Will Perserverance find it on Mars?
Abiogenesis, the question of the origin of life on Earth, is a fascinating one and on current information we only have one data point on which to base hypotheses. The facts are that life exists on Earth in amazing variety in many different niches from the coldest, darkest oceans to the driest deserts. Yet that life in all its diversity shares much in common.
With few and very interesting exceptions, the genetic code—the way information that terrestrial organisms use to function, grow and reproduce is stored—is shared across all extant species (and in extinct species where DNA is still recoverable). I know of no other plausible explanation for this than life’s diversity radiates from a common ancestor. So far direct fossil evidence takes life back at least 3.75 billion years and molecular phylogeny suggests an even earlier date for the universal common ancestor. It is reasonable to infer that a molten Earth was sterile and that life based on carbon and water could not have existed on this planet before it was cool enough for water to condense on its surface.
So we know life on Earth began around 4 billion years ago but we do not know how. There are religious explanations: divine creation. Life could have begun elsewhere and arrived on Earth embedded in material that transported it. Life could have begun by some natural process in a favoured location, Darwin’s
…warm little pond with all sorts of ammonia and phosphoric salts, light, heat, electricity etcetera present, that a protein compound was chemically formed, ready to undergo still more complex changes…
or perhaps more plausibly in the vortex of a hydrothermal vent (some of the earliest fossils have been found in hydrothermal vent debris dated to 4 billion years ago).
We don’t lack for hypotheses regarding abiogenesis. The Wikipedia article on abiogenesis lists many references to primary sources. What we lack is further evidence to allow us to better choose between hypotheses. Until now!
Is life unique to Earth? Is Earth the only place in the vastness of the observable universe and beyond that living organisms exist or have ever existed? We have learned a lot about elsewhere just from the electromagnetic radiation that arrives from beyond Earth and we have established that exoplanets orbiting other stars are common in our galaxy. Humans have visited our own Moon and brought back rock and soil samples that indicate the Moon is—and always has been—sterile. But NASA and the USSR during the cold war years of the sixties and seventies sent probes to Mars with the Mars Global Surveyor (launched in 1996 and continuing to function until 2006) producing a spectacularly detailed survey of the Martian surface, indicating features that could best be explained by water erosion. Could our nearest planetary neighbour once have supported life? Only by landing a probe on Mars could we begin to answer that question.
The first successful deployment of an unmanned vehicle was Sojourner from the Pathfinder mission launched in 1996. Its success encouraged and informed later missions, Curiosity (which is still operating) and the latest unmanned vehicle, Perserverance.
The hope is to use another unmanned vehicle as yet unlaunched to recover the rock samples prepared by Persereverance. This new vehicle will then deliver them to a lauch vehicle intended to deliver the samples to a satellite (European, whoopee, what could possibly go wrong) and eventually to land on Earth in 2031. Then we shall have our second data point.
|Mars is sterile||Life on Earth is unique hypothesis strengthened|
|Molecules closely related to life on Earth||Panspermia, common source for life on Earth and Mars|
|Evidence of life unrelated to that found on Earth||Life evolved separately on Mars, so life is likely to be teeming across the universe|
Maybe we will not need to wait until samples can be recovered and brought back to Earth. Perserverance is also tasked with “seeking signs of possible past microbial life in those habitable environments, particularly in special rocks known to preserve signs of life over time”.
Unless Perserverance finds signs that can be unequivocally interpreted as evidence of past life, we have perhaps another ten years for those samples to return to Earth and for us to examine the evidence for our second data point. Fingers crossed.
No. No life on mars or in mars rocks. the only reason life is inprinted in rocks is from great forces squeezing it there. its impossible to put biology inprint on rocks. it doesn’t happen today. Indeed the ROCKS were only turned to rocks by the same mechanism that inprinted the biology. VER very special events. Common on earth because of the unique great Noahs flood and minor later events.
If making bacteria is that easy then why can’t smart humanity do it witrh raw material in a lab/ How can mars do it? No execuse. If that easy then step one and two should be done in the labs as we speak.
Evolutionism and all rejection of god is just worthless speculation of humanity who don’t prove anything. Its truly not intelligent for them unless the show real evidence.
