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The Law of Evolution and entropy

  1. Jan 14, 2007 #1
    In my fall 2004 biology class at junior college, we covered the debate with the Creationists who point to the 2nd Law of Thermodynamics, that entropy increases. Ever since my 9th grade biology class in 1990-1, where we staged a debate over Creation vs. evolution, I've been trying to figure this out.

    Does the energy from the sunlight contribute to organization of chemical molecules into primordial biomass? I can't think of another source of energy to affect the chemical molecules on Earth, so...it must provide organization as well. Right?

    Otherwise, primordial biomass is not organized but simply a random arrangement of molecules. How then did it evolve into a single cell? A single cell requires organization; it can not be considered a random assortment of molecules. Does sunlight energy provide the organizing?

    I reviewed a book on the debate, and the author asserted that the 2nd Law of Thermodynamics is being misquoted or misrepresented. Evolution organizes like "water finding it's level". If so, why doesn't evolution occur for elements other than carbon? Why don't metals organize themselves through evolution?

    And how does a successful strain of DNA propagate itself more readily? Is it simply the fact of the successfullness itself, like a successful business growing larger and larger? That entails rational consumers who recognize it's lower prices or higher quality of products, so what mechanism operates the principle of natural selection in the females, not all of whom are rational (or even have brains in the case of plants and some other biology kingdoms)?

    For example, bacteria don't have brains, and yet operate under the principle of natural selection, right?
     
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  3. Jan 14, 2007 #2

    D H

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    Exactly. The Second Law of Thermodynamics pertains to [/i]closed systems only[/i]. The Earth is not a closed system. The argument that the Second Law of Thermodynamics precludes evolution is specious.

    Evolution does not answer that question. Evolution explains how life creates other life. How life came into being is a different (but related) subject, abiogenesis. While evolution is viewed by most as a fact, abiogenesis remains higly speculative.

    No other element has the ability to form the huge variety of chemical compounds that can be formed with carbon. This has not stopped science fiction authors from speculating on non-carbon life forms.

    One measure of evolutionary success is having viable offspring. No intelligent overseer is needed to deem a mutation as an "improvement". An "improvement" is something that enhances the odds that an organism will live long enough to produce offspring, produce offspring, and have those offspring produce more offspring. Neither an intelligent overseer nor rational consumers are needed.
     
  4. Jan 14, 2007 #3

    Gokul43201

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    I've seen dozens of discussions of this kind but I am yet to see a single calculation that in fact shows evolution to require a reduction in entropy (forget the gross misuse of the second law to an open system). Have you seen a derivation that computes a negative entropy difference between a human being (or any simple model of an organism, if you wish) and some kind of amino acid soup?
     
  5. Jan 15, 2007 #4
    I regret that I broke up my question between abiogenesis and evolution. I would prefer to simply discuss the mechanism involved in organizing and evolving both, namely, sunlight as you have indicated. I would like a bit of clarification:

    1. How does sunlight manage to organize matter into life? (if there's a short answer)

    2. When I compared carbon to metals, what I meant was why doesn't evolution happen for every element, in the biology sense or otherwise? Why couldn't metals organize themselves into a structure of some sort, again due to sunlight? I suppose metals have on occassion been found in various organized shapes and patterns, but it's hardly comparable to biological evolution, and usually not due to sunlight but simply due to random assortment, like matchsticks falling out of the box and spelling out a letter.

    3. How then does a minimal advantage toward production of offspring somehow propogate itself through the several generations of mutation to produce a wing on a land animal, for instance?

    o| Hiram
     
  6. Jan 15, 2007 #5

    russ_watters

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    Sunlight doesn't cause the organization, it just provides the energy to enable it. The "primordial soup" as people call it, is simply a collection of chemicals mixing and reacting together. Head drives chemical reactions.

