the sulfur
cycle, so that we can fully evaluate stagnation hypotheses for
extinctions (Permian) and perhaps glaciations (Neoproterozoic,
Ordovician). We also have been working on the causes of glaciation in
Earth history and their isotopic and geochemical record, with an initial
focus on the enigmatic Late Ordovician glaciation (Kump et al., 1999).
Future research will focus on the Huronian-era glaciation 2.5 Ga, with
fieldwork in Australia aimed at establishing an isotopic record of the
event that can be correlated worldwide. Finally, in support of our
fieldwork on paleosols, we are initiating the development of a
one-dimensional soil genesis model. The model will ultimately be used to
test the sensitivity of soil composition and weathering rates to changes
in upper boundary conditions, especially atmospheric composition
(especially the amounts of CO~2~, O~2~, and CH~4~) and climate. We will
be collaborating with Jon Chorover (Dept. Soil Science, Penn State) in
this endeavor. Such a model is sure to put our interpretations of
paleosol characteristics on a more quantitative footing.

In order to quantify the pO~2~ and pCO~2~ levels of the Atmosphere and
to identify the development of various types of organisms in the oceans
and on lands during the period of 3.5 Ga to 0.5 Ga, we will continue
geochemical investigations of the following rock sequences: (1). 2.7 Ga
red beds at Shevandowan, Ontario, Canada; (2) 3.0 Ga stromatolites and
paleosols at Steep Rock, Ontario, Canada; (3) 2.7 Ga paleosols at Mt.
Roe, Australia; (4) 3.0-2.4 Ga uraniferous quartz conglomerates in the
Witwatersrand, South Africa and in the Elliot Lake district, Canada; (5)
3.5-2.0 Ga shales and carbonates from South Africa, Australia, and
Canada; (6) 2.6-2.4 Ga banded iron formations in the Hamersley district,
Australia; and (7) \~0.7 Ga banded iron formation in Namibia

Task V.

Our research over the next 2 years focuses on developing an
understanding of sulfur and carbon cycling in the Proterozoic,
especially the origin of at least two very large positive carbon isotope
excursions in the Neoproterozic. Work will continue on samples collected
from Neoproterozoic Namibian strata. We have scheduled fieldwork in
August 1999 in the Adelaide geosyncline of Australia to sample strata of
equivalent age. We will collect an initial suite of samples to
demonstrate that there is coherence in sulfur isotopic trends for
Namibian and Australian rocks---i.e., that the signal is a global one.
Our work will provide constraints on the geochemical evolution of
seawater, particularly the timing of significant oxygenation of surface
waters and the timing and impact of dissolved oxygen penetration into
deeper-water masses.

Future simulations will incorporate supraspecific taxa (e.g., genera)
and will incorporate the most recent diversity data and timescale. The
current diversity curve is based on a global compilation of genus first
and last occurrences and is subject to severe sampling problems. We will
begin to compile a global database of marine macrofossil genus
occurrences for the Neoproterozoic through Cambrian in order to
alleviate this problem. Our new database will permit us to generate a
new sample-standardized diversity curve for this interval that is
relatively free of bias due to sampling intensity.

A major focus of our research for the second year will be Precambrian
paleosol sequences from Canada and Finland. This work will be carried
out primarily by graduate student Sherry Stafford. Samples have already
been collected from the Archean Steep Rock paleosol, Ontario, and the
Proterozoic Ville Marie paleosol, Quebec. We plan to do additional field
work at the Ville Marie site and to collect samples from the Proterozoic
Hokkalampi paleosol, Finland. These studies will involve careful
petrographic, geochemical and isotopic studies of preserved ancient
soils, and comparison with modern soils formed on similar parent
material in conjunction with Associate Members Oliver Chadwick
(University of California, Santa Barbara) and Robert Graham (University
of California, Riverside). Radiogenic isotopes will be used to help
differentiate between primary (pedogenic) processes and possible later
alteration by hydrothermal fluids. We will work with Associate Member
Gwen Macpherson (University of Kansas) to carry out *in situ* laser
ablation-ICP-MS trace element analyses on parent material and paleosol,
in order to constrain element mobilization processes during soil
formation, particularly those involving redox-sensitive element species.
This technique can also be used to pre-screen samples for U-Pb dating of
carbonate, which we hope to apply to Task V projects with Co-I Michael
Arthur.

# Scripps Research Institute

# PI: M. Reza Ghadiri

### Work and Research Accomplished During Year 1

A multidisciplinary research effort entitled: *Self-Reproducing
Molecular Systems and Darwinian Chemistry* has been established which is
directed at better understanding and discover of plausible factor that
may have led to the origins of life on earth and elsewhere in the
cosmos. During the first year of this program our multicentered research
tem (M. R. Ghadiri and J. Rebek at Scripps Research Institute; S. Benner
at the University of Florida; A. Ellington at University of
Texas-Austin; and C. Switzer at University of California-Riverside) has
made significant progress toward the proposed goals of the program
(*vida infra*).

