Evolution Questions

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    • #249
      ERS
      Participant

      Evolution is a topic everybody hears about (good, bad and everything in between), and it is fun to think about so why not!

      How would you explain the nature of the 2nd Law of Thermodynamics in relation to evolution? It states that in a closed loop system a reaction cannot increase in order or energy… The closed loop system obviously would have to include the sun as everything on this planet relies on sunlight to keep the energy flow going. The Theory of Evolution seems to contradict that law. How would you explain this?

      Thanks for any input!

      ERS

    • #18758
      biostudent84
      Participant

      Explain how it would contradicts that law. When used in ecology the Second Law applies to trophic levels. The further up the food chain you go, the less energy and less biomass there is.

    • #18760
      ERS
      Participant

      In ecology, the energy transfer from one trophic level to the next is only about 10%, and as you have hinted the higher up you go the less consumable biomass—beaks, bones, etc.. Because not all energy is transferred to the next level and there is a reduction in consumables; we can say that it is not an efficient system—i.e. it loses heat, energy etc. somewhere in the mix of things. So really the 2nd law of thermodynamics holds quite well in your ecology example—energy and order are not increasing. In the sense of evolution, as my original question was asking, it seems odd to say that a single-celled organism could ever become a multicellular organism even through the auspices of evolutionary genetics, as then the system would have a net increase in energy and order. Furthermore, it seems contradictory to the 2ndLT to say that a preceding generation of say a single celled organism will have less genetic information than the next. This again seems to be a net increase in energy and order. The 2ndLT seems to indicate that the next generation would have less information than the preceding one, through degeneracy and decay, so how would there ever be enough genetic information for a two or more celled organism? Maybe I am not phrasing this clearly yet, but do you see what I am trying to get at as far as contradiction?
      thanks again for any input.
      ERS

    • #18766
      biostudent84
      Participant

      I think you are mistaking information for energy. While, yes, as energy transfers, some is “lost”-usually in the form of waste heat. However, information is stored not unlike a computer–with the major difference being that computers store information in base 2 and genes store information in base 4 or base 20 (depending on how you look at it)–albiet a very adaptive and resilient computer.

      As for the sheer amount of the information, remember that the more “advanced” (definetly the wrong word, but you know what I mean) an organism evolves, the more Junk DNA is in the genome. Humans, for example, have DNA with a composition of 90% Junk DNA. Some flowering plants can run as high as 99% Junk DNA. Bacteria molecules use far less…I apologize for not giving a number, I apparently forgot to bring that book with me to school =/

    • #18775
      natrgrrl
      Participant
      quote ERS:

      Evolution is a topic everybody hears about (good, bad and everything in between), and it is fun to think about so why not!
      ERS

      I agree that evolution is fun to think about. Unfortunately, it seems to be a dividing enigma in America today.
      My question is how evolution can be disproved.

    • #18777
      ERS
      Participant

      ah Kyle, you seem to be getting to the root of my quandry. Doesn’t an increase in information result from an increase in energy?? It seems that they are tied. Meaning, how can you have more genetic information stored, without more sugar phosphate bonds etc.. formed, bonds being a “tie-up” or storage facility for energies and such???
      Maybe, I am still confusing the two, but at some level they do seem reliant on each other.
      further thoughts??
      ERS

    • #18785
      biostudent84
      Participant

      WOW! I never thought of that before. That seriously will have me thinking for a while. Perhaps the energy requirement for the increased number of bonds is not enough to violate the Second Law…but still, there is SOME energy being wasted in maintaining all this Junk DNA, right?

    • #18924
      brownpanda
      Participant
      quote :

      as then the system would have a net increase in energy and order.

      When we talk about order we are going into Complexity Theory. I’d better explain a bit about this….

      Complex systems have a great many independent variables which interact with each other in many ways. These complex systems have the abilty to balance order and chaos – the edge of chaos. The diversity of the interactions between these vraibles allows complex systems to self-orgnaise – a thing which happens spontaneously.

      (A famous example of self-organisation at work is French physicist’s Benard’s – he placed some liquid in a vessel and heated it. At the beginning, when temperature difference between the base and the top was low, heat was transferred by conducton and no macro-motion was observed. As the temperature difference between the base and the top increased, a thershold was reached and the movement in the liquid became chaotic. Suddenly, an ordered pattern appeared. A clear macro-movement was observed in rolls which were millions of times larger than themselves. When the liquid was contained in a round vessel, the motino of the rolls formed a hexagonal pattern on the surface of the liquid. This pattern is a result of hot liquid rising through the centre of the honeycomb cells, and the cooler liquid falling along thir walls. All this appears to eb the result of a force, but no such force is present….)

      Complexity’s greatest contribution has been to show that that Second Law is not the whole story. Complexity shows that not all systems tend towards disorder or entropy, and nature contains deep order which is believed to “emerge” naturally. So evolution is an example of life on the edge of chaos.

