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Thread: Replicator molecules

  1. #1 Replicator molecules 
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    Hi,

    Out of curiosity, do we know of other molecules than RNA and DNA that have the ability to be replicators?

    From what I know, DNA has evolved from RNA. Could RNA have evolved from a more simple replicator. Could life have started with a rather crappy replicator? If a simple cell reproduces 100 cells but only one has no error in his replicator, that could maybe be sufficient for a start.

    Nic.


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    Apparently some proteins are able to self-replicate.
    http://cba.mit.edu/events/03.11.ASE/docs/Lee.pdf


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    Quote Originally Posted by dan hunter View Post
    Apparently some proteins are able to self-replicate.
    http://cba.mit.edu/events/03.11.ASE/docs/Lee.pdf
    Thanks for the link Dan.

    According to the last paragraph, there might be several variants of these protein that can self-replicate. I read that DNA is not a protein, so there seems to be several classes of self-replicating molecules.

    I wonder whether RNA has evolved from another replicator or if it appeared as is. The evolution from RNA to DNA seems to suggest that some replicators can evolve.
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    DNA isn't a protein no, it's made up of more than one type of macromolecule: carbohydrates, nucleotides and proteins.
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    Quote Originally Posted by Nic321 View Post
    Quote Originally Posted by dan hunter View Post
    Apparently some proteins are able to self-replicate.
    http://cba.mit.edu/events/03.11.ASE/docs/Lee.pdf
    Thanks for the link Dan.

    According to the last paragraph, there might be several variants of these protein that can self-replicate. I read that DNA is not a protein, so there seems to be several classes of self-replicating molecules.

    I wonder whether RNA has evolved from another replicator or if it appeared as is. The evolution from RNA to DNA seems to suggest that some replicators can evolve.
    This depends on your criteria. As far as i know, there is no self replicating molecule. Only cells can replicate themselves, and only under very strict conditions. The self replicating proteins you speak off, can only produce a product protein from a substrate protein. It simply removes a part of the old one, or changes the setup slightly and voila, a new protein that is like itself.

    But, with this specificity, i would not call it self replicating.
    Growing up, i marveled at star-trek's science, and ignored the perfect society. Now, i try to ignore their science, and marvel at the society.

    Imagine, being able to create matter out of thin air, and not coming up with using drones for boarding hostile ships. Or using drones to defend your own ship. Heck, using drones to block energy attacks, counterattack or for surveillance. Unless, of course, they are nano-machines in your blood, which is a billion times more complex..
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    I suppose you could use that technicality and say that DNA is not self replicating, because it utilises RNA, enzymes, protein complexes etc.
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    Quote Originally Posted by Zwolver View Post
    Quote Originally Posted by Nic321 View Post
    Quote Originally Posted by dan hunter View Post
    Apparently some proteins are able to self-replicate.
    http://cba.mit.edu/events/03.11.ASE/docs/Lee.pdf
    Thanks for the link Dan.

    According to the last paragraph, there might be several variants of these protein that can self-replicate. I read that DNA is not a protein, so there seems to be several classes of self-replicating molecules.

    I wonder whether RNA has evolved from another replicator or if it appeared as is. The evolution from RNA to DNA seems to suggest that some replicators can evolve.
    This depends on your criteria. As far as i know, there is no self replicating molecule. Only cells can replicate themselves, and only under very strict conditions. The self replicating proteins you speak off, can only produce a product protein from a substrate protein. It simply removes a part of the old one, or changes the setup slightly and voila, a new protein that is like itself.

    But, with this specificity, i would not call it self replicating.
    This is technical I don't really know, but in the article it says in the conclusion that it this replication of peptides could have happened in prebiotic environment.

    I don't understand much of the article honestly ( well almost nothing... ) but they seem to say that these molecules are capable of autocatalysis.
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    Autocatalysis is as far as i know, that the process of a protein does not cost energy, or the protein is not used up, or hasn't used up any part of itself for this reaction. Autocatalysis doesn't mean copying itself.
    Growing up, i marveled at star-trek's science, and ignored the perfect society. Now, i try to ignore their science, and marvel at the society.

    Imagine, being able to create matter out of thin air, and not coming up with using drones for boarding hostile ships. Or using drones to defend your own ship. Heck, using drones to block energy attacks, counterattack or for surveillance. Unless, of course, they are nano-machines in your blood, which is a billion times more complex..
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    Hi Nic.
    I think that you are referring to the period where the cell was forming or may be even before that (the coacervates), where the genetic information was carried in RNA like molecules or even in protein-RNA like molecules, which were unstable. But once the cell appeared, the genetic information became contained in another type of molecule, the DNA, which is more stable and capable of protecting the information. So RNA became the intermediary between DNA and proteins, which are biomolecules that carry out many important functions.

    First of all, we can´t call crappy to the first "replicator"!! It´s almost disrespectful, he! but I think that what you are trying to say is that the first molecules that carried the hereditary information and were able to copy themselves, were not as complex as they are now. And that´s correct, but also expectable because cells were also much simpler.

    So, calling replicator to a molecule that copies itself somehow.... we only know that´s possible between DNA and RNA or viceversa. There is no biological process where a peptide is somehow read by an enzyme and synthesize another equal peptide in consequence. Nor other biomolecules that I´m aware of.

    And about the cited article, I didn´t read much, but it says something about joining pre-formed peptides. So... where do those peptides come from? They had to be synthesized before. So I wouldn´t call that replication of peptides.

    All right, that´s all.

    Bye!
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    Quote Originally Posted by M_Gabriela View Post
    Hi Nic.
    I think that you are referring to the period where the cell was forming or may be even before that (the coacervates), where the genetic information was carried in RNA like molecules or even in protein-RNA like molecules, which were unstable. But once the cell appeared, the genetic information became contained in another type of molecule, the DNA, which is more stable and capable of protecting the information. So RNA became the intermediary between DNA and proteins, which are biomolecules that carry out many important functions.

    First of all, we can´t call crappy to the first "replicator"!! It´s almost disrespectful, he! but I think that what you are trying to say is that the first molecules that carried the hereditary information and were able to copy themselves, were not as complex as they are now. And that´s correct, but also expectable because cells were also much simpler.

    So, calling replicator to a molecule that copies itself somehow.... we only know that´s possible between DNA and RNA or viceversa. There is no biological process where a peptide is somehow read by an enzyme and synthesize another equal peptide in consequence. Nor other biomolecules that I´m aware of.

    And about the cited article, I didn´t read much, but it says something about joining pre-formed peptides. So... where do those peptides come from? They had to be synthesized before. So I wouldn´t call that replication of peptides.

    All right, that´s all.

    Bye!
    Hi M_Gabriela,

    What do you mean by "protein-RNA like molecules"? According to what you say they were not in cells, right? Where the protein-RNA like molecules you are talking about the ancestor of RNA?

    From what you say, the replicator really started with a very simple and unreliable form, and became more complex and reliable, enabling more complex lifeforms to exist.

    So is it fair to say that it is not just the genes on a replicator which evolve, but the replicator too?

    What I was wondering is that new genes appear because of mistakes or mutations in the replicator. This process could not just lead to new genes but could also change the structure of the molecule itself, turning it into another form of replicator. The better forms of replicators could be selected favorably by natural selection.
    Last edited by Nic321; September 10th, 2014 at 04:07 PM.
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    Quote Originally Posted by Zwolver View Post
    Autocatalysis is as far as i know, that the process of a protein does not cost energy, or the protein is not used up, or hasn't used up any part of itself for this reaction. Autocatalysis doesn't mean copying itself.
    Ok, but it is still more simple that the replication of RNA or DNA. That kind of replication would happen without a cell, wouldn't it?

    Could these first self-replicating peptides, even if they need additionnal material from their environment, managed to have created a very simple cell around them? As soon as something can replicate, it can become more complex over time and perhaps alter its immediate environment to better replicate - that is, create a cell.
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    I was talking about a compound that could be RNA interacting with a protein. Nothing out of the ordinary... RNA interacts with proteins, as DNA does, all the time.
    Before the cell appeared, there is a theory that talks about the coacervates, which were primitive biomolecules enclosed in a vesicle by fosfolipids or other kind of lipids, i don´t remember. And they are said to be the primitive cells, where genetic information was contained in RNA molecules.

    I´m not sure what´s your definition of replicator. I mean, I never used that expression, so I´m not familiarized with the proper definition. I thought you were talking about molecules that can be synthesized using others or themselves as template, and with a proper machinery (enzymes, substrates, energy) and with the function of carrying the hereditary information.
    I thought that indirectly you were talking about DNA. That´s why I said that in the begginings, it´s more likely that the RNA had accomplished the mission of transporting the hereditary information. But as RNA is a very unstable molecule and much simpler (i wouldn´t say unreliable), during the evolution, DNA was selected as a better molecule for that job (more stable, double helix structure and other things that make it better).

    So the replicator, being the DNA molecule (or RNA when DNA didn´t exist yet), was selected not because of the genes or other information it contained, but because it´s structure was more suitable for the job of keeping safe the genetic information, than any other biomolecule.

    During evolution, genes changed, but genes are segments of DNA. What changes is the type of nucleotides (DNA is formed by 4 different types of nucleotides, A G C T), not the structure of nucleotides. That´s why genes change, but not the DNA structure.

    Now, what did change was the way DNA was regulated. In eukaryotic cells (more evolved) DNA undergoes modifications in order to activate/inactivate genes or to maintain certain areas more compacted than others. But this modifications are achieved by protein machinery that acts on DNA.

    So the combination of DNA with regulatory mechanism driven by proteins were selected as cells became more complex. But again, the basic structure was maintained.

    bye!
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    What I call replicator is pretty much what you understood, that is, the molecule which stored the genetic information. Sorry if it is not the scientific term.

