LIFE ON EARTH: 3.2 BILLION YEARS AGO:

Discussion in 'General Science & Technology' started by paddoboy, Feb 16, 2015.

  1. paddoboy Valued Senior Member

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    Ancient rocks show life could have flourished on Earth 3.2 billion years ago:

    A spark from a lightning bolt, interstellar dust, or a subsea volcano could have triggered the very first life on Earth. But what happened next? Life can exist without oxygen, but without plentiful nitrogen to build genes - essential to viruses, bacteria and all other organisms - life on the early Earth would have been scarce.

    The ability to use atmospheric nitrogen to support more widespread life was thought to have appeared roughly 2 billion years ago. Now research from the University of Washington looking at some of the planet's oldest rocks finds evidence that 3.2 billion years ago, life was already pulling nitrogen out of the air and converting it into a form that could support larger communities.

    Read more at: http://phys.org/news/2015-02-ancient-life-flourished-earth-billion.html#jCp
     
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  3. danshawen Valued Senior Member

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    Life will use whatever conditions and/ or resources are available in order to survive. They do not need to be complex (at first) in order to do so. It is always a work in progress. It has to be, otherwise mass extinctions caused by things like global warming or cooling would also sterilize. Whenever a venue for survival is cut off, another becomes expressed via the action of the hox genes. If all venues for survival are cut off, it will nonetheless re-create itself, although the specific form may be different.

    Another force is at work here. Spooky, eh? What do you think of the garden?
     
    Last edited: Feb 20, 2015
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  5. Ophiolite Valued Senior Member

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    Incorrect.
    1. It will use whatever conditions/resources its current phenotype permits it to use. This automatically places significant limits upon its options.
    2. It will use these in an attempt to survive. There is no assurance of success. Survival is not guaranteed.

    Incorrect. Compared with crystallisation in a magma chamber, or establishment of Hadley cells, the first life was biochemically complex.


    How so? A mass extinction is not equivalent to a total extinction. If that is what you are trying to say then you are just contrasting the definitions of two related, but different concepts.

    Please provide citations to support this claim.


    so, you claim that life would re-appear, on the Earth, if it were to suffer total extinction? That is a bold claim. Will you retract it, or support it?

    Really? And what force is that?
     
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  7. GeoffP Caput gerat lupinum Valued Senior Member

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    Me.

    Pee on a rock 3.2 billion years ago, and they never shut up about it.
     
  8. danshawen Valued Senior Member

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    By "total extinction", I mean complete elimination of all living genomes. But this is a fantasy short of any event other than conversion of our Sun to a red giant, consuming the entire mass of the Earth as fuel for fusion.

    I do claim that life would re-appear on Earth in some form short of the total extinction event in the previous paragraph. I do not have a citation. I do not have research other than the obvious observation that life exists now, and it probably didn't at some time in the distant past. Many of the materials necessary to create life here evidently originated in the cores of exploding supernovae. Positing a higher power as a motivation for this creation is an idea repugnant to me, but the fact that we are here and are having this conversation strongly suggests that it would happen even in the presence of a different set of energy resources, materials, and circumstances. Life is evidently not possible without the power of exploding supernovae, but this does not motivate me to believe the input to the system is possessed of the self-awareness necessary to intentionally create life from the substances it eventually produces through atomic fusion.

    http://www.biologytimes.com/primordial-soup-revisited/

    The Nobel-Prize winning work on hox genes (genotypes of bilaterally symmetrical animals starting with worms) and also crystalline studies of DNA(a) and (b) has lowered the bar in terms of the number of random mutations necessary to produce viable organisms from basically nothing but the amino acids produced in the Miller-Urey experiment. You only need about 60 amino acids, perhaps much less, in the right order for the process we refer to as life to begin from inanimate carbon-nitrogen-hydrogen-oxygen compounds. I've no idea if there may be simpler forms possible with other resources. This is a distinct possibility.

    As for what is the force that drives this proliferation of life, this is still anyone's guess. With the limited resources always accompanying it and the relatively fragile forms it prefers to take, this force seems far removed from omniscience or omnipotence. Nonetheless, it does what it can within the limits of the energy provided, and is flexible enough to seek means to render its own existence more resilient. That biological activity has something akin to a soul, even if we do not perceive anything like it with our limited senses or instrumentation.

    Life does something that inanimate things, even the growth of crystals, seem unable to achieve over the long term. If I were to paint a portrait of Dorian Grey (or anything else, for that matter), eventually the pigments would deteriorate. The canvas would be assaulted by the elements. One would be left with dust of what previously was a painting in far less than cosmological time.

