Path 11: Proteins-First (Peptide / Amyloid World)

Rationale: Life began with proteins or other poly-amino acids as the primary functional molecules, before genetic information. Short peptides could have formed and exhibited useful activities (like catalysis or self-aggregation), and only later did nucleic acids evolve to store the information to make proteins reliably. A variant posits self-replicating amyloid fibers (stacked beta-sheet proteins, like prions) as the first information-bearing polymers. Some peptides can self-assemble into repeating structures and even catalyze their own formation. For instance, certain small peptides (around 32 amino acids) have been shown to autocatalytically form by joining fragments – essentially a peptide making more of itself (studies by Ghadiri in the 1990s). Additionally, amyloid fibers (like those in prion diseases) template the conversion of other peptides into the same form, acting as an information carrier (the sequence isn’t copied, but the conformation is, which is a kind of record). Proteins are very versatile catalysts – perhaps early random peptides could assist reactions broadly, helping a protometabolism along even without exact genetic encoding. Freeman Dyson argued for a “double origin”: a primitive metabolism run by proteins and a separate replicating system later merged; this path focuses on the protein side emerging first.

Prerequisites: Amino acid polymerization under plausibly early conditions (e.g. thermal condensation on hot surfaces, peptide formation in drying lagoons, or with condensing agents like COS). Also, peptide chemistry and structural biology – understanding how and why certain sequences form stable structures (like beta-sheets) that could propagate.

Dependencies: Proteins-first doesn’t explain how to transmit information except via structural templating (which is limited). So it likely eventually tied in with RNA (maybe ribozymes and peptides co-evolved – the “RNA-peptide world” idea). It might rely on Path 1 or Path 5 to supply lots of amino acids and maybe Path 7 (minerals) to catalyze bonding.

Signs of Progress: Key experiments supporting this: Sidney Fox in the 1950s heated amino acids to get proteinoids that spontaneously formed cell-like microspheres and even showed catalytic activities (e.g. glycolysis-like reactions). More modern: demonstration of self-replicating peptide systems (e.g. a cyclic peptide that acts as a template for smaller fragments to come together into another copy). Another sign is evidence that pure peptides can exhibit heredity: recent studies found that certain amyloid fibrils can mutate and undergo selection in the test tube, behaving like genotype/phenotype combined. If a set of peptides can carry information (perhaps in their fold pattern) and undergo Darwinian evolution, that would be a breakthrough argument for this path. Partial support also comes from the ubiquitous role of peptides in modern enzyme cofactors (many enzymes require short peptides or their precursors), implying peptides may have been in the game early.

Base Camps

The original Deep Research document notes that detailed Base Camps for Path 11 “would follow similarly” to the first six paths (covering coacervates of amino acids, amyloid catalysis, and Dyson’s model) but were not fully enumerated in the source text due to length. The Inventory above provides the essential rationale and research directions.

Bibliography

(No separate path bibliography was provided for Path 11 in the source text; see the Hub page for cross-cutting references and the Partial Results section for relevant experimental findings.)