    Basically what I was saying is that this type of molecule ( like RNA, DNA, etc... ) can transform into another replicator molecule, for instance RNA transforming into DNA ( although both are still used together from what I understand ). I mean DNA didn't appear suddenly, it was an evolution of RNA. And as you say RNA is less stable and more simple than DNA, so there seems to be some sort of evolution of the type molecule containing the genetic information, from less complex to more complex. Hence the idea that RNA could itself maybe have evolved from an even more simple and less stable type of molecule which contained the first sort of primitive genes.

    In other words, what I am curious about is the possible evolution of the molecule encoding the genetic information towards more complexity. And not just on Earth, but in general. Does life always start with a simple type of replicator molecule that becomes more complex?

    I read the wiki article about coacervate and it says

    "This theory proposes that metabolism predated information replication. The debate as to whether metabolism or molecules capable of Template replication came first in the origins of life remains open[1] and for decades Oparin's theory was the leading approach to the origin of life question.".
    They have two different theories.

    I don't understand squat about the biology ( humm ) but apparently they don't know how they would reproduce:
    However, the lack of any mechanism by which coacervates can reproduce leaves them far short of being living systems

    Besides I found this wiki article about the RNA world hypothesis, it which it says:
    Prebiotic RNA synthesis[edit]

    Nucleotides are the fundamental molecules that combine in series to form RNA. They consist of a nitrogenous base attached to a sugar-phosphate backbone. RNA is made of long stretches of specific nucleotides arranged so that their sequence of bases carries information. The RNA world hypothesis holds that in the primordial soup (or sandwich), there existed free-floating nucleotides. These nucleotides regularly formed bonds with one another, which often broke because the change in energy was so low. However, certain sequences of base pairs have catalytic properties that lower the energy of their chain being created, causing them to stay together for longer periods of time. As each chain grew longer, it attracted more matching nucleotides faster, causing chains to now form faster than they were breaking down.
    These chains are proposed as the first, primitive forms of life.[54] In an RNA world, different forms of RNA compete with each other for free nucleotides and are subject to natural selection. The most efficient molecules of RNA, the ones able to efficiently catalyze their own reproduction, survived and evolved, forming modern RNA. Such an RNA enzyme, capable of self replication in about an hour, has been identified. It was produced by molecular competition (in vitro evolution) of candidate enzyme mixtures.[55]
    Competition between RNA may have favored the emergence of cooperation between different RNA chains, opening the way for the formation of the first protocell. Eventually, RNA chains developed with catalytic properties that help amino acids bind together (a process called peptide-bonding). These amino acids could then assist with RNA synthesis, giving those RNA chains that could serve as ribozymes the selective advantage. The ability to catalyze one step in protein synthesis, aminoacylation of RNA, has been demonstrated in a short (five-nucleotide) segment of RNA.[56]

    This is very interesting, primitive forms of RNA appeared and natural selection selected the best one, which became predominant. And they say they even evolved.
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    Maynard Smith tends to present evolution as the selection of the most stable forms, ie: the evolution of stability
    Evolutionarily stable strategy - Wikipedia, the free encyclopedia

    The problem is more stable replicators would replace less stable ones, just because they are more stable.
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    You asked if life always starts with a simple replicator? I only know our kind of life and the answer is yes! hehehe .................unless we start talking about Transformers, and their robotic-biological existance... hahaha. I think moderators would probably ban us,
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    There is anothor kind of life, those allah Akbar dudes... their replicator is for sure crappy lol...
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    Don't mean to be mean or unwelcoming or anything (hell on other forums I'd be branded a "newfag" regardless of what I have to say), but don't you think you're trying to go for topics that you, as of yet, can't really grasp since you lack the knowledge and understanding of the basics? I mean you said yourself you didn't understand that article and what not. Honestly, this is all very theoretical stuff and if you ultimately would like to have a timeline and for each stop on that timeline a name of the molecule from which the DNA we know today comes, then the answer is as so often with these things: It's not that simple. I mean I know of no molecule that could replicate itself without very very specific conditions. After all the replication of the DNA in cells is done through so many different mechanisms involving so many conditions and so many proteins who are intended for one specific job only, it's like the more you study the stuff the more you're in disbelief whether all of this could have actually developed by accident. The DNA is not a "replicator"...it doesn't replicate itself. It gets replicated through many different stages and by the help of very specific proteins.
    As you have already heard, even the most popular theories on how the first cells formed (not even the cell organelles, just the prototype of the cell membrane) are still very theoretical and holely at best.
    Basically somehow, somewhere a bunch of freakin' chemicals under the sea one day decided to all squeeze together in that membrane of phosphorlipids and shut themselves up from the rest of the ocean and by some freak accident something something happened and all these accidental partners in chemical crime interacted in some weird way noone could have predictet and replicatet themselves through combined effort...see what I mean...that's the story so far. You're asking a question you wouldn't have asked if you knew more about the basics because then you'd have known that this question cannot be answered the way you imagined.
    If you mean an instance in which a molecule gets replicated and multiplies in numbers gradually because other molecules interact with it in some freaky way in some special enviorment exept for DNA, then I know of none. In Chemistry a synthesis does not start off with the molecule you want, to use it to convert another molecule in to the molecule you want which you already had at the beginning of the process of synthesizing it. That is exclusively a organism, DNA thing from what we (or rather I) know.
    So yeah...study the basics of genetics and evolution theory and you should be fine.
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    Quote Originally Posted by Etsin View Post
    Don't mean to be mean or unwelcoming or anything (hell on other forums I'd be branded a "newfag" regardless of what I have to say), but don't you think you're trying to go for topics that you, as of yet, can't really grasp since you lack the knowledge and understanding of the basics? I mean you said yourself you didn't understand that article and what not. Honestly, this is all very theoretical stuff and if you ultimately would like to have a timeline and for each stop on that timeline a name of the molecule from which the DNA we know today comes, then the answer is as so often with these things: It's not that simple. I mean I know of no molecule that could replicate itself without very very specific conditions. After all the replication of the DNA in cells is done through so many different mechanisms involving so many conditions and so many proteins who are intended for one specific job only, it's like the more you study the stuff the more you're in disbelief whether all of this could have actually developed by accident. The DNA is not a "replicator"...it doesn't replicate itself. It gets replicated through many different stages and by the help of very specific proteins.
    As you have already heard, even the most popular theories on how the first cells formed (not even the cell organelles, just the prototype of the cell membrane) are still very theoretical and holely at best.
    Basically somehow, somewhere a bunch of freakin' chemicals under the sea one day decided to all squeeze together in that membrane of phosphorlipids and shut themselves up from the rest of the ocean and by some freak accident something something happened and all these accidental partners in chemical crime interacted in some weird way noone could have predictet and replicatet themselves through combined effort...see what I mean...that's the story so far. You're asking a question you wouldn't have asked if you knew more about the basics because then you'd have known that this question cannot be answered the way you imagined.
    If you mean an instance in which a molecule gets replicated and multiplies in numbers gradually because other molecules interact with it in some freaky way in some special enviorment exept for DNA, then I know of none. In Chemistry a synthesis does not start off with the molecule you want, to use it to convert another molecule in to the molecule you want which you already had at the beginning of the process of synthesizing it. That is exclusively a organism, DNA thing from what we (or rather I) know.
    So yeah...study the basics of genetics and evolution theory and you should be fine.
    Lol no. When you're wondering about something you don't always know the level of complexity of the answer. I have learned a few things about the subject, and it is just fine to me.
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    Quote Originally Posted by Nic321 View Post
    Hi,

    Out of curiosity, do we know of other molecules than RNA and DNA that have the ability to be replicators?

    From what I know, DNA has evolved from RNA. Could RNA have evolved from a more simple replicator. Could life have started with a rather crappy replicator? If a simple cell reproduces 100 cells but only one has no error in his replicator, that could maybe be sufficient for a start.

    Nic.
    It is a self replicating protein acting as a enzyme of sorts.
    “The authors show that a 32-amino-acid peptide, folded into an alpha-helix and having a structure based on a region of the yeast transcription factor GCN4, can autocatalyse its own synthesis by accelerating the amino-bond condensation of 15- and 17-amino-acid fragments in solution (see Fig. 1 on page 525).” Evolution - May 1997: Self-replicating proteins
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    It has the function of autosynthesize the peptide bond between two pre-existing peptides of 15 and 17 amino acid long. I don´t think that is self replication. May be we should find a definition for self replication
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    Quote Originally Posted by M_Gabriela View Post
    It has the function of autosynthesize the peptide bond between two pre-existing peptides of 15 and 17 amino acid long. I don´t think that is self replication. May be we should find a definition for self replication
    Agreed, aren’t these systems subject to the same fatal flaw of all these self replicators? That they reproduce under exceptional conditions, like having to be in a sea of constituent parts.
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    Well, with Nic, we agreed, I think, that the molecules that can "self replicate" would be the ones that use a template and an appropiate machinery (enzymes, substrates, energy), such as DNA and RNA (the latter using DNA as template).

    But proteins don´t use a "protein template" to synthesize a new polypeptide... that´s why proteins do not "self replicate". I also don´t think that there were proteins before RNA appearance....Proteins are not randomly synthesize from aminoacid... there´s actually a limited pool of proteins with associated function. The probability to assemble, I don´t know, 200 aminoacid randomly and have a functional protein in consequence is very near to 0. Functional proteins were selected during evolution and were compatible with our kind of life. For xample to be compatible they have to synthesize rapidly to adjust to the needs of our cells. Proteins, whose folding rate are within seconds, hours, days, they are not compatible with our metabolism, so they weren´t selected.
    And when I say our kind of life, I mean, from bacteria to higher mammals.

    bye
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    there were proteins before RNA appearance....Proteins are not randomly synthesize from aminoacid... there´s actually a limited pool of proteins with associated function. The probability to assemble, I don´t know, 200 aminoacid randomly and have a functional protein in consequence is very near to 0. Functional proteins were selected during evolution and were compatible with our kind of life. For xample to be compatible they have to synthesize rapidly to adjust to the needs of our cells. Proteins, whose folding rate are within seconds, hours, days, they are not compatible with our metabolism, so they weren´t selected.
    And when I say our kind of life, I mean, from bacteria to higher mammals.


