Perseverance looks for life

[XFool]

Perseverance: Nasa rover begins key drive to find life on Mars

BBC News

Nasa's Perseverance rover has reached a big moment in its mission on Mars.

"Tuesday will see the six-wheeled robot begin the climb up an ancient delta feature in the crater where it landed.

It will roll uphill, stopping every so often to examine rocks that look to have the best chance of retaining evidence of past life on the planet.

On its way back down, Perseverance will collect some of these rocks, placing the samples at the base of the delta to be retrieved by later missions"

[XFool]

Nasa's Ingenuity helicopter to fly over the hills of Mars

BBC News

The derring-do Mars helicopter is about to take on its greatest challenge yet.

"The Ingenuity drone, which accompanies Nasa's Perseverance rover, is going to start flying over the hills that surround their exploration location on the Red Planet.

The pair are currently on the floor of Jezero Crater, but the plan is for them both to climb up and out of this bowl."

[88V8]

Nasa's Ingenuity helicopter to fly over the hills of Mars
"The Ingenuity drone, which accompanies Nasa's Perseverance rover, is going to start flying over the hills that surround their exploration location on the Red Planet.

Astounding they can control it with the time lag. Makes driverless cars look pretty tame.

Moment of danger... they fly above the horizon, the natives may see them.

V8

[XFool]

Perseverance: Nasa Mars rover to lay down rocks for Earth return

BBC News

The American space agency's Mars rover Perseverance will this week begin dropping samples of rock on to the surface of the Red Planet.

"The materials have been packaged in small titanium tubes with the expectation they can be picked up by a future mission and brought home.

It's a major milestone in the quest to find out whether there is life on Mars."

[stevensfo]

Perseverance: Nasa Mars rover to lay down rocks for Earth return

BBC News

The American space agency's Mars rover Perseverance will this week begin dropping samples of rock on to the surface of the Red Planet.

"The materials have been packaged in small titanium tubes with the expectation they can be picked up by a future mission and brought home.

It's a major milestone in the quest to find out whether there is life on Mars."

I agree that if bacteria, bacterial spores or even fossils are found on Mars, it will be a great achievement.

Then there will be the DNA analyses, whether life arrived here from Mars on meteorites, vice versa, or both appeared together. Our solar system can be considered as a closed ecosystem.

But if signs of life past or present are discovered, it will not answer the biggest question of all, which is, does intelligent life exist elsewhere in the universe.

Personally, I would be surprised if there was never some kind of primitive microorganism on Mars or even Venus, albeit billions of years ago.

Deep down, the thought that we may be the only life in the universe is bloody terrifying!!

Steve

[9873210]

Then there will be the DNA analyses,

You'll want to verify there is DNA before you start analyzing it. There's too much extrapolation from a sample of one.

[stevensfo]

Then there will be the DNA analyses,

You'll want to verify there is DNA before you start analyzing it. There's too much extrapolation from a sample of one.

Not sure I understand your comment.

DNA is a remarkably stable molecule and we have instruments that can amplify sequences from the tiniest of fragments.

The first step will be to rule out contamination from Earth. Though this should be relatively easy.

Steve

[odysseus2000]

Then there will be the DNA analyses,

You'll want to verify there is DNA before you start analyzing it. There's too much extrapolation from a sample of one.

Not sure I understand your comment.

DNA is a remarkably stable molecule and we have instruments that can amplify sequences from the tiniest of fragments.

The first step will be to rule out contamination from Earth. Though this should be relatively easy.

Steve

What has always bothered me about these searches is that they assume that any alien life will have direct relations to earth life. Isn't it possible that if there was/is life of Mars that it will be off a form unrelated to Earth based life? For example if there is some kind of bacteria or virus like life on Mars, it would have to be able to survive very low pressures, extreme temperatures and high levels of ionising radiation and could have evolved different respiratory gases etc or maybe it doesn't breathe in anyway we would recognise.

If one was to take surface and sub-surface samples and put them in a mass spectrometer and then find molecules, would that not be a better indication for something of unknown form?

Regards,

[9873210]

Then there will be the DNA analyses,

You'll want to verify there is DNA before you start analyzing it. There's too much extrapolation from a sample of one.

Not sure I understand your comment.

DNA is a remarkably stable molecule and we have instruments that can amplify sequences from the tiniest of fragments.

The first step will be to rule out contamination from Earth. Though this should be relatively easy.