    But life, given the energy to do so, keeps repainting itself. Also, continuously consuming part of itself in order to do so. Somehow, it succeeds in enduring and propagating its form and purpose in conditions inanimate things would not.

    Science would not be nearly as much fun if it were not possible, in the words of Mark Twain, to derive such wholesale conjecture from only a trifling amount of observation.
     
    Last edited: Feb 21, 2015
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  9. Ophiolite Valued Senior Member

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    Mark Twain was an accomplished author, a keen observer of human nature and a great wit, but he was no scientist. I'll respond to your other points later.
     
  10. Dinosaur Rational Skeptic Valued Senior Member

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    I thought there was life on Earth 3.5 to 3.7 billion years ago.
     
  11. Ophiolite Valued Senior Member

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    The article relates to the first organisms capable of nitrogen fixation.
     
  12. Ophiolite Valued Senior Member

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    Dan, I'm sorry to seem like a nit-picking, anally retentive prick, but you don't seem to think before posting. Almost every sentence and certainly every paragraph contains some combination of errors, ambiguities, irrelevancies, gross exaggerations, misinterpretations or logical fallacies. In this instance:
    1. The sun may consume the Earth in its red giant phase (though this is not definite), but it certainly does not use the Earth's mass as fuel for fusion. That's pure nonsense.
    2. There are other events that could eliminate all life on the planet. Impact by a rogue planet is one example.

    That makes no sense. If life has not been totally eliminated then it cannot re-appear. If you meant to say that following a massive extinction, life would recover, then fine. However, that's not what you've posted. Please clarify.

    Most of that comes across as waffle. Your key point appears to be "life arose once, it can arise again". If that is your point then I agree it might arise again, but there is no assurance this will be the case.

    We do not know what precise conditions were necessary for the origin of life. We do not know if it was inevitable, or a unique event. Debate -rightly - is very active on this point. So, I comprehensively reject your assertion that life would reappear. You have provided no meaningful evidence to support that assertion.

    But here is what you originally said: ". Whenever a venue for survival is cut off, another becomes expressed via the action of the hox genes." Nothing in your remarks supports that absolute assertion.

    I can readily agree that hox genes are important elements in enabling evolution, but they do not provide a solution in every instance, as you have claimed. Hox genes arrived late in the evolution of life. They most certainly cannot "produce viable organisms from basically nothing but the amino acids". If an extinction event eliminated all multicellular life forms it would also eliminate all hox genes.

    Further, you don't need 60 amino acids, 20 will do; you haven't declared how DNA would be produced; you haven't demonstrated that the conditions obtaining in the Miller-Urey experiment would be present following a massive extinction event; etc.

    I hope you see how difficult it is to address the central points of your arguments when they are surrounded by inaccuracies and fluff. I look forward to continuing a discussion on these various points, but I hope you will be more focused and accurate in your replies.
     
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  13. wellwisher Banned Banned

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    Life is based on the analogy of mixing water and oil. If we add energy and mix water and oil these two materials will blend to form an emulsion. This emulsion is a state of high entropy; disorder. But this is not a stable state of high entropy because if we stop the agitator and thereby stop adding energy, the emulsion was will reverse back to two layers; oil on top of water. In this case, order appears from the chaos of the emulsion, with the entropy decreasing value to reflect this different state; without agitator.

    Life also tries to stores increasing energy value. As a tree grows, the larger the tree, has more fuel value. The storing of energy creates the water and oil (organic) analogy. There is a push to lower entropy into separate phases. The various organelles reflect phase state. The cell also has a lot of membrane materials which are essentially oils and waxes to help drive the separation.

    Since the entropy of the universe has to increase, this is done via changes in chemical compositions that will allow the potential between water and the oil/organic analogy to lower so entropy can increase. This is called evolution.
     
  14. Fraggle Rocker Staff Member

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    24,690
    What I have read is that Earth's orbit just happens to be at the very distance at which the Sun will expand to when it completes its transformation into a red giant. Our problem is that we cannot possibly calculate that distance with very much precision.

    Yes, the Sun may expand slightly beyond Earth's orbit. In this case, it will be vaporized and the matter that comprises it (and us) will be vaporized and mixed in with the other matter that already comprises the sun.

    But yes, it's also quite possible that the expansion may halt slightly inside Earth's orbit. In this case (depending on the exact distance), Earth has a chance of surviving as a planet. However, being so close to the sun, its temperature will rise enormously. The atmosphere will dissipate into space and all of the planet's water will vaporize and dissipate with it. Its surface temperature will, of course, be too hot to support life; such fragile objects as animals, plants and the other four kingdoms of living things (algae, fungi, bacteria and archaea) will melt, burn and/or vaporize.