Benner's group at the University of Florida has made major contributions
including a manuscript entitled *Organic Molecules on Mars? The NASA
Planetary Exploration Missions* suggesting that, contrary to the widely
held interpretation of experiments from the Viking 1976 landers, organic
molecules should be present on the surface of Mars^1^. Moreover, theory
and experiment have been exploited to show that the structures in the
Allan Hills meteorite are not too small to be remnants of life, if that
life is based on a single biopolymer capable eof both genetics and
catalysis. A 50-step metabolism for small cells has been proposed from
an understanding of organic reactivity^2^. Other important contribution
from Benner's laboratory largely funded from non-Astrobiology sources,
but central to the Astrobiology program's goal include: *Darwinian
Chemistry. A Quantitative Analysis of In Vitro Selection Experiments^3^*
which explores structure space in both functionalized and
non-functionalized nucleic acids which represents a substantial step in
their progress towards self-replicating systems in the laboratory: *The
Master Catalog. A Comprehensive Model for Life in Terrestrial
Biosphere*^4^ which is currently being analyzed to better understand the
microscopic processes by which proteins evolve; the *Universal Chemical
Features of Genetic Biopolymers*^5^ based on a second-generation model
of nucleic acids that emphasizes the importance of the polyanionic
nature of DNA as a genetic biopolymer.

Ellington's group is attempting to bridge the gap between the peptide
and RNA worlds by generating an interdependent set of self-replicating
nucleic acids and peptides. Such studies would serve to better identify
self-replicating molecular ensembles that may have been involved in the
origins of life on earth or be encountered on other planets. Their
objective is to reveal the extent to which sort oligopeptides could have
been involved in the earliest living terrestrial systems and the extent
to which peptides could have participated in error correction during
nucleic acid replication and vice versa. Toward these goals, Ellington's
group has been investigating the ability of peptides (based on fragments
of RNA binding protein called Rev) to act as a template for the ligation
of two RNA fragments -- derived from a previously in vitro evolved
35-nucleotide anti-REV protein aptamer. Encouraging preliminary results
indicate that when the RNA ligation reaction is conducted in the
presence of two forms of the Rev 17-reisedue peptides, sRevn and aRev, a
\>10 fold increase in the yield of full length aptamer is observed.
Other important contributions from Ellington laboratory which are not
funded by the Astrobiology sources, but central to our program's
objectives include approaches to replace natural amino acid monomers
with unnatural ones throughout an organism (dubbed "unColi") in order to
experimentally probe the question of non-natural life and bounds to
living systems.^6^

Ghadiri's group investigates molecular Darwinistic approach to the
origin of life issues by exploiting catalytic and self-replicating
peptide structures. The central goal of this research program is to
understand the molecular mechanisms that transform inanimate chemical
reactions into the animate chemistry of living systems. The approach has
been to rationally design and recreate various basic forms of
autocatalytic chemical networks in the laboratory and study how the
interplay of molecular information and nonlinear catalysis can lead to
self-organization and expression of emergent properties. Ghadiri and
coworkers have shown that short helical peptides can self-replicate, in
a template-dependant fashion, by catalyzing their own synthesis from
appropriately functionalized shorter peptide fragments and how such
species can be employed to construct self-organized (auto) catalytic
networks that can display some the of the basic properties often
associated with living systems such as selection, symbiosis, and error
correction. During the past year Ghadiri's group has developed *An
Exponential Replicator* fulfilling the structural and kinetic
requirements for the onset of Darwinian evolution; established the
*Emergence of a Peptide Replicator in High Salt* which highlights the
effects of environmental factors on template-directed catalysis; the
first description of *A Chiroselective Peptide Self-Replication*
addressing the important issue of origin of homochirality in terrestrial
proteins; and design, synthesis, and characterization of *A Reciprocal
Autocatalytic Peptide Network* which illustrates how self-reproduction
can emerge out of mutually autocatalytic set of chemical
reactions.^7-10^

