• ovdtogt
    378
    life: a replicating chemical reaction. Is this an accurate or even useful definition of life? And if so are we able to speculate how such a self replicating system could come into existence?
  • TheMadFool
    4.3k
    life: a replicating chemical reaction. Is this an accurate or even useful definition of life? And if so are we able to speculate how such a self replicating system could come into existence?ovdtogt

    How easy it is to reduce the wisdom of philosophy, the beauty of poetry and the joy of a painting to a chemical reaction in a chemist's lab.

    I heard a TED talk where a speaker remarked of a friend who said "I love my child more than is required by evolution". Reductionism maybe the way to go in science but it fails to completely capture the full range of experiences in the phenomena it attempts to explain.

    It could be that this belief that the whole is somehow greater than its parts is just an illusion, reflecting a lack of knowledge rather than anything real in such beliefs.
  • ovdtogt
    378
    How easy it is to reduce the wisdom of philosophy, the beauty of poetry and the joy of a painting to a chemical reaction in a chemist's lab.TheMadFool

    https://fs.blog/2011/10/richard-feynman-on-beauty/

    I have a friend who’s an artist and has sometimes taken a view which I don’t agree with very well. He’ll hold up a flower and say “look how beautiful it is,” and I’ll agree. Then he says “I as an artist can see how beautiful this is but you as a scientist take this all apart and it becomes a dull thing,” and I think that he’s kind of nutty. First of all, the beauty that he sees is available to other people and to me too, I believe. Although I may not be quite as refined aesthetically as he is … I can appreciate the beauty of a flower. At the same time, I see much more about the flower than he sees. I could imagine the cells in there, the complicated actions inside, which also have a beauty. I mean it’s not just beauty at this dimension, at one centimeter; there’s also beauty at smaller dimensions, the inner structure, also the processes.
  • TheMadFool
    4.3k
    I have a friend who’s an artist and has sometimes taken a view which I don’t agree with very well. He’ll hold up a flower and say “look how beautiful it is,” and I’ll agree. Then he says “I as an artist can see how beautiful this is but you as a scientist take this all apart and it becomes a dull thing,” and I think that he’s kind of nutty. First of all, the beauty that he sees is available to other people and to me too, I believe. Although I may not be quite as refined aesthetically as he is … I can appreciate the beauty of a flower. At the same time, I see much more about the flower than he sees. I could imagine the cells in there, the complicated actions inside, which also have a beauty. I mean it’s not just beauty at this dimension, at one centimeter; there’s also beauty at smaller dimensions, the inner structure, also the processes.ovdtogt

    Firstly congratulations for the depth of your aesthetic sense. Secondly I have nothing against describing and viewing life as a chemical reaction but there is something wrong in the view that life is just a chemical reaction. As I mentioned this maybe just a symptom of a gap in our understanding but there's a chance that life is much more than just a chemical reaction. A lot would depend on which of these two possibilities is true. If we're nothing more than glorified bags of chemicals than it would be very depressing but, on the other hand, if there's more than meets the chemist's eyes then the mystery deepens and all sorts of interesting and awesome possibilities are up for grabs.
  • ovdtogt
    378
    Firstly congratulations for the depth of your aesthetic sense.TheMadFool
    This is a quote from Richard Feynman not mine. Heard of him?
  • TheMadFool
    4.3k
    Heard of him?ovdtogt

    Yes and I also know he had a taste for topless bars :grin:
  • Pfhorrest
    592
    Life is self-productive machinery, where productivity is a property of mechanical work whereby it reduces the entropy of the system it is done upon. So life is a system that transforms a flow of energy through it (a machine) in such a way that that system’s own internal entropy is decreased.
  • Possibility
    778
    life: a replicating chemical reaction. Is this an accurate or even useful definition of life? And if so are we able to speculate how such a self replicating system could come into existence?ovdtogt

    I replied to you on the other thread, but I’ll repeat it here: I think that life is more a self-replicating system of interacting chemical reactions. This is at its most basic, mind you.