    And I think you misunderstand the concept randomness (in your first post): in Poker, is a Royal Flush a random hand? Can order arise from randomness?
    Carbon is special in its ability to be arranged into complex compounds due to its chemical structure. I'm not sure why you had that next to a sentence about the 2nd law of thermodynamics....
    Again, it is a matter of probability. If a mutation provides an advantage that makes animals with that mutation more likely than others to live long enough to produce offspring, then animals with that mutation will produce more offspring and eventually replace animals without that mutation.
     
    Last edited: Jan 15, 2007
  7. Jan 15, 2007 #6
    I don't want to be annoying, but I feel we are getting closer to the heart of the matter: probability. I haven't taken a class on probability in the last 9 years, but I still feel it's important to try to get a handle on the probalities entailed in evolution.

    1. Yes, a Royal Flush can arise from a randomized deck, and yes, simple proteins can appear under abiotic conditions with lightning.

    However, from what I remember in Brian Greene's book The Fabric of the Cosmos, entropy was like randomly arranging pages in a book. There is one correct order and many incorrect orders. The correct order can occur from a random shuffle, but it's astrononically more likely to produce an incorrect order out of the many arrangements that potentially can be produced.

    The moral of his story was that although entropy can decrease in theory, it's very unlikely to occur. Am I on the right track here?

    2. I give up. It occurred to me that the stars also organized themselves, and they are mostly hydrogen; the planets also self-organized.

    3. I hate to bring up this Creationist complaint, but I don't know how to reply to it: a mutated limb that will eventually become a wing does not appear to confer an advantage to producing offspring -- not until it's a functional wing. I recognize the advantage of fins to water animals, legs to land animals, and wings to air animals, but it's the in between phase that is difficult to visualize. Those intial mutations would have to be more heavily rewarded; otherwise the potential for a new type of limb never gets out of the starting gate -- even with millions of years of time to keep trying, I should think.
     
  8. Jan 15, 2007 #7

    russ_watters

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    A Royal Flush is very unlikely to occur too, but it still does. The likelihood of seeing a certain pattern depends on the complexity of the pattern and the number of times you try. A Royal Flush happens once in every 2.6 million hands, so you are unlikely to see one dealt to you in your weekend game, but at the WPT, if you have 5,000 players playing on average one hundred hands, odds are 50% that you will see someone dealt one.

    Poker is a game where the odds are known, though, and with abiogenesis, it is tough to know the odds. People are running experiments to try to pin them down, but for now the best that can be said is that there is no good reason to believe that it could not have happened that way. Entropy/probability does not forbid it.
    That organization is not evolution, it is essentially just a matter of buoyancy. Physical processes follow the laws of the universe, but they do not evolve. I guess you can get into a discussion about determinism here, but I don't think that it is really necessary...
    Yes, that is a typical specious creationist complaint. It is tough to know what else to say beyond that. Failure of creationists to have creative and logical thoughts is not a flaw in the theory...

    I'm sure if you think about it, you can come up with a numer of examples where fins, wings, and legs overlap in capability and are analogous to each other. Turtles, penguins, seals, flying fish, etc.
     
    Last edited: Jan 15, 2007
  9. Jan 15, 2007 #8
    Alright, we might be getting to the end of my questions:
    1. I can see from your posts that abiotic genesis is still not well mapped out. I read about it in my biology textbook as well as Freeman Dyson's Infinite in all Directions (1988), a rather dated version of it.

    Secondly, are you comparing poker's random assortments of cards to chemical molecules that randomly arrange themselves until a protein is formed?

    3. Just so you know, I do not debate Creationists regularly. The debate, if one wants to call it that, came up in my biology class, but I feel that pressure from them has been helpful to compel me to understand the Law of Evolution better. That is why I posted this thread; I read part of Brian Greene's The Fabric of the Cosmos, which turned out to have an entropy section; and I've been thinking about sunlight and how it effected evolution both directly and indirectly, but I haven't had the chance to discuss it with anyone. What a relief that I was heading in the right direction!
     