Rebek's group is interested in investigation programmed recognition
processes in the context of relatively simple synthetic molecules. The
system currently under study features the sequence-specific pairing of
calixarene oligomers based on the heterodimerization preferences of
aryl- and sulfonylureas. ^11-12^ Initial strategies involved the
connection of recognition units to a rigid scaffold, which directed them
to a common face for complementary pairing in a DNA-like fashion.
Synthesis of the scaffold and several dimers have been performed, namely
the AA, AS, and SS systems. The target systems were characterized by
both 1H NMR and GPC. The sheer size of the dimers, with molecular
weights in the range of 9000-10000, made characterization difficult --
NMR spectra were complicated and the compounds could not be detected by
routine mass spectrometry. However, with the tools available, the dimers
appeared to be pairing in a \[2+2\] fashion, as opposed to forming
polymeric or even oligomeric (cyclic), assemblies. Rebek's group has
made several recent efforts to streamline and further characterize these
systems. A more synthetically-accessible, flexible scaffold has been
made that serves to address the degree of preorganization required for
programmed recognition of these assemblies. The AA, AS, and SS variants
have all been prepared and analysis using electrospray mass-spectrometry
and fluorescence techniques is underway.

Switzer's group is focused on the synthesis of alternative nucleic acids
(ANAs) in order to optimize polymer structures that are subject to the
constraints of prebiotic availability, template-directed reproduction,
replication conservative mutation, and fitness. Switzer laboratory is
currently examining the structures made up al all purine ANAs, altered
charge ANAs, and expanded nucleobase ANAs. During the past year they
have discovered an unprecedented pentaplex DNA structure which is
significant because strand association within nucleic acids was not
previously known beyond the tetrameric state.13 This work demonstrates
that some features common to terrestrial DNA provide artificial limits
on its structure and physical behavior. In particular, Switzer's group
has found that DNA strands incorporation runs of iso-guanine associate
to yield pentaplexes via nucleobase quintets in the presence of
monovalent cations, such as cesium ions. This finding not only does
expand DNA molecularity from four strands; it also raises the question
of whether it is possible to expand DNA molecularity even further.

### 

### 

### 

### Work and Research Planned Year 2

Our multidisciplinary research team will continue pushing forward
various programs directed at the better understanding of living
chemistry and its origins outlined in the original scope of out
proposal. Combined efforts at exploiting abiotic systems (Rebek's
group), natural and nucleic acid-based systems (Benner, Ellington,
Switzer), and peptide and protein-based designs (Ghadiri, Ellington) are
expected to yield new findings as well as help to expand our fundamental
understanding of factors that can contribute to the evolution of
biological information and genotypic and phenotypic properties
associated with living systems (*vide infra*).

Benner's laboratory will focus on the development of functionalized
standard and non-standard DNA molecules as the staring point for
generating biological function. The goal is to develop molecular systems
that can direct the synthesis of replicates with the possibility of
mutation, selection, and therefore, evolution. The principal technical
goal is to develop polymerases that accept non-standard and
functionalized nucleotides. We also hope to improve out contact with
other members of our Astrobiology group, especially with Andrew
Ellington, whose expertise in protein shuffling should speed the work of
developing polymerases. Further, we hope to improve our contacts with
other Astrobiology nodes, already initiated with Monica Riley
(exploitation of the Master Catalog) and Andrew Knoll (the possibility
of very small extraterrestrial living cells).

Ellington's laboratory hopes to determine how generalizable
peptide-induced RNA ligation events are. In particular, we will try
several different Rev-binding RNA molecules (the aptamer currently under
investigation, the wild-type Rev-binding element, and an aptamer
selected against the Rev peptide target, rather than against the protein
target) with several different peptides (sREVn, aRev, and a selected,
unnatural Rev-binding peptide). One of the most important considerations
is whether the peptide-induced ligation is specific. Specificity will be
assessed by carrying out couplings in the presence of non-cognate
peptides (the arginine-rich motifs from HIV-1 Tat and HTLV-I Rex) and
other cations (spermidine, arginine). Once they defined a specific,
peptide-induced ligation, they will turn their attention to determining
if nucleic acids can template peptide ligation. Our eventual goal is the
development of a 'conservative' mechanism for nucleic acid: peptide
replication, in which full-length peptide templates nucleic acid
ligation, and full-length nucleic acid conversely templates peptide
ligation. In addition, Ellington's group will examine the mechanism by
which the 'unColi' incorporates unnatural amino acids throughout its
proteome by isolating the mutant tryptophanyl tRNS synthetase and
characterization of its kinetics and substrate specificity. Moreover,
several additional attempts to generate other unnatural organisms have
been initiated. First, we have made a 'mini-operon' that includes the
permease and synthetase, and have mutated the operon to generate a
library of variants. Following introduction of the variants into the
parental auxotroph we will select for unColi that can incorporate other
tryptophan analogues, including 5-fluorotryptophan and
6-fluorotryptophan. Having multiple unColi that incorporate chemically
related monomers would allow us to compare the evolution of different
genes under similar selection pressures. We eventually hope to use a
'gene ship' technology to look at the overall patterns mRNA expression
in unColi.

