Comment by pfdietz
6 days ago
It contains nucleobases. But does it contain ribose, or ribose linked to the nucleobases, or to phosphates? And more generally, does it also contain a grab bag of related chemicals that are not building blocks? The existence of such blocks as minor constituents of a soup of random chemicals doesn't mean much, especially as the concentration of any such constituent declines exponentially with its complexity.
https://www.nasa.gov/missions/osiris-rex/sugars-gum-stardust...
> The five-carbon sugar ribose and, for the first time in an extraterrestrial sample, six-carbon glucose were found.
The soup does matter, as does finding that the ingredients are everywhere.
Finding exponentially decreasing amounts of specific chemicals is about as informative as finding short words in strings of random letters.
Finding short words in strings of random letters at least establishes the existence of letters and words.
It doesn't demonstrate the existence of Shakespeare's works, but it's a building block that's good to know exists.
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It's a sample of one, but I think the takeaway is just that if the nucleobases are present on a random asteroid then they probably commonly occur. Of course as you note it takes a lot more than that to form these into nucleic acids.
I would guess there is a more primitive stage in the emergence of life where self-replicating soups (Kaufmann: metabolisms), including things like nucleobases and amino acids, capable of collective replication/expansion exist, before we get anything as sophisticated as nucleic acids and structural encoding.
The nucleobases can self polymerize into nucleic acids
Since nucleobases contain neither sugars nor phosphates, no they can't.
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