2001 Annual Science Report
Scripps Research Institute Reporting | JUL 2000 – JUN 2001
Self-Replicating (BL) Molecular Systems and Darwinian Chemistry - Benner's Laboratory
Self-Replicating (BL) Molecular Systems and Darwinian Chemistry (dm)
Benner’s group has made major contributions towards the objectives set forward by the NASA Astrobiology Roadmap. These include: (a) Established the importance of hydrogen bonding in nucleobase pairing, a critical step towards guessing how non-terrean genetic systems might be detected, for example, on Mars and Europa. (b) Continued the development of polymerases to support in vitro selection with functionalized nucleic acids on an expanded genetic alphabet, directed towards generating in the laboratory artificial experimental models for life. (c) Developed an assay to detected at femtomole levels the organic molecules that are most likely to be near the surface of Mars and that are likely to be similar to a class of organic molecules on early Earth. (d) Worked with Mars mission planners (MEPAG) to design their search for the signatures of life on Mars. (e) Served on a panel to review planetary protection protocols. (f) Joined with the Ecogenomics Focus Group, extracting genomic clues that couple events in the molecular record with mass extinctions, paleoecology biosphere transitions, and planetary events that couple geology to genomics. Organized database of protein sequences containing a complete history of macromolecular life on Earth (as it can be presently inferred from genomic sequence data. (g) Developed sophisticated evolutionary models (non-stationary forms of gamma distributions, for example) that analyze change in function in microorganisms, in particular, in response to changes in microbial ecology and movement in and out of extreme environments.
PROJECT MEMBERS:Steven Benner
J. Michael Thomson
RELATED OBJECTIVES:Objective 1.0
Determine whether the atmosphere of the early Earth, hydrothermal systems or exogenous matter were significant sources of organic matter.
Develop and test plausible pathways by which ancient counterparts of membrane systems, proteins and nucleic acids were synthesized from simpler precursors and assembled into protocells.
Replicating, catalytic systems capable of evolution, and construct laboratory models of metabolism in primitive living systems.
Expand and interpret the genomic database of a select group of key microorganisms in order to reveal the history and dynamics of evolution.
Describe the sequences of causes and effects associated with the development of Earth's early biosphere and the global environment.
Define how ecophysiological processes structure microbial communities, influence their adaptation and evolution, and affect their detection on other planets.
Identify the environmental limits for life by examining biological adaptations to extremes in environmental conditions.
Search for evidence of ancient climates, extinct life and potential habitats for extant life on Mars.
Determine the presence of life's chemical precursors and potential habitats for life in the outer solar system.
Define climatological and geological effects upon the limits of habitable zones around the Sun and other stars to help define the frequency of habitable planets in the universe.
Define an array of astronomically detectable spectroscopic features that indicate habitable conditions and/or the presence of life on an extrasolar planet.
Model the future habitability of Earth by examining the interactions between the biosphere and the chemistry and radiation balance of the atmosphere.
Understand the human-directed processes by which life can migrate from one world to another.
Refine planetary protection guidelines and develop protection technology for human and robotic missions.