Ghadiri's laboratory will focus its efforts in the next funding period
on two fronts: the establishment of an encoded 256-membered molecular
ecosystem and the design and analysis of an open flow reactor. The
ability to establish a functional molecular ecosystem will enable the
study of the behavior of a large collection of catalytic and
autocatalytic peptides, the process of self-organization, network
formation under a variety of reaction conditions and environmental
stimuli, and the phenomenon of emergence. Statistically, a large number
of possible interaction can be expected in a collection of 256 unique
peptide template sequences. Given pair-wise interaction (two body
networks), maximum of 32, 768 networks are possible -- more if multiple
body networks are involved. Therefore, there exists a great possibility
of discovering new forms of self-replicating peptides and higher order
processes of self-organization. Of particular interest is to see what
types of hierarchy of information processing would emerge. Would this
artificial molecular ecosystem reorganize (adapt) in response to changes
in its environment such as pH, ionic strength, temperature, etc. and
evolve to more fit systems? Clearly from the synthetic point of view,
there will be great challenge ahead of us in the coming year in
establishing a working molecular ecosystem. In parallel with the above
studies we will also construct a flow reactor in order to simulate and
enable monitoring of continuously evolving systems over long period of
time. All experiments will be monitored with the aid of high throughout
HPLC analysis and newly established MALDI mass spectrometry.

Rebek's laboratory in an effort to establish abiotic programmable
informational and self-organizing molecular systems will exploit
fluorescence-based techniques that have been widely used in the
biological realms for the study of protein structure and function. The
size and dynamics of our information systems are analogous to large
biomolecules, making their investigation of NMR at times inconclusive.
We intend to use fluorescence energy transfer strategies to investigate
such systems and their assembly processes. Simple "read-out" techniques
in the context of a simple calixarene-based heterodimeric assembly will
be investigated. The first involves quenching of a covalently appended
fluorophore, where intra-complex electron transfer only occurs following
formation of a dimeric structure. In the second example energy from an
excited donor is transferred non-radiatively to a nearby acceptor --
fluorescence resonance energy transfer. Each of these processes will
first be investigated in small model systems and ten extended to the
larger DNA-like assemblies described earlier. From here, the techniques
should be useful for studying an array of synthetic systems, from the
structure and dynamics of self-assembling informational polymers to
self-replication processes.

Switzer's laboratory will expand their activities in the area of
structures based on expanded nucleobases. They will explore molecular
recognition within pentaplexes, and the feasibility of creating DNA
hexaplexes (and beyond). Molecular recognition studies will address the
possibility of replication conservative mutation within these systems.
Switzer's group will also pursue aims (I) and (ii) and other aspects of
aim (iii) as outlined in the original proposal.

# 

# 

# University of California, Los Angeles

# PI: Bruce Runnegar

### Work and Research Accomplished During Year 1

Research within the Center for Astrobiology is focused on five main
themes: (1) the prediction, detection, and characterization of
extrasolar planetary systems that may be abodes for life; (2) the
geobiology and geochemistry of the oldest record of life on Earth and
Mars; (3) paleobiology of Earth's early life and the metabolic evolution
of early ecosystems; (4) genomic evolution, the tree of life, and the
fossil record of life on Earth; and (5) the detection of life in the
Solar System using meteorites and small space craft. As is explained
below, new strengths being developed for 2000 and beyond are: a major
thrust in microbial genomics that involves collaborations with NAI Penn
State and the Canadian Institute for Advanced Research (CIAR) at
Dalhousie University; a multi-disciplinary approach to understanding the
effects of Solar System dynamics on Earth's climate and life; and an
effort to understand the evolution of the carbon cycle from prebiotic to
modern times through laboratory experiments, numerical models and the
stratigraphic record in sedimentary rocks. Highlights of the work
underway are: (1) the discovery of a nearby cluster of young T Tauri
stars (TW Hydrae Association) that are in the process of forming
planets; (2) an assessment of the importance of lateral gene transfers
in the history of life through whole genome comparisons; (3) two
independent estimates of the flux of extraterrestrial material impacting
the early Earth; (4) measurements of the carbon isotopic compositions of
individual Precambrian microfossils and living hyperthermophiles; and
(5) the selection of a landing site for the Mars Polar Lander, currently
in transit to Mars.

## Discovery of a Nearby Cluster of Young T Tauri stars

Physics and Astronomy graduate student Richard A. Webb, together with
colleagues at UCLA and Yale University, has discovered five new T Tauri
systems comprised of seven stars and a brown dwarf that are only about
50 parsecs away and 10 million years old (Webb et al., 1999). Based on
their proper motions, high X-ray fluxes, and strong lithium absorption
bands in LRIS spectra, (Low-Resolution Imaging Spectrometer on the W.M.
Keck II telescope), the seven new young stars join 12 previously known T
Tauri stars in the TW Hydrae Association (TWA). This association is
unique in its proximity to Earth and its complete isolation from any
known molecular clouds.

