Jun 15 1978
From The Space Library
NASA announced that its scientists had apparently discovered a way to account for the formation on earth 4 billion yr ago of nucleic acids, one of two essential "building blocks of life." The discovery had followed earlier work by the same investigators (Dr. James Lawless, team leader at Ames Research Center; Dr. Edward Edelson, National Research Council fellow; and Lewis Manring, student at the Univ. of Santa Clara) that revealed a mechanism to explain the formation of the other critical building block, protein. Taken together, the findings answered a years-old question about the chemical evolution of life on earth.
Theorists had wondered how the building blocks of life, randomly scattered on the shores of primitive oceans, could continuously congregate and organize over millions of yr in concentrations high enough to produce living organisms. The explanation was found in substances common on the shores of primitive oceans: metal clays. Dr. Lawless had mixed low-concentration solutions of DNA-forming nucleotides with commonplace metal clays, and found that most clays attracted them. One type of metal clay containing zinc had preferentially attracted all six of the building blocks of DNA and RNA nucleotides. Especially significant was that zinc clay had attracted 97% of the nucleotide 5-prime adenosine monophosphate (AMP), most common DNA building block in living systems and essential precursor to ATP, the basic energy molecule present in every life form. Zinc also had been a constituent of the enzyme DNA polymerase, which linked DNA building blocks (nucleotides) in living cells; enzymes had acted as super catalysts, drastically speeding many life processes.
Dr. Lawless had done another experiment in which zinc clay had preferentially attracted the "5-prime" life-form over the "2-prime" and "3-prime" forms, the 5-prime form being the only one found in living organisms. The result had suggested a mechanism for incorporating this life-specific building block into the first DNA-like material.
Scientists had previously applied electric discharges or other energy release to ammonia, methane, and water vapor to produce small quantities of basic life molecules; however, until Lawless's discovery, they could not explain the behavior of life-building blocks in primordial water. Lawless's group would also try to show metal clays linking nucleotides into polynucleotides, the next step toward forming a DNA-like molecule. (NASA Release 78-85)
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