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Author | Topic: Evolution vs. Thermodynamics | |||||||||||||||||||||||
blitz77 Inactive Member |
quote: But the organisms you are talking about have cell membranes and means of protecting themselves. Without these forms of protection, how would they survive? And do any of those living thingies not have cell membranes?
quote: So you would have to say there were permanent volcanic clouds hanging in the sky to protect earth? What about winds, etc moving them around?
quote: So in such an atmosphere, there wouldn't be much if at all any free hydrogen in the air, or ammonia, as in an oxidizing atmosphere they would be quickly oxidized. So what is the alternative model you have for producing organic molecules?
quote: So would you say that it could concentrate enough for proteins to form? After all, an average sized protein contains 500 amino acids. Give me a concentration (molarity) of peptides in water that you suggest would have proteins forming.
quote: As the planet cooled, wouldn't energy have mostly radiated out into outer space? Tell me how the energy produced by cooling can be used.
quote: I believe you have interpreted the article wrongly. The diagram given there is an enantiomer (non-superimposable mirror images). They are mirror images, but they cannot be superimposed on each other without the reflection. Like your left hand and your right hand are non-superimposable mirror images. The article is talking about how they can determine which are left-handed and which are right-handed peptides using their optical properties. That is why L and D isomers are called optical isomers. If you looked around more carefully, such as this article from the same site, they distinguished L and D forms by seeing how well they bond to a left-handed cryptophane. [This message has been edited by blitz77, 08-01-2002]
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John Inactive Member |
[QUOTE]Originally posted by blitz77:
[B]But the organisms you are talking about have cell membranes and means of protecting themselves. Without these forms of protection, how would they survive? And do any of those living thingies not have cell membranes?[/quote] [/b] I think we are talking about different time frames and about different organisms. For the first, the time frame I have in mind, I think, is much earlier initially than what you seem to be thinking about. This point is much more important latter in the post. For the second, the first organism to inhabit the vents probably had cell membranes. I see the vents as spewing important components, not as efficient manufacturers. I'd be lying if I said I had all the details.
quote: Given the time frame I have in mind, I think it is fair to assume a pretty dust-heavy atmosphere. Nonetheless, I am not taking a hard line on the volcanic clouds, just pointing out that the mechanisms blocking UV today are not the only possible mechanisms.
quote: I'll check again, but I believe the scenario was covered in the article I cited.
[quote]So would you say that it could concentrate enough for proteins to form? After all, an average sized protein contains 500 amino acids. Give me a concentration (molarity) of peptides in water that you suggest would have proteins forming.[/b][/quote] Starting with 500 amino acids is jumping the gun. If I am not mistaken, a sequence of 30 or so acids has been shown to replicate. Besides, we are talking about a BILLION years or so. Chemicals have lots of time.
quote: Of course it would radiate into outer space---- VIA the oceans and the atmosphere.... the energy is used to drive chemical reations.
quote: Ok. Fair enough, but my left and right hands are non-superimposable because there are slight differences between the two. I don't get it. I don't see how you can have it both ways. ------------------http://www.hells-handmaiden.com
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gene90 Member (Idle past 3843 days) Posts: 1610 Joined: |
[QUOTE][B]But the organisms you are talking about have cell membranes
[/QUOTE]
[/B] Cell membranes are composed primarily of phospholipids with a hydrophobic head and hydrophilic tail. When mixed with water, they spontaneously form the bilayered membrane because that is the lowest energy configuration. All you need is a mix of phospholipids or molecules with similar properties (hydrophobe and hydrophile ends) in the soup and you end up with membranes forming spontaneously.
[QUOTE][B]So you would have to say there were permanent volcanic clouds hanging in the sky to protect earth? What about winds, etc moving them around?[/QUOTE] [/B] Because the entire planet is covered with clouds, wind is irrelevant and unable to part them. Take a look at Venus.
[QUOTE][B]So what is the alternative model you have for producing organic molecules?[/QUOTE] [/B] Anaerobic environments are common on Earth today. Also there is the thermal vent environment of the deep sea. (Where the ocean would block UV even without help from the atmosphere).
[QUOTE][B]After all, an average sized protein contains 500 amino acids. Give me a concentration (molarity) of peptides in water that you suggest would have proteins forming.[/QUOTE] [/B] Concentration of reagents for this reaction would only alter the rate of reaction. If you had only two AA molecules in an entire ocean, you could still have a "protein forming" when they eventually link up. The question is meaningless the way it is stated.
[QUOTE][B]As the planet cooled, wouldn't energy have mostly radiated out into outer space?[/QUOTE] [/B] That depends on the thickness of the atmosphere. And even today there is a lot of geothermal energy being released into the environment, namely hot vents and volcanism. Cooling is something that would take more than a billion years and is still occuring today.
