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Information Theory Places New Limits On Origin of Life
KentuckyFC writes:
Most research into the origin of life focuses on the messy business of chemistry, on the nature of self-replicating molecules and on the behavior of autocatalytic reactions. Now one theorist says the properties of information also place important limits on how life must have evolved, without getting bogged down in the biochemical details. The new approach uses information theory to highlight a key property that distinguishes living from non-living systems: their ability to store information and replicate it almost indefinitely. A measure of this how much these systems differ from a state of maximum entropy or thermodynamic equilibrium. The new approach is to create a mathematical model of these informational differences and use it to make predictions about how likely it is to find self-replicating molecules in an artificial life system called Avida. And interestingly, the predictions closely match what researchers have found in practice. The bottom line is that according to information theory, environments favorable to life are unlikely to be unusual.
It's a fallacy that entropy always increases ON EARTH, and therefore life is impossible to have evolved naturally, because it violates the 2nd law of thermodynamics. That's only true in a closed system, which most definitely the Earth is not. There's this "Sun" bombarding the planet with energy, constantly.
Stop bringing thermodynamics into biochemical or origin of life questions. It's irrelevant.
Except in a universe with billions and billions of galaxies, each containing billions and billions of stars ... some of us assume that, statistically, the 'unusual' happens all the time.
In the last 30 years our understanding of how many stars have planets has changed entirely. We used to think there would be a small amount with planets and that we were really unique. Now, not so much.
These conditions may well be unusual. But there's a lot of unusual to go around, to the point that it almost seems like it would be happening over and over again.
Lost at C:>. Found at C.
And this is the only information that you need.
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We understand entropy, but have we considered that a symmetrical and opposite phenomena could exist and be primarily responsible for creation of life? That is, some property of information to self-organize that leads to creation of life, and later to creation of intelligence?
The empirical data can't violate information theory any more than it can violate quantum physics. If the purpose is to establish bounds on the solutions, this approach is perfectly reasonable.
Ezekiel 23:20
There are a few points along the way where development of life on earth had to go one way, or the other, and was not able to sustain both directions. For example, the chirality of amino acids where the overwhelming majority of them are L forms even though there is no physical restriction on the creation of the D form. Similarly the DNA double helix is right-handed in almost all cases.
One interesting thing about this is that if we were to find a planet filled with plants made up of D amino acids and left-handed DNA we may find ourselves unable to consume those plants for nutritional value.
Damn_registrars has no butt-hole. Damn_registrars has no use for a butt-hole.
If we define life as the ability to organize and propopagate information then the highest form of life is a salt crystal or any self propagating organization of atoms with long range order. A diamond has far lower entropy than any living system. Like wise if we define it as system that processes energy to propogate itself then we have Fire as the ultimate for of life.
clearly gasses (disorded are dead) and crystals are dead. SO is life a liquid (in the middle of the two)? Again obviously not.
The best definition of a living system in terms of information tehory concepts I have come across is the one by David Wolpert who coined in the term self-dissimilarity in reaction to the vogue study of self-similarity in self-organizing systems. For example, a pile of sand is self-organizing system that is ever changing but also ever-self simmilar. it's not alive either
so solids, liquids, gasses and self-simmilar self organizing systems are all bankrupt as a informational definition of life. What's self-dissimilarity then?
It's the concept that the organizational principles of a system can suddenly change as one crosses scales.
imagine one zooms out from a microsope from the atomic scale. at first you see the atom and it has some interesting symmetires in the way the electron oribits have some simmilarities. at a higher scale we see the molecule. then the collection of molecules. soon we see the patterning of molecules.
we observe that this is infact cell. then many cells. then it's an organ. then its many organs. then an animal. then a school of fish. then zooming our we see schools of fish separated across the ocean.
the key insight is this. at each scale everything you infer about the information content and predictibitly of adjaceny in the pattern works to predict the patterns propoagation at a slightly larger zoom. Up until it suddenly fails. you reach the edge of the liver or the edge of the cell or the edge of the animal. then the lower scale is useless in predicting how the next scale up is organized.
these abrupt steps in dissimilarity is a halmark of living systems. the degree of information gain at the step is phenomenal. this is different than saying for example that a composite rock is alive. the difference is that the system is processing information and energy across these organizational boundaries. that's pretty much the best definition of life interms of a single defintion that can be plotted on a graph. the x-axis is the zoom, and the y-axis is the predictability of the next larger scale from the lower one. you see steps. that plus the processing of information across steps is a living system. If you accept this you might feel like their are non-traditional defintiions of life as well. for example, if a bacteria is living thing, is it possible that a community of bacteria is also a lvifing thing. Perhaps the earth is too.