    Well actually proteins do exhibit a calculable probability to assemble randomly. In the case from my cited paper they should be as follows:

    300 (about the number of naturally occurring amino acids.

    Given the above I get…

    300^32 * 300^17 * 300^15 = 300^64 (I did not consider chirality)

    In terms of probability the system has a probability of 1 in 300^64

    Evaluating this probability against Borel’s cosmic limit.

    1 in 300^64 << 1 in 10^50…

    You are right this event can not happen according to Borel but falls short of Dembski’s universal bound ( 1 in 10^150).

    “I don´t know, 200 aminoacid randomly and have a functional protein in consequence is very near to 0.”

    1 in 300^200 does fall bellow Dembski’s bound… So by both definition the probability is zero.

    “For xample to be compatible they have to synthesize rapidly to adjust to the needs of our cells. Proteins, whose folding rate are within seconds, hours, days, they are not compatible with our metabolism, so they weren´t selected.”

    Interesting point, do you have a citation?
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    Quote Originally Posted by M_Gabriela View Post
    Well, with Nic, we agreed, I think, that the molecules that can "self replicate" would be the ones that use a template and an appropiate machinery (enzymes, substrates, energy), such as DNA and RNA (the latter using DNA as template).

    But proteins don´t use a "protein template" to synthesize a new polypeptide... that´s why proteins do not "self replicate". I also don´t think that there were proteins before RNA appearance....Proteins are not randomly synthesize from aminoacid... there´s actually a limited pool of proteins with associated function. The probability to assemble, I don´t know, 200 aminoacid randomly and have a functional protein in consequence is very near to 0. Functional proteins were selected during evolution and were compatible with our kind of life. For xample to be compatible they have to synthesize rapidly to adjust to the needs of our cells. Proteins, whose folding rate are within seconds, hours, days, they are not compatible with our metabolism, so they weren´t selected.
    And when I say our kind of life, I mean, from bacteria to higher mammals.

    bye
    I think that is a pretty good analysis for a beginner. 70/100 for the score.
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    "Functional proteins were selected during evolution and were compatible with our kind of life. For xample to be compatible they have to synthesize rapidly to adjust to the needs of our cells. Proteins, whose folding rate are within seconds, hours, days, they are not compatible with our metabolism, so they weren´t selected."

    This last statement baffles me totally. Take for instance “folding” it is indeed specifically coded for in DNA (thus selected), in particular, in some disease studies a single SNP in DNA can alter and cause aberrant behavior in the coded protein (the fault attributed to folding).


    Bingo... a fitness selection.

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    About citations, there are books that talk about protein folding... I have to go to work. When I come back I´ll give some titles.
    About your second post... protein folding occurs after they were synthesized... Mutations may cause a problem with folding giving non functional proteins... That is one type of mutation. But I didn´t understand that thing of fitness selection.

    Gotta go!!

    byee
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    Quote Originally Posted by GTCethos View Post


    Well actually proteins do exhibit a calculable probability to assemble randomly. In the case from my cited paper they should be as follows:

    300 (about the number of naturally occurring amino acids.

    Given the above I get… [bla bla]

    Why do you believe that a protein of 300 amino acids assembled randomly without having an evolutionary history that was most definitely not random? This strawman version of evolution that you follow is doing you no favours at all.

    Shuffle a deck of cards, look at the sequence and then repeat two more times. What do you think the probability of getting those three sequences was? Astronomical odds are met routinely with ease - the illusion of improbability comes when you calculate the odds after the fact.
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    Why do you believe that a protein of 300 amino acids assembled randomly without having an evolutionary history that was most definitely not random? This strawman version of evolution that you follow is doing you no favours at all.



    The 300 amino acids is not a real figure, I am simply giving in to some assertions that (most amino acids are possible in meteorites). If someone claims that a full compliment of the 22 amino acids (life as we know contain them) were possible in space. The others must be also possible.


    If you do not like the estimate just assume the 22 amino acids were the only ones present (all assumption in your favor).


    This gives 1 in 22^200 power. Still fails both probability limits.


    chances still zero.


    If the chemistry you refer to in a prebiotic universe is not subject to accepted probability then you are thinking of another chemistry. the one the one science assumes is observable.
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    Shuffle a deck of cards, look at the sequence and then repeat two more times. What do you think the probability of getting those three sequences was? Astronomical odds are met routinely with ease - the illusion of improbability comes when you calculate the odds after the fact.



    The only problem is that your example is not probability…


    You desire... (a certain order/all possible orders)


    Now what is the probability of getting three deck of card sequences in the same order in a row? First sequence order is 52! (52 factorial). Other sequences the same…


    Total probability is 52! x 52! x 52! or 152!
    = 1 in 1.3 x 10^267


    Web factorial calculator…
    http://www.calculatorsoup.com/calculators/discretemathematics/factorials.php
    Last edited by GTCethos; September 16th, 2014 at 01:01 PM. Reason: my error
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    “Astronomical odds are met routinely with ease “


    Good, go win the loto…
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    Quote Originally Posted by Robittybob1 View Post
    Quote Originally Posted by M_Gabriela View Post
    Well, with Nic, we agreed, I think, that the molecules that can "self replicate" would be the ones that use a template and an appropiate machinery (enzymes, substrates, energy), such as DNA and RNA (the latter using DNA as template).

    But proteins don´t use a "protein template" to synthesize a new polypeptide... that´s why proteins do not "self replicate". I also don´t think that there were proteins before RNA appearance....Proteins are not randomly synthesize from aminoacid... there´s actually a limited pool of proteins with associated function. The probability to assemble, I don´t know, 200 aminoacid randomly and have a functional protein in consequence is very near to 0. Functional proteins were selected during evolution and were compatible with our kind of life. For xample to be compatible they have to synthesize rapidly to adjust to the needs of our cells. Proteins, whose folding rate are within seconds, hours, days, they are not compatible with our metabolism, so they weren´t selected.
    And when I say our kind of life, I mean, from bacteria to higher mammals.

    bye
    I think that is a pretty good analysis for a beginner. 70/100 for the score.
    How kind! Also, I´m from a spanish speaking country so I had to think it in spanish and translate to english. For that I should have a higher score, hahahaha ; )
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    Quote Originally Posted by GTCethos View Post

    “For xample to be compatible they have to synthesize rapidly to adjust to the needs of our cells. Proteins, whose folding rate are within seconds, hours, days, they are not compatible with our metabolism, so they weren´t selected.”

    Interesting point, do you have a citation?
    Well, That resumed comment is for what I remembered from a class. So, I´ve been checking the power point of that class and there are only citations to books.
    1) Fersht, A. Structure and mechanism in protein science (1999) Freeman Press.
    Chapters 1, 11, 17 y 18
    2) Advances in Protein Chemistry (1995) Vol. 46.
    Chapter 3 (Free energy balance in protein folding)
    3) Branden y Tooze. Introduction to Protein Structure (1999)
    Garland Publishing, Inc.
    4) Whitford, D. Proteins. Structure and function (2005)
    Editorial John Wiley & Sons

    That class was all about why proteins fold... I would give you the power point but is in spanish...
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    Is anybody here familiar with the work of Julius Rebek on self-replicating molecules?

    Unfortunately the only copy I can find of his paper on it is hidden behind a paywall.
    http://pubs.acs.org/doi/abs/10.1021/...49&volume=112&
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    I tried to get some of this read online and failed.


    1) Fersht, A. Structure and mechanism in protein science (1999) Freeman Press.
    Chapters 1, 11, 17 y 18
    2) Advances in Protein Chemistry (1995) Vol. 46.
    Chapter 3 (Free energy balance in protein folding)
    3) Branden y Tooze. Introduction to Protein Structure (1999)
    Garland Publishing, Inc.
    4) Whitford, D. Proteins. Structure and function (2005)
    Editorial John Wiley & Sons



    Good but do you have anything I can read? In particular supporting your following statement:


    “so they weren´t selected”


    A simple synopsis would help.
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    Quote Originally Posted by dan hunter View Post
    Is anybody here familiar with the work of Julius Rebek on self-replicating molecules?

    Unfortunately the only copy I can find of his paper on it is hidden behind a paywall.
    An Error Occurred Setting Your User Cookie
    I know very little about Julius Rebek and his work.


    I visited the cited article and immediately got a headache. It appears that this scientist is an expert in reactive intermediates (some biological “enzymes” and some not) from my meager understanding they are core mechanisms to metabolism in organisms.


    Prebiotic sugar synthesis has long been difficult to explain in terms of prebiotic chemistry. There are innumerable articles on this subject.


    Here is a taste of one:


    “Iron(III) hydroxide oxide [Fe(OH)O] efficiently catalyzed the condensation of 25 MM dl-glyceraldehyde to ketohexoses at 25°C (pH 5–6). At 16 days the yields were sorbose (15.2%), fructose (12.9%), psicose (6.1%), tagatose (5.6%), and dendroketose (2.5%) with 19.6% of triose unreacted.”
    Iron(III) hydroxide oxide [Fe(OH)O] is one of those theoretical “reactive intermediates” as far as I know.


    It also might be noted that simple sugar (ribose) also form part of the backbone to RNA and DNA. Also:


    Ribose (β-D-ribofuranose) forms part of the backbone of RNA. It is related to deoxyribose, which is found in DNA. Phosphorylated derivatives of ribose such as ATP and NADH play central roles in metabolism. cAMP and cGMP, formed from ATP and GTP, serve as secondary messengers in some signalling pathways.https://en.wikipedia.org/wiki/Ribose



    So you can guess the implication to abiogenesis.
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    I´ll see what can I do... but it´s actually a deduction...
    There are many proteins that could be synthesized from a DNA template (for the simple reason that there could be billions of DNA templates). But how many of them would produce polypeptide chains that are able to fold properly and give a functional activity? Not that many...
    Would it make any sense if proteins that can not fold in less than seconds be a part of a living being? what use would they have? Does a DNA template that produce a non functional protein be selected if not useful ? Probably not (Now.. we could have that DNA template in our hereditary material but it would not express) Why would a cell spend energy in something not useful?


