[AndrewC]

And if you're going to claim the lability of RNA prevents such an organism from existing, you have to address the objection that the organism had surely evolved a means to protect its RNA.

The objection is that the organism had to exist before it evolved a means to protect its RNA.

And of your examples, the longest is 46(23) residues, not much of a life precursor.

[Right Wing Professor]

The objection is that the organism had to exist before it evolved a means to protect its RNA.

There is strong evidence RNA predeced DNA; there's no evidence (and I think much reason to doubt) RNA was the first carrier of information.

And of your examples, the longest is 46(23) residues, not much of a life precursor.

If you search the database for DNA crystal structures, I doubt you'll find anything a whole lot longer. The small size is a result of the experimental difficulties of crystallizing and solving the structure of big bits of nucleic acid.