    I speculate on this all the time. The way I see it, the diversity and changeability of carbon molecules and carbon chains in chemical reactions enables a broad variety of different reactions to potentially occur alongside each other in ‘primordial soup’ conditions, and to interact with each other in an even wider variety of ways. I’m probably doing a terrible job of explaining the situation, but the possibility of a chemical reaction interacting with another chemical reaction several times in several different ways across the duration of each event certainly increases the chances of developing some kind of spatial-temporal relationship between the these chemical reactions.

    But I don’t think it’s just about the interactions, rather about the information available when this occurs (I think this also relates to @Pfhorrest’s entropy reduction above, given that entropy=missing information).

    We could consider the basic interaction between two particles as a one-dimensional awareness: where only a single bit of information about one particle is presented to another, and is immediately integrated. It could be an increase in vibration, or trajectory, etc. The particle has the capacity to be aware - only in that briefest interaction, and only very vaguely - of more (than itself). More than what, it cannot possibly know, yet it manifests/integrates the information within itself.

    A chemical reaction, however, can be considered a two-dimensional awareness: where two or more particles interact for a duration. During that duration, the chemical reaction forms a relationship-entity, and has the capacity to also be aware of any third particle that may interact. If two interactions occur during that time, this relationship-entity can even make a basic distinction between these interactions, as one-dimensional information (a distinction in relation to itself). This distinction can then inform the results of the chemical reaction.

    Life develops from a three-dimensional awareness: two chemical reactions, as enduring relationship-entities, interact with each other, with the capacity to acquire information about the other chemical reaction in relation to its own duration. This means that each chemical reaction can make a distinction between two or more different chemical reactions that it interacts with (in relation to their distinction from itself), and can also interact with those relationship-entities for a duration, forming a more complex entity/relationship (life) - one that has the capacity to be aware of interactions as gradients (two-dimensional information), and inform its various chemical reactions, creating movement, etc.
  • khaled
    1.1k
    I think of this one when I'm not in the best moods

    Life: A sexually transmitted disease
  • Wayfarer
    8.9k
    Life is self-productive machinery,Pfhorrest

    Machines are assembled by external agent, namely , humans. Organisms even at the most basic level exhibit goal-directed behaviours and the ability to maintain homeostasis which are found in machines (aside from those machines in which such attributes are emulated in silicon, again by human agents.)

    Living things, generally, manifest an attribute which is not at all associated with chemical reactions, namely, intentionality and agency.
  • Pfhorrest
    592
    Machines are assembled by external agent, namely , humansWayfarer

    Not as the term is used in physics, which is the sense of which I mean it here. A physical machine is a system that transforms a flow of energy from one form to another, or a system that does work, again in the specific sense of that word used in physics.
  • Wayfarer
    8.9k
    A 'notional' machine? Or are there examples in physics?
  • ovdtogt
    378
    I was trying to define Life in it's most fundamental essence in the hope/belief one could extrapolate from there to discover something meaningful about Life. Unfortunately I think this is beyond my comprehension. Far cleverer people are looking on the quantum level into the processes of Life.
  • Possibility
    778
    life: a replicating chemical reaction. Is this an accurate or even useful definition of life?ovdtogt

    The short version: No.

    Life defined as a replicating chemical reaction is an oversimplification. It isn’t accurate, and as a definition of life it doesn’t distinguish an understanding of life from other replicating chemical reactions - like a star - so it isn’t very useful.

    I think we could define life more accurately, at its most basic, as a self-replicating system of various chemical reactions.

    And if so are we able to speculate how such a self replicating system could come into existence?ovdtogt

    The short version: of course we are.

    If you want me to speculate here, it’ll take more than two sentences. I think there is a way of looking at how chemical reactions can be informed by other chemical reactions over a duration, which points to a capacity for life. But an impetus that would underly both the chemical reactions and the resultant replicating system is the clincher.
  • ovdtogt
    378
    Life defined as a replicating chemical reaction is an oversimplification.Possibility

    To find simplicity in complex 'reality' is the essence of 'knowledge'. We are looking for building blocks not for buildings. Try to find a definition of life in 1 sentence and work your way up from there.

    But an impetus that would underlie both the chemical reactions and the resultant replicating system is the clincher.Possibility

    I totally agree with you there. First you need a integrated 'system' and then it needs to be able to replicate itself.

