Bill wrote a speculative paper on the transition from inanimate molecules to simple living control systems, which was published in 1995: “The origins of purpose: The first metasystem transitions”. (The full citation is at the end of this post.)
I have just become aware of much earlier work and very recent work that supports this. It is too bad that Bill also was (evidently) unaware of the earlier work. Rich (1962) first proposed that RNA served for both replication (the function of DNA) as well as self-maintenance, meaning control to protect the structure of the molecule from disturbances and to restore it after disruption. White (1976) and Gilbert (1986) also deal with both replication and metabolism. Here is a quotation from Gilbert’s 1986 letter to Nature:
"UNTIL recently, when one thought of the varied molecular processes at the origin of life, one imagined that the first self replicating systems consisted of both RNA and protein. RNA
served to hold information, whereas protein molecules provided all the enzymic activities
needed to make copies of RNA and to reproduce themselves. The cycle that developed a
self-replicating system out of the primitive soup of amino acids and nucleotides had two
radically different components.
“Now it seems possible that the informational and catalytic properties of these two
components may be combined in a single molecular species.”
The most recent work, led by Elisa Biondi at the Foundation for Applied Molecular Evolution, demonstrated experimentally that long RNA molecules form when nucleoside triphosphates do nothing more than percolate through basaltic glass, which was abundant at the appropriate stage in the formation of the earth. A general account is in this Phys.org news bulletin. Many thanks to Dag for sending this to me.
This is strong support for the widely accepted hypothesis called RNA World. There is a good overview in the Wikipedia article about it.
The relevant planetary surfaces have been disrupted subducted by vulcanism and tectonic plate movements on earth, but on Mars the primordial basaltic glass is still intact on or near the surface, so one outcome of this research is to give some direction to NASA in their search for evidences of life on Mars. Bill would have loved that!
References:
Gilbert, W., 1986. Origin of life: The RNA world. Nature, 319(6055), pp.618-618.
Jerome, Craig A., Hyo-Joong Kim, Stephen J. Mojzsis, Steven A. Benner, & Elisa Biondi. (2022). Astrobiology 22.6 ahead of print. Mary Ann Liebert, Inc. DOI: 10.1089/ast.2022.00271 URL: https://www.liebertpub.com/doi/epdf/10.1089/ast.2022.0027
Rich A (1962) On the problems of evolution and biochemical information transfer. In Horizons in Biochemistry, edited by M. Kasha and B. Pullman, Academic Press, New York, NY, pp. 103–126.
White, H.B., 1976. Coenzymes as fossils of an earlier metabolic state. Journal of molecular evolution, 7(2), pp.101-104.
I also really like Bill Powers’ speculative (but very prescient and ahead-of-his-time) Origin of Life paper. The first two pages are especially interesting to me, about the asymmetry.
Bill Martin, quoted here, is a metabolism person who defends a theory of origins at alkaline hydrothermal vents. I think Bill Powers’ paper adds tremendous insights to origins with the point about deviation from inputs.
“‘This is a very exciting finding,’ says Martin, ‘not only because it maps out a new route to RNA-based peptide formation, but because it also uncovers new evolutionary significance to the naturally occurring modified bases of RNA.’ The results point to an important part played by RNA at the origins of life, but without requiring RNA alone to self-replicate, Martin adds."
“Amplification permits organisms to vary their actions by a large amount in response to small deviations of their inputs”. […] “For amplification to exist, there must come into being some process that can systematically draw on external energy sources to make energetically small causes into larger effects. In the chemical world, this would seem to suggest that the next step would be the appearance of catalysts. More likely, as catalysts would initially be only those that naturally occur, it would be the appearance of molecular species in which association and dissociation processes are catalyzed by existing substances, and whose reaction products (or other properties) affect the participation of catalysts in the reactions.”
The negative feedback discussed so far here holds between populations of molecules and their chemical environment. In these catalytic processes is the beginning of metabolism, which provides the internal source of energy that is used to amplify differences (error).
The ‘Origins of purpose’ paper can be paired profitably with Bill’s 2001 ‘Neglected phenomenon’ paper.
Harold Black at Bell Labs first worked out the mathematics of amplification (and negative-feedback control) and invented the electronic amplifier in 1927. The oral history shows how, like Bill, he had to go out on a limb more than once, pursuing questions that seemed to his employer to be of questionable value.
Thank you very much for sharing the “Neglected Phenomenon” paper! It really is a perfect companion read with the Origins of Purpose paper, and I look forward to reading the links to the history of amplidication and negative-feedback control. I am sharing this lecture, in case of interest. It has a very interesting account of the catalytic properties that could be given by native metals at alkaline hydrothermal vents. If pressed for time but still interested, you can look in at 30-35-minute mark to see what they have been able to recover in the lab. I think Powers’ papers can add considerable insight to this model that is different from the one he proposed. Thank you again for sharing the companion paper.
Excellent video! Thank you, Virginia. I am not trained in organic chemistry, but the argument is not that difficult to follow. Fascinating that the transition metals Fe, Md, Ni, Co, etc. are (in a sense, primitive) catalysts, and serpentinization catalyzes H20 releasing H2 for the (proto-metabolic?) chemical processes that produce more and more complex molecules. Among them, the origin of RNA is still considered speculative. Fascinating story line. Bring popcorn for the illustrative video clip near the end.