  10. Jan 15, 2007 #9

    russ_watters

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    Pretty much, yeah - though not necessarily a protein.
    Not sure why you keep calling it that - it's a theory.
     
  11. Jan 15, 2007 #10
    My biology professor said that evolution is now considered by many to be a law, not merely a theory. It has born out for numerous tests for over a hundred years, longer than the Law of Relativity that Albert Einstein originally wrote. ;-)

    o| Hiram
     
  12. Jan 25, 2007 #11
    as for the improbability of abiogenesis, this is true in the sense that the chances of all the reactions that occurred in order to eventually generate life actually occurring, are very low... but this is in no way an argument in favor of creationism, as some might argue... for me, it's quite the opposite; for me it is an excellent example of the unfathomable size of the universe (size in time, space, and complexity) ...

    think of all of the billions of billions of planets* in the universe that have the conditions necessary for life to arise, and think of the billions and billions of chemical and physical reactions that are constantly occurring in all those planets... surely, now, the odds of a life to be created in at least one of those planets go up exponentially (however unlikely this might be to reproduce in a single experiment a-la primeval soup experiment. -- on the other hand, imagine this same type of experiment being repeated trillions and trillions of times on trillions and trillions of different labs)

    and all you need is that first initial spark...

    i am sure that if we had some sort of infinitely complex computer that could calculate all those factors, all those little variables (many of them unknown to us perhaps), we would find that the odds are not as low as we think they are... it's just our tiny little human brain that can't picture it ... on second thought, I believe such a computer does exist: it's called the universe :)

    I wonder what the odds of an invisible man that has always existed and knows everything and makes people out of mud would be...



    * planets that exist now, that existed in the past, and that will exist in the future.
     
    Last edited: Jan 25, 2007
  13. Jan 25, 2007 #12
    I've heard the same thing said about eyes... that an eye cannot be useful until it is a functioning eye... but is this really reasonable?

    suppose you have a pond full of swimming "fishes" with no eyes... what if, due to a genetic mutation, one of those fishes was born with a patch of skin that was highly sensitive to light... nothing close to being an eye, but very useful still! -- just being able to tell the direction of the sun/moon and weather you are in a shadow poses a big advantage over those fishes that can't.
    is it so hard to imagine that, through millions of years of evolution, that little patch of photosensitive skin could become an eye? (with every generation, the offspring with the better "vision" would have a higher chance of survival)

    the same can be said about a wing or leg... a perfect modern example: flying squirrels. what they have is not exactly wings, just a membrane.
    still, this "not-yet" wing is very useful to them and in millions of years, if we haven't brought them to extinction by then, it's very possible that we will have "winged squirrels," and they will probably be very delicious.
     
    Last edited: Jan 26, 2007
  14. Jan 27, 2007 #13
    Last edited: Jan 27, 2007
  15. Jan 27, 2007 #14

    russ_watters

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    That isn't the way science works. A theory cannot somehow 'graduate' to become a law. By definition, they are always provisional because it is impossible to know everything there is to know.

    Now it can be said that evolution is a fact, but don't let that confuse you: "Evolution" is both a name for an observed effect (the differentiation of species) and a title of a theory. The observed effect is factual data. The theory will always be a theory.

    And please don't think that weakens the theories of gravity and evolution to call them theories. Calling them "theories" merely means they fit all existing data and make testable, accurate predictions. that's a pretty tall order!
     
    Last edited: Jan 27, 2007
  16. Jan 27, 2007 #15

    russ_watters

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    The funniest thing about this objection comes from the book "Darwin's Black Box", which is an attempt to shoot down evolution. The author goes to great lengths to make the "irreduceably complex" argument about eyes. He spends a good fraction of the book on it, saying that if you take this piece or that piece away, it wouldn't work. But then he lists a dozen or so examples of less-evolved eyes that do their jobs just fine...and then says that that doesn't mean anything! Huh? :uhh:
     
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