    I think you would first need a physical structure, similar to an exoskeleton (porous rock or calcium deposits?) in which a certain (natural) chemical process takes place. Possibly a process that makes lipids which in turn creates a substitute skin. Do you know of a chemical process capable of making lipid from inorganic compounds?
  • Possibility
    778
    To find simplicity in complex 'reality' is the essence of 'knowledge'. We are looking for building blocks not for buildings. Try to find a definition of life in 1 sentence and work your way up from there.ovdtogt

    I did - I adjusted yours.

    I think you would first need a physical structure, similar to an exoskeleton (porous rock or calcium deposits?) in which a certain (natural) chemical process takes place. Possibly a process that makes lipids which in turn creates a substitute skin. Do you know of a chemical process capable of making lipid from inorganic compounds?ovdtogt

    Skin comes later. First you need to have a system that moves of its own accord - that responds as a whole to internal chemical reactions.
  • ovdtogt
    378

    But an impetus that would underly both the chemical reactions and the resultant replicating system is the clincher.Possibility

    I would think a degree of separation of a chemical process from it's surrounding would be a fairly necessary prerogative. The 'system' would need to develop a certain amount of control over the process at a fairly early stage.
  • TheMadFool
    4.3k
    To find simplicity in complex 'reality' is the essence of 'knowledge'. We are looking for building blocks not for buildings. Try to find a definition of life in 1 sentence and work your way up from there.ovdtogt

    Agreed. Simplicity has a special status in knowledge, especially science where it is an important condition for a good hypothesis. However, you will agree that reality has a richness, both in variety and depth, of experiences that should be appreciated for its complexity and simplifying everything verges on oversimplification.
  • ovdtogt
    378
    oversimplification.TheMadFool
    I like to start with an (over)simplification that we can agree on and then work our way up from there. Lets see if can agree on the 'basics'.

    We know life at it most basic level can be defined as a chemical process and then speculate how 'life' might have conceivably evolved from there.
  • Pfhorrest
    592
    I think you’re thinking of much more complicated systems than are necessary to count as machines. Simple machines include things as elementary as a wedge or an inclined plane that can easily be found all throughout nature with nobody having designed them (unless you want to beg the question about God).
  • ovdtogt
    378
    Simple machines include things as elementary as a wedgePfhorrest

    The problem is not the wedge. How this wedge was able to start making copies of itself is the problem.
  • Pfhorrest
    592
    Replication is not a necessary feature of life, but since you asked: organic molecules are already very complex nanomachines that interact with each other to produce other molecules that interact to produce other molecules etc. With energy input into the system it’s possible for these reaction chains to form loops, that then fill their environment with their constituent molecules. Any change that allows for shorter more efficient loops will fill the environment with more of its constituents, and so on until you arrived at a self-replicating molecule, a nanomachine that builds copies if itself. Evolution as you hopefully understand it already can then take over from there.
  • NOS4A2
    1.7k


    I have a friend who’s an artist and has sometimes taken a view which I don’t agree with very well. He’ll hold up a flower and say “look how beautiful it is,” and I’ll agree. Then he says “I as an artist can see how beautiful this is but you as a scientist take this all apart and it becomes a dull thing,” and I think that he’s kind of nutty. First of all, the beauty that he sees is available to other people and to me too, I believe. Although I may not be quite as refined aesthetically as he is … I can appreciate the beauty of a flower. At the same time, I see much more about the flower than he sees. I could imagine the cells in there, the complicated actions inside, which also have a beauty. I mean it’s not just beauty at this dimension, at one centimeter; there’s also beauty at smaller dimensions, the inner structure, also the processes.

    But by “seeing much more of the flower than he sees”, ie. dissecting it and examining its parts, you’ve destroyed the flower.
  • ovdtogt
    378
    As long as you don't destroy the last flower on earth, I don't see the problem.
  • ovdtogt
    378
    Replication is not a necessary feature of lifePfhorrest

    Show me one life form that has come into existence without replication. The essence of life has to be that it can produce an (almost) identical copy of itself.
  • NOS4A2
    1.7k


    As long as you don't destroy the last flower on earth, I don't see the problem.