Steve

I meant that Martian life may not use DNA. There are other polymers, and more diverse mechanisms, that could perhaps store and process genetic information.
There are several possibilities, including:

1. DNA is the only thing that can do the job. So all life from whatever origin uses DNA.
2. DNA is a one of a small number of chemicals that can do the job. Some fraction of unrelated life will use DNA, some won't.
3. There are infinitely many schemes that can support life, DNA is very rare and perhaps evolved only on Earth.

Discovering Mars life, and that Mars life does or does not use DNA does not limit the possibilities very much. Nor would it conclusively say whether or not Earth and Mars life had independent origins. It would still only be a sample of two and you really need an out group to anchor a phylogenetic tree.

One of the first task if any Mars life is found and characterized is to search many places on Earth to see if the same characteristics exist here.

[ursaminortaur]

Then there will be the DNA analyses,

You'll want to verify there is DNA before you start analyzing it. There's too much extrapolation from a sample of one.

Not sure I understand your comment.

DNA is a remarkably stable molecule and we have instruments that can amplify sequences from the tiniest of fragments.

The first step will be to rule out contamination from Earth. Though this should be relatively easy.

Steve

I meant that Martian life may not use DNA. There are other polymers, and more diverse mechanisms, that could perhaps store and process genetic information.
There are several possibilities, including:

1. DNA is the only thing that can do the job. So all life from whatever origin uses DNA.
2. DNA is a one of a small number of chemicals that can do the job. Some fraction of unrelated life will use DNA, some won't.
3. There are infinitely many schemes that can support life, DNA is very rare and perhaps evolved only on Earth.

Discovering Mars life, and that Mars life does or does not use DNA does not limit the possibilities very much. Nor would it conclusively say whether or not Earth and Mars life had independent origins. It would still only be a sample of two and you really need an out group to anchor a phylogenetic tree.

One of the first task if any Mars life is found and characterized is to search many places on Earth to see if the same characteristics exist here.

One other possiblity would be that Mars life used DNA but of the opposite chirality to that on Earth - so called mirror life.

https://en.wikipedia.org/wiki/Mirror_life

Many of the essential molecules for life on Earth can exist in two mirror-image forms, referred to as "left-handed" and "right-handed", but living organisms do not use both. Proteins are exclusively composed of left-handed amino acids; RNA and DNA contain only right-handed sugars. This phenomenon is known as homochirality.[8] It is not known whether homochirality emerged before or after life, whether the building blocks of life must have this particular chirality, or indeed whether life needs to be homochiral.[9] Protein chains built from amino acids of mixed chirality tend not to fold or function as catalysts, but mirror-image proteins have been constructed that work the same but on substrates of opposite handedness.[8]

The concept

Hypothetically, it is possible to recreate an entire ecosystem from the bottom up, in mirror form.[10]

Advances in synthetic biology, like synthesizing viruses since 2002, partially synthetic bacteria in 2010, or synthetic ribosomes in 2013, may lead to the possibility of fully synthesizing a living cell from small molecules, where we could use mirror-image versions (enantiomers) of life's building-block molecules, in place of the standard ones. Some proteins have been synthesized in mirror-image versions, including polymerase in 2016.[11]

Reconstructing regular lifeforms in mirror-image form, using the mirror-image (chiral) reflection of their cellular components, could be achieved by substituting left-handed amino acids with right-handed ones, in order to create mirror reflections of all regular proteins. Analogously, we could get reflected sugars, DNA, etc., on which reflected enzymes would work perfectly. Finally we would get a normally functioning mirror reflection of a natural organism — a chiral counterpart organism.

Electromagnetic force (chemistry) is unchanged under such molecular reflection transformation (P-symmetry). There is a small alteration of weak interactions under reflection, which can produce very small corrections, but these corrections are many orders of magnitude lower than thermal noise - almost certainly too tiny to alter any biochemistry.[citation needed] However, there are also theories that weak interactions can have a greater effect on longer nucleic acids or protein chains, resulting in much less efficient conversion of mirror ribozymes or enzymes than normal ribozymes or enzymes.[12]

Mirror animals would need to feed on reflected food, produced by reflected plants. Mirror viruses would not be able to attack natural cells, just as natural viruses would not be able to attack mirror cells.[10]


There have been some recent suggestions that the chirality of life on Earth may be down to the interaction of organic molecules with cosmic rays which if true would probably mean that life on Mars would adopt the same chirality but the evidence for this is fairly weak at present.

https://news.unl.edu/newsrooms/unltoday/article/why-is-dna-right-handed-unl-finding-supports-hypothesis/

https://www.quantamagazine.org/cosmic-rays-may-explain-lifes-bias-for-right-handed-dna-20200629/#:~:text=Cosmic%20rays%20may%20have%20given,the%20beginning%20of%20life%27s%20history.&text=Lopsided%20interactions%20between%20cosmic%2Dray,handed%20DNA%20and%20RNA%20helixes.

