All of the bases in DNA and RNA have now been found in meteorites

[Frank Robert]

The discovery adds to evidence that suggests life’s precursors came from space

A 2-gram chunk from this rock — a piece of the meteorite that fell near Murchison, Australia, in 1969 — contains two crucial components of DNA and RNA now identified for the first time in an extraterrestrial source, researchers say.

A 2-gram chunk from this rock — a piece of the meteorite that fell near Murchison, Australia, in 1969 — contains two crucial components of DNA and RNA now identified for the first time in an extraterrestrial source, researchers say.

“We’ve completed the set of all the bases found in DNA and RNA and life on Earth, and they’re present in meteorites,” says astrochemist Daniel Glavin of NASA’s Goddard Space Flight Center in Greenbelt, Md.​

 

[Ligurian]

The discovery adds to evidence that suggests life’s precursors came from space

A 2-gram chunk from this rock — a piece of the meteorite that fell near Murchison, Australia, in 1969 — contains two crucial components of DNA and RNA now identified for the first time in an extraterrestrial source, researchers say.

A 2-gram chunk from this rock — a piece of the meteorite that fell near Murchison, Australia, in 1969 — contains two crucial components of DNA and RNA now identified for the first time in an extraterrestrial source, researchers say.

“We’ve completed the set of all the bases found in DNA and RNA and life on Earth, and they’re present in meteorites,” says astrochemist Daniel Glavin of NASA’s Goddard Space Flight Center in Greenbelt, Md.​

Good thread.
So, maybe we all came from another planet?... not just the O-negs and red-heads.

Is there a planet like Earth that already sustains life?

 

[Occams Barber]

Good thread.
So, maybe we all came from another planet?... not just the O-negs and red-heads.

Is there a planet like Earth that already sustains life?

It doesn't necessarily follow that life came to Earth via meteorite. The article talks about life's 'precursors' being found on/in meteorites - not life itself.

Is it more likely, for instance, that the chemical amalgamation of these precursors happened on Earth, perhaps in combination with Earthbound components?

OB

 

[Tanj]

Well everything on earth came from space. It's just possible some of it arrived later than the rest.

 

[SkyWriting]

The discovery adds to evidence that suggests life’s precursors came from space

A 2-gram chunk from this rock — a piece of the meteorite that fell near Murchison, Australia, in 1969 — contains two crucial components of DNA and RNA now identified for the first time in an extraterrestrial source, researchers say.

A 2-gram chunk from this rock — a piece of the meteorite that fell near Murchison, Australia, in 1969 — contains two crucial components of DNA and RNA now identified for the first time in an extraterrestrial source, researchers say.

“We’ve completed the set of all the bases found in DNA and RNA and life on Earth, and they’re present in meteorites,” says astrochemist Daniel Glavin of NASA’s Goddard Space Flight Center in Greenbelt, Md.​

And other stuff.

Every year 5,200 tons (4,700 metric tons) of interplanetary dust particles reach the Earth's surface, a new study reports.Apr 16, 2021

 

[sjastro]

The Murchison meteorite also contains the oldest material ever found silicon carbide grains considerably older then Earth and have been dated at round 7 billion years old.

We determined interstellar cosmic ray exposure ages of 40 large presolar silicon carbide grains extracted from the Murchison CM2 meteorite. Our ages, based on cosmogenic Ne-21, range from 3.9 ± 1.6 Ma to ∼3 ± 2 Ga before the start of the Solar System ∼4.6 Ga ago. A majority of the grains have interstellar lifetimes of <300 Ma, which is shorter than theoretical estimates for large grains. These grains condensed in outflows of asymptotic giant branch stars <4.9 Ga ago that possibly formed during an episode of enhanced star formation ∼7 Ga ago. A minority of the grains have ages >1 Ga. Longer lifetimes are expected for large grains. We determined that at least 12 of the analyzed grains were parts of aggregates in the interstellar medium: The large difference in nuclear recoil loss of cosmic ray spallation products 3He and 21Ne enabled us to estimate that the irradiated objects in the interstellar medium were up to 30 times larger than the analyzed grains. Furthermore, we estimate that the majority of the grains acquired the bulk of their cosmogenic nuclides in the interstellar medium and not by exposure to an enhanced particle flux of the early active sun.

