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Ryugu asteroid samples contain all DNA and RNA building blocks

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Re: Ryugu asteroid samples contain all DNA and RNA building blocks

#91

Post by GetTheFacts »

vpribish wrote: post #83
general_reveal wrote: post #80

Earlier quoted context omitted.

[flagged]

pray tell, where do we learn this simple truth?

>pray tell, where do we learn this simple truth?

Praying[0] is a good start! That, coupled with large amounts of suspension of disbelief[1] helps too.

I suggest drinking (or whatever your preferred brain-fogger might be) heavily. That helps you ignore the details -- because the "devil is in the details" and we mustn't have that, right?

[0] Also known as "begging an imaginary sky daddy for help"

[1] https://en.wikipedia.org/wiki/Suspension_of_disbelief

Re: Ryugu asteroid samples contain all DNA and RNA building blocks

#92

Post by nomel »

adrian_b wrote: post #77
marcosdumay wrote: post #61

Earlier quoted context omitted.

We know 2 things that are apparently incoherent: 1 - Abiogenesis is incredibly rare. We don't know how much exactly, but it's a lot. 2 - Abiogenesis happened on Earth about as soon as it became possible. Where "as soon as" means within half a billion years, but it's still way quicker than its rarity implies. A lot of people think panspermia is what made those two happen. Life had about a full billion years to appear…

Life cannot appear in any of the small bodies that become meteors, because there is no source of energy for it. Life can appear only on big planets or on big satellites, like the big satellites of Jupiter and Saturn, if they have a hot interior and volcanism. Volcanism brings at the surface substances that are in chemical equilibrium at the high temperatures of the interior, but which are no longer at chemical equili…

> because there is no source of energy for it.

Couldn't it have started in the accretion disk?

Re: Ryugu asteroid samples contain all DNA and RNA building blocks

#93

Post by [deleted] »

0x000xca0xfe wrote: post #8

One longstanding theory is that life first began on Earth when asteroids carrying fundamental elements crashed into our planet long ago. I'm no expert but this sounds strange. Surely those fundamental elements would also form in vast quantities on their own on an entire planet with volcanoes and oceans? Wouldn't a couple asteroids be the literal drop in the ocean in comparison? The missing part is how do they form se…

[deleted]

Re: Ryugu asteroid samples contain all DNA and RNA building blocks

#94

Post by gus_massa »

adrian_b wrote: post #70
make3 wrote: post #34

Earlier quoted context omitted.

read up on the RNA world theory, it's so cool

Parts of the RNA world theory are correct, but other parts are completely bogus and completely illogical. What is correct is that RNA must have existed a very long time before DNA, during which RNA was the only nucleic acid. Moreover, self-replicating RNA must have existed before ribosomes and proteins (where "protein" means a polypeptide that is synthesized using a RNA template). It should be obvious that neither ri…

I read a few times your comment and I went from "Nah" to "It makes a lot of sense". I'm adding the "ATP word" to my list of interesting ideas.

Some related stuff:

* https://www.science.org/doi/10.1126/science.adt2760 They made RNA that copies itself, but it use as a starting point activated triplets of bases. i.e, if ATP is AR-PPP, they use a mix of something compounds like AR-P-AR-P-AR-PPP that stil have the triphosphate to store energy and be easy to link, but already have tree linked bases. This is even more difficult that a soup of ATP and friends.

* https://en.wikipedia.org/wiki/PAH_world_hypothesis The idea is that before the RNA word, there was something simpler, like this. Is it possible to use ATP to build more PAH? I also remember about a version of RNA that instead of ribose it used something smaller (glicerol?), but I can't find it.

Re: Ryugu asteroid samples contain all DNA and RNA building blocks

#95

Post by georgemcbay »

shevy-java wrote: post #65

That's not really new. It seems as if some people try to project "there is life outside of planet Earth". Well, the thing is ... is this question important? You already have life here. Synthetic biology will also progress. So why is it important if life is anywhere else? I don't understand it. There is nothing magic in RNA or DNA. Granted, right now we can not easily explain how life gets "bootstrapped", but recently…

> It seems as if some people try to project "there is life outside of planet Earth". Well, the thing is ... is this question important? You already have life here.