## 

## 

## 

## Whole Genome Trees and the Evolutionary Role of Lateral Gene Transfers 

Comparisons of completely sequenced microbial genomes have demonstrated
that gene transfers between organisms have occurred throughout the
history of lift. Research by Maria C. Rivera and her colleagues in MCD
Biology and the Molecular Biology Institute has allowed genes to be
separated into two functional classes - informational (e.g., those
involved in DNA transcription and replication) and operational (e.g.,
those involved in metabolism). They were able to show that informational
genes are less subject to lateral gene transfer than are operational
genes and therefore more accurately record the long history of life
(Rivera, et al., 1998; Jain, et al., 1999). In a complementary study,
Microbiology and Molecular Genetics postdoctoral fellow Sorel T.
Fitz-Gibbon and Earth and Space Sciences graduate student Christopher H.
House have used the presence or absence of protein encoding genes in
thirteen complete microbial genomes to obtain a universal tree
(Fitz-Gibbon and House, 1999). Their work underscores the fact that
lateral gene transfer has not obliterated the phylogenetic signal from
modern genomes. Their tree is very similar to the one obtained using
only small subunit rRNA genes.

## Estimates of the Flux of Extraterrestrial Material Impacting the Early Earth

UC Presidential Postdoctoral Fellow Stephen J. Mojzsis and colleagues
form the University of Rochester, UC San Diego and NAI ARC have measured
iridium and platinum through a sedimentary succession \>3.8 billion
years old (Anbar et al., 1999). Even though this lies within the "late
heavy bombardment" period of Earth history, noble metals are not
abundant in these metamorphosed sediments. This suggests rapid
deposition and hospitable conditions between infrequent large impacts.
In contrast, IGPP Research Scienctist Frank T. Kyte and his colleagues
from UC San Diego, the Max-Planck Institute in Mainz, Stanford, and
Louisiana State use chromium isotopes to demonstrate that 3.5 billion
year old Barberton Mountain spherule beds were formed by large impacts.
They suggest that the heavy bombardment may have lasted until 3.2
billion years ago.

## Carbon Isotope Compositions of in situ Precambrian Microfossils and Modern Mesophiles and Hyperthermophiles

Christopher House, working with UCLA colleagues, has obtained precise
measurements of the carbon isotope compositions of individual
microfossils in cherts from the o.8 billion year old Bitter springs
Formation, central Australia, and the 2 billion year old Gunflint Iron
Formation of Canada (House et al., 1999). Different types of
microfossils have different isotopic compositions that average out to
give the bulk rock value. The older microfossils are lighter that the
younger ones. Parallel experiments involving modern mesophiles and
hyperthermophiles grown by House in Karl Stetter's facility in
Regensberg, Germany, are being used to interpret the
paleomicrobiological data.

## 

## 

## 

## 

## Mars Polar Lander Site Selection

The Mars Polar Lander successfully completed its second course
correction on March 15 and will remain on its current trajectory until
September 1, when the flight path will be targeted for a specific
landing zone near the south pole 217-225^0^W, 73-75^0^S). In the
interim, David Paige and his collaborators are using mages and data from
the Mariner 9, Viking, and Mars Global Surveyor missions to select a
suitable landing site. Three MGS instruments -- the Orbital Camera
(MOC), the Laser Altimeter (MOLA), and the Thermal Emission spectrometer
are providing crucial data for site selection. The MOLA results will be
used to assess the meter-scale roughness of the gently-sloping,
wind-ablated, layered terrain in the landing zone.

### Work and Research Planned Year 2

## Geochemical Signatures of Microorganisms and their Biomolecular Basis

This work will involve a close collaboration between Christopher House,
who is moving to a faculty position at Penn State; Sorel Fitz-Gibbon, a
CAB postdoc in Jeffrey Miller's laboratory at UCLA; James G. Ferry at
Penn State; and Karl Stetter, who holds joint appointments at the
University of Regensberg and UCLA. The plan is to use massive gene
expression experiments to investigate gene products that may be expected
to leave trace element or isotopic signatures in rocks. Crispin T.S.
Little, currently at the Natural History Museum, London will join the
project as a CAB postdoc. He is investigating the paleobiological record
of massive sulfides associated with ancient hot vents and sedimentary
exhalative ore deposits. Bruce Runnegar and J. William Schopf, in
conjunction with NAI colleagues and collaborators, will be studying
early Archean environments of this type in Western Australia during the
Summer of 1999.