Lifetimes of interstellar dust from cosmic ray exposure ages of presolar silicon carbide

 

[SelfSim]

Is it more likely, for instance, that the chemical amalgamation of these precursors happened on Earth, perhaps in combination with Earthbound components?

Nice one!
Or perhaps in other words: interaction between a certain type of precursor system(s) and its environment, selects for certain kinds of reactions whilst ruling out others, and the kinds of reactions conserved by this 'natural selection', are precisely those that we now see in evolvable life-as-we-know-it?

Darwinian abiogenesis!

 

[Gottservant]

But why did it not "evolve" on the meteroid?

We know it was not "created" on the meteroid - because God planned for it to produce on Earth.

 

[Occams Barber]

But why did it not "evolve" on the meteroid?

We know it was not "created" on the meteroid - because God planned for it to produce on Earth.

To have evolution you first need life. What was on the meteoroid was not a lifeform. It was some of the chemical precursors (i.e. 'building blocks') of life. After the meteoroid reached Earth these precursors may have combined chemically with other earth based chemistry to produce the first life form(s).

Once you have a lifeform, evolution becomes possible.

OB

 

[Gottservant]

To have evolution you first need life. What was on the meteoroid was not a lifeform. It was some of the chemical precursors (i.e. 'building blocks') of life. After the meteoroid reached Earth these precursors may have combined chemically with other earth based chemistry to produce the first life form(s).

Once you have a lifeform, evolution becomes possible.

OB

Yes but specifically what selection pressure changed, between meteor and Earth?

There is a selection pressure for "living already"?

 

[Gene2memE]

For anyone that is interested in astrobiology, NASA has a free, 100 page primer on basically everything you could want or need to know, barring going out and getting a masters or a PhD.

The second edition was published in 2016: https://www.liebertpub.com/doi/epdf/10.1089/ast.2015.1460

An expanded third edition is being worked on at the moment, and will hopefully be published by the end of this year or early in 2023.

 

[Gene2memE]

Yes but specifically what selection pressure changed, between meteor and Earth?

Probably not a selection pressure. If life on earth did evolve from chemical precursors generated on asteroid or comet, what changed was likely the energy gradient these molecules encountered and the number of other chemicals they could encounter. Say, in something like liquid water.

There is a selection pressure for "living already"?

This sentence doesn't make sense. Are you sure you know what you're asking?

 

[Gottservant]

Probably not a selection pressure. If life on earth did evolve from chemical precursors generated on asteroid or comet, what changed was likely the energy gradient these molecules encountered and the number of other chemicals they could encounter. Say, in something like liquid water.

This was scintillating! You really grounded the beginning of life in the growing of charge, so well!

I think what we need most: is a simplicity of perspective - when it comes to science: you have a real chance of it, there!

This sentence doesn't make sense. Are you sure you know what you're asking?

I am asking if there was a selection pressure that governed, from stage one an energy gradient, to stage two, a living creature.

You sort of put them in context with each other, but didn't suggest a transition or motivating factor.

Without a motivating factor, I doubt life would be anything.

 

[Bungle_Bear]

You sort of put them in context with each other, but didn't suggest a transition or motivating factor.

Without a motivating factor, I doubt life would be anything.

What motivating factor do you see for hydrogen and oxygen combining to form water?

 

[Shemjaza]

Yes but specifically what selection pressure changed, between meteor and Earth?

There is a selection pressure for "living already"?

The building blocks of life seem to be able to develop anywhere... but the chemistry of all the life we know about is much more limited.

Simple life needs resources, energy and liquid water... all stuff that is rare or in a non useful format in space.

 

[Frank Robert]

Yes but specifically what selection pressure changed, between meteor and Earth?

There is a selection pressure for "living already"?

You first need protolife that represents the stage immediately prior to the evolution of the first living organisms. There is nothing to select before there are mutations.

 

[Gottservant]

There is nothing to select before there are mutations.

Not even adaptations?

That is a problem?

 

[Shemjaza]

Not even adaptations?

That is a problem?

If there weren't any mutations then there weren't any adaptations.

They are advantageous variations and variations are caused by mutations.

 

[Kylie]

Yes but specifically what selection pressure changed, between meteor and Earth?

There is a selection pressure for "living already"?

Earth would have had much more resources, for a start.

 

[Frank Robert]

Not even adaptations?

That is a problem?

Not even adaptations?

That is a problem?

Creationists tend to have many problems that science doesn't.