( It is worth noting that the explanation as to which form is more affected by cosmic rays and the subsequent effect of that is the exact opposite in the two papers. The first saying that DNA of the opposite chirality would be more likely to be destroyed whereas the second says that our form would be more likely to be affected but that that would produce more mutations which would aid the development of that form of life. In both cases the effect would be small so for the moment I think the jury is still out as to whether cosmic rays are the explanation.)

[stevensfo]

Then there will be the DNA analyses,

You'll want to verify there is DNA before you start analyzing it. There's too much extrapolation from a sample of one.

Not sure I understand your comment.

DNA is a remarkably stable molecule and we have instruments that can amplify sequences from the tiniest of fragments.

The first step will be to rule out contamination from Earth. Though this should be relatively easy.

Steve

I meant that Martian life may not use DNA. There are other polymers, and more diverse mechanisms, that could perhaps store and process genetic information.
There are several possibilities, including:

1. DNA is the only thing that can do the job. So all life from whatever origin uses DNA.
2. DNA is a one of a small number of chemicals that can do the job. Some fraction of unrelated life will use DNA, some won't.
3. There are infinitely many schemes that can support life, DNA is very rare and perhaps evolved only on Earth.

Discovering Mars life, and that Mars life does or does not use DNA does not limit the possibilities very much. Nor would it conclusively say whether or not Earth and Mars life had independent origins. It would still only be a sample of two and you really need an out group to anchor a phylogenetic tree.

One of the first task if any Mars life is found and characterized is to search many places on Earth to see if the same characteristics exist here.

Funnily enough, I was thinking about the role of DNA just now. It's possible that, given the different conditions on Mars, RNA may play the same role, as it does in the RNA viruses on earth. The problem is that RNA is not nearly as stable as DNA and exists either for very short periods (coding proteins in cells) or in small viruses where it's protected by a protein coat. There is a theory that billions of years ago, life started off based on RNA and as conditions changed, slowly evolved to using DNA for longer term storage of info.

However, having a fertile imagination, I wonder if it's possible for protein chains to play a role in storing info. There are long structural protein strands like keratin and collagen that have similar structures to DNA. Maybe on some planets, an organism uses these?

So if frozen viral particles are found on Mars, it will be important to identify them asap. Personally, given the dangers of viruses, I'd be happier setting up labs on Mars rather than bringing rock samples back to earth!!

Cue next blockbuster disaster movie!

Steve

[ursaminortaur]

Then there will be the DNA analyses,

You'll want to verify there is DNA before you start analyzing it. There's too much extrapolation from a sample of one.

Not sure I understand your comment.

DNA is a remarkably stable molecule and we have instruments that can amplify sequences from the tiniest of fragments.

The first step will be to rule out contamination from Earth. Though this should be relatively easy.

Steve

I meant that Martian life may not use DNA. There are other polymers, and more diverse mechanisms, that could perhaps store and process genetic information.
There are several possibilities, including:

1. DNA is the only thing that can do the job. So all life from whatever origin uses DNA.
2. DNA is a one of a small number of chemicals that can do the job. Some fraction of unrelated life will use DNA, some won't.
3. There are infinitely many schemes that can support life, DNA is very rare and perhaps evolved only on Earth.

Discovering Mars life, and that Mars life does or does not use DNA does not limit the possibilities very much. Nor would it conclusively say whether or not Earth and Mars life had independent origins. It would still only be a sample of two and you really need an out group to anchor a phylogenetic tree.

One of the first task if any Mars life is found and characterized is to search many places on Earth to see if the same characteristics exist here.

Funnily enough, I was thinking about the role of DNA just now. It's possible that, given the different conditions on Mars, RNA may play the same role, as it does in the RNA viruses on earth. The problem is that RNA is not nearly as stable as DNA and exists either for very short periods (coding proteins in cells) or in small viruses where it's protected by a protein coat. There is a theory that billions of years ago, life started off based on RNA and as conditions changed, slowly evolved to using DNA for longer term storage of info.

