why not have a double helix crystalline form be precipitated in other worlds and solar systems. We see spectrographic dta of several of the nucleotides (ACGT and U) from star clusters waaaay out there.
That means that these nucleotides (and several proteins , are ubiquitous throughout the galaxy (and maybe the universe), but lets at least recognize the similarity of chemical components in our own
You wouldn't sniffle at CO2 or NH3 or CO or H2O as common compounds throughout space. AO why not several nucleotides??
Believe it or not that idea doesn't really bother me much, assuming you have some idea as to how far it can get you and how you'd go about it.
Part of the problem is stellar distances. If you scale our own system to have the radius of Pluto's orbit be about a yard, then the sun would be the width of a human hair and Alpha Centauri, the nearest thing involving main sequence stars, would be a bit more than four miles out yonder.
Thus, if your plan is to have the ingredients of life spread throughout our galaxy by floating around between star systems, it might take a sort of a long time...
Having ideas and archetypes float around from place to place might be faster and some claim that might be all it takes:
Rupert Sheldrake is another one of these guys you ought to know about on general principles.
Back to the book I was talking about and the theory in question... The claim is that our system was originally in two parts, a sun/Jupiter/Mercury part with spin axes (still) roughly perpendicular to the plane of the system, and a Saturn/Neptune/Mars/Earth part with spin axes now all roughly 26 degrees from perpendicular. The Sun/Jupiter system would have been bright, and the Saturn system would have been dark. Venus and Uranus of course are special/oddball cases.
The claim is that what we see on this planet now are remnants of what used to be a double living world: humans and dolphins and other creatures with smaller eyes for the bright world, and dinosaurs and hominids and others with much larger eyes adapted to life on a planet orbiting a brown dwarf star, with just a pale purple light.
What's funny is that the creatures of both parts of the thing are not only DNA/RNA based, but entirely similar in that the advanced creatures are/were all quadrupeds with two eyes, two nostrils, two ears, a mouth, a tail... In other words, a dinosaur or a hominid might look strange enough to us, but they don't really look "alien". And if you want to believe that both of those original living worlds evolved, then you need to explain how they evolved into roughly the same kinds of things by random chance.
The obvious conclusion appears to be that all living worlds, everywhere, are information-driven.