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One hypothesis is than the RNA predate DNA and even cells. Imagine a soup of RNA strings who replicate themselves. That said, this auto-replicating RNAs did not have been find on earth. Even an auto-replicating RNA is already too complex to be the fist steep. There may have been pre-RNA auto replicating molecules like TNA (not actually found too).

A path like: (pre-TNA world ?) -> (TNA world ?) -> RNA world -> Ribonucleoprotein world -> Simple cells & viruses with DNA & RNA

https://en.wikipedia.org/wiki/RNA_world https://www.ncbi.nlm.nih.gov/books/NBK26876/ https://www.newscientist.com/article/dn21335-before-dna-befo...

It's one of the steeps before the cells than may have come from outer space because we did not find trace of them on earth. The other hypothesis is than they have disappear since then, because of later steeps in life history like the Great Oxidation Event.