What's intriguing here is that systems with this property may imprint themselves on other systems. you might for example be able to spot radio emissions or atmospheric molecular composition that displays the imprint of dissimilar steps in it's self organization.
SO unless this theory considers this, I'm skeptical about it. Salt is self organizing but it's not alive. It is however highly probable. Indeed eutectic separation is highly propable but it's just physics not life.
Some drink at the fountain of knowledge. Others just gargle.
environments favorable to life are unlikely to be unusual.
How can you not argue against not having that be untrue?
I blew my wife's mind the other day when I pointed out that we are literally just a small component of a single, globe-spanning, four billion year long chemical reaction. A single, very long running checmial reaction. It's pretty neat when you think about it.
...but it's being eaten...by some...Linux or something...
Except we there is so much we do know........ for sure
There is water on the moon, and mars.
Gravity is real, ok !
....if we were to find a planet filled with plants made up of D amino acids and left-handed DNA we may find ourselves unable to consume those plants for nutritional value.
More importantly, they would not be able to consume us for nutritional value.
If it's unlikely that life can appear I think it's even more unlikely that intelligent life can occur.
I once did put what I thought was plausible figures into the Drake equation and ended up with a value of about 0.8.
Mostly because I think that the chance of an intelligent civilization is low. I find it much more likely for life to appear and spread in a galaxy than for intelligent life to appear that is able to develop technology.
If builders built buildings the way programmers wrote programs, then the first woodpecker would destroy civilization.
So, we'd be junk food?
Great, that makes me feel much better. :-P
Lost at C:>. Found at C.
Considering our planet only has another billion years before its turned into a crispy planet like Venus (killing all life in the process) due to our sun exhausting its hydrogen supply, it seems even less likely that intelligent life which can spread beyond its planet would have time to evolve.
or they will taste like peppermint. :)
Too esoteric?
The Kruger Dunning explains most post on
We also assume information cannot travel through space faster than c, so we put a restriction on how fast DNA can spread. Or should we assume this is wrong until we prove that it cannot happen via empirical evidence?
Meh. Information is basically tied to entropy. You can reduce entropy (which is to say, you can order information); it just takes energy to do so (and in the process releasing waste heat).
So, basically, this says nothing more useful than "Life requires a source of free energy, and a way to reject waste heat."
Sure, but we knew that already.
http://www.geoffreylandis.com
not able to sustain both directions
But either direction may have turned out to be viable. So at this decision node, the probability of life would be 1. On the other hand, given an initial equal distribution of forms, had one been non viable, the other would have out-competed it.
What we need to look for is what the probability of local maxima or dead ends is. Where some process is preferred at that point and is selected. But for which more advanced branches do not exist.
Have gnu, will travel.
This is bad news for humanity.
Fail. The level of confidence in Quantum Theory describing physical reality is pretty well established, but it is both incomplete and not absolute truth. Information theory, on the other hand, does not apply to reality unless you grossly simplify, hence it is actually impossible for anything real to "violate" it, it is just not close enough to reality.
Most ACs are not even worth the keystrokes to insult them. Be generically insulted by this and ignored otherwise.
This is not information theory or quantum theory, this is Information Theory and Quantum Theory. It is astonishing that there are still people around that do not understand the difference and claim they are "just theories". No. They are not. Apparently the educational system is far worse then generally assumed.
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...right?
Never let a lack of data get in the way of a good rant.
a key property that distinguishes living from non-living systems: their ability to store information and replicate it almost indefinitely.