However, having a fertile imagination, I wonder if it's possible for protein chains to play a role in storing info. There are long structural protein strands like keratin and collagen that have similar structures to DNA. Maybe on some planets, an organism uses these?

So if frozen viral particles are found on Mars, it will be important to identify them asap. Personally, given the dangers of viruses, I'd be happier setting up labs on Mars rather than bringing rock samples back to earth!!

Cue next blockbuster disaster movie!

Steve

I think you have watched too many Hollywood SciFI movies (The Andromeda Strain etc). Viruses require the ability to invade cells and take over their machinery in order to reproduce this means that viral diseases are confined to infecting particular groups of organisms and find it difficult to cross-infect between even fairly closely related species. Hence it would seem unlikely that a virus from Mars would be well adapted to infect and co-opt the machinery of human cells (or indeed if it wasn't descended from some ancient Earth organism which had been transported to Mars be able to infect anything on Earth).

[stevensfo]

Then there will be the DNA analyses,

You'll want to verify there is DNA before you start analyzing it. There's too much extrapolation from a sample of one.

Not sure I understand your comment.

DNA is a remarkably stable molecule and we have instruments that can amplify sequences from the tiniest of fragments.

The first step will be to rule out contamination from Earth. Though this should be relatively easy.

Steve

What has always bothered me about these searches is that they assume that any alien life will have direct relations to earth life. Isn't it possible that if there was/is life of Mars that it will be off a form unrelated to Earth based life? For example if there is some kind of bacteria or virus like life on Mars, it would have to be able to survive very low pressures, extreme temperatures and high levels of ionising radiation and could have evolved different respiratory gases etc or maybe it doesn't breathe in anyway we would recognise.

If one was to take surface and sub-surface samples and put them in a mass spectrometer and then find molecules, would that not be a better indication for something of unknown form?

Regards,

I believe that the cockroach is pretty much suited to Mars. Either that or the Tardigrade.

Maybe a few MPs....?

Steve

[stevensfo]

You'll want to verify there is DNA before you start analyzing it. There's too much extrapolation from a sample of one.

Not sure I understand your comment.

DNA is a remarkably stable molecule and we have instruments that can amplify sequences from the tiniest of fragments.

The first step will be to rule out contamination from Earth. Though this should be relatively easy.

Steve

I meant that Martian life may not use DNA. There are other polymers, and more diverse mechanisms, that could perhaps store and process genetic information.
There are several possibilities, including:

1. DNA is the only thing that can do the job. So all life from whatever origin uses DNA.
2. DNA is a one of a small number of chemicals that can do the job. Some fraction of unrelated life will use DNA, some won't.
3. There are infinitely many schemes that can support life, DNA is very rare and perhaps evolved only on Earth.

Discovering Mars life, and that Mars life does or does not use DNA does not limit the possibilities very much. Nor would it conclusively say whether or not Earth and Mars life had independent origins. It would still only be a sample of two and you really need an out group to anchor a phylogenetic tree.

One of the first task if any Mars life is found and characterized is to search many places on Earth to see if the same characteristics exist here.

Funnily enough, I was thinking about the role of DNA just now. It's possible that, given the different conditions on Mars, RNA may play the same role, as it does in the RNA viruses on earth. The problem is that RNA is not nearly as stable as DNA and exists either for very short periods (coding proteins in cells) or in small viruses where it's protected by a protein coat. There is a theory that billions of years ago, life started off based on RNA and as conditions changed, slowly evolved to using DNA for longer term storage of info.

However, having a fertile imagination, I wonder if it's possible for protein chains to play a role in storing info. There are long structural protein strands like keratin and collagen that have similar structures to DNA. Maybe on some planets, an organism uses these?

So if frozen viral particles are found on Mars, it will be important to identify them asap. Personally, given the dangers of viruses, I'd be happier setting up labs on Mars rather than bringing rock samples back to earth!!

Cue next blockbuster disaster movie!

Steve

I think you have watched too many Hollywood SciFI movies (The Andromeda Strain etc). Viruses require the ability to invade cells and take over their machinery in order to reproduce this means that viral diseases are confined to infecting particular groups of organisms and find it difficult to cross-infect between even fairly closely related species. Hence it would seem unlikely that a virus from Mars would be well adapted to infect and co-opt the machinery of human cells (or indeed if it wasn't descended from some ancient Earth organism which had been transported to Mars be able to infect anything on Earth).

