Comment You could also get started with two molecules ... (Score 2) 127
You could also start with:
- two molecules that (moderately) accurately copied each other (though getting them both at the same time makes the time scale to the big event much longer.)
- A molecule that makes NEARLY always inacurate (but occasionally acurate and complete) copies of itself. (This also drastically pulls in the time to a two-molecule solution.)
- A molecule that makes inaccurate copies but with string of typical errors that occasionally loops back to an accurate and complete (mod a few errors in unimportant places) copy of a previous version.
These could eventually mutate into a version that can perform a one-step copy-itself loop.
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I've always been partial to an RNA-only origin. RNA can do it all (self-copy, enzymes, energy transport batteries in at least two sizes with self-pluggin-in connectors: ATP/ADP and UTP/UDP, expression regulation, directed genetic code editing, etc.). It's also still doing a lot of that in current lifeforms, especially in key parts (such as many of the components of the DNA duplication, DNA repair, DNA-to-MRNA copy, gene expression regulation, MRNA exon-eliminating editing, and MRNA directed protein synthesis machinery)