More than 20 years ago, there was an article about what looked like fossilized imprints with chemical activity attributable to life in a meteorite from Mars. I don’t know if it was discredited later, or if nothing else has happened since, and the enthusiasm just evaporated for lack of further news.
(Now the ear worm is of an oldie and very danceable Cuban rhythm.)
My brief and superficial research suggests that remote “robot” experiments have their limits and results so far have been inconclusive. Bringing back samples for human experimenters to look at will, I hope, result in more definitive answers. Or we wait for humans to report back from Mars.
Mars has had its share of wishful thinking!
Those meteorite samples have been reexamined.
You may be right, Robert, but so far the evidence is inconclusive. Would it be a problem for your world-view if life were found to have existed on Mars?
I’ve heard that someone suggested we should make anything we leave on other planets biodegradable so that it will disappear and not litter the place. Maybe they know something we don’t! 🙂
Whatever a world view means it is so impossible for life to be otherthen on earth that it mighty seriously question biblical presumptions or would perfectly.
Nothing there. No fun I know.
I have to wonder what language this post must have been mistranslated from. But still, science fiction authors occasionally posit life so utterly alien that we wouldn’t recognize it, or might not consider it “alive”, or would otherwise not fit our concept of life. How sophisticated would any self-aware digital entity have to be, before we’d consider it to be alive? Must life be biological? How close are we to a proposed singularity, where computer programs can create smarter programs, which in turn create smarter programs, and digital intelligence explodes exponentially?
These particular rocks from Mars may not have signs of life, but they are very likely to actually be from Mars. Others can be found among meteors that fall onto Antarctic glaciers and are swept into particular areas along the edge of the glacier and can be collected there. Mars seems to have cooled down before Earth did (it is smaller, plus farther from the sun). And rocks do get blasted off Mars and get to Earth. Life could have originated there and then spread to Earth. That has one unfortunate implication — if we find signs of past (or examples of present) life on Mars, it may not be OOL 2.0. It may only be OOL 1.1. Related to life on earth, not an independent origin, though very fascinating for being possibly an earlier diverging lineage. For OOL 2.0 we may have to go farther, to moons of Jupiter or some such.
It would need to replicate 2-for-1 to increase exponentially! That’s the heart of biology: 1 DNA molecule becoming two identical ones. It’s not enough for linear ‘improvement’ to take place; to mimic biology, it needs to spread. It is this – despite the robo-denials we see routinely in these here parts – that gives the conditions for evolution, by differentials in the net rate of spread of different variants. It’s also this characteristic that makes me, despite sound chemical counterargument, continue to favour ‘RNA world’ as the likely precursor state.
Do you mean are there general physical restaints on how life could be constructed? If living things elsewhere have to obey the same laws of physics and chemistry, I guess so — if we assume life has to be chemical. All life we know revolves around carbon. Could silicon, with similar properties (to an extent) replace carbon? At the most fundamental, can we assume that however arranged, living things must exploit an energy source to maintain organisation and resist equilibrium with its environment. We don’t know. We need another data point.
Could there have been a precursor to the precursor?
OK, so you see there are implications. I guess you don’t need to prepare just yet for how to deal with them if they turn up. 😉
But it could also suggest life might have come from elsewhere and seeded both Mars and then Earth. I can hardly wait. Ten years will fly by!
Quite irrelevant. If it is incapable of reproduction, growth and development it’s not alive.
Yes, by definition.
All pedantry aside: We tend to treat conscious and alive as synonyms, because the only conscious beings we know are animals (including humans). The vast majority of living beings is not conscious though. Vice versa I don’t see any good reason to suppose that consciousness is restricted to organic life forms, in principle.
(Playing Devil’s advocate) unless we have an agreed definition of consciousness, what is and what is not conscious is hard to categorize and is there a binary choice and sharp line? What about “run and tumble” strategies in flagellated bacteria? Navigating towards food or away from toxins requires a minimal awareness of the immediate surroundings.
I do not know. I am just following the general procedure of “if it behaves like it is aware of stuff then it is probably conscious”. That naturally limits my candidates to things that display behaviour.
No, it doesn’t. If I am not mistaken bacterial chemotaxis is controlled by molecular feedback mechanisms. Awareness requires, to the best of our knowledge, a nervous system. Brains and all that.