I think you have watched too many Hollywood SciFI movies (The Andromeda Strain etc).

Guilty as charged, m'lud.

However, we do not know exactly how the integration process proceeds with all viruses and how long they survive.

One theory is that chloroplasts and mitochondria originally started off as separate viruses and then integrated into other cells to form a symbiotic relationship, supplying energy to the cell.

You're correct that a virus cannot easily enter into a cell, but a watery environment and the correct temperature could help.

Steve

[ursaminortaur]

Then there will be the DNA analyses,

You'll want to verify there is DNA before you start analyzing it. There's too much extrapolation from a sample of one.

Not sure I understand your comment.

DNA is a remarkably stable molecule and we have instruments that can amplify sequences from the tiniest of fragments.

The first step will be to rule out contamination from Earth. Though this should be relatively easy.

Steve

What has always bothered me about these searches is that they assume that any alien life will have direct relations to earth life. Isn't it possible that if there was/is life of Mars that it will be off a form unrelated to Earth based life? For example if there is some kind of bacteria or virus like life on Mars, it would have to be able to survive very low pressures, extreme temperatures and high levels of ionising radiation and could have evolved different respiratory gases etc or maybe it doesn't breathe in anyway we would recognise.

If one was to take surface and sub-surface samples and put them in a mass spectrometer and then find molecules, would that not be a better indication for something of unknown form?

Regards,

I believe that the cockroach is pretty much suited to Mars. Either that or the Tardigrade.

Maybe a few MPs....?

Steve

Cockroaches need oxygen to survive. They could hold their breath for about 40 minutes but after that would suffocate in the Martian atmosphere which has 0.13% oxygen compared to Earth's 20%. Tardigrade's also need oxygen if they are to be active but can put themselves into a dormant tun state in which they can survive for something like 30 years. However they would eventually die on Mars.

Although most MPs are windbags it is doubtful that would help them survive the lack of oxygen on Mars.

[ReformedCharacter]

One theory is that chloroplasts and mitochondria originally started off as separate viruses and then integrated into other cells to form a symbiotic relationship, supplying energy to the cell.

Steve

I don't think that's correct, they never started as viruses.

RC

[ursaminortaur]

Not sure I understand your comment.

DNA is a remarkably stable molecule and we have instruments that can amplify sequences from the tiniest of fragments.

The first step will be to rule out contamination from Earth. Though this should be relatively easy.

Steve

I meant that Martian life may not use DNA. There are other polymers, and more diverse mechanisms, that could perhaps store and process genetic information.
There are several possibilities, including:

1. DNA is the only thing that can do the job. So all life from whatever origin uses DNA.
2. DNA is a one of a small number of chemicals that can do the job. Some fraction of unrelated life will use DNA, some won't.
3. There are infinitely many schemes that can support life, DNA is very rare and perhaps evolved only on Earth.

Discovering Mars life, and that Mars life does or does not use DNA does not limit the possibilities very much. Nor would it conclusively say whether or not Earth and Mars life had independent origins. It would still only be a sample of two and you really need an out group to anchor a phylogenetic tree.

One of the first task if any Mars life is found and characterized is to search many places on Earth to see if the same characteristics exist here.

Funnily enough, I was thinking about the role of DNA just now. It's possible that, given the different conditions on Mars, RNA may play the same role, as it does in the RNA viruses on earth. The problem is that RNA is not nearly as stable as DNA and exists either for very short periods (coding proteins in cells) or in small viruses where it's protected by a protein coat. There is a theory that billions of years ago, life started off based on RNA and as conditions changed, slowly evolved to using DNA for longer term storage of info.

However, having a fertile imagination, I wonder if it's possible for protein chains to play a role in storing info. There are long structural protein strands like keratin and collagen that have similar structures to DNA. Maybe on some planets, an organism uses these?

So if frozen viral particles are found on Mars, it will be important to identify them asap. Personally, given the dangers of viruses, I'd be happier setting up labs on Mars rather than bringing rock samples back to earth!!

Cue next blockbuster disaster movie!

Steve

I think you have watched too many Hollywood SciFI movies (The Andromeda Strain etc). Viruses require the ability to invade cells and take over their machinery in order to reproduce this means that viral diseases are confined to infecting particular groups of organisms and find it difficult to cross-infect between even fairly closely related species. Hence it would seem unlikely that a virus from Mars would be well adapted to infect and co-opt the machinery of human cells (or indeed if it wasn't descended from some ancient Earth organism which had been transported to Mars be able to infect anything on Earth).

