2003 Annual Science Report
Scripps Research Institute Reporting | JUL 2002 – JUN 2003
Benner - Self-Reproducing Molecular Systems and Darwinian Chemistry
The specific details of the organic chemistry that is found in the life that we know on Earth need not be universal. Nevertheless, the organic molecules that support life universally must have features that enable Darwinian evolution, believed to be the only mechanism for obtaining function from inanimate matter within the context of living systems. We have concluded a five year study that combines synthetic chemistry with studies of the structure of modern terrean biochemistry and genomics, set within the context of the types of environments that exist in the solar system, to ask what type of chemistry might support life. This has relevance to NASA missions, as it defines the kinds of biosignatures that they must seek. By expanding our understanding of the intimate connection between molecular reactivity and living processes, however, it supports a research strategy that moves forward in time from the most primitive replicating systems to complex life.
At the same time, the explosion of genome sequence information is enabling a research strategy that moves backwards in time from modern day life on Earth to antiquity. Extracting information about the historical past from genomic sequence data requires advanced models for how proteins and DNA change their sequence when these molecules are subjected to selection pressure. Coupling these models with laboratory experiments that resurrect proteins from extinct forms of life for study, this program has defined the temperature environments of some very early bacteria, correlated the emergence of new ecological strategies in fungi during the time of the dinosaurs, and explored the use of historical models to the understanding of human disease. Interactions within the evogenomics focus group have been critical to this effort.
Several of the specific advances are captured in the “highlights” section.
PROJECT INVESTIGATORS:Steven Benner
PROJECT MEMBERS:Tang Li
RELATED OBJECTIVES:Objective 1.1
Models of formation and evolution of habitable planets
Outer Solar System exploration
Sources of prebiotic materials and catalysts
Origins and evolution of functional biomolecules
Earth's early biosphere
Foundations of complex life
Effects of extraterrestrial events upon the biosphere
Environment-dependent, molecular evolution in microorganisms
Co-evolution of microbial communities
Biochemical adaptation to extreme environments
Adaptation and evolution of life beyond Earth
Biosignatures to be sought in Solar System materials
Biosignatures to be sought in nearby planetary systems