Re: Mineral surfaces as possible source of earliest life
Starting in the 1960s Cairns-Smith, at my alma mater the University of Glasgow, proposed that clay crystals were the first life.
A.G.Cairns-Smith "The origin of life and the nature of the primitive gene." Journal of Theoretical Biology Volume 10, Issue 1 January 1966
It is proposed that life on earth evolved through natural selection from inorganic crystals.
During the formation of a crystal, certain kinds of lattice imperfections usually replicate as a necessary part of the crystallization process. In so far as those imperfections that replicate are thus self-selecting, any crystallization process is likely to involve a rudimentary biological evolution. Under simple laboratory conditions, such evolution would be limited by the absence of any selection pressure for the elaboration of very complex imperfection patterns. In principle, however, the evolution of such genographs could proceed to high levels since, in the form of such patterns, many kinds of crystals could, in principle, hold very large amounts of information.
According to the specific theory that is proposed, the primitive genographs were patterns of substitutions in colloidal clay crystallites. (The theoretical information density in such a crystallite is comparable to that in DNA.) Evolution proceeded through selective elaboration of substitutional genographs that had survival value for the clay crystallites that held them (at first through genetically controlled adsorption of a “spectrum” of organic molecules) within a complex, dynamic, primitive environment. A gradual “take-over” of the control machinery by organic macromolecules—a genetic metamorphosis—is then considered to have occurred.
The arguments are based on general considerations leading first to the idea of some kind of genetic metamorphosis having occurred, and then to the conception of the primitive gene as a crystal. The specific (silicate) theory follows. Finally, a speculative outline is given for the main stages between the inorganic crystal and the first purely “organic” organisms.