How common the building blocks of life are out in the universe has important implications for open questions like the intersection of the Drake Equation and the Fermi paradox which has likely relevance to our own future here on Earth.

...though I happen to think what we know so far isn't comforting in the sense that the building blocks of life do appear to be very common and the most likely reason that we have to ask "Where is everybody?" in spite of that is that the Great Filter is probably expansionist self-destruction of the sort we are currently speed-running as a society.

Re: Ryugu asteroid samples contain all DNA and RNA building blocks

#96

Post by api »

I’ve wondered before if the idea that life originated on Earth might be the last geocentrism to fall.

Speculation of course, but it would fit a certain historical pattern.

Maybe life is all over the damn place, just a thing that happens under certain thermodynamic constraints, and it arrived on board comets or some similar mechanism.

Maybe space contains spores of minimal super simple organisms that can survive being vacuum freeze dried for incredibly long periods of time. When they land somewhere suitable they do stuff.

Maybe life originated long, long ago. The wildest speculation I have is that it originated shortly after the big bang during a brief period when the temperature of the universe was temperate, but that’s very far fetched for numerous reasons. More likely that it pops up from time to time and spreads over cosmic time scales.

But it only evolves to high levels of complexity in environments that are very friendly to a lot of life, have abundant energy, and are stable enough for a very long time. That may be the rare thing.

Re: Ryugu asteroid samples contain all DNA and RNA building blocks

#97

Post by bahmboo »

lazide wrote: post #37
BinaryAsteroid wrote: post #32

Earlier quoted context omitted.

The timing of the delivery is what's important here. These building blocks, organic matter, and water would have been depleted in the proto-Earth due to Solar irradiation. There needs to be some mechanism that delivers these ingredients from the outer Solar System. Bombardment by smaller rocks makes the most sense, and was likely triggered by the migration of Giant Planets, leading to a period of heavy bombardment (o…

Huh? Those smaller rocks would be even more irradiated, as they have no atmosphere? They’d also have to contend with re-entry.

Meteorites are generally cold when they reach the surface of the earth. The heat of reentry is very brief and generally just on the surface. That's my understanding.

Re: Ryugu asteroid samples contain all DNA and RNA building blocks

#98

Post by dylan604 »

foxglacier wrote: post #88
adrian_b wrote: post #58

Earlier quoted context omitted.

Atmospheric entry is completely relevant because some people have made the illogical claim that meteorites falling on Earth could have contributed with such complex organic substances, like the nucleobases, to the appearance of life on Earth. The icy bodies from the outer Solar System that contain such organic substances are very easily vaporized during entry in the atmosphere of the Earth, so only a negligible fract…

Wouldn't a big enough asteroid have an inner part which survives entry? You seem to be saying that it's impossible for any meteorite that might have these chemicals to not be completely vaporized which seems doubtful. Have you got a source?

So you survived re-entry. Now, you get to survive impact. Seems like the energy released would also be damaging

Re: Ryugu asteroid samples contain all DNA and RNA building blocks

#99

Post by qsera »

kmaitreys wrote: post #52
qsera wrote: post #38

Doesn't multi-world interpretation pretty much answer how life originated? I mean, even if the starting state require to bootstrap life have impossibly low chance to happen random, multi-world interpretation implies that there will be some worlds where it happened, and observation of life is only possible in such worlds..

Multi-worlds is not really relevant here. You are just asking the question how the building blocks of life form in the Universe and how can they reach a planet like ours.

I mean, Multi worlds is the only way this impossibly random event can occur on its own.

Re: Ryugu asteroid samples contain all DNA and RNA building blocks

#100

Post by kstrauser »

qsera wrote: post #99
kmaitreys wrote: post #52

Earlier quoted context omitted.

Multi-worlds is not really relevant here. You are just asking the question how the building blocks of life form in the Universe and how can they reach a planet like ours.

I mean, Multi worlds is the only way this impossibly random event can occur on its own.

That's not true. If life has the odds of one in a quadrillion of happening, and we're here to discuss it, then we're that one in a quadrillion. If we weren't, we wouldn't be alive. By definition, we were the lucky ones with the perfect conditions that resulted in us.
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