As Douglas Hofstadter pointed out, it's actually more complicated than merely indefinite replication. It has to allow variance while still retaining the ability to replicate. Sure, there are clones everywhere, especially outside the animal kingdom, and they still considered "living". So the quote is still technically true. But it doesn't capture how immensely more difficult it was for life we observe here on Earth to come about. It also raises an interesting question. Did non-varying life have to come about first, in order to saturate the environment with organic compounds? Did the varying life then come about later, piggy-backing on this enriched environment? Or can you go straight from an abiotic world to varying life?
"Love heals scars love left." -- Henry Rollins
The sun might have 5 billion years left in it, but it will swell and render the earth uninhabitable in only 1 billion. Given that it took 1.5 billion years for life to form on earth at all, and another 3 billion after that to turn into something intelligent, the window (from our single data point) seems rather tight. A little setback here or there, an ill-timed asteroid impact (or lack of a well-timed impact) and you've got nothing.
We don't have a state-run media we have a media-run state.
Wow. That was pretty bold of you.
Ezekiel 23:20
> a key property that distinguishes living from non-living systems: their ability to store information and replicate it almost indefinitely
My cp command is alive!!
... the window (from our single data point) seems rather tight.
Except that our sun isn't the most common type of star in the universe. IANAA (Astronomer), but I recall hearing (possibly from the New Cosmos series) that dwarf stars are far more common than G type stars. Since they put out a constant volume of energy for a very, very long time, this would give life plenty of time to evolve into intelligent lifeforms. The more massive a star, the shorter a window of time for life to evolve near it, so it would make sense for us to focus our efforts looking at smaller stars.
HA! I just wasted some of your bandwidth with a frivolous sig!
the educational system is far worse then generally assumed.
Yep. The education system even fails to teach spelling.
(Sorry, I just couldn't resist. ;)
And then he created the arXiv, to guarantee that crackpots and armchair-surfing physicists would have a safe bunker from which to lob garbage at other scientific disciplines without ever having to step out from under the shade of their brethren. Until it's peer-reviewed, it's not newsworthy. For shame, Medium.
Bio questions? Ask me to start a Q&A journal. Computer analogies available for most topics!
There are no misspelled words in the quoted excerpt. The error is improper use of the word "then" versus the presumptively intended word "than," and thus the mistake is classified as a grammatical error.
Sorry, I just couldn't resist.
Write failed: Broken pipe
It's worse. Most people who complain about the use of the word 'theory' don't know what it means in a scientific context either, and spread one of several nonsense definitions they saw on a forum or heard on a youtube video.
Required reading for internet skeptics
That's called inferential reasoning, and in some circles it is another way of saying "speculation".
In the example you mentioned, space can move. And it can move faster than the speed of light.
"The new approach is to create a mathematical model ... And interestingly, the predictions closely match what researchers have found in practice"
Unless the mathematical model was built *before* any of those practical empirical test results, it is not at all interesting or surprising that the model happens to match the pre-existing data.
All models are flawed, by definition. These holy "Theories" you have such emotional attachments to simply use models. In a 100 years, they will be superseded and allow us to do things we can't think of today. Like GPS wouldn't work if we relied on Newton's theory of gravity.
or they will taste like chicken. :)
Too esoteric?
There. FTFY.
No, no, you're not thinking; you're just being logical. --Niels Bohr
I agree. A theory is, after all, a predictive model, and science wouldn't work if any theory was considered unassailable truth. This brings up a couple other problems with the public understanding of science that are often overlooked: The belief that science ultimately leads to truth (a failure of our educations system, no doubt) and the belief that we've got it all just about sorted, with a few details left to be filled-in.
Required reading for internet skeptics
Steaks and Ice Cream and Chocolate and what not made with D Amino acids and no weight gain. Fantastic
Only to those who refuse to see the evidence around them (Romans 1:19-20).
What I find odd is in TFS where is says "environments favorable to life are unlikely to be unusual"...
In light of past attitudes, would it not be more informative to say "environments favorable to life are unusually likely"?
You have the right to remain sentient. If you give up the right to remain sentient, you will be elected to public office
There's a difference between the colloquial use of the word "theory" and the scientific use, which many people don't understand. In the colloquial use, "theory" means "hypothesis," so that the layman becomes confused when it's used in science. Hence expressions like, "only a theory." Even educated people will use expressions like, "Gravity is only a theory," as if that explained anything.
