Uracil found in carbonaceous asteroid

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In summary, This sample of Uracil, one of the four nucleobases in ribonucleic acid, was detected in aqueous extracts from the near-Earth carbonaceous asteroid Ryugu. This suggests that prebiotic molecules commonly form on carbonaceous asteroids and were delivered to the early Earth.
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Extraterrestrial origin of a sample of Uracil, one of the four bases of RNA. Would imply biochemistry and therefore life is common across the universe, just needing an environment in which to evolve:

Abstract:
The pristine sample from the near-Earth carbonaceous asteroid (162173) Ryugu collected by the Hayabusa2 spacecraft enabled us to analyze the pristine extraterrestrial material without uncontrolled exposure to the Earth’s atmosphere and biosphere. The initial analysis team for the soluble organic matter reported the detection of wide variety of organic molecules including racemic amino acids in the Ryugu samples. Here we report the detection of uracil, one of the four nucleobases in ribonucleic acid, in aqueous extracts from Ryugu samples. In addition, nicotinic acid (niacin, a B3 vitamer), its derivatives, and imidazoles were detected in search for nitrogen heterocyclic molecules. The observed difference in the concentration of uracil between A0106 and C0107 may be related to the possible differences in the degree of alteration induced by energetic particles such as ultraviolet photons and cosmic rays. The present study strongly suggests that such molecules of prebiotic interest commonly formed in carbonaceous asteroids including Ryugu and were delivered to the early Earth.https://www.nature.com/articles/s41467-023-36904-3.pdf
 
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BWV said:
Extraterrestrial origin of a sample of Uracil, one of the four bases of RNA. Would imply biochemistry and therefore life is common across the universe, just needing an environment in which to evolve:

Abstract:
The pristine sample from the near-Earth carbonaceous asteroid (162173) Ryugu collected by the Hayabusa2 spacecraft enabled us to analyze the pristine extraterrestrial material without uncontrolled exposure to the Earth’s atmosphere and biosphere. The initial analysis team for the soluble organic matter reported the detection of wide variety of organic molecules including racemic amino acids in the Ryugu samples. Here we report the detection of uracil, one of the four nucleobases in ribonucleic acid, in aqueous extracts from Ryugu samples. In addition, nicotinic acid (niacin, a B3 vitamer), its derivatives, and imidazoles were detected in search for nitrogen heterocyclic molecules. The observed difference in the concentration of uracil between A0106 and C0107 may be related to the possible differences in the degree of alteration induced by energetic particles such as ultraviolet photons and cosmic rays. The present study strongly suggests that such molecules of prebiotic interest commonly formed in carbonaceous asteroids including Ryugu and were delivered to the early Earth.https://www.nature.com/articles/s41467-023-36904-3.pdf
Thanks @BWV , I came across this post looking for black holes!Just a quick note on Hayabusa https://en.wikipedia.org/wiki/Hayabusa2 Worth reading.

Philae had similar ambitions if you recall https://en.wikipedia.org/wiki/Philae_(spacecraft)

in terms of Uracil RNA and abiogenesis it is worth checking this out. https://www.ncbi.nlm.nih.gov/books/...t RNA preceded,gradually been replaced by RNA.

@Bill has posted on origin of life mechanisms including this including a talk by Nick Lane, where he pretty much dismissed this the delivery of these organic building blocks as an important step to abiogenesis.He prefers looking a mechanism here on earth for the origin of life.

Also Bill Martin.

https://www.physicsforums.com/threads/origin-of-life-chemistry-interview-with-bill-martin.1050731/

https://www.physicsforums.com/threads/nick-lanes-on-sean-carrolls-podcast.1016752/

Intuition tells me these delivery systems must have played a part somewhere but then my experience tells me that nature does not care too much about human intuition.
 
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My understanding is two camps exist - replication first or metabolism first. This evidence would speak to replication first, so the metabolism camp (Nick Lane) is hostile?
 
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BWV said:
My understanding is two camps exist - replication first or metabolism first. This evidence would speak to replication first, so the metabolism camp (Nick Lane) is hostile?
I think the word hostile is probably overstating it. He cites Laplace, "I have no need of that hypothesis."
It was not part of his talk, it comes up in the Q&A.