    Did you try the NCBI? There is a book section

    bye
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    Quote Originally Posted by M_Gabriela View Post
    I´ll see what can I do... but it´s actually a deduction...
    There are many proteins that could be synthesized from a DNA template (for the simple reason that there could be billions of DNA templates). But how many of them would produce polypeptide chains that are able to fold properly and give a functional activity? Not that many...
    Would it make any sense if proteins that can not fold in less than seconds be a part of a living being? what use would they have? Does a DNA template that produce a non functional protein be selected if not useful ? Probably not (Now.. we could have that DNA template in our hereditary material but it would not express) Why would a cell spend energy in something not useful?


    Did you try the NCBI? There is a book section

    bye
    I think you have a very important point there, so the first selected proteins must have assisted the replication process. New ideas are sometimes expressed clumsily, sorry.
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    I´ll see what can I do... but it´s actually a deduction...
    There are many proteins that could be synthesized from a DNA template (for the simple reason that there could be billions of DNA templates).
    The majority of all proteins in the human body are coded for:

    It is also estimated that human body has the ability to generate 2 million different types of proteins, coded by only 20,000-25,000 of our genes.http://www.innovateus.net/health/how-many-proteins-exist-human-body


    The two million number come from the fact of “open reading frames” in our DNA. This is an amazing function that defies any explanation by evolutionists.


    But how many of them would produce polypeptide chains that are able to fold properly and give a functional activity?

    Most of all of them…

    Not that many…


    Please provide a citation….

    Would it make any sense if proteins that can not fold in less than seconds be a part of a living being? what use would they have? Does a DNA template that produce a non functional protein be selected if not useful ?


    Many paradigms in evolution lack adequate explanation… how do I answer this in terms of science?

    Probably not (Now.. we could have that DNA template in our hereditary material but it would not express) Why would a cell spend energy in something not useful?


    Answer this question and maybe you will win a Nobel prize.

    Your statements continue to baffle me….

    Shortly after transcription a protein will assume its “native” three dimensional state… All proteins do this and its three dimensional state is essential to its function:

    “the line of sight from the genetic blueprint for a protein to its biological function is blocked by the impenetrable jungle of protein folding, and some researchers believe that clearing this jungle is the most important task in biochemistry at present.http://www.nature.com/horizon/proteinfolding/background/importance.html


    Now according to the Levinthal's paradox some proteins folding is literally not measurable and can not be simply characterized because of its rapid transformations. ( a problem that currently lacks a evolutionary explanation).

    Now….

    It is customary when making such stamens as:

    “a protein’s folding was not selected” or “not many proteins fold” ( I paraphrase).

    That you are easily able to support those stamens with some kind of simple evidence such as a wiki article or a science journal article. No one here on this forum would let me get away with any kind of statements like you are making without some kind of citation.

    I simply want to update my understanding of protein action by reviewing such information that you may have. If you wish participants to take notice of your assertions please just provide some kind of evidence.
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    Did you check the NCBI?

    Ok... I´ll try to prepare a post with appropiate citations when I get back home
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    I am not going to throw softballs like some other participants here....
    I wished to finish an earlier point about the availability of ribose in a prebiotic setting.


    The evidence that is currently available does not support the availability of ribose on the prebiotic earth, except perhaps for brief periods of time, in low concentration as part of a complex mixture, and under conditions unsuitable for nucleoside synthesis.http://www.ncbi.nlm.nih.gov/pubmed/2453009



    Without ribose you have no RNA or DNA molecules… The entire argument of the RNA and DNA worldview simply falls apart.


    How do you get a RNA molecule without ribose?
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    [QUOTE=GTCethos;593451]
    I´ll see what can I do... but it´s actually a deduction...
    There are many proteins that could be synthesized from a DNA template (for the simple reason that there could be billions of DNA templates).
    The majority of all proteins in the human body are coded for:

    It is also estimated that human body has the ability to generate 2 million different types of proteins, coded by only 20,000-25,000 of our genes.http://www.innovateus.net/health/how-many-proteins-exist-human-body


    The two million number come from the fact of “open reading frames” in our DNA. This is an amazing function that defies any explanation by evolutionists.


    But how many of them would produce polypeptide chains that are able to fold properly and give a functional activity?

    Most of all of them…

    Not that many…


    There are approx. 30.000 proteins.
    We have a large of DNA but only 2-3% code for proteins... That you can search in any page I don´t need to give you a citation...
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    [QUOTE=M_Gabriela;593470]
    Quote Originally Posted by GTCethos View Post
    I´ll see what can I do... but it´s actually a deduction...
    There are many proteins that could be synthesized from a DNA template (for the simple reason that there could be billions of DNA templates).
    The majority of all proteins in the human body are coded for:

    It is also estimated that human body has the ability to generate 2 million different types of proteins, coded by only 20,000-25,000 of our genes.http://www.innovateus.net/health/how-many-proteins-exist-human-body


    The two million number come from the fact of “open reading frames” in our DNA. This is an amazing function that defies any explanation by evolutionists.


    But how many of them would produce polypeptide chains that are able to fold properly and give a functional activity?

    Most of all of them…

    Not that many…


    There are approx. 30.000 proteins.
    We have a large of DNA but only 2-3% code for proteins... That you can search in any page I don´t need to give you a citation...
    There seems to be some very dubious science in your reply, and I'm surprised you are getting away with it.
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    There are approx. 30.000 proteins.
    We have a large of DNA but only 2-3% code for proteins... That you can search in any page I don´t need to give you a citation…



    This supports what now?


    Folding, conservation of non encoding DNA? Most of DNA as I understand it is regulatory…
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    There seems to be some very dubious science in your reply, and I'm surprised you are getting away with it.



    I do not want to get away with anything… just present me a reasonable argument.


    By the way “Crow” has become a delicacy to me. Feed away.
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    Quote Originally Posted by GTCethos View Post
    There are approx. 30.000 proteins.
    We have a large of DNA but only 2-3% code for proteins... That you can search in any page I don´t need to give you a citation…


    This supports what now?


    Folding, conservation of non encoding DNA? Most of DNA as I understand it is regulatory…
    I would like citations too. Surely just because the poster has an anti-creationist point of view that they should NOT be allowed to post unsupported rubbish.
    I find evolution beyond question but I am a believer too, so I'm interested in the truth.
    Last edited by Robittybob1; September 17th, 2014 at 02:55 PM.
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    I would like citations too. Surely just because the poster has an anti-creationist point of view that they should be allowed to post unsupported rubbish.
    I find evolution beyond question but I am a believer too, so I'm interested in the truth.


    So let us go forth with the truth, by all means.
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    Quote Originally Posted by GTCethos View Post
    I am not going to throw softballs like some other participants here....
    I wished to finish an earlier point about the availability of ribose in a prebiotic setting.


    The evidence that is currently available does not support the availability of ribose on the prebiotic earth, except perhaps for brief periods of time, in low concentration as part of a complex mixture, and under conditions unsuitable for nucleoside synthesis.http://www.ncbi.nlm.nih.gov/pubmed/2453009



    Without ribose you have no RNA or DNA molecules… The entire argument of the RNA and DNA worldview simply falls apart.


    How do you get a RNA molecule without ribose?
    Mmmm. You can´t just say no to a theory because of one paper. May be they should consider other sugars replacing ribose...May be RNA structure in the origins was different.

    So, I´ve been looking for papers. I found this review that may be interesting. So I will give you the link just in case you are interested in reading it.
    https://www.bioscience.org/2014/v19/...1/fulltext.htm

    I know I still have to give the other citations. I´ve been trying to get the books but are quite difficult to find. I have also been looking at the Biochemistry from Stryer...but couldn´t read much. This night I´ll be able to read a little more so may be I can write a more detailed post about protein folding and relate it to what I previously wrote.

    bye
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    So, I´ve been looking for papers. I found this review that may be interesting. So I will give you the link just in case you are interested in reading it.



    A good citation…. I need some time to go thru this….




    Mmmm. You can´t just say no to a theory because of one paper. May be they should consider other sugars replacing ribose...May be RNA structure in the origins was different.



    Well… OK. I hate to ask you this but what sugar are we talking about and what RNA would result?


    I know I still have to give the other citations. I´ve been trying to get the books but are quite difficult to find. I have also been looking at the Biochemistry from Stryer...but couldn´t read much. This night I´ll be able to read a little more so may be I can write a more detailed post about protein folding and relate it to what I previously wrote.



    I do not want you to be pressured into any obligation. We are just having a friendly learning experience. Learning is hinged on information and I try to stay away from personal speculation as much as possible. A personal frailty…
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    Quote Originally Posted by GTCethos View Post
    There seems to be some very dubious science in your reply, and I'm surprised you are getting away with it.



    I do not want to get away with anything… just present me a reasonable argument.


    By the way “Crow” has become a delicacy to me. Feed away.
    It was more to do with what M_Gabriela was saying.
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    The Peptidated RNA world view it is still subject to the availability of ribose (which I am claiming was not present in that warm little pond).


    Your paper (https://www.bioscience.org/2014/v19/...1/fulltext.htm) says the following:


    From your article:


    “Some simulated prebiotic syntheses such as those of nucleotides and RNA polymers yet remain problematic,”



    This admission has showed up in a number of similar papers over the years. The simple sugar problem is always a highlight in the “origin of life debate” and until it is resolved progress is all but nye for the RNA world view.


    Here are some sections referring to “ribose”.