      Disclaimer: I only read a book on this, and don’t claim to be an expert of any sort. My info may be wrong.

      By the way, it may help to read about self-organisation, chaos, and complexity theory on the net or in books.

    • #18925
      biostudent84
      Participant

      Which book do you speak of?

      Also, how does this apply to the increasing quantity of DNA in the most recently evolved species?

    • #18929
      junkyarddawg
      Participant

      Speaking of disproving evolution…what do any of you think about the new fossil find of the “minature” human? Even the pros are saying that evolutionary theory will have to be re-written. Sure throws a “monkey-wrench” (pun intended) into all of the previous versions doesn’t it?

    • #18930
      ERS
      Participant

      Panda,
      You offered some interesting thoughts here, one of your statements was:

      “Complexity shows that not all systems tend towards disorder or entropy, and nature contains deep order which is believed to “emerge” naturally.”

      can you elaborate on what kind of systems in nature follow this apparent breach of the 2LTD?? I am curious as to why a law would have an exception, and if there are actual examples in nature? You mentioned the organization of cooling liquid, but even that has its limits as eventually the system has a net loss of heat (i.e. cooling) which is still in line with the 2LTD.

      Any thoughts Kyle? Has anyone seen any of this in their studies?
      take care
      ERS[/quote]

    • #18933
      biostudent84
      Participant

      I don’t know…this idea hints on chaos theory, a theory that I’ve never put much stock in the first place.

      The only violation that evolution violates the 2LTD is where there are more molecular bonds in DNA the more “advanced” an organism becomes. The sheer amount of information, I still say cannot be applied to 2LTD.

      The only thing I can think of so far is that the excessive Junk DNA is still used, albiet only a small amount. DNA fragments have the ability to move around the chromosome, and some signals to begin reading the DNA are located up to 1,000 basepairs “upstream” of the actual site to be read. These other basepairs are part of this Junk DNA. Other than that, I’ve come across nothing yet that would explain this.

    • #18943
      ERS
      Participant

      that makes two of us then on chaos theory!

    • #18946
      brownpanda
      Participant
      code :You mentioned the organization of cooling liquid...which is still in line with the 2LTD.

      Well, actually, it isn’t really. The fact that the liquid organises itself goes against the very concept of entropy, or at least, so it seems to me.

      As I said, I’m not really that clear of everthing myself, so when it comes to explaining, I may not be the best person to win you over, so to speak.

      Personally, when I think about it, chaos theory does seem to explain a lot and still makes sense to me.

    • #18949
      biostudent84
      Participant

      You forget that entropy is usually paired with enthalpy. While it is true, that the natural order of things is trying to make the universe more entropic, it is also trying to make the universe less enthalpic. Self organization of molecules is simply those particles arranging themselves so that they are in a more stable position, by being less entropic.

      Water, our most common substance here on earth, is MUCH more entropic in its gaseous form. However, it is most commonly found in its liquid form. Why? Because there is less energy in liquified water than there is in gaseous water.

      Enthalpy and Entropy are directions on a two way street. Molecules try and maneuver into states where BOTH are moderately low. To completely appease one would be to completely offend the other. Compromise between the two are essential for overall stability.

    • #19070
      mith
      Participant

      I think the Second Law is an overall trend not a constant rule. Suppose you have a box of balls of different colors. If you shake the box the chances are it will get more chaotic, but there is a thin sliver of chance that they actually arrange themselves by colors.

    • #19402
      RobJim
      Participant

      How would you explain the nature of the 2nd Law of Thermodynamics in relation to evolution? It states that in a closed loop system a reaction cannot increase in order or energy… The closed loop system obviously would have to include the sun as everything on this planet relies on sunlight to keep the energy flow going. The Theory of Evolution seems to contradict that law. How would you explain this?”

      Well, it would be helpful if you were explicit in how you thought the TOE violated the 2nd Law.

      If you are comparing, say, a human being with a hypothesized single celled ancestor of that human, the system you have to look at is immense. It includes every organism in the evolutionary chain; the food each one ate, and the waste each one produced; the heat given off by the organism; the gasses breathed in and breathed back out, etc.

      The short answer is probably that any entropy that seems to be “missing” is actually present in the form of body heat, dung, urine, exhaled breath, and other waste products.

    • #19477
      thank.darwin
      Participant
      quote ERS:

      Evolution is a topic everybody hears about (good, bad and everything in between), and it is fun to think about so why not!

      How would you explain the nature of the 2nd Law of Thermodynamics in relation to evolution? It states that in a closed loop system a reaction cannot increase in order or energy… The closed loop system obviously would have to include the sun as everything on this planet relies on sunlight to keep the energy flow going. The Theory of Evolution seems to contradict that law. How would you explain this?