I was surprised myself, all those precursors just lying around waiting to be synthesized.
I thought the theory would involve both in some way, the engine evolves from an RNA type molecule that was brought here by a meteor.
Rather than an either or situation.
 
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pinball1970 said:
I think the word hostile is probably overstating it. He cites Laplace, "I have no need of that hypothesis."
It was not part of his talk, it comes up in the Q&A.

I was surprised myself, all those precursors just lying around waiting to be synthesized.
I thought the theory would involve both in some way, the engine evolves from an RNA type molecule that was brought here by a meteor.
Rather than an either or situation.
Did the early earth have concentrations of carbon similar to the asteroid? if so, then this find may show that its easy to get these complex molecules given carbon and an energy source rather than demonstrating that life was 'seeded' by an asteroid. Either way, it does indicate that extraterrestrial life (at least in simple forms) may be abundant
 
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BWV said:
Did the early earth have concentrations of carbon similar to the asteroid? if so, then this find may show that its easy to get these complex molecules given carbon and an energy source rather than demonstrating that life was 'seeded' by an asteroid. Either way, it does indicate that extraterrestrial life (at least in simple forms) may be abundant
We need @davenn for composition side. Dave?
 
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Camps and Hostility
BWV said:
My understanding is two camps exist - replication first or metabolism first. This evidence would speak to replication first, so the metabolism camp (Nick Lane) is hostile?
There are many camps, including RNA first, metabolism first, and compartment first (or lipid first or something like that). These are what I consider the three main subsystems of animated (Or autopoietic) chemical systems. They are all ultimately needed for a functional and self-sustaining system. There are also others. when you talking about first, the first has to be with respect to something (like being alive or ??).
Since I don't know of an agreed upon life definition, I don't think these are fruitful arguments to get into.

From what I have read of Nick Lane he is not really hostile to RNA firsters, but thinks their emphasis is wrong.
Nick Lane, Mitchell, and others like them came along after the RNA hypothesis was proposed (by Crick in the 1960s or 1970s, I think). They might have been considered interlopers of the RNAers. Some of them can be nasty on occasion.

Organic Synthesis and it Location
pinball1970 said:
Nick Lane, where he pretty much dismissed this the delivery of these organic building blocks as an important step to abiogenesis.
He prefers looking a mechanism here on earth for the origin of life.
I don't think Lane is just dismissing the non-terrestrial synthesis of organic molecules (but not really denying it).
  • He does not think it is necessary for the mechanisms he likes.
  • He has doubts that there would be enough organic chemicals falling to earth, after being diluted in the ocean, to be able to drive any biochemical reactions to any reasonable extent. Especially without some containment (or compartmentalizing or isolating) mechanisms to prevent things from diffusing away.
  • He wants to avoid relying on non-terrestrially produced organic chemicals because they provide an undesired fallback which he would rather avoid (thus letting his theory stand on its own rather than rely on a space origin).
  • The mechanisms Lane and Martin seem to like are small local (in situ) organic synthesis sites, in small contained spaces, where concentrations can build up and lead to other secondary reactions.
It is also helpful to any scheme of early chemical synthesis to have a source of chemicals and energy to drive dynamic reactions. Chemicals at thermodynamic equilibrium are not going to do much reacting to make new larger chemicals. some hypotheses involving geochemistry (like alkaline hydrothermal vents) have this.

Early Conditions
Nucleic Acid production used to be considered a difficulty for prebiotic chemistry, but not so much now.

Many people often think of prebiotic conditions as a few kinds of chemicals which could catalyze themselves to make bigger and better cooperating collections of molecules. Catalysis modifies reaction kinetics, but does not change thermodynamic conditions which actually drive reactions.

It now seems likely that geochemical processes (like serpentinization and the actions of natural catalysts) would produce a complex mix of organic chemicals including parts of core metabolism (the Krebs cycle) and some other molecules derived from the (like membrane lipids) all at once. There is no good reason for pure collections of molecules to arise. This is now known as dirty chemistry, another camp maybe.
 
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BWV said:
Would imply biochemistry and therefore life is common across the universe,
I'm not sure I agree wityh that,. You can make the same argumenty for carbon, Or protons. :smile:

I think it does improve the odds, in the same way as finding so many exoplanets improves the odds, and indeed life may be common - or not.
 
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