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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.
Wait. If they are unlikely to be unusual, then they are likely to be usual. Right ?
Maybe we deserve this world ?
And this is the only information that you need.
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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
Oh, shit ... yes, I'm a moron ... I got the opposite out of that.
So, information theory tells us life should be common.
Lost at C:>. Found at C.
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...
....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.
So, we'd be junk food?
Great, that makes me feel much better. :-P
Lost at C:>. Found at C.
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.
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This is bad news for humanity.
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.
Most ACs are not even worth the keystrokes to insult them. Be generically insulted by this and ignored otherwise.
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
For some definitions of likely and usual anyway. In probability, "unlikely" generally has a specific meaning defined in the paper, hence "not unlikely" is not necessarily likely. Probably not unique anyway.
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?"
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