From: specimenNOSPAM@curioustaxon.omy.net   
      
   On 8/23/25 6:06 AM, MarkE wrote:   
   > On 22/08/2025 11:19 pm, RonO wrote:   
   >> On 8/21/2025 6:26 PM, MarkE wrote:   
   >>> A perspective on OoL from Dr. Edward T. Peltzer. Quotes following are   
   >>> interview excerpts.   
   >>> _______   
   >>>   
   >>> I did have many discussions with Miller and Bada on many subjects,   
   >>> but the issues of pre-biotic chemistry and the origin of life were   
   >>> the most common. Both were excellent chemists. You could ask them   
   >>> about almost anything and they would have an answer or know where one   
   >>> could look to find out. In some cases, I suspected they already knew,   
   >>> but wanted to give me the experience of scouring the library to find   
   >>> out. One could say that they taught me everything I new about   
   >>> prebiotic chemistry at the time.   
   >>>   
   >>> During his doctoral studies at the Scripps Institution of   
   >>> Oceanography (SIO), he was mentored by two luminaries in prebiotic   
   >>> chemistry: Stanley Miller, renowned for the Miller-Urey experiment   
   >>> simulating early Earth conditions, and Jeffrey Bada, an expert in the   
   >>> field of amino acid racemization and a prominent figure in the study   
   >>> of organic compounds in meteorites.   
   >>>   
   >>> As for the various individual [OoL] theories, here are a few of the   
   >>> fatal errors. Hydrothermal vents do not make organic compounds, they   
   >>> destroy them.   
   >>>   
   >>> Surface based synthesis might yield a few useful compounds, but many   
   >>> compounds with a diverse range of functionality are needed for the   
   >>> first organism. RNA is too unstable outside a living cell to offer   
   >>> much hope of it doing anything in the pre-biotic soup if somehow it   
   >>> was formed (which is exceptionally unlikely).   
   >>>   
   >>> My least favorite theory among all the options is the lipid world.   
   >>> Assuming that one could get a collection of similar chain length   
   >>> fatty acids bonded to glycerol to make triglycerides (which itself is   
   >>> highly unlikely in the pre-biotic soup of randomly generated   
   >>> compounds), then one could form an artificial vesicle (alternatively   
   >>> called a coacervate or liposome) with a lipid bilayer film. What you   
   >>> then have is not much more than a “soap bubble.” There is no interior   
   >>> metabolism, no ion- transport pathways in the “membrane”; it is   
   >>> nothing more than a film- coated droplet. How it would acquire an   
   >>> internal metabolism, etc., is anyone’s guess. But guesses, as   
   >>> entertaining as they might be, are not a scientific explanation of   
   >>> how life arose abiotically.   
   >>>   
   >>> Random undirected chemistry does not yield biopolymers. Organisms   
   >>> need proteins, DNA &/or RNA, polysaccharides, etc. These polymers are   
   >>> uniform in that they are composed of a monomeric class of compounds   
   >>> bound together in very specific ways: proteins are chains of amino   
   >>> acids linked by peptide bonds; DNA & RNA are chains of nucleotides   
   >>> linked by phosphate bridges; polysaccharides (e.g., starch &   
   >>> cellulose) are chains of glucose molecules linked by α-(1,4)   
   >>> glycosidic bonds in starch (amylose) and β-(1,4) glycosidic bonds in   
   >>> cellulose. Random, undirected chemical reactions do not yield these   
   >>> pure polymers. Instead, they yield polymers formed by random   
   >>> condensations of whatever compounds are at hand, producing high   
   >>> molecular weight compounds without a well-defined structure. Examples   
   >>> of this are fulvic and humic acids, melanoids, etc. Their structures   
   >>> are complex, involve monomers from a variety of compound classes and   
   >>> without a common bonding pattern. As such, they exhibit little to no   
   >>> biological activity and store no information.   
   >>>   
   >>> The biggest challenge of all will be to convince the folks who dream   
   >>> up the various theories for the origin of life to include the impact   
   >>> of competing reactions on their pathways as opposed to writing “just   
   >>> so stories.”   
   >>>   
   >>> The origin of homochirality (D-sugars, L-amino acids, etc.) has   
   >>> proved to be a difficult problem to solve. The goal needs to be   
   >>> chiral purity otherwise just a single wrong isomer can completely   
   >>> foul the functionality of the biopolymer (protein, DNA/RNA, etc.).   
   >>> Homochirality is always up against racemization, the process by which   
   >>> chiral molecules get mixed with their mirror images (enantiomers).   
   >>> Any such lack of purity among chiral molecules is deadly to life. All   
   >>> three of the proposed processes to achieve homochirality fail for   
   >>> such reasons. First, they are slow and only achieve a partial   
   >>> enrichment of the desired form. Second, racemization reactions work   
   >>> faster to undo this enrichment. What little progress is made is   
   >>> quickly lost. Third, the racemization rate increases with   
   >>> temperature. So, the condition needed to speed-up other synthesis   
   >>> processes works against homochirality. The source of homochirality   
   >>> remains an unsolved mystery.   
   >>>   
   >>> Another problem for abiotic synthesis is that some amino acids have   
   >>> two amino groups, and some have two carboxylic acid groups. This   
      
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