[QUOTE][B]Tell me how the energy produced by cooling can be used.[/QUOTE] [/B] You misread the post. Energy is not produced by cooling.
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blitz77 Inactive Member |
quote: Ok, fair enough, but which model do you prefer? The cell membranes originating and replicating by the addition of more lipids until it splits into two, or cell membranes + self-replicating molecule inside?But anyway, correct me if I'm wrong, wouldn't the lipid membrane prefer to stay in 1 globule instead of splitting into two, as splitting into two exposes a bigger surface area to the water, which is disfavored by thermodynamics. If you say cell membranes + self replicating molecules, it makes it a lot more complicated to produce the first organism. quote: I'll agree with you that it could be possible.
quote: I'll check it out.
quote: But the 30 or so sequence that replicates cannot really mutate. If there is only a small mutation, the mechanism would be lost. In a larger molecule, mutations could be tolerated more.
quote: But wouldn't this still be heat energy?
quote: I don't think you understand why they put the "non-superimposable mirror image" thing there. It is because if you put one hand on top of the other, they do not overlap exactly. The L and D molecules just differ in the arrangement, clockwise or counter-clockwise. They are mirror images, so when they say non-superimposable it means that the two molecules are not identical arrangement.
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John Inactive Member |
quote: Without a complete model it is impossible to say which to back, and no model is complete enough to fit the bill. That said, I suspect that you something of both going on initially--perhaps for millions of hundreds of million years. Lipids just form, as has been pointed out, so no sense repeating it. What I imagine is that self-replicating molecules developed on their own and eventually colonized the bubbles of lipids.
quote: The bubbles will become unstable once they react a certain size, so splitting is inevitable disfavored or not.
quote: Life, or what was to be life, took a very long time to emerge. This is only a problem with a very short time-frame.
quote: Yes. Why is that a problem?
quote: hmmm..... I still have my doubts. I'll look it up again. [Removed extraneous quote UBB code. --Admin] ------------------http://www.hells-handmaiden.com [This message has been edited by Admin, 08-01-2002]
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blitz77 Inactive Member |
quote: This does not explain how in the end the self-replicating molecule would produce the bubbles of lipids for a membrane.
quote: I'm not sure how big they need to be to become unstable... so around a few cell sizes they would become unstable?
quote: But there is a very short time frame... the earliest bacteria in the evolutionist model appeared immediately after surface water became available.
quote: Give me some chemical reactions in which the addition of heat produces lower entropy molecules (without using a mechanism for decreasing entropy, as before abiogenesis there wouldn't be a mechanism). Why does ATP have to be used to form the required molecules instead of using just heat? I know that reversing an equation such as A -> B + C + X Joules could produce a more complicated molecule with the addition of energy, but without a mechanism for delivering the joules in a useful way it just wont work. [This message has been edited by blitz77, 08-02-2002]
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John Inactive Member |
quote: True. But assuming a selective advantage to living in these lipid bubble, we can also assume selective pressure towards maintaining and eventually generating the bubbles.
quote: ok... maybe someone can tell us for sure.
quote: The Earth formed around 4.5 billion years ago. Maybe someone can comment here, but the oceans seems to have formed around 700 million to a billion years later. The earliest reported fossils are about 3.5 billion. This is a very brief time frame for life to emerge. Interestingly, this 3.5 bya bacterial fossil is about a billion years older than anything else yet discovered, and the find is much debated. Basing an argument on this, thus far, anomolous and uncertain find, is not a good plan.
Nature - Not Found A Non-Biological Origin For Carbon In Ancient Rocks quote: Sorry, but this is mostly smoke screen. 1) What other common energy source is there but heat? 2) You seem to be denying that organic molecules cannot form spontaneously, and this has been shown to happen in the lab. [/B][/QUOTE] ------------------http://www.hells-handmaiden.com [This message has been edited by John, 08-02-2002]
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blitz77 Inactive Member |
quote: Definitely not spontaneously because it consumes more energy than it produces. You had sparks in the Urey-Miller experiment, and that wasn't heat. Anyway, the reducing atmosphere is debatable. And the concentration of the required constitutents is not spontaneous. [This message has been edited by blitz77, 08-02-2002]
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blitz77 Inactive Member |
Actually, let me change my tack. Heat, for it to do anything useful, requires a temperature gradient. A really big temperature gradient. (Take a look at power stations). If everything is the same temperature, it can't do anything useful. And also, heat prefers to stay as heat (it is very stable), while sparks do not. They prefer to get converted into heat. You cannot have heat converting into bond energy-The two great trends in the universe is for higher entropy and lower energy. 2nd law of thermodynamics-you need the gradient, as I said, for it to do anything. Even with the gradient, heat stays as heat. Heat does not get converted, only entropy increases because of the decrease in the gradient. You cannot have both heat converting into bond energy, as well as a decrease in entropy-only way bond energy can be produced using heat is if entropy increases.