    The loss of that many flowers would be devastating.
  • TheMadFool
    4.3k
    I like to start with an (over)simplification that we can agree on and then work our way up from there. Lets see if can agree on the 'basics'.

    We know life at it most basic level can be defined as a chemical process and then speculate how 'life' might have conceivably evolved from there.
    ovdtogt

    That's a good strategy. Answer the easy questions first and then attempt the tough ones is a good technique.

    It has worked so far right? The world is lit up with electricity, we jet across continents, we do organ transplants, etc. These are all a piece of cake before the mind/consciousness problem, a compelling description of which has eluded even the best among us.

    It's not an error to start from the simple and then proceed to the complex. :up:
  • ovdtogt
    378
    Yes. You would think we would have figured out how to create a basic cell by now. One that is able to synthesize organic molecules.
  • Enrique
    68
    Sorry to crash the party, but I've read a couple books recently outlining some facts pertinent to this discussion that you guys will probably find very interesting. Somewhat long-winded and I'm no pro, but I think a few minutes of perusing will be rewarded with snazzy biochemistry knowledge.


    Despite the centrality of photosynthesis to the modern biosphere, it has been found that prokaryotic organisms can survive in many climes, wherever energy can be harnessed by chemistry. Competing theories were formulated that considered the possibility of extremophile prokaryotes as the first lifeforms, a likely option considering the possibly turbulent conditions of an earth that, 3.8 billion years ago, was still in volcanic apoplexy. It became common currency that early Earth was profuse in nitrogen and carbon dioxide gas as well as water, with paltry amounts of ammonia and methane, conditions prevailing in the interface between the atmosphere and Earth’s surface, but due to the chaos induced by land birthing tectonic shifts and magma emissions it seemed likely that life would have burgeoned in more stable deep ocean environments, though a viable energy source of course had to be available.

    This led scientists to deep sea hydrothermal vents surrounded by teeming populations of single-celled life. Near boiling ocean water heated by the molten mantle beneath earth’s crust froths above fissures that inject hot gas and simple sub-units of macromolecules such as amino acids and other carbon compounds into rock enclosures, eroding microscopic pores into their bulk. Chemicals circulate in and around these tiny chambers that act like nodes between wormlike tunnels connecting this collective chemistry to the outer ocean. It is postulated that dissolved gases such as carbon dioxide, hydrogen and nitrogen, organic molecules, and proton gradients from hydrogen atoms stripped of electrons all subsist in this supercharged environment, a conjunction which provides conditions for a lifelike metabolic cycle without the presence of membranes; networks of linked pores within the rock are the totality of requisite structure, functioning like a congregate of cell walls. Metal ore surfaces exposed within the chambers may catalyze energy transfer, acting the role of primitive enzyme. It is an intriguing model, one that seems to explain what would be bacterial descendants living in droves nearby, and scientists have recently committed to testing it.

    An experiment was designed that placed a solid clay brick with microscopic pores and channels in a sealed cylinder of aqueous solution. A tube pumped a heated flow of water through the clay in such a way that circulation was achieved, and further tubes introduced the gases and organic molecules of hydrothermal vents to solution in a concoction that mimicked actual conditions with high fidelity. Scientists planned to set the apparatus in motion and determine whether larger molecules can be formed this way. The effort is ongoing and should disclose much about how life’s metabolism may spontaneously irrupt into existence.

    It is not hard to imagine a sort of membranous biofilm adhering to the interior of the rock, becoming gradationally studded with as well as inhabited by amassing macromolecular clusters conjuncted to the nutrient rich external cycle, expanding and budding off living vesicles as the first cellular organisms. Each evolutionary step is improbable on its own, but metabolic self-sufficiency together with mutational self-replication only had to materialize once or rarely, and billions of years of naturalistic trial and error in prokaryotic time is like a macrocosm of the universe.