    Notably, while 'peptidyl RNA' by usage usually implies o-peptide-RNA structures where the peptide is conjugated to the 3' terminus ribose of the RNA through an ester linkage, in 'peptidated RNA' the peptide can be conjugated to any position on the RNA.



    A quick note on protein folding…
    ”(III)Protein folds and domains. Protein studies have amply underlined the importance of protein folds and domains as key elements of protein structure and function.” found in your citation.


    There are other important issues with the RNA world view but without the basic building blocks being possible it seems like a hopeless argument. But that is for you to decide.
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    I just realized not everyone is familiar with “eating crow” and what it means.


    Eating crow is an American colloquial idiom,[1] meaning humiliation by admitting wrongness or having been proved wrong after taking a strong position.” wiki


    And I have done a lot of that…..
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    @M_Gabriela; Please be welcome to the forum! Es bueno, si! And please don't judge us by GTCethos or Robittybob1. It's mostly an accident that no qualified member or a moderator has come around to challenge or correct their behavior. They (GTCethos and Robittybob1) are not mean on purpose, they just do not know any better.

    @Robittybob1; It's just a guess on my part, but, I suspect that M_Gabriela has a science degree or on the way to earning one from a university. Probably one related to biology. You make yourself appear a fool to any respectable lurker when you presume to challenge an obviously superior knowledge base. I suspect that you are capable of achieving a reasonable state of knowledge, but that won't be possible if you don't learn to more critically examine whom you let influence you.

    @GTCethos; You are frustratingly disingenuous. Now I only have a very general knowledge of biology. But this general knowledge is enough to positively determine that you are attempting to insert speculation into a hard science fora. I will be reporting that.
    I was some of the mud that got to sit up and look around.
    Lucky me. Lucky mud.
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    That problem with the ribose is actually interesting.... I would have to read more about it. I´ll ask my boss if he knows something about.

    So.... it is actually very difficult to get the books from internet... that´s not helpful... but I saw the class again and may be... I can clarify your first request... So this would be a translation of part of the class.

    It all started with this question:

    1)
    If we synthesized a protein of 100 aminoacid, ¿what is the probability that the protein will fold and have functional activity?
    ¿How many proteins of 100 aminoacid do we have in nature?

    20^100=1.3x10^130 possible proteins.

    As the numbers of protons and neutrons in the universe are around 10^76 (I don´t have a citation for this, just take it for granted ; ))…. It´s impossible to have so many proteins of 100 aminoacids.

    By the way most of the proteins are much bigger…

    2)
    ¿How many total proteins do we have in nature?

    Let´s assume that we have 10^10 species approximately and that each genome has 30.000 genes (which is wayyyy too much; humans have 30.000 genes)
    Then we would have 3 x 10^14 proteins (many of them repeated…beause of homology of sequences between species)

    So, proteins of 100 aminoacid long: 1,3x10^130
    Total Proteins in the nature: 3 x 10^14 !!

    3) So, if we divide these two numbers (proteins of 100 aminoacid/proteins in nature), that would give around x10^116.

    Meaning... for every sequence we have now in nature there are x10^116 proteins of 100 aminoacid that didn´t appear.

    If we go back to the first question, how probable is that a 100 aminoacid protein would fold? We can´t say it wouldn´t fold...we can´t say anything for now.

    After millions of years of evolution, we only got a tiny sample of possible proteins. And what proteins are those? The ones that folded correctly!

    4) If we calculate how much time would it take to a 100 aminoacid protein to fold, it would be 1.7^28 years!!!!!!!!!!! (I have the math for that calculation if needed; it is based on how much time would it take to explore all possible conformations).

    But most of the proteins folds in 0.1-1000 sec.

    So, is protein folding a random process? No!

    How can that be? Every time a protein fold, it must necessarily follow a favoured path that narrow the searh (of possible conformations).

    So, evolution played a big role. The sequences that were selected were the ones whose folding rates are compatible with life. The ones that followed folding paths that allows them to fold in a time compatible with life.

    What would happen if we synthesize a protein with a random sequence that was not “filtered” by evolution? Would it fold? Probably not…(opinion)

    In one of yur post you said:
    Now according to the Levinthal's paradox some proteins folding is literally not measurable and can not be simply characterized because of its rapid transformations. ( a problem that currently lacks a evolutionary explanation).
    Why do you say it lacks of evolutionary explanation?

    Mmmm. You can´t just say no to a theory because of one paper. May be they should consider other sugars replacing ribose...May be RNA structure in the origins was different.





    Well… OK. I hate to ask you this but what sugar are we talking about and what RNA would result?
    It was just an opinion. I don´t really know... I have to look into the ribose problem...


    I´m going to sleep!!

    bye
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    Quote Originally Posted by GiantEvil View Post
    @M_Gabriela; Please be welcome to the forum! Es bueno, si! And please don't judge us by GTCethos or Robittybob1. It's mostly an accident that no qualified member or a moderator has come around to challenge or correct their behavior. They (GTCethos and Robittybob1) are not mean on purpose, they just do not know any better.
    I never felt bad at all. Actually they are correct.. I should have given citations. It´s just that they are very hard to find, because they are from books that I don´t have. he.

    I do have a degree.. in Biotechnology. I said it in my presentation...

    Thank you for welcoming me!

    bye
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    Quote Originally Posted by GiantEvil View Post
    @M_Gabriela; Please be welcome to the forum! Es bueno, si! And please don't judge us by GTCethos or Robittybob1. It's mostly an accident that no qualified member or a moderator has come around to challenge or correct their behavior. They (GTCethos and Robittybob1) are not mean on purpose, they just do not know any better.

    @Robittybob1; It's just a guess on my part, but, I suspect that M_Gabriela has a science degree or on the way to earning one from a university. Probably one related to biology. You make yourself appear a fool to any respectable lurker when you presume to challenge an obviously superior knowledge base. I suspect that you are capable of achieving a reasonable state of knowledge, but that won't be possible if you don't learn to more critically examine whom you let influence you.

    @GTCethos; You are frustratingly disingenuous. Now I only have a very general knowledge of biology. But this general knowledge is enough to positively determine that you are attempting to insert speculation into a hard science fora. I will be reporting that.
    Didn't Gabriela say some some weird things? They would be jumped upon if I had said them, so why was she not pulled into line like the rest of us?
    You might think I'm a fool but I'm sure you are wrong.
    It was #42 where I couldn't follow her logic Replicator molecules
    It was just a request to have references like they'd expect from myself. I have remarked several times how well Gabriela is doing, so I'm far from pulling her down or being mean.
    Stick to the science.
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    It was just an opinion. I don´t really know... I have to look into the ribose problem…



    Forgetting all that came before (great effort by the way) I accept your opinion (really all you had to say in the first place"this is just my opinion").
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    Quote Originally Posted by Robittybob1
    It was #42 where I couldn't follow her logic
    If you will notice that your quote of the incongruous wad of misquotes originated at GTCethos post #38. GTCethos acknowledged his authorship of the wad of misquotes by his post #44.

    Quote Originally Posted by "Robittybob1
    You might think I'm a fool but I'm sure you are wrong.
    I specifically said "You make yourself appear a fool..."
    And then I said something nice; "I suspect that you are capable of achieving a respectable state of knowledge..."
    Which I followed up with some really helpful advice that you should really pay attention to! I.e; "...learn to more critically examine whom you let influence you!​"
    I was some of the mud that got to sit up and look around.
    Lucky me. Lucky mud.
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    Quote Originally Posted by GiantEvil View Post
    Quote Originally Posted by Robittybob1
    It was #42 where I couldn't follow her logic
    If you will notice that your quote of the incongruous wad of misquotes originated at GTCethos post #38. GTCethos acknowledged his authorship of the wad of misquotes by his post #44.

    Quote Originally Posted by "Robittybob1
    You might think I'm a fool but I'm sure you are wrong.
    I specifically said "You make yourself appear a fool..."
    And then I said something nice; "I suspect that you are capable of achieving a respectable state of knowledge..."
    Which I followed up with some really helpful advice that you should really pay attention to! I.e; "...learn to more critically examine whom you let influence you!​"
    You might be right about the misquoting for it gets tricky to keep the posts truncated concise. You have to know where to put the
    and
    tags and not everyone gets it right.

    I just felt preached at when you said ""...learn to more critically examine whom you let influence you!​" so I try not to be influenced by people who preach to me. Exception is when John Galt says, "jump", I reply, "how high?"
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    Quote Originally Posted by Robittybob1
    I just felt preached at when you said ""...learn to more critically examine whom you let influence you!​" so I try not to be influenced by people who preach to me. Exception is when John Galt says, "jump", I reply, "how high?"
    And as such you should then consult John about that particular piece of advice I have given, as John is not one of the bad kids and will not perpetrate moral turpitude in your person.
    I was some of the mud that got to sit up and look around.
    Lucky me. Lucky mud.
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    Quote Originally Posted by GiantEvil View Post
    Quote Originally Posted by Robittybob1
    I just felt preached at when you said ""...learn to more critically examine whom you let influence you!​" so I try not to be influenced by people who preach to me. Exception is when John Galt says, "jump", I reply, "how high?"
    And as such you should then consult John about that particular piece of advice I have given, as John is not one of the bad kids and will not perpetrate moral turpitude in your person.
    Strangely enough he is in my "Bad Books" at the moment for something he said yesterday. But over all I think he has a bit time for me, yet he hurt my feelings yesterday. I think there are times when running this forum just about makes him crazy! He is only human!

    To be honest I have no idea what "will not perpetrate moral turpitude in your person" means. I'll analyse it later but I'm about done here.
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    Quote Originally Posted by Robittybob1 View Post
    Quote Originally Posted by GiantEvil View Post
    Quote Originally Posted by Robittybob1
    I just felt preached at when you said ""...learn to more critically examine whom you let influence you!​" so I try not to be influenced by people who preach to me. Exception is when John Galt says, "jump", I reply, "how high?"
    And as such you should then consult John about that particular piece of advice I have given, as John is not one of the bad kids and will not perpetrate moral turpitude in your person.
    Strangely enough he is in my "Bad Books" at the moment for something he said yesterday. But over all I think he has a bit time for me, yet he hurt my feelings yesterday. I think there are times when running this forum just about makes him crazy! He is only human!

