One aspect of this question is exploring the possibility of self-replicating molecules. Is it possible that there could be a chemical compound which somehow reproduces itself?
This history of science admits of a number of “holy grail” quests, some of which have plausible claims to success, like the search for metallic hydrogen, and others of which have failed spectacularly, like attempts to isolate samples of phlogiston or aether. Other “holy grail” quests include the Grand Unified Theory (GUT) or the possibility of life outside of planet Earth.
Historically, such quests often trigger hasty claims, which must then be retracted. Such is the case with self-replicating molecules.
With barely-suppressed fanfare, an article titled “Oligoarginine peptides slow strand annealing and assist non-enzymatic RNA replication” appeared in June 2016. The authors wrote of “self-folding” molecules and the “self-assembly” of compounds.
The core motive of such research is the unstated subtext that self-reproducing non-living chemical structures could eventually lead to life.
Living structures reproduce themselves routinely. Non-living structures have never, so far, been observed to reproduce themselves.
The question for the philosophy of science is whether it is possible, even in principle, for a molecule to self-replicate.
The empirical question searches for instances of self-replication. The a priori question asks if such a thing is at all possible.
In any case, the particular publication mentioned above was retracted in October 2017. The article and its retraction both appear in the journal Nature Chemistry, edited by Stuart Cantrill. It was not the first, and will not be the last, overeager announcement of progress toward the discovery of a self-reproducing compound.
More promising than the observational task is the theoretical question. Without examining any particular chemical structure, the philosophy of science can ask what would be required to demonstrate the plausibility of the idea of a self-replicating molecule in general. Which general principles of covalent bonding, of ionic bonding, or of chemical reactions, etc., would indicate that it is at all possible, in principle, for there to be a self-replicating molecule?
It would be a mistake to confidently predict any outcome to this search - such predictions lead to retractions like the one mentioned above, made by Tony Jia, Albert Fahrenbach, Neha Kamat, Katarzyna Adamala, and Jack Szostak.
The fewer triumphalist claims on behalf of self-replicating compounds, the better.