## Metabolic Evolution of the Earliest Eukaryotes

In addition to the comparative genomics approach being used by the Lake
lab to address this question, Patricia Johnson at UCLA and Andrew Roger
at Dalhousie University, together with a CAB postdoc, plan to explore
Martin and Muller's "hydrogenosome" hypothesis for the origin or
eukaryotes. They will do this by locating and sequencing genes that are
expressed in hydrogenosomes -- mitochondrion-like bodies that lack any
relic of a genome. This research will complement planned investigations
of the fossil record of early eukaryotes in India and North America.

A third area of innovation is a multidisciplinary approach to carbon
cycle evolution as revealed through geochemical studies of abiotic
organic matter synthesis (manning, Mojzsis, LaTourette, and CAB graduate
student Alice Ormsbee); a continuing exploration of the oldest Earth
materials for evidence of carbonaceous matter (House, Mojzsis, Schopf,
Harrison, McKeegan); investigations of significant secular changes in
the coupled carbon-sulfur-oxygen-phosphate cycles by focusing on large
positive carbon isotope excursions (Runnegar, collaborator Matthew R.
Saltzman, University of Iowa, and potential CAB postdoc, Roberta
Hotinski); and matching long-period perturbations in the Earth's orbit
obtained from lengthy numerical integrations of Solar System dynamics
with striking features of the sedimentary record including impacts and
carbon isotope excursions (Runnegar and Research Scientist Ferenc
Varadi).

In addition to these areas of innovation, each of the topics that were
addressed during 1999 will be continued and extended. For example, an
object that may be in orbit about one of the nearby T Tauri stars (TWA
6) was imaged by the Hubble Space Telescope recently. If it is not a
background object it has a mass of about 5 Jupiters and thus would be,
by far, the smallest extrasolar "planet" so far imaged. When conditions
for new observations become acceptable in some month time, this will be
a focus of renewed activity. In the meantime, Zuckerman and Webb will go
to Chile to observe another possible cluster of nearby young stars.

## Ongoing NASA Instruments and Missions

UCLA Astrobiologists are intimately involved with new instruments and
ongoing NASA missions. The near infrared spectrometer, NIRSPEC, which
was constructed under IAN S. McLean's direction was delivered to the
Keck Observatory in Hawaii (SOFIA), directed by Eric E. Becklin should
begin flying in 2000. And Mission control for the Mars Polar Lander will
be in the new Science and Technology Research Building (STRB) on the
southern end of the UCLA campus when the spacecraft lands on December 3.

# University of Colorado

# P.I.: Bruce M. Jakosky

### Work and Research Accomplished During Year 1

Created a Center for Astrobiology at the University of Colorado, staffed

by a Professional Research Assistant, to oversee research, teaching, and

outreach activities.

Designed (but not yet implemented) an undergraduate and graduate

program in astrobiology. A new undergraduate course has been created and

will be taught each semester for the near future.

Participated in substantial outreach using public talks, interaction
with

the media, web sites, and web chats.

Obtained significant new results on the processes of formation of stars

(and implications for formation of planets) involving detection and
imaging

of protoplanetary disks around young stars, irradiated stars powered by

young stars and their disks, and photo-ablation of disks.

Developed new concepts on implementing the program for Direct Isolation

of Catalysts and Enzymes, in how to improve sensitivity of the technique

and to detect single molecules.

Carried out research on laboratory and modeling studies of the
condensation

of ice grains for understanding formation and radiative properties of
clouds,

and initiated collaborations for research on the chemistry of reducing

atmospheres and three-dimensional modeling of the circulation of
terrestrial-

planet atmospheres.

Work on the origin of gas exchange progressed with new insights into the

early evolution of stomata (the main and most common anatomical
structures

in land plants associated with aeration) and on the origin of water

conducting cells (with a key publication integrating paleobotanical
information with developmental studies of basal land plants)

Published initial results on geochemical energetics capable of
supporting

life on Mars, and began detailed follow-on analysis. Published results
from

Mars Global Surveyor mission and relevance to potential for life on
Mars.

### Work and Research Planned Year 2

Completion of first new faculty (Norman Pace) hire in astrobiology and
set-up of his RNA chemistry laboratory, and carry out search for second
new faculty hire.

Implementation of graduate certificate program in astrobiology, with
supporting graduate courses.

Obtaining spectroscopic observations of Orion\'s protoplanetary disks to
further test our models of their photo-destruction, including
acquisition of a velocity resolved data cube of the entire Orion Nebula,
obtaining spectra (with the Hubble Space Telescope) of the 300 nm bands
of OH as a direct test of UV induced photo-ablation, studying of the
growth rate of \`proto-planetary gravel\', and initiation of a large
scale imaging survey of all nearby star forming regions.

