Clays and the Origin of Life: The Experiments

Area of Science:

• Astrobiology
• Geochemistry
• Origin of Life Studies

Background:

• Current research on the origin of life is dominated by organic chemistry (Soup), molecular biology (RNA world), and inorganic chemistry (metabolism).
• Emerging data from Mars and carbonaceous chondrites highlight the potential significance of clay minerals in abiogenesis.
• Fe-clays, such as nontronite and ferrous saponites, were present on early Mars, prompting investigation into their role in Martian life's origin.

Purpose of the Study:

• To review the experimental findings and ongoing research concerning the role of clays in the origin of life.
• To investigate the catalytic potential of Fe-clays in the emergence and evolution of metabolism on Earth.
• To emphasize the importance of smectite-group clay minerals, including montmorillonite and nontronite, in origin of life research.

Main Methods:

• Review of experimental data on clay minerals and their interaction with organic molecules.
• Analysis of findings from Mars missions and carbonaceous chondrites concerning clay formation and composition.
• Focus on adsorption and polymerization of amino acids and nucleotides on clay surfaces.

Main Results:

• Discovery of chiral amino acids (e.g., isovaline) forming on clay mineral surfaces in carbonaceous chondrites.
• Evidence suggests amino acid formation from simple molecules (CO2, NH3, HCN) on clay surfaces.
• Organic molecules, including dicarboxylic acids and amino acids, can catalyze the formation of Fe-clays.

Conclusions:

• Clay minerals, particularly Fe-clays, played a significant role in the origin of life on Earth and potentially on Mars.
• Clays likely acted as catalysts for the formation of essential organic molecules like amino acids.
• Further experimental analysis is required to fully elucidate the catalytic functions of clays in abiogenesis and early metabolism.