    Perhaps by then humans will have the technology to construct shelters that withstand the onslaught of solar radiation. Perhaps they will have mastered nuclear engineering and be able to create food and water from the heavy elements that are still available.

    But this scenario is several billion years in the future. If our descendants have developed that level of technology, I'd hope that they will also have developed fast, reliable, high-capacity space travel. In that case, they will have had quite a long time to evacuate the planet and establish new colonies elsewhere in the galaxy. Only a few scientists will remain until the last minute to study the Sun's transformation.
     
  15. Ophiolite Valued Senior Member

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    9,232
    Three points:

    1. As the sun continues to convert mass to energy its gravitational attraction reduces and the planets all move to slightly larger orbits. The most recent calculations suggest this is likely to place the Earth far enough out to avoid "consumption" by the sun.
    2. If it were to be absorbed into the sun only a small proportion of its mass is hydrogen. This mass is miniscule compared with the available hydrogen in the sun. So, dan's remark that it would provide "fuel for fusion" is poor poetry and worse science.
    3. From the standpoint of life it is academic, since the Earth will have been reduced to a barren, Venus-like planet in about one billion years time on account of the increase in solar luminosity.
     
  16. Fraggle Rocker Staff Member

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    24,690
    One billion years is still about six thousand times longer than the existence of our species, not to mention about two hundred thousand times longer than the time from the discovery of bronze metallurgy, which could be called the beginning of more-or-less "modern" technology.

    Hopefully that will give us plenty of time to establish a galactic civilization, so the demise of one planet--no matter how beloved--will not make us extinct.
     
  17. danshawen Valued Senior Member

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    Aerobraking due to interaction of the remaining mass of the Earth with the red giant's solar wind is all that is necessary to de-orbit the mass that previously was Earth. It will fall into the core of the red giant Sun, where fusion continues to take place for each and every element with atomic numbers South of iron.

    Basically multicellular life on Earth started out as nearly bilaterally / radially symmetrical creatures resembling worms. The hox genes control organ and appendage expression, sort of a "swiss army knife" of survival. If an appendage or organ is expressed that does not impact survival, that appendage or organ is pruned by natural selection. This is an easy concept, although I have not seen it explicitly expressed in this manner. I don't wonder, this should be news to some people. But I don't think of such ideas as "fluff".

    @Opthiolite: I make no representation that anything I think or write about here or elsewhere is absolute truth. I do try to be certain that it has been minimally researched, and you are very welcome to call me on that any time I run off the rails. Not only does it not offend, but it is exactly the reason I do this. I want to get it right, or at least, as close as possible. It does not do to obsess about the wrong things, even in small measure. That would be pathological.
     
  18. Ophiolite Valued Senior Member

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    While this is imaginative please provide a citation demonstrating that this is more than your imagination at work.

    This turns out to be wrong.
    1. What makes you think that the planet could retain integrity sufficient to allow it to "fall" or do anything as a unit?
    2. Why, given the excessive turbulence within the expanded sun, would anything fall towards the core.
    3. The main thing fusing in the commonest of red giants is hydrogen, with some fusing of helium to carbon and a few other minor pathways in others. It id does not involve fusion for each and every element with atomic numbers South of iron.
    4. In a red giant the helium fusion and other minor pathways, if occurring , will take place in the core. However the principal fusion is of hydrogen in a shell surrounding the core.

    All well and good, however you emphatically stated that:

    "The Nobel-Prize winning work on hox genes (genotypes of bilaterally symmetrical animals starting with worms) and also crystalline studies of DNA(a) and (b) has lowered the bar in terms of the number of random mutations necessary to produce viable organisms from basically nothing but the amino acids produced in the Miller-Urey experiment."

    You offered this in defence of your claim that life could reappear on a largely sterilised Earth. Your argument, as presented was, that hox genes could facilitate the reemergence of complex life. If that is not what you should state clearly now what you did mean.

    My counterpoint is that if mullticelullar life is eliminated then hox genes are eliminated so they can hardly contribute to its reemergence.

    Throwing out some (partially incorrect) statements about genetics and DNA and failing to integrate them within any argument definitely constitutes "fluff" in my lexicon. If you think you have something substantive to say on the matter then say it - with a suitable logic flow and appropriate citations.

    I shall certainly do so. As a case in point it took me less than a minute to confirm the errors I thought were present in your comments about the sun's red dwarf stage. Your minimal research on that must have been miniscule.

    Dan I intervene in these matters because you speak with a degree of confidence that would lead casual readers into thinking your version of concepts was correct. I believe this forum has an educational value, but only if we are rigorous in our facts. I shall continue to hound you and anyone else who is less than rigorous. I expect the same treatment in return.
     