But this is how language works. Meanings shift through use (or misuse) over time. Think of how the word "addiction" is now used to describe anything from actual addiction, to compulsive behavior, to anything you might enjoy, or do, often. The meaning has become so watered-down that I believe we may need a new word to describe actual addiction. Perhaps the same is true of "theory?"
-- sudon't
Air-ride Equipped
Currently at this point in time we have the technological capacity to survive the more or less complete destruction of our biosphere. Would it be pretty? No. Would we be prolific, no. Would we easily be wiped out by a failure or disaster affecting our crude makeshift survival, yes.
But we could. There's no reason a technological civilization of our stage cant make it to the next stage given a bit of luck and a solid motivation to make it. I wager, that people surviving the death of our biosphere 1 billion years from now might have NO problem being motivated and cautious and wise enough to live happily ever after.
The elephant in that room is that we most likely wouldn't even recognize ourselves at that point and this most likely has happened in the past and will be proven one day. If we get that far.
The phrase "...places new limits on..." suggests that they have found that Life is even less likely. But the phrase, "...favorable to life are unlikely to be unusual...", however awkwardly, suggests that Life is more likely.
When Fascism comes to America, it will call itself Anti-Fascism, and tell you to give up your guns.
Take all the static measurements possible of a live mouse. Then suffocate it. Immediately repeat all the measurements. They will be identical. Yet the difference in entropy (in the sense of disorder) between the live mouse and the mouse carcass is dramatic. “Life” is one of the great scientific unknowns. Creating the conditions for life is not the same as creating life from scratch. When Louis Pasteur started his work, the assumption of the scientific community was that microbes regularly spontaneously came into being. To date, science has never observed such a phenomena.
Information does travel through space at a velocity faster than c - see the EPR paradox, which was subsequently questioned by Bell, and then experimentally tested by Alan Aspect (sorry I don't know the correct French spelling for his name).
Based on the evidence, quantum information does seem to travel faster than c.
Given the paradox of the wave-function collapse within the Copenhagen interpretation of QM (once a particle is measured it takes on a definite set of properties, which means that the wave-function must collapse everywhere simultaneously) it suggests that quantum information is transfered instantaneously.
Many people have an emotional need for the presumed eternal correctness of "a law of science", even though no such thing can exist. And they are incompetent to rate the relative stability of various different theories.
Well, everyone is incompetent to rate the relative stability of various different theories except, perhaps, in their own small area of expertise. That's why we are forced to depend on experts. Then we need to decide how much to trust each expert. It's not a simple problem, and it's probably intrinsicly insoluble if you have a NEED for correctness. (Making a best-guess choice is fairly easy, though, but figuring what your error bars are can be difficult.)
It's not basically a problem with the educational system, though that clearly makes things worse than they need to be, largely by instilling a belief in "correct answers" rather than in "probably correct answers"...which is the best that one can ever do.
I think we've pushed this "anyone can grow up to be president" thing too far.
More, any particular god is a hypothesis. It doesn't rise to the level of a theory until you can use it to make verifiable predictions that are then tested.
FWIW, there are several gods that I have tested, some of them gave weakly positive results. None of them matched the gods of any standard religion, which religions have so defined their gods that emperical tests are impossible.
N.B.: This does not prove that they are incorrect, it proves that there is no reasonable way to chose between them, and the null hypothesis is a member of every set.
I think we've pushed this "anyone can grow up to be president" thing too far.
Actually it will be a lot worse than Venus and due to a different cause in that the sun would actually be irradating many times more energy on it, and possibly even engulfing it in hot plasma. Venus is heated by the insulation of a huge amount of CO2, the Earth with that much CO2 would be equally hot, and Venus without it would be just a tropical Earth. And when the sun expands the CO2 will be irrelevant (I would think the heat would actually make it escape to space), not that that is going to help any.
Information does travel through space at a velocity faster than c - see the EPR paradox, which was subsequently questioned by Bell, and then experimentally tested by Alan Aspect (sorry I don't know the correct French spelling for his name).
Based on the evidence, quantum information does seem to travel faster than c.