I think you have watched too many Hollywood SciFI movies (The Andromeda Strain etc).

Guilty as charged, m'lud.

However, we do not know exactly how the integration process proceeds with all viruses and how long they survive.

One theory is that chloroplasts and mitochondria originally started off as separate viruses and then integrated into other cells to form a symbiotic relationship, supplying energy to the cell.

You're correct that a virus cannot easily enter into a cell, but a watery environment and the correct temperature could help.

Steve

No, the theory is that the cells of multicellular life eukaryotes came about from the fusion of two prokaryotic cells (one an archaeon and one a bacterium with the bacterium providing the mitochondria - and in a later second such fusion a bacterium providing the chloroplast).

Though there is a variant of this theory which also involves a large DNA virus as a third component but in that variant the virus eventually usurps the nucleus.

https://en.wikipedia.org/wiki/Viral_eukaryogenesis

The viral eukaryogenesis hypothesis posits that eukaryotes are composed of three ancestral elements: a viral component that became the modern nucleus; a prokaryotic cell (an archaeon according to the eocyte hypothesis) which donated the cytoplasm and cell membrane of modern cells; and another prokaryotic cell (here bacterium) that, by endocytosis, became the modern mitochondrion or chloroplast.

[9873210]

However, having a fertile imagination, I wonder if it's possible for protein chains to play a role in storing info. There are long structural protein strands like keratin and collagen that have similar structures to DNA. Maybe on some planets, an organism uses these?

It's pretty easy to dream up schemes that can store information*. It's a bit harder to find schemes that are stable, but not too stable.
The really hard part is the mechanisms for transcription, replication and other metabolism. DNA does not replicate, cells replicate.**

* For example alternating ethylene and propylene in poly-whatever. A bit of information is stored in the presence or absence of the methyl side group. Methylation is used to store epigenetic information in DNA.

** Labs can also replicate, but is that a good basis for life?

[stevensfo]

However, having a fertile imagination, I wonder if it's possible for protein chains to play a role in storing info. There are long structural protein strands like keratin and collagen that have similar structures to DNA. Maybe on some planets, an organism uses these?

It's pretty easy to dream up schemes that can store information*. It's a bit harder to find schemes that are stable, but not too stable.
The really hard part is the mechanisms for transcription, replication and other metabolism. DNA does not replicate, cells replicate.**

* For example alternating ethylene and propylene in poly-whatever. A bit of information is stored in the presence or absence of the methyl side group. Methylation is used to store epigenetic information in DNA.

** Labs can also replicate, but is that a good basis for life?

Which may be a good model for the early earth in which RNA was the store of information and slowly switched to DNA while retaining the cell's ability to divide the DNA molecules into two new cells.

To be honest, I can't remember anything about methylation of DNA, but it's been 40 years!

Ethylene and Propylene are just ethanol (booze) and propanol (rubbing alcohol/car ice spray) with extra double carbon bonds. Don't see them having much impact on life, apart from a form of anti freeze.

Though on Mars.....?

Steve

[9873210]

However, having a fertile imagination, I wonder if it's possible for protein chains to play a role in storing info. There are long structural protein strands like keratin and collagen that have similar structures to DNA. Maybe on some planets, an organism uses these?

It's pretty easy to dream up schemes that can store information*. It's a bit harder to find schemes that are stable, but not too stable.
The really hard part is the mechanisms for transcription, replication and other metabolism. DNA does not replicate, cells replicate.**

* For example alternating ethylene and propylene in poly-whatever. A bit of information is stored in the presence or absence of the methyl side group. Methylation is used to store epigenetic information in DNA.

** Labs can also replicate, but is that a good basis for life?

Which may be a good model for the early earth in which RNA was the store of information and slowly switched to DNA while retaining the cell's ability to divide the DNA molecules into two new cells.

To be honest, I can't remember anything about methylation of DNA, but it's been 40 years!

Ethylene and Propylene are just ethanol (booze) and propanol (rubbing alcohol/car ice spray) with extra double carbon bonds. Don't see them having much impact on life, apart from a form of anti freeze.


Steve

You missed the "poly" part. Polyethylene and polypropylene are large alkanes with no double bonds. The names are from the manufacturing process not the chemical structure. You can encode a lot of information in the branching structure of a large alkane.