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No. Life is self-propagating information. Chemical reactions are merely the medium.
Jazerus fucked around with this message at 00:20 on Jan 12, 2016 |
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Jan 12, 2016 00:13
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| # ¿ Apr 27, 2024 21:25 |
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To be more specific, life is self-propagating information capable of detecting environmental conditions and responding to them. The chemistry of biological systems is a tool through which these responses are expressed. Some chemical arrangements, like lipid membranes, are used mostly for mechanical reasons like durability and polarity. Others, like neurotransmitters and receptor proteins, are employed because their interaction follows a specific algebraic function and thus computationally behaves as that function. This allows the lifeform to chemically represent and analyze external information internally and respond to it. The life isn't actually in the chemistry. It's in the genetic information that expresses a total design for a self-propagating and adapting chemical machine. This information's form is an emergent property of nucleic acid structure, but nucleic acids are just very convenient substrates on which to represent a chemical instruction set. A completely accurate translation of this information structure to another medium (such as a digital electronic representation) would be "life" just as much as the one implemented through chemistry. 
Jazerus fucked around with this message at 03:23 on Jan 12, 2016 |
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Jan 12, 2016 03:07
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Phyzzle posted:Doesn't information require some being who can potentially perceive it? Yes, the information written in a book can be said to exist separately from a physical copy of the book, but if the last speaker of that language dies without leaving a translation key, the information is lost. Unless "the information" can sort of hover around a book with no potential readers, a perceiver is required. If life is information, who is the perceiver? Yes, but it does not require consciousness. That is why I specified that the information must be able to both detect and respond to its environment. Take a bacterium that responds to chemical signals. The perception is implemented through a natural algorithm - chemoreceptors with a low binding affinity. These receptors allow the bacterium to perceive chemical concentrations, as they release messenger proteins or cause membrane polarity changes when the chemical they are sensitive to binds to them. A higher concentration causes more receptors to simultaneously fire. This alters the chemistry and thus behavior of the organism - a response to perception. This is a precursor to neural processing; in fact, all neurons carry out a great deal of processing in chemical "analogue mode" that is converted to an electrical output for relay, since it's a cheap and fast way to implement specialized local calculations while action potentials are very expensive. A bacterium has no need to relay information electrically, generally, since it is unicellular, so it doesn't. A bacterium has no precise macro-scale coordination to accomplish, so it has no need for a consciousness even if it could implement one, but don't mistake bacterial information processing as fundamentally different from your brain's - it's just a matter of scale. By establishing both messengers and receptors within the cell, the genetic information has created a mechanism for self-perception without, necessarily, self-awareness in a higher sense. Everything in the cell is an expression of the underlying information and every meaningful signal is a perception either of the self or the environment. Jazerus fucked around with this message at 22:24 on Jan 16, 2016 |
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Jan 16, 2016 21:54
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The Belgian posted:This statement is without meaning. thanks for your stellar input  Could you elaborate? Jazerus fucked around with this message at 23:40 on Jan 16, 2016 |
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Jan 16, 2016 23:37
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The Belgian posted:Why do you want to mix up the object with information (whatever information might be). Because there is no cell, no object, without the information contained in the structure of the relationship between DNA and protein. It encodes for a precise dynamic processing and resource collection machine that has as its goal the propagation of its underlying informational structure. The DNA contains sequences that act as amplifiers or inhibitors on its own activity in response to chemical signals which robustly transmit specific information about the status of the self or environment. This is something which can only be accomplished if other sections of the DNA code for those messengers, and still others for receptors which release those messengers in response to specific cues. The actual objects involved actually matter very little, except in that they fulfill specific roles - the organism is the relationship between the objects. The information. quote:EDIT: this seems like mixing up a house and a picture of that house. It isn't a picture of the house. It is a blueprint for an ever-changing house which dictates how the house changes, and is so intimately linked to the house that a change to the blueprint automatically alters the house. Such a blueprint is a fuller representation of the house than any particular configuration of the house is. Jazerus fucked around with this message at 00:14 on Jan 17, 2016 |
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Jan 17, 2016 00:07
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The Belgian posted:Oh, if you want to call that information, the I'm fine with things. Though I see the objects themselves as nothing but the relationships. Well, it's the basis of information, I should have said. Information is contained and processed in the structure of the relationships. A single relationship doesn't really contain information out of context - it is what that relationship will do to the overall structure that determines its informational content. A receptor transmits information because one relationship, between its stimulus and itself, enables another relationship, messenger release. Without a messenger to release, the relationship does cause a change in the protein which indicates that it has, say, had a photon collide with it - but the informational content is dissipated because there is nothing observing the change (unless a human is watching with an electron microscope - then the information of "photon detected!" survives, though it didn't get to its intended recipient). Jazerus fucked around with this message at 00:58 on Jan 17, 2016 |
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Jan 17, 2016 00:54
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Phyzzle posted:Ah, okay, you were using information in a very different way from "informing Bob about his rectal cancer", and more to mean a set of related states. Could Conway's Game of Life contain real life-forms? Basic patterns in Life are just inanimate machines and the "physics" or rules are simpler than our own so implementing a real life-form would require more elaborate spatial arrangements to do computation with than in our ruleset, where there are distinct differences of kind down to the most fundamental levels of both matter and energy. Since it is a less varied universe than our own, the diversity of information to be processed is not all that large either. However, there's no reason a sufficiently complex initial setup couldn't generate both a changing environment and an adapting pattern that at least minimally qualifies as alive. Jazerus fucked around with this message at 00:22 on Jan 18, 2016 |
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Jan 18, 2016 00:20
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minasole posted:Additionally, sometimes they can mislead us..For instance, mathematical models cannot fully represent true biological phenomena because they don't account for the spatial factor. They only assume that all chemicals can react with each other without accounting for spatial factors. Additionally, they don't account for inhibitory events, etc....Some scientists (even legit ones) introduced some kind of these supposed models into computers, played with complexity and supposedly got some incredible results, such as bacteria, flowers, animals, etc... While I will never doubt the ability of scientists in general to create and use overly simplified models as though they perfectly correspond to reality, the spatio-chemical dynamics of biological systems are not actually ignored by scientists. In fact, there is a lot of fascinating research about how the distance between a signal molecule release location and the location of its receptor determine the dynamical properties of the signalling system which allow it to perform information processing operations, to name just one of the many topics of research that revolve around modeling the "spatial factor".
