What would be proto-life?

Discussion in 'Biology & Genetics' started by cosmictotem, Oct 9, 2015.

  1. cosmictotem Registered Senior Member

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    In an attempt to try to understand how life could arise in the Universe, I found myself thinking about what pro-life would look like. In other words, something one step down from what we generally understand as "self-sustaining" life.

    If we accept there are degrees of complexity to different life-forms, perhaps there are different degrees of proto-life.

    Jeremy England is using physics and math to come to similar conclusions about how energy is absorbed and dissipated and raises some questions for me.

    Since it's obvious that energy is driving the production of life, what would it look like for a system to absorb energy such as sunlight but be just under our definition of what we think qualifies as "life"?

    What if this proto-life form can absorb energy (sunlight) to sustain the appearance of life while that energy is applied to it, but have no capacity to store that energy? For example, when sunlight first strikes such a collection of Matter, the appearance of growth and vitality occurs but quickly disappears once the application of sunlight ceases.

    Such a collection of Matter would have no ability of motion or to reproduce and thusly would permanently "die" when the first "animating" instance of energy (sunlight) disappeared. However, if there was an abundance of Matter similarly organized being produced of Earth, the next time the sun appeared, a new collection of this short-lived proto-life, dependent on direct external energy for "animation", would rise forth in response and also "perish" with the sunset.

    Now since such a primitive interaction is dependent on external energy input (sunlight), what if one of these pieces of proto-life accidentally "figured out" how to absorb the dissipating energy of the transformed decaying matter of the previous "generation" of proto-life to sustain its own "life" long enough (longer than the previous one day "life" span) to still be "alive" when the next sunrise appeared?f

    If you have something that can be "animated" by the absorption and transformation of light energy, in feeding off the decaying structures of its predecessors, such an existent would still be feeding on the same sunlight that provided it with the appearance of animation and "life", would it not?

    In effect, the sun acts like the electrical socket and matter, the device. And later incarnations of matter later incorporated a portable "battery", probably from the fusion and/or absorption of other "living" structures. This onboard battery significantly extended the length and appearance of "life" and animation than having to be dependent on direct sunlight.

    Of course, this all exemplifies a way of looking at life. It's solely the transformation and absorption of external energy that makes us appear alive. Once you have biological systems that can do that, pretty much any ability can evolve out of it, including consciousness. Consciousness, as a consequence, is really no more an remarkable result than is photosynthesis. Without the energy input, all of it stops. We ourselves are nothing but walking batteries, perhaps, in this view.

    Even the language and mediums involved lend themselves to extend the metaphor:

    We are made of matter and that matter came from the Earth. Earth and soil, in a certain configuration, can be used to create an earth battery. We store energy just like a battery and power the various emergent processes that give us animation,etc...
     
    Last edited: Oct 9, 2015
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  3. timojin Valued Senior Member

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    I imagine you are well versed with Chloroplast, so why don't you analyze proto chloroplast , and take from there.
     
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  5. Yazata Valued Senior Member

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    Yes, I've been thinking about that too. I conceive of proto-life a chemical replicators capable of reproduction and subject to natural selection. I don't know what form they would take. Perhaps very short strands of naked nucleic acids, RNA or DNA. Maybe some kind of protein.

    Yes. The simplest existing cellular life, bacteria and archaea, are already exceedingly complex in molecular biological and biochemical terms. They aren't something that is likely to jump fully-formed out of a 'primordial soup'. They look to me like like the products of a long process of pre-biotic development that came before them.

    I don't know enough about chemistry to plausibly speculate about the origin of life in terms of energy and P-chem.

    The energy source might not have been sunlight. There's speculation that life may have originated around undersea geothermal vents, which were probably much more numerous early in the Earth's history. So the energy source may have been ambient temperature. But yes, early proto-life probably didn't have any on-board energy metabolism.

    These events might not have even been happening inside cell-like membranes. It would appear to us to be complex chemical reactions in the vicinity of geothermal vents being driven by the heat of the vents like a non-stop Bunsen burner.
     
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  7. Aqueous Id flat Earth skeptic Valued Senior Member

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    Not sure if any of that comes close to explaining the protocell. And it seems like solar energy was not necessarily directly exploited like this. Chemical and geothermal energy would be more likely sources of relatively high amounts of energy at the molecular level. (Except for some compounds which react to light.) Light and esp. heat from the Sun would seem more likely to affect the drying of pools where concentrations of dissolved chemicals and particulate matter would tend to concentrate, increasing the likelihood of certain reactions, and then to cause rainfall which would create fresh pools and dilute existing ones. Then wave action from winds fueled by the Sun (esp. due to uneven heating) would stir things together, possibly even blowing particulate matter around where it would eventually mix with, and potentially react with, other stuff.
     
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  8. Magical Realist Valued Senior Member

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    Have you considered liquid crystals as a form of proto-life?

    "We found this to be a remarkable result," Clark said. "It means that small molecules with the ability to pair up the right way can seek each other out and collect together into drops that are internally self-organized to facilitate the growth of larger pairable molecules.

    "In essence, the liquid crystal phase condensation selects the appropriate molecular components, and with the right chemistry would evolve larger molecules tuned to stabilize the liquid crystal phase. If this is correct, the linear polymer shape of DNA itself is a vestige of formation by liquid crystal order."

    - See more at: http://www.astrobio.net/topic/origi...ife/liquid-crystal-life/#sthash.5L4fevHi.dpuf
     
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  9. cosmictotem Registered Senior Member

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    Yes, crystals were my first thought. I actually didn't really think in terms of the chemistry because, frankly, I don't understand it yet. But I had some vague idea of crystals growing in response to some energy input. In the same vein, I thought there should be kinds of inanimate matter that respond in some way to sunlight. Energy gets passively absorbed and transformed into something else is how I'm thinking about it. Isn't that what all life is? Energy transformed into a crystal or a bacteria or a tree or a human? It seems like the energy of sunlight or ocean vents or minerals gets pushed into these different forms.

    I'm most definitely out of my depth in terms of explaining anything scientifically, though.
     
  10. cosmictotem Registered Senior Member

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    I say sunlight but, of course, I meant any source of energy or, as you detail, multiple sources at once or in sequence. I know the chemistry plays an important role, but, oddly, I try not to even consider the chemistry yet. I just try to imagine how a source of energy could give the most simplest preliminary impressions of animation, growth or life.

    Also, instead of trying to imagine how a membrane of a simple cell would have formed, I try to imagine pre-membrane proto-life that could "use" some already existing inanimate cover in which to conduct its processes at first.
     
  11. Magical Realist Valued Senior Member

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    Microscopic cubes of hematite conduct electricity under blue light. In a hydrogen peroxide bath the crystals grow and reproduce like cells. This would definitely be an example of light energy being harnessed for some sort of molecular self-assembly process.

    http://www.wired.com/2013/01/living-crystal/
     
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  12. cosmictotem Registered Senior Member

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    Awesome reply. Thank you! I have been trying to find an example like this for the last month without having the words for it. The fact that these crystals, in a sense, "reproduce" like cells is more than I expected to get. I'm out of the house right now but will surely delve into this more deeply tomorrow when I am home. I might have more to say about it in subsequent posts.

    Thanks again, MR!
     

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