      Thanks for any input!

      ERS

      Well the 2nd law of thermodynamics says that energy always goes down hill towards entropy- Organisms on this plant stay together because they have a large energy source (the sun) – when we die our energy is released because we no longer have a way to keep it all together?

    • #23346
      MMGW
      Participant

      When considering whether evolution of a human from a single celled ancestor violates the 2nd law of thermodynamics, it’s helpful to think about fetal development. Ask yourself why the development of an adult human body from a single cell doesn’t violate the 2nd law. Why would the evolution of humans from single celled ancestors over 3 billion years violate the 2nd law when the development of a human from a single cell in a few months does not?

      Several comments:

      1). Remember that the second law doesn’t forbid a local decrease in entropy. So, consdering life on earth as a system and comparing entropy now to the entropy for the “life-on-earth” system 3 billion years ago misses the point. The “life-on-earth” systems gets energy from the sun and from the earth itself, and this must be taken into account. Just as the development of a human body in fetal develpment is “allowed” by the second law because the fetus is not a closed system, the evolution of life on earth doesn’t violate the 2nd law for the same reason.

      2) The 2nd law has nothing to do with information. Unfortunately, the term “entropy” has been used in the field of information theory, but it has a somewhat different meaning and it doesn’t apply to the 2nd law.

      3) The 2nd law of thermodynamics relates to entropy not disorder. The 2nd law is a mathematical law that expresses the relationship between energy and work. Entropy, however, is not “disorder.” For example, in some chemical reactions, a number of simpler molecules combine spontaneously (i.e. without adding any energy to the system) into more complex molecules. This is “allowed” by the 2nd law because these reactions release heat. In these reactions, ENTROPY increases but, DISORDER decreases. Thermodynamic entropy increases even though the system is becoming more complex and more orderly. The point? Simply, the point is that entropy and disorder are two different things and they should not be confused. (Although they are confused almost constantly, even by scientists.)

    • #23469
      clarence
      Participant
      quote ERS:

      How would you explain the nature of the 2nd Law of Thermodynamics in relation to evolution? It states that in a closed loop system a reaction cannot increase in order or energy… The closed loop system obviously would have to include the sun as everything on this planet relies on sunlight to keep the energy flow going. The Theory of Evolution seems to contradict that law. How would you explain this?

      Thanks for any input!

      ERS

      I think ERS’s argument for the incompatibility of evolution and the second law of thermodynamics can be put this way, or in a more similar form:

      P1 The second law of thermodynamics “states that in a closed loop system a reaction cannot increase in order or energy”.
      P2 The universe is a closed system.
      P3 Evolution is the development of order from disorder.
      C Therefore, evolution and the second law of thermodynamics are contradictory.

      In my opinion, the first two premises of ERS’s argument are misinformed, in regards to the accurate nature of thermodynamics.

      In response to premise 1:

      The exact form of the second law of thermodynamics says, “No process is possible in which the sole result is the transfer of energy from a cooler to a hotter body.” (Atkins 1984, The Second Law). In exact form the law is not related to evolution. When the second law is phrased in another equivalent way, confusion arises. It is most often rephrased as “The entropy of a closed system cannot decrease.” Entropy is an indication of unusable energy and often, BUT NOT ALWAYS, corresponds to intuitive notions of disorder or randomness. In fact, the mathematically quantifiable concept of entropy can not be equated to the common-sense notion of “disorder” in any meaningful way. Statistical mechanics, the application of statistics to the field of mechanics concerning the motion of particles or objects when subjected to a force, and by extension thermodynamics, has exactly nothing to say about the kind of order we think about intuitively in everyday life. Thermodynamics is not explainable in terms of qualitative metaphors, only by mathematical equations such as S = k ln W, Boltzmann’s entropy equation.

      In response to premise 2:

      The maximum entropy of a closed system of fixed volume is constant, but because the universe is expanding, its maximum entropy is ever increasing, giving ever more room for “order” to form. (Stenger 1995, The Unconscious Quantum). Absolutely closed systems do not even exist even under ideal laboratory conditions. It can also be said that the idea of isolated systems is an abstraction for pedagogical purposes

      To sum up:

      Life is irrelevant to the 2nd law; disorder and entropy are not the same; order from disorder is common in living and nonliving systems. Seeds sprouting into flowering plants, eggs developing into chicks, snowflakes with their six-sided crystalline symmetry forming spontaneously from randomly moving water vapor molecules and salts with precise planes of crystalline symmetry forming spontaneously are a few examples of order coming from disorder in nature. (The mechanisms by which these processes occur are explained by earlier posts.)

    • #89467
      Alberts
      Participant

      Entropy theory is an extremely wrong theory. The 2nd law of thermodynamics is a great and correct theory. Keep in mind that the 2nd law of thermodynamics is not the same thing as entropy theory.

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