Given the paradox of the wave-function collapse within the Copenhagen interpretation of QM (once a particle is measured it takes on a definite set of properties, which means that the wave-function must collapse everywhere simultaneously) it suggests that quantum information is transfered instantaneously.
This most probably shows that the wave-function-collapse interpretation does not have much to do with the reality and is just an artifact of the theory. There are other interpretations which do not involve such mysterious collapses and provide smooth transition from quantum to macroscopic level. The logically most consistent one is the many-worlds interpretation (http://en.wikipedia.org/wiki/Many-worlds_interpretation).
Actually, this is very important factor of the "cycle of life" in many cases.
Being able to eat plants is good, but having them be able to recycle humans/animals waste products (including bodies) is equally important. Otherwise, what are you going to feed the plants?
Related work:
http://arxiv.org/abs/1209.1179
surprisingly no references between Adami and England.
"Self-replication is a capacity common to every species of living thing, and simple physical intuition dictates that such a process must invariably be fueled by the production of entropy. Here, we undertake to make this intuition rigorous and quantitative by deriving a lower bound for the amount of heat that is produced during a process of self-replication in a system coupled to a thermal bath. We find that the minimum value for the physically allowed rate of heat production is determined by the growth rate, internal entropy, and durability of the replicator, and we discuss the implications of this finding for bacterial cell division, as well as for the pre-biotic emergence of self-replicating nucleic acids."
Actually, in colloquial use "theory" means any form of speculation.
And did you exchange a walk on part in the war for a lead role in a cage? - Pink Floyd.
Plants might not be intelligent enough to realize that until too late (for us).
Information theory and quantum physics are in a different category. Quantum physics is a model of reality that happens to predict certain kinds of observations to a high degree of accuracy. Information theory is mathematical truth and not a model. Information theory is inviolable. Quantum physics is violable to the extent that it does not describe reality perfectly.
"Theory" also means scientifically a body of knowledge, like "information theory". It has multiple meanings in the scientific world too.
Well, if that is the best you can contribute, then my point is made.
Most ACs are not even worth the keystrokes to insult them. Be generically insulted by this and ignored otherwise.
Yet the Theory of Information is not a model, but a mathematical theory and as such it is not flawed at all, because it cannot be. Really, don't throw around big words you do not understand.
Most ACs are not even worth the keystrokes to insult them. Be generically insulted by this and ignored otherwise.
Wrong for the case at hand. While you are right about the theory from Physics mentioned (Quantum Theory), you failed to see that the Theory of Information is from mathematics, and mathematical theories are not required to be models at all. They happen to always be true. Really, get at least some basic knowledge before you shoot your mouth off.
Most ACs are not even worth the keystrokes to insult them. Be generically insulted by this and ignored otherwise.
Indeed. And for example a mathematical theory like Information Theory cannot be wrong. It has zero requirements to apply to anything real though. For a physical theory, the requirements are entirely different, and it can turn out to be wrong, even if it was a Theory. The latter is exceedingly unlikely though.
This incidentally points out the problem with the original article: You cannot simply remove a Theory form its field and apply it within another. It often becomes a theory in the process or may even be completely false in the target area. For example, look at some finite geometries in mathematics and then try to apply them in physics. That usually gives you an instant fail.
Most ACs are not even worth the keystrokes to insult them. Be generically insulted by this and ignored otherwise.
You are wrong. The Theory of Information is eternal and cannot be wrong. It is not possible for a mathematical Theory to be wrong. It is possible for it to not apply to reality (in fact that is true for basically all of them). For the other Theory mentioned (Quantum Theory), you are right, but that is not the only kind of Theory that exists in science.
Really, does nobody understand the basics of modern science anymore?
Most ACs are not even worth the keystrokes to insult them. Be generically insulted by this and ignored otherwise.
I am not really sure what they claim. I am sure though that Information Theory is not a physical theory and may well not apply to the problem at hand. They might have fallen for some kind of "quantum mysticism" here, which basically is a surrogate religion. "Quantum Information theory" is not really a Theory, but more speculation and quite possible wishful thinking. But people seem to use it to derive arbitrary bombastic conclusions.
