Editing Openai/686aedb2-60b0-8003-98a8-e1766cf496a6 (section)

=== Assistant: Below is an appraisal of Islam & Powner’s 2017 review, framed around the three phrases that set off your “skeptic-meter… ===
Below is an appraisal of Islam & Powner’s 2017 review, framed around the three phrases that set off your “skeptic-meter.”

==== What the authors actually show ====
* They collate work (much of it from Sutherland’s group) in which simple feed-stock molecules such as HCN, formaldehyde and hydrogen sulfide give, in one reaction network, activated pyrimidine nucleotides, 12 proteinogenic amino-acid precursors, and glycerol phosphate—all without enzymes. They call this “cyanosulfidic protometabolism.” Prebiotic Systems Chemistry by …
* They highlight cases where molecules sort or purify themselves by crystallisation, sublimation, phase separation or volatility; e.g. ribose-configured amino-oxazoline (a nucleotide precursor) crystallises out of a messy mixture, removing unwanted isomers. Prebiotic Systems Chemistry by …

My take
* The chemistry really does “assemble itself” in the sense that no cell or polymeric catalyst is involved—only small molecules plus UV light, minerals, pH shifts, etc.
* But the phrase still oversells things: yields remain modest, conditions are hand-tuned (pH 7 buffer here, UV there), and no experiment yet produces a self-replicating macromolecule. So “self-assembly” means spontaneous under lab-imposed conditions, not spontaneous anywhere, anytime.

==== The phrase appears only in the one-paragraph “Bigger Picture” preamble, where they say future chemical systems “can self-assemble, process information, orchestrate reaction pathways…” Prebiotic Systems Chemistry by … ====

  The body of the paper never demonstrates information processing in the Shannon or genetic sense. The closest they get is:
* selective crystallisation of one stereoisomer over others (a rudimentary form of “selection”);
* phosphate-mediated interconversion of ribo- and arabino-configured intermediates, steering the pathway toward biologically relevant stereochemistry. Prebiotic Systems Chemistry by …

These are examples of chemical discrimination, not of storing and transforming symbolic information.

Bottom line: the claim is aspirational. Nothing in the review shows a prebiotic system reading, copying or transmitting a code.

==== Here the authors’ evidence is stronger: ====
* They document how one set of reagents (HCN + H₂S + Cu¹⁺/Cu²⁺ + light) feeds multiple branches that converge on nucleotide, amino-acid and lipid precursors with surprisingly little tar formation. Prebiotic Systems Chemistry by …
* Later sections show that simple additives (phosphate, urea) and physical separations (evaporation, crystallisation) can channel otherwise chaotic mixtures toward specific metabolites—“complexity overcoming clutter.” Prebiotic Systems Chemistry by …

Yet “orchestrate” is still anthropomorphic. What’s doing the “manipulating” is a carefully staged sequence of pH changes, UV irradiation windows, and mineral buffers chosen by the chemist. Remove that external choreography and the network reverts to sludge.

==== 1. Concrete chemistry, not arm-waving. The paper compiles hard-won routes to activated pyrimidine nucleotides that bypass the ribose-plus-base roadblock and reach millimolar yields Prebiotic Systems Chemistry by … . ====
# Network thinking. By showing common feed-stocks for lipids, amino acids and nucleotides, it narrows the gulf between “one molecule at a time” lab demos and the integrated metabolism life would need.
# Acknowledges clutter. Large portions of the review dissect why earlier approaches made tar and how selective steps (e.g., phosphate-controlled crystallisation) can purge it.

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==== Your worry that “complex molecules cannot create themselves” is, in part, semantic. In prebiotic chemistry selection pressures come from differential stability, solubility, photolysis, etc., not foresight. Powner and colleagues use teleological verbs (“orchestrate”, “choreograph”) as shorthand for these blind filters. When stripped of rhetoric, the claim is: under certain plausible early-Earth conditions, small-molecule reaction networks can spontaneously enrich the same building-blocks biology later used. That is a weaker, but still scientifically meaningful, statement. ====

===== Islam & Powner marshal impressive empirical progress toward cleaning up “prebiotic clutter,” but their headline language runs ahead of what has actually been shown. Self-assembly is demonstrated for intermediates, orchestration for limited networks; information processing remains an unfulfilled ambition. =====

If you want the field to move from metaphor to mechanics, the next milestones would be:
# Continuous, geologically credible settings that yield the same products without human scheduling.
# Autocatalytic or templated reactions that copy sequence information with measurable fidelity.
# Feedback coupling where one reaction branch actively modulates another (true “orchestration”).

Until then, treat the grander phrases as motivational banners, not settled fact.