    To be honest I have no idea what "will not perpetrate moral turpitude in your person" means. I'll analyse it later but I'm about done here.
    If it helps: Moral turpitude - Wikipedia, the free encyclopedia
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    It was just an opinion. I don´t really know... I have to look into the ribose problem…



    Anything new on ribose? Or would you rather I drop the issue?
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    I couldn`t ask anything. I had a lot of work but I`ll read something this weekend. We`ll see if something interesting appears. And of course I`ll ask my bosses... though they are immunologists...Probably they won`t know anything!! : D
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    Quote Originally Posted by dan hunter View Post
    “which looked like a blob of lemon Jell-O, represented the fruits of a 20-year effort to construct something that looked like life from the cacophony of chemicals that were available on the early Earth.”

    I see ribose was in the first constituent in the brew. That is our problem… how is ribose present in the first place?

    Also mentioned…

    That means it doesn’t have the informational content of RNA, an essential characteristic of life.



    In the modern cell, cooking up an RNA molecule is a complex process involving multiple enzymes that link a sugar (ribose) to one of four nucleobases

    All from:
    Self-Assembling Molecules Like These May Have Sparked Life on Earth | WIRED

    Remove the ribose here and it is back to square one.
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    Quote Originally Posted by GTCethos View Post
    Quote Originally Posted by dan hunter View Post
    “which looked like a blob of lemon Jell-O, represented the fruits of a 20-year effort to construct something that looked like life from the cacophony of chemicals that were available on the early Earth.”

    I see ribose was in the first constituent in the brew. That is our problem… how is ribose present in the first place?

    Also mentioned…

    That means it doesn’t have the informational content of RNA, an essential characteristic of life.



    In the modern cell, cooking up an RNA molecule is a complex process involving multiple enzymes that link a sugar (ribose) to one of four nucleobases

    All from:
    Self-Assembling Molecules Like These May Have Sparked Life on Earth | WIRED

    Remove the ribose here and it is back to square one.
    It was arguments like this that made me in 2010 realise there was the strong possibility that life did not start on Earth. There are other planets in the Solar System.
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    Hello!!! I´ve been reading and I found this very interesting paper with hypothesis about the first sugars in the prebiotic RNA. Also, it contains information about prebiotic nuclebases.
    And it was free, unbelievably...
    The Origin of RNA and ?My Grandfather?s Axe?


    Excerpt:
    Moreover, ribose appears optimal for its structural role in RNA (Eschenmoser, 2007), and therefore, ribose seems more likely a product of evolution as opposed to a “frozen accident” (i.e., a sugar that was initially incorporated because it was available at the time proto-RNA formed).The questionable status of ribose as the original TC inspired some researchers to consider threose (20;Figure 1B), a four-carbon sugar, as a possible preribose TC. Threose is simpler to form by abiotic reactions, at least conceptually, and is attractive on structural grounds, since nucleic acids containing the threose sugar (TNA) form stable duplexes (Schöning et al., 2000). One should also consider the possibility that the TC of proto-RNA might not have been a cyclic sugar (Joyce et al., 1987). In support of this possibility, oligonucleotides containing a simple glycerol moiety in place of ribose (Meggers and Zhang, 2010) and, more recently, those containing a glyceric acid (21; Figure 1B) substitution have demonstrated that acyclic nucleic acids can form stable duplexes with RNA (Hernández-Rodríguez et al., 2011), a property often considered a prerequisite for any pre-RNA candidate


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    Thanks for the article...

    We recognize that there are still many challenges to address before we can construct a complete and chemically sound evolutionary framework from proto-RNA to RNA.

    So they didn't make one yet… unfortunately their alternative does not necessarily exist in the current environment.
    Once again, we must consider that other molecules, not necessarily present in the environment today, might have played an important role in the origin of nucleic acids.

    You know I have read at least a dozen similar articles. Still from my perspective the problem is still intractable…
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    It was arguments like this that made me in 2010 realise there was the strong possibility that life did not start on Earth. There are other planets in the Solar System.

    My money is on Java the Hut… He looks prebiotic and only relies on George Walton Lucas for his dubious origin.
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    Quote Originally Posted by GTCethos View Post
    It was arguments like this that made me in 2010 realise there was the strong possibility that life did not start on Earth. There are other planets in the Solar System.

    My money is on Java the Hut… He looks prebiotic and only relies on George Walton Lucas for his dubious origin.
    I'm serious.
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    Quote Originally Posted by GTCethos View Post
    Thanks for the article...

    We recognize that there are still many challenges to address before we can construct a complete and chemically sound evolutionary framework from proto-RNA to RNA.

    So they didn't make one yet… unfortunately their alternative does not necessarily exist in the current environment.

    You pretend to find pro-RNA in the world today?? That won´t happen... At least not in nature...that proto-RNA was replaces by RNA lots of millons years ago.
    Find it in a lab??? Mmmm.... I don´t know if labs would create a pro RNA with the primitive molecules. It must be very difficult to imitate conditions on earth at that time...

    Why do you want pro-RNA?

    Interestingly, the problem was not only ribose, also the nucleobases and phophodiester bond were problematic... I saw other papers for that too...
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    Quote Originally Posted by Robittybob1 View Post
    Quote Originally Posted by GTCethos View Post
    Quote Originally Posted by dan hunter View Post
    “which looked like a blob of lemon Jell-O, represented the fruits of a 20-year effort to construct something that looked like life from the cacophony of chemicals that were available on the early Earth.”

    I see ribose was in the first constituent in the brew. That is our problem… how is ribose present in the first place?

    Also mentioned…

    That means it doesn’t have the informational content of RNA, an essential characteristic of life.



    In the modern cell, cooking up an RNA molecule is a complex process involving multiple enzymes that link a sugar (ribose) to one of four nucleobases

    All from:
    Self-Assembling Molecules Like These May Have Sparked Life on Earth | WIRED

    Remove the ribose here and it is back to square one.
    It was arguments like this that made me in 2010 realise there was the strong possibility that life did not start on Earth. There are other planets in the Solar System.
    do you have a citation?
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    I know about some kind of aminoacids came with meteorites. There are papers about it like this one (not free):

    http://www.nature.com/nature/journal...l/416401a.html
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    You pretend to find pro-RNA in the world today?? That won´t happen... At least not in nature...that proto-RNA was replaces by RNA lots of millons years ago.

    If it is not observable or reproducible, how is it science and not just speculation?
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    Quote Originally Posted by M_Gabriela View Post
    Quote Originally Posted by Robittybob1 View Post
    Quote Originally Posted by GTCethos View Post
    Quote Originally Posted by dan hunter View Post
    “which looked like a blob of lemon Jell-O, represented the fruits of a 20-year effort to construct something that looked like life from the cacophony of chemicals that were available on the early Earth.”

    I see ribose was in the first constituent in the brew. That is our problem… how is ribose present in the first place?

    Also mentioned…

    That means it doesn’t have the informational content of RNA, an essential characteristic of life.



    In the modern cell, cooking up an RNA molecule is a complex process involving multiple enzymes that link a sugar (ribose) to one of four nucleobases

    All from:
    Self-Assembling Molecules Like These May Have Sparked Life on Earth | WIRED

    Remove the ribose here and it is back to square one.
    It was arguments like this that made me in 2010 realise there was the strong possibility that life did not start on Earth. There are other planets in the Solar System.
    do you have a citation?
    It was my own work proving beyond doubt to the whole world that "Life first started on Mercury" but no one believed me! Google it.
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    Quote Originally Posted by Robittybob1 View Post
    Quote Originally Posted by M_Gabriela View Post
    Quote Originally Posted by Robittybob1 View Post
    Quote Originally Posted by GTCethos View Post
    Quote Originally Posted by dan hunter View Post
    “which looked like a blob of lemon Jell-O, represented the fruits of a 20-year effort to construct something that looked like life from the cacophony of chemicals that were available on the early Earth.”

    I see ribose was in the first constituent in the brew. That is our problem… how is ribose present in the first place?

    Also mentioned…

    That means it doesn’t have the informational content of RNA, an essential characteristic of life.



    In the modern cell, cooking up an RNA molecule is a complex process involving multiple enzymes that link a sugar (ribose) to one of four nucleobases

    All from:
    Self-Assembling Molecules Like These May Have Sparked Life on Earth | WIRED

    Remove the ribose here and it is back to square one.
    It was arguments like this that made me in 2010 realise there was the strong possibility that life did not start on Earth. There are other planets in the Solar System.
    do you have a citation?
    It was my own work proving beyond doubt to the whole world that "Life first started on Mercury" but no one believed me! Google it.
    Was it critical and reproducible?? I´ll try to look it
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    Quote Originally Posted by GTCethos View Post
    You pretend to find pro-RNA in the world today?? That won´t happen... At least not in nature...that proto-RNA was replaces by RNA lots of millons years ago.

    If it is not observable or reproducible, how is it science and not just speculation?
    It is science.

    Threose is simpler to form by abiotic reactions, at least conceptually, and is attractive on structural grounds, since nucleic acids containing the threose sugar (TNA) form stable duplexes (Schöning et al., 2000). One should also consider the possibility that the TC of proto-RNA might not have been a cyclic sugar (Joyce et al., 1987). In support of this possibility, oligonucleotides containing a simple glycerol moiety in place of ribose (Meggers and Zhang, 2010) and, more recently, those containing a glyceric acid (21; Figure 1B) substitution have demonstrated that acyclic nucleic acids can form stable duplexes with RNA (Hernández-Rodríguez et al., 2011), a property often considered a prerequisite for any pre-RNA candidate.
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    Quote Originally Posted by M_Gabriela View Post
    Quote Originally Posted by GTCethos View Post
    You pretend to find pro-RNA in the world today?? That won´t happen... At least not in nature...that proto-RNA was replaces by RNA lots of millons years ago.