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  19. danshawen Valued Senior Member

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    What makes you or anyone else think that academics have a hammerlock on original ideas, or for that matter, that I would care, even if they had an idea expressed on the subject?

    You are conversing with someone who no longer cares about such things,. That said, I do care about credit where credit is due, for honesty's sake. To conduct a thorough search would require more time than I have left to live. Are you requesting that I just shut up and conduct uncompensated research until that happens?
     
  20. Ophiolite Valued Senior Member

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    Lose the arrogance, why don't you. It's tiresome.

    If this idea has been proposed by others - and that is where you have got it from - then I would like to read their arguments, consider their evidence and review their maths. Therefore it is reasonable to ask for a citation.

    If it is your idea then you need to support that idea with reasoned argument and evidence. That is a rule of the forum. (I don't recall if it is an explicit rule, it is certainly an implicit one.) Of course you could simply have rephrased your absolute assertion, so that it was no longer absolute. You could so easily have said "I wonder if the planet might aerobrake in the solar wind to the extent that it spiraled into the sun?" I would have responded: "What a neat idea. I wonder if anyone has done any work on that. I'll do a literature search."

    But instead you had to indulge your arrogance by making an absolute assertion.

    I am requesting that you stop making unsupported absolute statements. Speculate to your hearts content, but please make it clear that it is a speculation, or an opinion, or even a question. Spewing out unsopported, poorly researched claims is unwelcome on a science forum.
     
  21. danshawen Valued Senior Member

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    3,950
    Ophiolite;

    I'm not trying to be arrogant, really.

    It is true that after extensive computer modeling, the fate of the Earth is uncertain mainly because the Sun itself will lose mass, and as it does so, the orbit of the Earth may be further away, perhaps enough to avoid being engulfed in the photosphere. The references for this are on the Red Giant article on Wikipedia if you want them. I see no need to duplicate them here.

    However, the orbits of Mercury (which actually has ice!) and Venus (which has lots of carbon and oxygen) will also be engulfed, not to mention the capture of another 2 billion years worth of captured asteroids and comets. Much of this acquired mass will be converted to photon energy before the Sun goes full red giant as well, even if it takes millions of years for a photon to traverse the distance from the core to the photosphere. The sacrifices of the innermost planets of the solar system may offer a brief reprieve, if they are still close enough.

    Do you have a strong opinion on this avenue of simulation? Would you feel better if the Earth became part of a planetary nebula surrounding a white dwarf? These appear to be the only two choices, barring some catastrophic event like Billy T here described in one of his works of fiction.

    If you wish a more "scholarly" discussion of any of this, or anything else, might I suggest taking it to the Physics or Astronomy stack exchanges. If you wish to meet more irritating academics (some only 14 or 15 years old), and who act the part, sometimes as moderators, perhaps your interests would be better served there. If you actually like "arrogant", as well as "smarmy" and "condescending", they are hard to beat. In some circles, scholarly means all of the above.

    In their support, they are all about references. Sometimes, they even duel with them. I found this distasteful, even if you don't. If you read some of their moderator chat rooms, you will find them very distasteful indeed. They get academic credit for what they write, and many of them would cut each other's throats to get it.
     
    Last edited: Feb 23, 2015
  22. Ophiolite Valued Senior Member

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    9,232
    Just be aware that is how you are coming across.

    1. So, at last - it's like pulling teeth - you agree with what I said at the outset, when challenging your flawed assertion.
    2. So, I don't need the references, nor do I need Wikipedia, in this instance. I was familiar with that research long before this thread existed.

    Why do you think the presence of ice and carbon and oxygen is significant? Do you think Mercury has very little oxygen? How do you imagine the mass of those asteroids and comets compares with the mass of, for example, Venus.

    The outcomes are all of low grade academic interest.


    This is a science forum. If I want to listen baseless waffle I can go to the pub.
     
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  23. danshawen Valued Senior Member

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    Likewise! And not a bad idea, either.

    I've learned a lot here. My interest in such forums peaked last June when the discussion of the discovery of the Higgs Boson was heating up. I really wanted to know where it was going. What I discovered was a true delight, and it's very addictive. Even my detractors here contributed to a deeper understanding more than they know. Furthermore, there is NO ACADEMIC VENUE anywhere for me to scratch such an itch. But the itch is now relieved. The research and whatever comes of it is in the best of hands.

    There's lots of iron in Mercury. Iron makes no difference to fusion processes, because it contributes no energy. Composition does matter. The amount of mass in a Venus or Earth sized planet may extend the fusion life of the Sun by a million years, give or take.

    As you said, of low grade academic interest anyway.

    Evolutionary genetics / biology is a much more active area of academic interest. The details are mind-boggling, even if many Young Earth Creationists reject them wholesale.
     

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