Biochemical evolution III: Polymerization on organophilic silica-rich surfaces, crystal-chemical modeling, formation of first cells, and geological clues

Catalysis at organophilic silica-rich surfaces of zeolites and feldspars mi ght generate replicating biopolymers from simple chemicals supplied by mete orites, volcanic gases, and other geological sources. Crystal-chemical mode ling yielded packings for amino acids neatly encapsulated in 10-ring channe ls of the molecular sieve silicalite-ZSM-5-(mutinaite). Calculation of bind ing and activation energies for catalytic assembly into polymers is progres sing for a chemical composition with one catalytic Al-OH site per 25 neutra l Si tetrahedral sites. Internal channel intersections and external termina tions provide special stereochemical features suitable for complex organic species. Polymer migration along nano/micrometer channels of ancient weathe red feldspars, plus exploitation of phosphorus and various transition metal s in entrapped apatite and other microminerals, might have generated comple xes of replicating catalytic biomolecules, leading to primitive cellular or ganisms. The first cell wall might have been an internal mineral surface, f rom which the cell developed a protective biological cap emerging into a nu trient-rich "soup." Ultimately, the biological cap might have expanded into a complete cell wall, allowing mobility and colonization of energy-rich ch allenging environments. Electron microscopy of honeycomb channels inside,we athered feldspars of the Shap granite (northwest England) has revealed mode rn bacteria, perhaps indicative of Archean ones. All known early rocks were metamorphosed too highly during geologic time to permit simple survival of large pore zeolites, honeycombed feldspar, and encapsulated species. Possi ble microscopic clues to the proposed mineral adsorbents/catalysts are disc ussed for planning of systematic study of black cherts from weakly metamorp hosed Archaean sediments.