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Author | Topic: Thermodynamics, Abiogenesis and Evolution | |||||||||||||||||||||||
Loudmouth Inactive Member |
quote: There are naturally occuring pyramids, well sort of. At the bottom of mountains there are piles of debris that stack themselves just like a pyramid. There is your mechanism. Reactants at a higher energy go DOWNHILL to form polymers. The second law of thermo is the mechanism, since reactants with higher energy will go to a lower energy state in the form of the polymer. The problem with your pyramid analogy is that you are starting from a lower energy state and moving towards a higher energy state. For example, DNA nucleotides without their phosphate groups will not spontaneously bind. However, if the high energy phosphates are included, then the nucleotides will spontaneously polymerize. I don't know if you are familiar with plasmid ligation, but to keep a cut plasmid from going back to its circular configuration you use calf intestine phosphatase to remove the phosphates from the nicked ends. If you don't remove the phosphates the plasmid will self ligate, or reform the complete circular formation. I guess my point is this. There is no reason polymerization has to be an uphill event with respect to entropy, given that the polymerization units are at a higher energy state. Therefore, your pyramide analogy isn't accurate. Added in edit: Instead of pyramids, maybe you should explain why mountain formation is non-spontaneous because it goes against gravity. [This message has been edited by Loudmouth, 04-13-2004]
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Loudmouth Inactive Member |
quote: So maybe this is why abiogenesis research is still ongoing? I think you are mistaking dead ends in research with impossible goals. The very fact that scientists are very frank about plausible pathways and prebiotic activators should tell you that they fully realize the thermodynamic and free energy problems that face abiogenesis. I think we can all agree that science has not found a reliable pathway, and I think that we can all agree that entropy factors into pathways hypothesized by abiogenesis scientists. You seem to understand what you are talking about. What I can't understand is what you are all in a huff about. None of us are arguing that the most plausible pathways violate the 2LoT. I think we can all agree that any pathway in abiogenesis must adhere to known physical and chemical laws, such as thermodynamics. I think we can also agree that there may be a viable pathway, using available energy in a prebiotic environment, that leads to nucleotide polymerization. Just to go back to one of my previous examples, it seems at times that you are arguing against mountain formation (which goes against gravity, ie uphill) while claiming that plate tectonics is not enough to explain an uphill "reaction". Maybe you could clarify things by answering one question. Do you think that a pathway exists within the confines of a prebiotic environment that would result in nucleotide polymerization? Only that one may exist, not if one has been found. My opinion is that scientists are answering a bigger question first, could nucleotide polymers, either DNA or RNA, result in an imperfect replicator. If they are able to show this, then they will start searching for a viable polymerization pathway. There are already hints that simple organic compounds could pre-activate nucleotides and could lead to simpler organic compounds once the reactions and conditions are optimized.
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Loudmouth Inactive Member |
DNAUnion,
So you would agree that any abiogenesis pathway must include an input of energy to make polymerization possible? I think we all agree on this one. What we are disagreeing with is the thermodynamics poses a problem within abiogenesis. I think this same problem is faced by many inorganic reactions, but these reactions occur nonetheless, usually through a high energy intermediate or an input of energy such as heat differential or pressure. Instead of 2LoT being a problem, it is actually a blessing in that it narrows down the list of possible reactants and reactions. What you see as a "problem" others see as a hurdle, a hurdle that to this point has not been cleared. The same could be said for HIV, cancer, ALS, and many other viable fields of study. Perhaps you meant that the 2LoT poses a problem, but not an insurmountable one? Or do you see the 2LoT as prohibiting any polymerization outside of ATP/enzyme driven elongation?
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Loudmouth Inactive Member |
quote: Massive amounts of energy, free high energy photons, immense pressures, etc. Any input of energy can decrease entropy. The second law of thermodynamics does not deal with order/disorder directly. It could just as easily be described as "heat will always move towards a colder object." It is a law about the movement of energy. Breaking down the word thermodynamics you get thermo=heat and dynamics=movement. Heat just increases the number of states matter can be in (more order) as compared to fewer states in a colder object (less order). It has nothing to do with complexity.
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Loudmouth Inactive Member |
quote: The input of energy was energy. At the start of space/time in that small singularity there was all the energy and mass that ever was in our universe. Imagine squeezing all of the mass and energy in the entire universe into the palm of your hand. And also, don't forget that mass and energy can change camps, mass becoming energy and energy becoming mass.
quote: Which is exactly what has been hypothesized.
quote: First of all, there was no explosion. Space/time expanded and matter/energy expanded with it, similar to a balloon being blown up. Secondly, from what I understand hydrogen and helium were the predominant forms of matter directly after the Big Bang. Only through nuclear fission within massive stars were heavier elements made, and then dispersed through the universe when these massive stars became supernovae. Hence the phrase "we are all made of stardust." I agree that within the original space no "organized" matter or heavier elements could have been present, but this doesn't mean they couldn't form afterwards in separate conditions (stars).
quote: Gravity. A slight difference in mass on one side of a loose, gaseous body can cause a preferrential spin. Imagine two cars coming at each head on and hitting off center. What results is that each car will start to rotate around the other one. Same thing happens when matter starts to come together in a vacuum.
quote: Something that evolutionists and creationists can both agree on. The only difference is how we investigate these wonders to learn more about them. Added in edit: to prevent a drift into the Big Bang event, we should probably take the cosmological questions to the appropriate thread. Start one of your own if you feel you still have questions. [This message has been edited by Loudmouth, 04-14-2004]
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Loudmouth Inactive Member |
quote: Even science can't agree on what the first cell looked like. You seem to be assuming things that aren't true. Also, the first "life" or rather the first replicators were not cells but rather acellular systems, according to abiogenesis theories that is. Perhaps your greatest mistake is putting words in the mouths of scientists. Before you attack a scientific theory you should first learn what the theory states, otherwise you are just flailing in the wind.
quote: Sure, lets replicate the original situation on a prebiotic Earth. First, we need an aquatic environment equalling that of the entire ocean. So I guess we will have to build tanks to fit all of the water in the oceans. Then, we need to add the inorganic components, reflecting the ratios in a prebiotic Earth. This would probably require the entire volume of topsoil in the world, but what the hay. Next, we have to let this mixture incubate for about 500 million years. If we follow this procedure, it should result in cellular life.
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