Let me put it this way-Making a complex molecule is a decrease in entropy. The absorption of heat makes a temperature gradient with the surroundings (yet another decrease in entropy). Thus it doesn't work (you can't have them both decreasing in entropy).I'm not sure whether this makes sense, tell me if I'm wrong please. [This message has been edited by blitz77, 08-02-2002]
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John Inactive Member |
quote: oh geez..... we have a power supply....
quote: Miller-Urey is not the only experiment that has had sucess.
quote: Sure is, if not altogether abandonned. I posted something to this effect already.
quote: Wow, deja vu.... We've been throught this before. ------------------http://www.hells-handmaiden.com
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blitz77 Inactive Member |
quote: Refer to my previous one-you must have just finished writing this one and not noticed my next one.
quote: You could talk about how radiation of heat into outer space of course generates the gradient. But in the water, the gradient would be quite small on the molecular size-the ones next to each other would have nearly the same heat energy. So, when molecules absorb the heat from the surroundings to produce a complex molecule, it would have to create a much larger gradient (thus violating the law of thermodynamics), simply because producing the complex molecule requires a lot of heat energy. Sorry for the terrible previous post (message 38). [This message has been edited by blitz77, 08-02-2002]
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John Inactive Member |
quote: Yeah, you're right.
[quote][/b]You cannot have heat converting into bond energy[/b][/quote] Then we have no chemistry? Yes?
quote: Fine by me.
quote: I am not exactly sure what you are trying to say. The post was very confusing. But, it seems to have undermined all of chemistry. Try again, perhaps that will help me understand. ------------------http://www.hells-handmaiden.com
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blitz77 Inactive Member |
quote: -Without an at least equal increase in entropy somewhere else (usually, if not always the conversion of some other form of energy into heat), as with the absorption of heat in producing the bond energy, it would produce a temperature gradient elsewhere (= decrease in entropy). Thus you need something else to supply the increase in entropy at least equal or greater to the decrease in entropy (2nd law of thermodynamics). Oh well, gotta go sleep. Think on it, and tell me if its nonsense. [This message has been edited by blitz77, 08-02-2002]
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John Inactive Member |
quote: Fine.
quote: You don't need this step. The energy used to produce the bond balances the entropy.
quote: Sleep? You work nights or you are halfway around the world from me. ------------------http://www.hells-handmaiden.com
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Randy Member (Idle past 6267 days) Posts: 420 From: Cincinnati OH USA Joined: |
The thermodynamic arguments on this thread that has become about abiogenesis rather than evolution seem a little confused to me. I only have time to reply to a few made by Blit77
Blitz77: But anyway, correct me if I'm wrong, wouldn't the lipid membrane prefer to stay in 1 globule instead of splitting into two, as splitting into two exposes a bigger surface area to the water, which is disfavored by thermodynamics. Randy: OK, You are wrong. You are thinking of the splitting up of oil droplets which is unfavorable because of increased oil/water interfacial area. The bilayer membrane is a thermodynamically stable phase. The hydrophilic portions of the lipid molecules are exposed to the water so there is no thermodynamic cost to expose more area to water and I don’t think splitting a hollow shell into two hollow shells results in much change in surface area anyway. The only cost may be a very small one from increased curvature of the membrane. This can be more than compensated for by other factors especially if more lipid can be incorporated into the new membranes. Blitz77:The two great trends in the universe is for higher entropy and lower energy. Randy: No energy is conserved. You have forgotten the FIRST law of thermodynamics. Blita77:Let me put it this way-Making a complex molecule is a decrease in entropy. The absorption of heat makes a temperature gradient with the surroundings (yet another decrease in entropy). Thus it doesn't work (you can't have them both decreasing in entropy).I'm not sure whether this makes sense, tell me if I'm wrong please. Randy: OK you are wrong. If this were true polymerization reactions would not be spontaneous and many of them are highly spontaneous. Complex molecules can form spontaneously under the appropriate conditions of temperature and pressure. Polymerization reactions release heat to compensate for the decrease in entropy of the monomers. It is the free energy change and not the entropy change that determines the direction of a reaction and the free energy changes depends on temperature and pressure. You are trying to argue that the second law of thermodynamics prevents unknown reactions that may have occurred at unknown conditions of temperature and pressure. This invalidates all your thermodynamic arguments leaving you with arguments from incredulity. Randy
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