    If it is not observable or reproducible, how is it science and not just speculation?
    It is science.



    Threose is simpler to form by abiotic reactions, at least conceptually, and is attractive on structural grounds, since nucleic acids containing the threose sugar (TNA) form stable duplexes (Schöning et al., 2000). One should also consider the possibility that the TC of proto-RNA might not have been a cyclic sugar (Joyce et al., 1987). In support of this possibility, oligonucleotides containing a simple glycerol moiety in place of ribose (Meggers and Zhang, 2010) and, more recently, those containing a glyceric acid (21; Figure 1B) substitution have demonstrated that acyclic nucleic acids can form stable duplexes with RNA (Hernández-Rodríguez et al., 2011), a property often considered a prerequisite for any pre-RNA candidate.
    Not reproducible, not observable... All speculation is then science.
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    Quote Originally Posted by GTCethos View Post
    Quote Originally Posted by M_Gabriela View Post
    Quote Originally Posted by GTCethos View Post
    You pretend to find pro-RNA in the world today?? That won´t happen... At least not in nature...that proto-RNA was replaces by RNA lots of millons years ago.

    If it is not observable or reproducible, how is it science and not just speculation?
    It is science.



    Threose is simpler to form by abiotic reactions, at least conceptually, and is attractive on structural grounds, since nucleic acids containing the threose sugar (TNA) form stable duplexes (Schöning et al., 2000). One should also consider the possibility that the TC of proto-RNA might not have been a cyclic sugar (Joyce et al., 1987). In support of this possibility, oligonucleotides containing a simple glycerol moiety in place of ribose (Meggers and Zhang, 2010) and, more recently, those containing a glyceric acid (21; Figure 1B) substitution have demonstrated that acyclic nucleic acids can form stable duplexes with RNA (Hernández-Rodríguez et al., 2011), a property often considered a prerequisite for any pre-RNA candidate.
    Not reproducible, not observable... All speculation is then science.
    Did you read all the papers citated for each sentence? are they all speculation or lab work?
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    It is early days yet. I am hoping that one day we will be able to work it out and know how living things started. If they go to Mercury and find organic material there my money is on that implies it started there. But it may be 20 years into the future before the mission is started and years to work out how to get in close to the Sun. I might never get to see it myself, but I am hoping.
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    Quote Originally Posted by Robittybob1 View Post
    It is early days yet. I am hoping that one day we will be able to work it out and know how living things started. If they go to Mercury and find organic material there my money is on that implies it started there. But it may be 20 years into the future before the mission is started and years to work out how to get in close to the Sun. I might never get to see it myself, but I am hoping.
    The temperature in Mercury is to high to sustain life (http://en.wikipedia.org/wiki/Mercury_(planet)). There are thermophilic microorganisms on earth, but it is impossible to have life beyond 150° C more or less because DNA breaks down (How Thermophiles Survive, Part II: DNA | Bitesize Bio)

    I know nothing about the young solar system... may be the conditions in Mercury billions of years ago may have been appropiate enough to sustain life. Well, what about Mars if not? Is NASA not taking samples from Mars fields?

    Don´t forget meteorites... like the paper I cited. They found aminoacid like molecules in one of them.

    bye
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    Quote Originally Posted by M_Gabriela View Post
    Quote Originally Posted by Robittybob1 View Post
    It is early days yet. I am hoping that one day we will be able to work it out and know how living things started. If they go to Mercury and find organic material there my money is on that implies it started there. But it may be 20 years into the future before the mission is started and years to work out how to get in close to the Sun. I might never get to see it myself, but I am hoping.
    The temperature in Mercury is to high to sustain life (http://en.wikipedia.org/wiki/Mercury_(planet)). There are thermophilic microorganisms on earth, but it is impossible to have life beyond 150° C more or less because DNA breaks down (How Thermophiles Survive, Part II: DNA | Bitesize Bio)

    I know nothing about the young solar system... may be the conditions in Mercury billions of years ago may have been appropiate enough to sustain life. Well, what about Mars if not? Is NASA not taking samples from Mars fields?

    Don´t forget meteorites... like the paper I cited. They found aminoacid like molecules in one of them.

    bye
    You've got the right idea, you have to look at conditions right back at the beginning. Life has evolved to survive in the conditions here now.
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    Quote Originally Posted by M_Gabriela View Post
    Quote Originally Posted by GTCethos View Post
    Quote Originally Posted by M_Gabriela View Post
    Quote Originally Posted by GTCethos View Post
    You pretend to find pro-RNA in the world today?? That won´t happen... At least not in nature...that proto-RNA was replaces by RNA lots of millons years ago.

    If it is not observable or reproducible, how is it science and not just speculation?
    It is science.



    Threose is simpler to form by abiotic reactions, at least conceptually, and is attractive on structural grounds, since nucleic acids containing the threose sugar (TNA) form stable duplexes (Schöning et al., 2000). One should also consider the possibility that the TC of proto-RNA might not have been a cyclic sugar (Joyce et al., 1987). In support of this possibility, oligonucleotides containing a simple glycerol moiety in place of ribose (Meggers and Zhang, 2010) and, more recently, those containing a glyceric acid (21; Figure 1B) substitution have demonstrated that acyclic nucleic acids can form stable duplexes with RNA (Hernández-Rodríguez et al., 2011), a property often considered a prerequisite for any pre-RNA candidate.
    Not reproducible, not observable... All speculation is then science.
    Did you read all the papers citated for each sentence? are they all speculation or lab work?

    All the papers cited in that Wikipedia quote, lead to a paper (Hud, N.V. et al., 2013) written last year. It cites the articles, thereby providing a nice overview for the advancements made concerning abiogenesis. Some of the articles are used in my sticky Abiogenesis: An Introduction to the Origin of Life in the Biology sub-forum. I will read the article tomorrow and add it if it fits into the introduction. Have you read any of those papers and if so, what are your thoughts on them?
    "The only safe rule is to dispute only with those of your acquaintance of whom you know that they possess sufficient intelligence and self-respect not to advance absurdities; to appeal to reason and not to authority, and to listen to reason and yield to it; and, finally, to be willing to accept reason even from an opponent, and to be just enough to bear being proved to be in the wrong."

    ~ Arthur Schopenhauer, The Art of Being Right: 38 Ways to Win an Argument (1831), Stratagem XXXVIII.
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    I posted the link to the paper on post #67, I didn´t get it from wikipedia.

    Many of those articles are not free. I tried to see the Eschenmoser 2007 but is not free. I tried to see the Schoning et al, 2000 but it´s a Science article, so not free. And it happened the same with the others I was interested to read.

    The idea was to present published articles (better if they are reviews) to probe that there are scientific and critical reasearch on the matter.

    GTCethos made me wonder about the ribose problem and I ended up seeing that the problem was not only with the pentose, also with the nucleobases and even the phosphodiester bonding... So I found it very interesting. It makes sense that prebiotic RNA was different from the present one.
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    I will will be departing this thread for about 1 week... No I still have not covered all the articles. Very good stuff.

    You people are great...
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    Quote Originally Posted by GTCethos View Post
    I will will be departing this thread for about 1 week... No I still have not covered all the articles. Very good stuff.

    You people are great...
    See you in one week. You will be missed!

    I´ll see if I can get the articles from the lab computer.
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    Quote Originally Posted by M_Gabriela View Post
    I posted the link to the paper on post #67, I didn´t get it from wikipedia.

    Many of those articles are not free. I tried to see the Eschenmoser 2007 but is not free. I tried to see the Schoning et al, 2000 but it´s a Science article, so not free. And it happened the same with the others I was interested to read.

    The idea was to present published articles (better if they are reviews) to probe that there are scientific and critical reasearch on the matter.

    GTCethos made me wonder about the ribose problem and I ended up seeing that the problem was not only with the pentose, also with the nucleobases and even the phosphodiester bonding... So I found it very interesting. It makes sense that prebiotic RNA was different from the present one.

    We referred to the same paper, I double-checked it.
    Also, you can try to enter the title of the paper in Google Scholar and look for PDF-links. Universities often download those papers for lectures or to be used as supplementary materials. For example, the paper by Schöning, K.U. et al. is available here. If that does not work, you can always send a mail to the contact address that is often provided and ask for the paper. I am certain that some of the authors will be happy to send you the full article.
    "The only safe rule is to dispute only with those of your acquaintance of whom you know that they possess sufficient intelligence and self-respect not to advance absurdities; to appeal to reason and not to authority, and to listen to reason and yield to it; and, finally, to be willing to accept reason even from an opponent, and to be just enough to bear being proved to be in the wrong."

    ~ Arthur Schopenhauer, The Art of Being Right: 38 Ways to Win an Argument (1831), Stratagem XXXVIII.
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    Quote Originally Posted by Cogito Ergo Sum View Post

    Also, you can try to enter the title of the paper in Google Scholar and look for PDF-links. Universities often download those papers for lectures or to be used as supplementary materials. For example, the paper by Schöning, K.U. et al. is available here. If that does not work, you can always send a mail to the contact address that is often provided and ask for the paper. I am certain that some of the authors will be happy to send you the full article.
    Awsome. Thanks!
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    Quote Originally Posted by GTCethos View Post

    Not reproducible, not observable... All speculation is then science.
    From the paper:Glycosylation-Dependent Lectin-Receptor Interactions Preserve Angiogenesis in Anti-VEGF Refractory Tumors
    Here we describe the synthesis and base-
    pairing properties of TNA oligonucleotides containing the five canonical purine and py- rimidine nucleobases. The tetrose-based oli- gonucleotides indeed show efficient base pairing which is similar to that of pentose- based RNA with regard to specificity, strand orientation, and pairing strength. In addition, TNA oligonucleotides of the
    L-series are ca- pable of cross-pairing with RNA and DNA.