But does it? We only have one data point. I mean are we limited to the level of imagination of early Startrek episodes? Aliens limited to who could fit into a suit and wear prosthetics. I’m not sure we have enough imagination regarding how alien life might exist in structure and function and in what environments.
ETA we should try to avoid anthropomorphism. Look what it has done for Charlie. 😳
No idea. That’s the reason why I am open to consciousness outside of organic life forms.
I don’t know if we’re communicating here. I refer back to Asimov’s robots’ “positronic brains.” These were clearly not biological, apparently running some bogglingly sophisticated software, and fully self-aware, conscious, capable of moral quandaries, motivated by self-preservation, etc. If you stretch things a bit, they could even reproduce, because they controlled the manufacturing process.
In a nutshell, these robots were capable of reproduction, growth and development, and did all three. Other fictional examples include the SADEs of S.H.Jucha, and the Culture’s “minds” of Iain M. Banks. None of them biological, all of them very obviously alive.
Your definition strikes me as constricted and myopic.
To also play devil’s advocate, I think you might be making what I would call “Charlie’s mistake”, albeit at a very different place along the awareness continuum.
Plenty of bacteria would qualify for the ‘displaying behavior in response to their surroundings’ definition of ‘conscious’.
To state my position, I’m with you on the requirement for a nervous system. Brain, not so much. But I’m also making an arbitrary cut-off.
But I see that Charlie is elaborating on his latest positioning of the goal-posts on the other thread: ‘thinking about thinking”, indeed. I guess I will have to wade through that.
If you mean, could silicon’s binding properties rival carbon as a basis for life as we know it, I strongly doubt it. But could silicon’s semiconductor properties support life as we don’t know it? I think we’re still a long way from acing the Turing test, but much closer than we were 20 years ago.
You missed the joke. If those robots and digital entities are alive, then they are clearly biological. Biology is the study of life.
I thought it was funny.
Then you misunderstood me. My comment was just meant to draw attention to the distinction between conscious intelligence and life. If you believe that conscious entities should qualify as living things, then that is fine by me. Just be aware that we are also using that term for slime molds and such, based on different criteria.
That hurt, man.
Yes, that was poorly phrased. I was talking about signs that certain animals have a sense of “what it feels like”. I don’t get those vibes from bacteria.
Can you review the evidence for this claim?
Not even original!
Me too. I did say I was playing Devil’s advocate. Organosilicons don’t match carbon for variety. But on an alien world with different circumstances, temperature, pressure, atmosphere, who knows?
I’m not qualified to that, Bill. But the relatively new science of molecular phylogenetics has produced some interesting results by genome comparison. Here is a fairly recent paper which I’d like to understand better that analyses Eukaryota, Archaeabacteria, and Eubacteria by molecular clock methods to produce a tree phylogeny.
Joe G kindly reviewed Alan’s OP. A bit misguided though.
Personal incredulity and willful ignorance. I wonder if there’s any evidence for these claims.
Personal incredulity? Where? I don’t see Alan here being personally incredulous. As per willful ignorance, he seems informed enough to know that organisms share a mostly universal genetic code, etc.
Sorry Joe G, but your personal and naïve credulity about magical beings in the sky is not an argument. I also think that Alan knows about mythologies, only he has enough knowledge to understand where those mythologies belong. Clue: not in the set of potential explanations for the features listed.
Alan is not producing the diversity of life himself, so I take you to mean that Alan doesn’t know of any mechanisms capable of producing the diversity of life starting from a common ancestor. However, you seem to be willfully ignorant here, since many people have explained to you the mechanisms capable of doing precisely that. They’re collectively called evolution.
I think someone very close to you claimed that personal incredulity is not an argument.
Every day more and more life forms arise, naturally, from their parent ones. All of them have ribosomes, naturally produced, since nobody has seen anything unnatural going on there, and these ribosomes process coded information. All goes on very naturally.
To go one step further, let’s not forget that we’re part of nature. We’re capable of coding and decoding. If that wasn’t possible in nature, then we’d be unable to do that ourselves. I’d guess that you’d think that we’re able to do this by magic instead, but we’ve been able to understand how we operate, the energy necessary for us to be able to do any of it, the chemical reactions and the physical structures involved, and nowhere do we find anything unnatural about any of it. So, if not willfully, you’re certainly ignorant.
