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Table 1 Quotes confusing cross-catalysis with hypercyclic coupling

From: On the propagation of a conceptual error concerning hypercycles and cooperation

“They also showed that these types of peptides can symbiotically replicate each other through a hypercycle, with autocatalytic rate enhancements of several thousands over the background reactions” ([17], p. 420)
“Given the proximity of the Joyce and Ghadiri labs at the Scripps Research Institute, perhaps such crossreplicating nucleic acid and peptide hypercycles are already being born, either planned or unplanned” ([18], p. 14)
“A system containing two self-replicating coil peptides, R1 and R2, exhibited a form of symbiosis in which each sequence was able to catalyse the formation of the other.... the two replicators are not mutually exclusive, and a hypercyclic network is evident” ([19], p. 277)
“Since this initial breakthrough, chemists have devised increasingly complex cross-catalytic systems and are currently working on hypercycles, which are crosscomplementary self-replicating systems with more than twotemplate molecules. In these systems template A catalyzes the formation of template B, which catalyzes the formation of template C, etc., until the final template catalyzes the formation of template A to complete the cycle” ([20], p. 125104–2)
“self replicating peptides have been designed with many of the fundamental properties of living systems, including dynamic error correction, chiroselectivity and hypercycle catalytic networks.” ([21], p. 901)
“Diagram of a hypercycle in which two autocatalytic replicators, R1(E/N1) and R2(E/N2), are connected to each other via a cross-catalytic network. R1 catalyzes the formation of R2, as well as of itself, and vice versa, which prevents one replicator from overwhelming the other and enables the two to reproduce as a single coherent unit.... A hypercycle is a collective of two or more self-replicating species interlinked through a cyclic catalytic network. Lee et al. have designed a simple form of a hypercyclic network from two peptide replicators.... This mode of catalytic coupling prevents one replicator from overwhelming the other and unifies two otherwise competitive species into a single cooperative reproducing entity.” ([22], p. 461)
“Given that discrete peptides and organic compounds have been shown to be capable of self-replication, the emergence of novel properties from combinatorial libraries of such replicators can be readily imagined. As an example, Ghadiri and coworkers have shown the emergence of coupled hypercycles of replicating peptides” ([23], p. 258)
“This led to a mutualistic, interconnected cycle in which valine-substituted replicators could make isoleucine substituted replicators, and vice versa..... Peptide hypercycles. Green represents a peptide with, say, valine in a key position, while red represents a peptide with an isoleucine in the same position. Unlike nucleic acids, they are capable of efficient cross-replication” ([16], p. 362)
“For a peptide replicator, templating is less exact, so the formation of a mutant template is common. The mutant template can catalyze formation of mutant progeny or parental progeny, and the two species form a mutualistic network… The replication hypercycle consists of two intertwined polymerization and recombination cycles. In one cycle, polymerization of the short RNA fragments comprising the polymerase and recombinase occurs through primer extension and dissociation of sense/antisense strands. In the other cycle, the reconstituted recombinase stitches the RNA fragments. Recombination is directed by internal guide sequences, forming longer, more complex ribozymes” ([24], p. 2099)
“There must have been a different, better path to origins, perhaps via the evolution of a hypercyclic network rather than a single ribozyme” ([24], p. 2100)
“Hypercycles are unique in that individual reproductive cycles are connected by functional linkages. Within the context of the proposed hypercycle, short RNA fragments are replicated by the polymerase and then stitched together by the Azoarcus ribozyme. This obviates the requirement that a complex replicase spontaneously emerge from simple precursors as well as the need for the polymerase to act on structured templates. Thus, while neither species can efficiently self-replicate, each can survive in the context of the hypercycle. Envisioning this mutualistic network begs the problem of how to confine benefits to the two members of the network.” ([24], p. 2101)
“The three-membered cycle shown here resembles a hypercycle as envisioned previously but without hyperbolic growth.” ([14], p. 76)
“Vaidya et al. show that variants of such RNA fragments can assemble and act on one another to form cooperative self-assembly cycles very much like the proposed hypercycles, in which ribozyme 1 aids assembly of ribozyme 2; 2 aids 3; and 3 aids 1” ([15], p. 48–49)
  1. References from within quotations have been removed.