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Feb 10, 2016 21:54
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The Belgian posted:Yes, it can't jsut be all the states get propegated equally as was initially proposed. But why are some of the states preferred? Part of it would be by drawing the macro/micro state distinction and noting that 'perceptor' is a macro state to some extent which corresponds to a nulber of micro states. But clearly that way you still only cover a very small part of the state space, so why the preference? Some states are preferred because they assist in self-replication. Such states are propagated through time by the replication process itself. There is a drive toward perception because it is, by definition, the only way to correlate action with the current environmental context. A self-replicator - even something as simple as an RNA molecule - which randomly acquired a useful perception-action mechanism would be at a tremendous advantage over randomly acting self-replicators and quickly dominate, even if the perception was only weakly correlated with the full state of the environment and the action thus only barely appropriate. Perception is at the very core of life, right beside self-replication. The information received through perception is what narrows the state space by restricting possible actions. That's what perception does, on a mechanical level; allows or disallows certain internal states based on interaction with the external state.
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Feb 27, 2016 04:48
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The Belgian posted:As I said in the edit, there's an advantage once you have a perceptor but there's not before you do. You can't just get the first perceptor by cycling through the state space as that would take absurdly long times as I've given several examples of. This is not so. You are considering far too large of a state space; there are inherent physical properties of nucleic acids that lend themselves to developing both self-replication and perception. The template nature of a single-stranded nucleic acid allows for easy copying - that much is, of course, obvious. You must, however, consider the roles that RNA can play in the cell/in viral processes/etc. today, and extrapolate backwards to understand how a population of free-living RNA strands is exceedingly likely to develop some sort of perceptive ability. The most relevant is probably tRNA. tRNAs have nucleotide sequences that bind amino acids. These are not particularly complicated sequences and in modern tRNAs they are at the end of a hairpin loop structure, which is a common secondary structure formed easily by chance. No specific sequence is required; many possible states can create a loop and binding site of some sort. All of this is important because it is a state that is beyond trivial to form by accident simply due to the specific properties of RNA, given a long but reasonable (that is, 500 million to 1 billion years, not universe lifetimes) span of time. This structure, however, is inherently perceptive. Almost any sort of binding site is, because almost always, the act of binding changes the conformation of the rest of the molecule. A change in conformation leads to a change in behavior. This is a perception-action cycle, one which doesn't necessarily provide an advantage yet, because the action is poorly correlated with the perception. The perceptual capability remains, however, and now evolution can work on the rest. Different instances of the loop will change in their own way and create a wide library of binding affinities and potential substrates - that is, many different perceptual tools, ones which can, together, perceive concentrations and the composition of the environment. Any form of life larger than a free-living nucleic acid didn't have to make this jump, which I agree would be absurd for a bacterium or other system of many, many, many molecules to randomly form and then make use of. If you're saying that the formation of a population of free-living nucleic acids is absurdly unlikely in the first place, well, that doesn't appear to be the case given the chemical environment of the early Earth. Once they do arise, their ability to form complicated, versatile, functional structures out of the same few subunits while still being simple enough to sustain population sizes dwarfing those of modern prokaryotes for a given area makes the initial huge state space much easier to meaningfully cycle through. Edit: By the way, this: SurgicalOntologist posted:For a complementarist approach, see for example Language as a system of replicable constraints. Jazerus fucked around with this message at 19:50 on Feb 27, 2016 |
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Feb 27, 2016 18:45
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McDowell posted:I thought this was interesting. A common ancestor of most animals had fine neuron cilia that we have but other animals like lobsters can live without. We don't really have those either, to my knowledge. They are part of a design that is really efficient for small, very symmetrical, long invertebrates because it efficiently coordinates motion, especially legless motion. That's why worms have conserved that design but arthropods haven't, most likely. Individual nerve projections from the midline is still the basic organizational principal that vertebrates use, of course, but scaled up to fibers instead. This guy is in the middle of getting rid of that design and transitioning to moving around on legs controlled by larger nerve clusters.
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Mar 4, 2016 01:30
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McDowell posted:I think that is a very linear perspective of 'intermediate form' that I don't subscribe to. Thinking of nerve growth you need different cues for different structures to grow in the proper direction/orientation (much like how plants grow in response to gravity and light) - if the fossil is a common ancestor it seems possible that one set of critters went one way - keeping and developing more complex neuron genes - while others mutated, lost sophistication, but get along fine. I never asserted that it was a naturally inferior design or anything. It isn't. In fact, it's an incredibly efficient one, for the right body size and type. The additional complexity of other designs basically arose to surmount the distance issues that develop when you have a larger body. Once you have a different body plan - as indicated by this critter having legs - a different organization is called for. Both us and arthropods developed much more sophisticated nervous systems than what this thing has because we have more complicated bodies, though we came to somewhat different solutions. You are mistaking the efficiency of the worm-like nervous system at the appropriate scale for sophistication, but it really isn't, if you read about it in any detail. Organization on the level of individual neuron projections isn't inherently complex. In fact, at that level, simple is much better.
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Mar 4, 2016 04:21
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