    Quantum mechanics, in particular superposition, has been implicated theoretically in one of its stranger applications, namely to the theory of evolution. It has long been a quandary as to how the extremely improbable leap from inorganic to organic chemistry transpired, especially how the first self-replicating molecules emerged when they cannot even perform any functions at all without the enzymes that simple intuition tells us they must have preceded in time. Looking at the relationship of DNA with the crucial enzymes DNA polymerase and reverse transcriptase, it is hard to see how the vastly complex symbiotic evolution through hundreds if not thousands of more primitive forms could have occurred. We have not recreated it in a lab, as the basic ingredients simply do not yet come close to the refined machinery of actual life in our experiments. The means of evolution have been quite alien to the evidentiary legacy of molecular genetics.

    What seemed even hypothetically impossible a few decades ago has become more tenable in the 21st century. Researchers discovered that RNA, single-stranded replicators, are much more prone to mutation than DNA, as RNA polymerase does not proofread its genetic copying, so unprecedented enzymes are constantly being produced by new code in even modern eukaryotic cells, some of which can perform novel functions and change the intracellular metabolism, at least temporarily. RNA’s replicational flexibility shortens the theoretical timeframe necessary for substantial evolutionary transition. Ribozymes have also been observed in the cytoplasm, hybrids of RNA strands and protein chains that catalyze some of their own functions. This could be a descendant molecular species of the missing link: self-directing replicators. It is becoming increasingly convincing to think of the living cell not as a factory or manufacturing plant with a fixed and inextricably interdependent set of mechanical structures, but rather as a dynamic ecosystem in which its elements are semi-autonomous, competing with each other, coalescing into flexible symbiosis, adapting to the general nanoscale environment at a rapid rate.

    Even with the viability of a microscopic RNA and ribozyme ecosystem as the breeding ground of what became modern life, the chances of a collection of thousands of different types of symbiotic macromolecules each containing thousands of atoms arising in perfect evolutionary sequence is astronomically small by the standards of Newtonian-influenced conventions in solution chemistry. A degree of functional order on that scale emerging out of a completely inorganic environment would require a much longer duration than the entire 14 billion year history of the universe in the context of thermodynamically-driven diffusion along with energy transfer between particles of a roughly spherical nature and their particle chains and loops, let alone the less than 3 billion year incubation of prokaryotic life. This led scientists to wrack their brains about what could accelerate the rate of evolutionary formation.

    The tentative solution, still in its purely theoretical and experimental stages, is the idea that certain protons and electrons in macromolecules can be in superposition with themselves as they undergo some kind of vibrational fluxing within and between atoms, existing as multiple overlapping wave phases modeled according to the Schrodinger equation of quantum physics, meaning that each macromolecule is in hundreds of different configurations at once, greatly reducing the time necessary to achieve a functional, adaptationally effective form. The beginning of the replicator-generating evolutionary process would lack competition, with relatively primitive molecules free to adopt all possible forms instantaneously, until in this blindingly fast metabolic tailoring of the organic to the inorganic surroundings a real replicator or replicator/enzyme hybrid was born.

    Expansion and diversification of replicator populations would exert additional forces of natural selection as self-propagation inclined towards greater relative efficiency, causing the replicators' sites of quantum behavior, modellable as superposed wave functions, to collapse into forms providing greater reproductive fidelity, more stable, thermodynamically-driven structures adapted for the inheritance of enduring traits, though the pragmatisms of faster reaction rate, magnified biochemical triggering and more complete energy transfer must have kept quantum effects from becoming entirely vestigialized, a total decoherence. Though heredity has not yet been created from non-life in the lab, it may be the fastest and most inevitable step in evolutionary history, capable of happening in myriad ways. Quantum mechanics makes it almost assured that we will someday evolve nascent life out of inorganic chemistry by artificial means, perhaps very soon.


    Snazzy factoids, wouldn't you agree?
  • Pfhorrest
    592
    Self-replication is necessary for evolution to happen, and evolution is necessary for life to come into being in the first place, but once there exist living things that can make other things, those other things don't have to be able to reproduce to count as alive. Mules can't reproduce, for example, but they're still alive. And in principle we could build a new thing that doesn't reproduce but is otherwise alive in the way we normally think of it.

    Also, fire is a self-replicating chemical reaction. Is fire alive?
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