Some time last year, I found an article on Wikipedia about the smallest something to be able to reproduce.

I don't remember exactly what it was, but I am fairly certain that after the initial discovery another of the previous organism (this one slightly smaller) was discovered.

I think that the smallest something might have been the smallest self-replicating protein, or smallest self-replicating molecule, or something like that.

It was not mentioned in this thread: Which organism has the smallest genome length?

It had a strange, stand-out name and I believe it was discovered in the 90s.


You're probably thinking of the Spiegelman Monster. It was actually discovered in 1965, but it was discovered that it became shorter over time in 1997.

It also wasn't included in that thread, and it has a strange name.


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    $\begingroup$ I don't understand how this fits the criterion of 'self-replicating' since it seems to require the addition of a replicase enzyme to the in vitro system. $\endgroup$
    – Alan Boyd
    Jan 29 '14 at 10:22
  • $\begingroup$ @AlanBoyd Neither do I, but it seemed to fit (some of) the criteria, and I thought it was worth a shot. Apparently it was correct! $\endgroup$ Jan 29 '14 at 17:43

A research team (Lee et al.) has discovered what maybe the smallest known self replicating RNA molecule - actually a 32-unit-long "a-helical peptide" whatever that is. It is based on the yeast transcription factor GCN4. The 32 peptide sequence is so small, that one could describe it in text form simply as:


Two of those lines are likely to be pre-cursor molecules required (the food), and one is likely to be the RNA sequence, I think the final line.

This is a lot smaller than the smallest known or simplest genome, which could be Carsonella ruddii, which lives off sap-feeding insects, has taken the record for smallest genome with just 159,662 'letters' (or base pairs) of DNA and 182 protein-coding genes. Source: https://www.nature.com/news/2006/061009/full/news061009-10.html

Also, it's likely you should checkout this study: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4187685/ "Systems Biology Perspectives on Minimal and Simpler Cells "

  • $\begingroup$ The first part of this answer is complete nonsense. It talks about RNA and shows a peptide sequence, refers to a precursor as food, and quotes something called the journal of creation. $\endgroup$
    – David
    Jun 27 '19 at 6:53
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    $\begingroup$ Although this answer cites "creation.com" as the source and (as David says) includes some obvious gibberish, the actual source is a 1996 Nature paper A self-replicating peptide. It is, obviously, about a peptide rather than RNA. It is not particularly responsive to the question, but may still have some relevance. $\endgroup$
    – iayork
    Jun 27 '19 at 15:10
  • $\begingroup$ Fair call, I was too excited to quote that sequence, which I like a lot. It was good to learn about Spiegelman Monster, I should have taken a squiz at that: I'd agree the dwarf genome with only 218 bases AFAIK would be likely correct, because it is a organism whereas mine is just..... a "thing". Half correct. The question is wrong! :) $\endgroup$
    – Tomachi
    Jun 27 '19 at 18:17

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