Most ACs are not even worth the keystrokes to insult them. Be generically insulted by this and ignored otherwise.
You knocked that strawman down so hard!
However, a thing that is not white *is* necessarily non-white.
Yeah, finally biology (the 'butterfly collecting' adventure labeled as a science) has something like a 'first principle' to hang on to.
Nothing shows biology to be more a 'butterfly collecting' venture than the repeated surprise biologists express when they find life in environments where they never expected to. You would think they had learned by now. Regardless, a theory with bona fide first principles clearly lays out that finding life supporting environments is the norm.
"Consensus" in science is _always_ a political construct.
You cannot simply remove a Theory form its field and apply it within another.
Sometimes that statement turns out to be wrong. And when it does, you occasionally get some amazing stuff.
For a physics example, group theory turns out to have several remarkable applications. One can derive the elementary subatomic particles from it, for example, or determine the vibration modes of gases of molecules with symmetries.
Or geometry applied to dynamical systems helps study the existence and properties of chaotic behavior. For example, local divergence of solutions to a differential equation can be determined by the curvature of the solution space (it happens when the curvature is negative, meaning the space has a sort of "saddle" shape) and a bounded set of locally divergent solutions in a finite dimensional space exhibits chaotic behavior (well to my knowledge, I may be ignorant of important exceptions).
One of the powers of math is that when you have a mathematical theory or model, if the premises of the thing apply, then so do its consequences and conclusions - even if you are completely ignorant of the theory and the association with whatever system you're dealing with.
Some fields are particularly amenable to transplant into other areas. Information theory is one of these fields that transplants to a wide range of fields, though perhaps not easily. The reason is that a lot of scientific analysis boils down to extrapolating from a heavily transformed dependent observation the actual phenomena we wish to observe. Information theory provides a variety of tools for trying to find underlying phenomena for derived observations (such as interpreting what a seismograph network is observing deep underground from altered vibrations that originated with known small earthquakes throughout the world).
Space can move faster than light, but nothing else can move through space faster than light. We can see galaxies moving away from us faster than light, but we will never be able to get to them and eventually they will be beyond out light horizon and no new information will come from them.
Presuming that you are serious rather and trying for funny...
I know that *I've* made errors in proofs. I know that at various times articles have been recalled from mathematical journals because of errors in the proof. IIRC there was a proof recalled 6 mo.s after it had been published just a year or two ago.
Math is a lot more secure at it's foundations than any other physical science, basically because the foundations are of the form "If we assume...". This doesn't mean any proofs derived from those foundations are unassailable. Errors in reasoning happen, and can be quite difficult to detect.
I think we've pushed this "anyone can grow up to be president" thing too far.
IIRC, useful information cannot travel faster than light. If you have two entangled particles, and you measure the spin of one in your desired orientation, you know the probability distribution of spins for when the other guy measures the spin of his in his desired orientation. If you could control what the spin measurement would be without breaking the entanglement, you could transmit a bit FTL or backwards in time or whatever you wanted, but you can't.
You're using a word that has no defined meaning here: "simultaneously". You can use it for two events at the same point in spacetime, or you can use it to describe what you perceive from your reference frame, but events not at the same place aren't simultaneous in a different reference frame. For it to have a meaning, there would have to be a specific reference frame where the laws of physics differed from other reference frames, and we have piles of evidence that that doesn't exist.
"When you have eliminated the unacceptable, whatever is left, however improbable, must be the truthiness" - Holmes
Mathematical theories are always correct, but there's no guarantee that they apply to anything actually physical. If somebody found a way to reliably transmit information faster than Shannon's Theorem allows, we'd have to agree that Shannon's Theorem doesn't apply to that, and figure out where our assumptions went wrong.
"When you have eliminated the unacceptable, whatever is left, however improbable, must be the truthiness" - Holmes
The Theory of Information is a mathematically construct, and (assuming all the proofs were done right) is eternal and cannot be wrong. Similarly, vector algebra (same disclaimer) is eternal and cannot be wrong. However, under Newtonian physics we assumed that velocities add like vectors, and now we know they don't.
"When you have eliminated the unacceptable, whatever is left, however improbable, must be the truthiness" - Holmes