And as far as we can see, it works naturally. It diverges naturally. The coded information changes naturally, Since it changes, new encoded information arises all the time, again, naturally.
Why should we doubt? It happens all the time all around us. Your personal incredulity notwithstanding.
So there’s no natural reproduction Joe G? Because each time there’s reproduction new codes arise, by mutation. All naturally. As per the only one you know about (talk about willful ignorance), do you mean humans? As I said above, we’re part of nature, whatever we do, we do naturally. Not only that, our own nature, our own being, depends in those “code processing systems.” You’re therefore engaging in a cart-before-the-horse fallacy. You’re implying that the very beings whose existence depends on those “code processing systems”, made those very “code processing systems.” That we made everything, even ourselves and our own ancestors.
Sure what you want is to imply a magical being in the sky, but, given that philosophical problem, you’re trapped now in having to explain how the code information systems behind the “Intelligent Designer” came to be, to show evidence of that being’s existence. However, the code processing system of that mythological being would have to have arisen, ahem, naturally, and you’re back where you started, only with the extra weight of a bunch of absurd mythologies to prove real. Why not cut to the chase and start with the nature that’s already around you?
Nope. That says you didn’t know that humans are part of nature. So far, I’ve never seen any human produce anything without complying with every natural demand required for doing so.
Thus, before jumping to ludicrous conclusions involving magical beings in the sky, I prefer to wait for some actual, and pretty strong, evidence. Knowing you, nothing will satisfy your personal incredulity, mixed with that naïve credulity about magical beings in the sky, and nothing will work against your willful ignorance. So, to finish, I invite you to check Matthew 7:3-5 in your Bible.
Have a great day!
Possibly, but I think transition to RNA (or DNA) would be a hard problem. Transition from RNA to DNA is a breeze – happens now, in both directions, with full preservation of sequence. I think a hypothesised precursor would need to have the fundamental properties of xNA – not least, some equivalent to semiconservative replication, which gives the conditions for ‘improvement’ by adaptation due to the possibility of competitive increase in copy number. But also it needs some way of preserving that which was successful pre-xNA in an xNA world, suggesting a need for an improbable genetic continuity through presumably rather different molecules. If they weren’t different, the precursor would be xNA! So I tend to feel it’s genetics all the way down.
It’s kinda strange too, that ATP, and to a lesser extent GTP, have such a central role in energy metabolism and signalling.
Maybe nicotinamide predates the pyrimidines? (I’m just making stuff up here…)
Thanks for the paper. It appears establishing precise time scales with direct fossil evidence is challenging.
You always do.
Really? In a test tube, “abiogenesis style”?
In real life. Look up “transcriptase” and “reverse transcriptase”. ETA and “RNA polymerase”.
No, in life. I’m not arguing that the transition from RNA to DNA would be an example of abiogenesis, so feel free to dispel that particular misunderstanding.
What tools did your proposed creator of life use? Did it have hands? Did it do it with it’s mind?
When did all this happen?
Apologies, Corneel, I’ve mainly been using my phone to comment and I missed this earlier (small screen and having abandoned Chrome and its spam for Firefox which has a mind of its own) and you make a distinction worth pursuing, I think. Organic life evolved on Earth. Can we construct a silicon brain capable of simulating human consciousness? Are such simulants alive or is a requirement for life that it reproduces rather than being created. Is organic life (carbon and water) the only possibility or can we conceive of some self-replicating electronic organisms?
Hey Joe G! I’m sorry to tell you this, but your reasoning doesn’t look too much like reasoning, let alone like intelligent reasoning. It looks a lot more like rage outbursts.
Sez the guy who edits a paragraph to hide his blunder and then lies about it several times in a row.
No Joe G, you’re failing to understand a few words. Alan said that he doesn’t know of any other plausible explanations. That’s not personal incredulity, that’s an honest assessment. The keyword there is plausible. “common design” is not plausible, since there’s no designers to point to, and since it would involve loads of fallacious thinking. Lots of philosophical/reasoning blunders.