Investigate the chemistry of methane-rich atmospheres and determine the
role that impacts on Mars might play in maintaining an early greenhouse
atmosphere, both with an eye toward understanding the habitability of
Earth-like planets.

Begin implementation of DICE procedures and analysis of selection and
amplification of RNA catalysts, for understanding RNA world and origin
of life.

Continue analysis of geochemical availability of resources on Mars, in
particular the energy that can drive metabolism of possible organisms
and the availability of geochemical sources of elements needed to
support life.

Begin analysis of philosophical aspects of the search for life
elsewhere, including both the nature of scientific proof and the
implications for the martian meteorites and Mars sample return and the
connections between science and society.

Continue analysis begun this year of major events in the evolution of
life on Earth.

**NAI Virtual Collaboration**

The NAI has been chartered as a virtual institute \"without walls\"
whose members are geographically dispersed. Falling communication costs
make attainment of this objective possible, although there remains much
uncertainty regarding how to best map researcher work practices to our
emerging technology.

### Work Accomplished Year 1

At present there are eleven science teams, which in turn are composed of
teams that are at a further twenty or so additional geographic sites.
Collaboration were deployed in two venues in FY 1999, namely high
quality systems to conference rooms at the eleven lead sites, and lower
levels of support to people\'s computer desktops.

## Conference Rooms Systems 

Polycom videoconference systems and 60\" rear projection electronic
whiteboards from Smartboard were purchased, deployed and tested at the
eleven lead member sites. The video systems have been connected using
BRI-ISDN lines, which provides three ISDN lines per video unit. A
switching unit or \"bridge\" at JPL is used for multipoint 13-way
conferencing, which includes the eleven NAI lead sites, NASA HQ, and the
Centro de Astrobiologia in Spain. Microsoft Netmeeting is used on the
electronic whiteboards to allow shared viewing of presentations and
shared use and viewing of scientific applications software. Multipoint
Netmeeting data conferences are also done through a Netmeeting bridge at
JPL.

## Desktop Systems

The main tool deployed for desktop support is the Postdoc (post
document) file sharing system developed by the NASA Ames Research
Center. This software has been implemented as part of an internal NAI
Intranet website (URL http://nai.arc.nasa.gov). The Postdoc portion of
the site allows files to be posted to what is essentially an FTP system
that uses a web-based interface. Postdoc that acts as an extension of
the user's computer desktop by emulating the appearance of a personal
computer's file and folder system. Postdoc also allows creation of mail
lists. Mail sent through the lists is also archived for later viewing.

Netmeeting on Windows PC\'s and Timbuktu on Macintosh PC\'s are used to
support users working at their desks by enabling application sharing
between researchers. Netmeeting and Timbuktu can also be used by
researchers sitting at their desks to view from applications being run
on the whiteboards in the NAI conference rooms.

Some other desktop collaboration tools that are testing are use Real
Media video webcasts and use of tablet computers as a means of creating
and sharing chemical drawings during Netmeeting data conferences.

Telephones remain a critical element of the collaboration environment,
and are used both at the desktop and in the conference rooms.

## Collaboration Activities Conducted

The NAI videoconference and whiteboard systems were installed between
April and July 1999. So far these systems have been used for several
point to point discussions, including one seminar simultaneously viewed
at the Ames Research Center in California and the Johnson Space Center
in Texas, and for several eleven-way monthly video conferences amongst
the principal investigators that are largely of an administrative
nature. We are collectively experimenting with other ways to use the
systems effectively including multi-site seminars, topical science
discussions, and workshops, as well as use of Real Media webcasts of
these sessions to member desktops. By the end of 1999 we plan to conduct
three or four hours of video conferencing per week at each NAI lead
site, with remote interactions from the other member sites enabled via
telephone and web broadcast.

### Work Planned Year 2

By far the largest single activity during FY 2000 will be the
maintenance and operation of the existing base of NAI collaboration
resources. This includes paying for ISDN and data communications
charges, and equipment lease and maintenance fees, coordinating
videoconference operations, and the operation of the NAI Intranet
(Postdoc) server.

In FY 2000 we will operationally adopt use of Real Media video webcasts
to increase the flow of information to users unable to be present in one
of the NAI conference rooms. Member feedback from tests in FY 1999 was
very positive, particularly from sites that otherwise have not been able
to participate in NAI virtual interactions.

NAI technology studies in FY 2000 will shift from enhancement of
Postdoc, to co-funding the ScienceDesk project, which will be
responsible for development of NAI-specific science collaboration tools.

Studies to evaluate enhanced drawing tools for sharing information will
continue, as well as studies exploring conversion of video conference
systems from ISDN to IP networking in order to reduce costs. We will
also explore options for extending virtual interaction support to
researchers out in the field.

