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Objectives

How Does Life Begin and Develop?

Objective 1
Sources of 0rganics on Earth

Objective 2
Origin of Life's Cellular Components

Objective 3
Models for Life

Objective 4
Genomic Clues to Evolution

Objective 5
Linking Planetary and Biological Evolution

Objective 6
Microbial Ecology

Does Life Exist Elsewhere in the Universe?

Objective 7
The Extremes of Life

Objective 8
Past and Present Life on Mars

Objective 9
Life's Precursors and Habitats in the Outer Solar System

Objective 10
Natural Migration of Life

Objective 11
Origin of Habitable Planets

Objective 12
Effects of Climate and Geology on Habitability

Objective 13
Extrasolar Biomarkers


What is Life's Future on Earth and Beyond?

Objective 14
Ecosystem Response to Rapid Environmental Change

Objective 15
Earth's Future Habitability

Objective 16
Bringing Life with Us beyond Earth

Objective 17
Planetary Protection


   

Question: How Does Life Begin and Evolve?
Genomic Clues to Evolution

Objective 4: Expand and interpret the genomic database of a select group of key microorganisms in order to reveal the history and dynamics of evolution.

 

Modern computational techniques in genomics and bioinformatics give exciting new insights into biological structure and function at all levels. Using these increasingly sophisticated techniques, detailed studies of evolutionary dynamics at the genome level should be conducted, ultimately to allow the reconstruction of the development of genetic complexity through evolutionary relationships. Recognizing that simple mutation and selection are not the sole drivers for evolutionary change, we must define the roles of mechanisms such as gene transfers between organisms, and gene duplication and gene rearrangement within an organism. Using the large array of databases now available, we must extend studies of individual gene families to previously uncharacterized microbial species. These studies, along with phylogenetic studies of evolutionary orthologues for key metabolic and information-processing systems in living cells, comparisons of sequences from discrete evolutionary lineages, and evolutionary studies of complex gene families within a single genome, will help determine when and how key biological functions arose and spread.

Implementation

Near- and mid-term:

  • Exploit the genomic databases that are already available, studying them in order to infer sequences of evolutionary steps and thus to estimate mechanisms (for example, duplication vs. transfer of genes). Notable progress for eukaryotic organisms can be expected using this approach.

  • Expand the databases by instituting a program of genomics focused on organisms representative of the metabolic diversity found among the prokaryotes. Full closure, with complete coverage of an organism's genome, is not required. Instead, information highly useful for the goals of the Astrobiology program can be obtained from the techniques of so-called "random genomics," in which accessible fragments resulting from diverse cleavages are sequenced.

  • Develop new information systems to organize and interpret molecular sequence data in order to determine the mechanisms, frequency, and impact of key molecular drivers of evolution.

Future Extensions:

  • This effort will contribute to a model for the evolutionary dynamics of microbial genomes, with potential applications that range from a reconciliation of biomolecular records of early life with geologic records, and also to enabling revolutionary new vistas in bioengineering.
         


Questions? Comments?

Responsible NASA Official:
Mary Voytek

Last Updated: October 27, 2014