Mockery Joe G. Not strawman. You’re still credulous about magical beings, despite the reasoning/philosophical blunders involved.
Calm down Joe G. Your rage gets the worst out of you. It doesn’t do you any good though. You miss 99% of what you’re supposed to read.
There’s plenty of evidence that our current life forms diverged from prior life forms. Plenty too of some of the mechanisms proposed. Sure, lots of work still to go on, but, since we know it happened, it;’s a matter of continuing to work to understand how. Scientists find more scenarios, further data fills in gaps and give us further clues, etc. In the meantime, magical beings in the sky are outstanding in their absence in any of the findings produced by the labour of scientists. That’s to be expected, but you don’t care, right Joe G? Do you know what’s meant by a god-of-the-gaps argument? It’s not good.
Yes, there is. It happens all the time. I told you already. We don’t see magical beings participating on any of it. So, if you want them considered, produce the evidence. Catch them in the act. As hard as people have looked into the processes behind, say, reproduction, they haven’t caught any magical beings interfering.
So to answer my point about your personal incredulity, you double down on your personal incredulity? Do you know what irony means?
All the life I see around me is natural, and all of it reproduces, no problem, without any magical beings being caught in the act of making it so. Scientists discover a lot about how it happens, and everything they find is physical, requiring no magic. They can even disturb the process physically, and the results of those disturbances point to the processes being, indeed, due to the factors those scientists inferred to be involved.
So, again, I prefer to wait until a magical being is caught in the act before letting such a ludicrous idea contaminate my mind. You, on the other hand, proceed backwards. You engage into believing a ludicrous proposition just because you grew up loving those fantasies.
So your mother was impregnated by the holy spirit? Because if your father and mother did something together that resulted in you, then there you have the most direct evidence you could wish for.
Really? It happens by design just because you say so, evidence and reason be damned?
Again, it happens all the time. Reproduction is physical. We don’t see spirits entering life forms and resulting in reproduction. We see life forms engaging in collecting the materials and the energy necessary for making their offspring. We see them engaging in attracting mates for the physical interaction necessary for reproduction. Nothing indicates that the physical is out of the question. Nothing indicates that anything else is needed.
Personal incredulity doubling down with god-of-the-gaps. It doesn’t look like you understand your problems, as blind as you are with rage, and as unwilling as you are to try and turn that unhealthy skepticism from science to your own beliefs Joe G. If you did that you’d notice that your “proposition” is in much worst shape than you imagine evolution to be, and you’d be empty handed.
I’d be willing to consider “designers,” as long as the foundational philosophical problems could be solved, and as long as pretty good evidence of their workings arose. You, on the other hand, are unwilling to consider natural phenomena because you detest the idea, and evidence doesn’t matter as long as you can point to some incomplete answers, or make a good effort not to understand the answers available.
So far, we only see natural processes going on around us. That seems to suffice, even if we’re still working on some of the answers. After all, what we don’t know is evidence that we’re still far from having all the answers. Even that we might never get there. But ignorance is just that, ignorance. Not a good foundation to propose ludicrous “answers” like your imaginary designers.
Calm down. Have some tea. Have a great day.
Wait. Wasn’t this thread about the second coming of Millerurey? Or was it Darwin the first Martian?
And as long as you’re on some sort of truth serum, why not admit both “evolution” and abiogenesis are bogus claims?
Also, “a breeze” is not what you should call something you can’t even duplicate. But hey, that was before the truth serum, right?
No you poor illiterate little monkey, the thread is about discussing the possibility that life, different from that on earth, could be discovered, thus providing us with a second instance of life. Giving us a second data point to try and figure out if there’s more than one way for life to get started.
Allan’s comment was easy to understand regardless of what the thread is about. If only you could read. I keep telling you to read carefully, and you keep writing the first thing that comes to your addled mind, after a less-than-shallow pass, despite the frequency with which you ridicule yourself. I’m serious: read more carefully and you’ll avoid a lot of the embarrassment you suffer each and every time you post.
“Second coming” wrote as mockery by a religious nut! 🤣😂
You think Milller and Urey were martians?
What the fuck are you on about?
Perserverance mission is still looking good!
I feel your pain. 😢😆😊
Only seven more years to wait now.