Expansion of NAI membership as a result of new grant awards generated
through a second CAN solicitation is expected to lead to acquisition of
several additional video conference, electronic whiteboards, and
associated communication services in FY 2000.

# NAI Education and Public Outreach

### Work Accomplished Year 1

The NASA Astrobiology Institute's Education and Public Outreach Office
simultaneously serves internal and external functions. In the first year
we committed ourselves to building a strong partnership with each member
institute to develop a comprehensive interest in educating the American
Public and the global community on the activities of the Institute and
the field of Astrobiology. Individual site visits to each principal
investigator, science team, and education and outreach group, and
monthly telecons allow us to support the specialized efforts of each
lead member institute. Each is engaged in a range of outreach
activities, according to their expertise, interest, the commitment of
researchers, and the needs/desires of their community. We are able to
generate new working relationships internally by providing introductions
and by disseminating information on individual plans and
implementations. The NAI Office uses a Project Performance database to
track these projects.

An important aspect of NAI's outreach is in supporting individual
members projects, coordinating projects to enhance their impact and
benefit, and assisting in the creation of institute-wide efforts. In the
first year the NASA Astrobiology Institute focused on educating both
public and professional communities on the organization and activities
of the institute. We created a traveling exhibit, print materials, an
interactive website, and represented the institute at over twelve
conferences and workshops nationwide. The exhibit has been on display
with accompanying NAI products at the American Astronomical Society,
International Society for the Study of the Origins of Life and
International Bioastronomy Conference (co-sponsored by Life Sciences).

We present the field of Astrobiology to the public with the emphasis on
the role of NAI in Astrobiology research, space missions, and technology
development. The Institute brochure introduces each lead member
institute and their research focus. A separate but visually linked
brochure describes the Astrobiology Roadmap, in brief. A series of
'one-pagers' providing a research synopsis of each lead member
institution is in preparation. The public receives print products
(developed by NAI and distributed to lead member institutions) at public
lectures, Open House Days, and at other outreach activities. The
pocketed large-size brochure is available to package document sets for
specific audiences, i.e. science, educators, media, public. We respond
to individual inquiries, and have prepared FAQs for students and
interested observers on our website. The attention that we pay to
Astrobiology's external constituencies pays off in improved public
understanding of Astrobiology topical content and its effective use in
classrooms.

The NASA Astrobiology Institute was featured to the education community
at the following conferences: The National Council of Teachers
Association, National Council of Teachers of Mathematics, Space Science
Institute, Bioastronomy Conference, and the upcoming National
Association of Biology Teachers. Educators were introduced to the field
of Astrobiology and the Institute through a series of printed products
produced by the NAI. The "Reaching For the Stars" tri-fold was created
specifically for educators to point out that Astrobiology is an ideal
theme for interdisciplinary studies. A companion "Resource List" was
developed to enrich their initial introduction to Astrobiology by
offering educators web references.

In our efforts to reach K-14 classrooms and partner with museums,
planetaria, and science/technology centers, associations have been
forged with multiple external curriculum development organizations. Both
TERC and SETI Institute are preparing high school Astrobiology
curricula, website(s), and multimedia products. Classroom of the Future
is producing a career video aimed at middle and high school students to
involve them in Astrobiology as a future career opportunity. The STELLAR
summer workshop, funded in part by NAI, is both creating lesson plans,
CD-ROMs, and website materials and providing guidance to interested lead
member institutions in 'how-to' produce such workshops in their locales.

Our Internet presence is complex and interactive.
(http://nai.arc.nasa.gov). The Internet site offers sections geared to
the interests of general visitors, educators, students, and the media.
Through featured articles presented on the home page and on line chats
linked by their themes, the site also offers interactive communication
via on-line Forum.

The NASA Astrobiology Institute believes in combining "outreach"
activities that reach beyond the confines of the scientific enterprise
with "in-reach" that coordinates the individual strengths of our various
partners is the most effective way to bring the enchantment of the
living universe to the attention of those who inhabit it.

### Work Planned Year 2

The NASA Astrobiology Institute's Postdoctoral Fellowship program will
be fully implemented this year. This an important contribution to the
Educational and Outreach program which is being administered by the
National Research Council.

The curriculum focus will be the TERC developed Educator Resource guide
focusing on Astrobiology in the classroom. This will be created with
input from each lead member institute with a focus on their area of
research. Also in cooperation with TERC a learning center for the NAI
website will be developed.

The Education and Public Outreach office of the NAI will continue to
bring Astrobiology to the public. This will be expanded by providing
model conference programs, trainings, and presentations nationally and
internationally.

#