    It also says
    Unlike
    the nucleic acid alternatives that we have
    studied previously, TNA could potentially
    serve as a template in nonenzymic templatedirected

    formation of RNA sequences. This
    property remains to be experimentally tested
    (
    24).
    So they did synthesize the oligonucleotide. Was this the first RNA? Probably not. But it is a possibility.
    So, what did I learn from this thread? That RNA, as it is today, didn´t exist in the prebiotic nature. And that there are many laboratories around the world who ask themselves what the alternatives are, and speculate and make science (experimental research) of the possibilities...
    The most likely hypothesis is that the first replicator was a RNA like-molecule but with a different structure, that was more adecuate to the environment and the availability of molecules back then...
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    “That RNA, as it is today, didn´t exist in the prebiotic nature. And that there are many laboratories around the world who ask themselves what the alternatives are, and speculate and make science (experimental research) of the possibilities...
    The most likely hypothesis is that the first replicator was a RNA like-molecule but with a different structure, that was more adecuate to the environment and the availability of molecules back then…



    This substitute sugar would exhibit the same structural characteristics then? I do not believe that the resultant structure would accommodate the needed “coding” of complex life (odds are against it)… Just to say this is an alternative to ribose is still speculation.


    I never claimed man could not synthesize a simple sugar in the laboratory. Still, can this sugar exist de-novo… let us talk proof.
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    Quote Originally Posted by GTCethos View Post
    “That RNA, as it is today, didn´t exist in the prebiotic nature. And that there are many laboratories around the world who ask themselves what the alternatives are, and speculate and make science (experimental research) of the possibilities...
    The most likely hypothesis is that the first replicator was a RNA like-molecule but with a different structure, that was more adecuate to the environment and the availability of molecules back then…


    This substitute sugar would exhibit the same structural characteristics then? I do not believe that the resultant structure would accommodate the needed “coding” of complex life (odds are against it)… Just to say this is an alternative to ribose is still speculation. .
    It is speculation. But with experimental research support. And this substitute for ribose is a posible explanation for the ribose problem
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    Quote Originally Posted by M_Gabriela View Post
    Quote Originally Posted by GTCethos View Post
    “That RNA, as it is today, didn´t exist in the prebiotic nature. And that there are many laboratories around the world who ask themselves what the alternatives are, and speculate and make science (experimental research) of the possibilities...
    The most likely hypothesis is that the first replicator was a RNA like-molecule but with a different structure, that was more adecuate to the environment and the availability of molecules back then…


    This substitute sugar would exhibit the same structural characteristics then? I do not believe that the resultant structure would accommodate the needed “coding” of complex life (odds are against it)… Just to say this is an alternative to ribose is still speculation. .
    It is speculation. But with experimental research support. And this substitute for ribose is a posible explanation for the ribose problem

    From one intractable problem to the next….


    Scientists identify religious gene, intractable research problem….


    http://combatblog.net/?p=1879


    Here is another intractable problem scientists are working on. Have they identified a “liberal” gene yet? Great if that discovery came with a genetic cure.
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    In that link the only thing they say is that religious people have more children. How is that related to a religious gene?
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    From: http://www.lifescied.org/content/7/1/132.long

    Dean Hamer's book, The God Gene: How Faith is Hardwired into Our Genes, details a recent example of a purported link between a particular gene and human behavior (Hamer, 2004). The book was covered heavily by the popular press, including an article in Time magazine featured on the magazine's cover (Kluger et al., 2004). In his book, Hamer contends that one's predisposition toward spirituality is influenced by genetic factors. More controversially, he proposes that the VMAT2 gene is one of many potential genes that impinge on spirituality. Hamer identifies one particular variation, a change from an A to a C, present in 28% of the alleles in his data set, as a marker for the more “spiritual” version of this gene. This work has not been published in a scientific journal.


    No wonder I didn´t find anything relevant on NCBI
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    Just assume all the organic compounds are present for life. They just all get together and start interacting. What could possibly be wrong now.


    Information is missing that describes the proteins, enzymes and all the rest of the higher order organic compounds. Since necessity to form life is missing in chemistry, what is left? Only probability…


    Estimate of the probability of forming a simple de novo life form is…


    1 in 10^1000 chance… Impossible.
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    Quote Originally Posted by GTCethos View Post
    Just assume all the organic compounds are present for life. They just all get together and start interacting. What could possibly be wrong now.


    Information is missing that describes the proteins, enzymes and all the rest of the higher order organic compounds. Since necessity to form life is missing in chemistry, what is left? Only probability…


    Estimate of the probability of forming a simple de novo life form is…


    1 in 10^1000 chance… Impossible.
    But we don't know that kind of probability. Maybe we are in an extremely large inflationary universe, and that kind of probability is sufficient for life to appear a very large number of times.

    There is also the concept of quantum multiverse, in which the universe splits in a very large number of branches every fraction of a second. From what I have read, some reputable scientists take that theory serioulsy.

    However, if the probability of the emergence of life is extremely low ( say once per billion of galaxies or whatever ), maybe that probability is lower than the probability that an already existing species spreads life on another planet. How does one evaluate the 2 probabilities it is nearly impossible. But I don't see some sort of 'god' being required to explain the appearance of life.

    I still think there is a more mundane explanation with chemical processes and that life is not that uncommon. It always seems very complicated, even impossible, until the explanation is discovered.
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    Quote Originally Posted by GTCethos View Post
    Just assume all the organic compounds are present for life. They just all get together and start interacting. What could possibly be wrong now.


    Information is missing that describes the proteins, enzymes and all the rest of the higher order organic compounds. Since necessity to form life is missing in chemistry, what is left? Only probability…


    Estimate of the probability of forming a simple de novo life form is…


    1 in 10^1000 chance… Impossible.
    I´m lost. I have no idea why you posted this and I don´t undestand where this probability number comes from...
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    ”But we don't know that kind of probability. Maybe we are in an extremely large inflationary universe, and that kind of probability is sufficient for life to appear a very large number of times”


    We as people do not deal with such small probabilities in our lives. Borel’s upper limit for 1 in 10 to the 50th (Put in simple terms is the absolute limit of number of chemical reactions that have happened since the Big Bang), or Dembski's estimate (definition by product of two different quantities) of 1 in 10 to the 150th (a general limit on all possibilities in the universe).

    There is also the concept of quantum multiverse, in which the universe splits in a very large number of branches every fraction of a second. From what I have read, some reputable scientists take that theory serioulsy.


    The multiverse is a convenient avoidance of the anthropic principle that is observed in our universe. Unfortunately it does not meet Carl Popper’s falsifiability for scientific definition. As an opinion you can accept it. Many scientists reject it out of hand.

    Could you acknowledge that a probability of 1 in 10^450 is, by falling below Dembski’s definition, not able to happen in this universe?

    I still think there is a more mundane explanation with chemical processes and that life is not that uncommon. It always seems very complicated, even impossible, until the explanation is discovered.


    What you are saying here, correct me if I am wrong. That there is a “necessity in chemistry” that life must just come together by chemical principles . My problem with that is that no observable evidence exists.

    “This proposition was once proposed formally in a book by Dean H. Kenyon and Gary Steinman but Dean Kenyon recanted the formal proposition (may not be a formal Hypothesis) in 1976 reportedly from a book by A.E. Wilder-Smith. Nucleobases in the double helix is bonded via N-glycosidic bonding.”

    Simply that two bonded nucleobases do not chemically bond to two other bonded nucleobases via a covalent bond. The double pair arrangement in the observed DNA is not a bond demonstrating any tendency to happen spontaneously and not out of necessity.
    Last edited by GTCethos; October 5th, 2014 at 10:05 PM.
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    GTCethos,

    Well, personaly I see the problem as being deeper than even the probability that life may appear on a particular planet.

    The problem is not that life and intelligent creatures CAN appear, the problem is how come "I" appeared. The universe/multiverse or whatever could well have created intelligent beings, but not me. The fact that "I" exist makes me think that the probability that beings like me exist is in fact not very low, but very high, close to 1. For that to be possible, a multiverse is a pretty good explanation for me, especially when one looks at the theory of inflation, where universes have zero energy, and are created in phenomenal numbers.

    I don't see how god would help that much. He would have had to create an infinte or extremely large number of thinking beings also for "me" to exist ( and not just someone else ), which means he would have needed an extremely large universe/ multiverse anyways. If you need a extremely large multiverse, you might as well say that the universes in that multiverse form naturally from one another ( with inflation or whatever ).

    This being said, in that inflationnary multiverse, there might be super-intelligences that could eventually have figured out how to provoke inflations to create universes. Some scientists are wondering whether it would be possible. I wouldn't call them gods because these creators are natural. This idea is still very speculative of course.

    As for the extremely low probability you are talking about regarding the appearance of life on out planet, I don't take that too seriously. I already had a discussion on another forum with a creationnist who came up with a crazy number like that that he seems to have pulled out of his a$$.

    We don't know the process which lead to the first forms of life, so we can't calculate that probability. In any case in a very large multiverse it will still happen a very large number of times.

    I am not a scientist, so I would just say it is my 2 cents on this.
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    This being said, in that inflationnary multiverse, there might be super-intelligences that could eventually have figured out how to provoke inflations to create universes. Some scientists are wondering whether it would be possible. I wouldn't call them gods because these creators are natural. This idea is still very speculative of course.



    Actually the multiverse can be labeled a “superfluous ontological apparatus”. That from Occam’s razor.




    Probability or should I say the “problem of probability” is at the root of abiogenesis and the multiverse questions. You see if you provide a infinite number of universes you solve the infinite improbability of forming life, gods, intelligence…ect. Besides the fact that there may never be any falsifiability in the multiverse, it is just another complication to resolving technical problems (it being the mother of all complications).


    Good philosophical dream but not science.

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