Are the sugars ribose and deoxyribose self assembling

I can't find any study which shows if ribose and deoxyribose are self assembling or if they need to be assembled in a living organism like the sugar glucose. If anyone knows of a study please respond. If they are not self assembling then abiogenesis would be impossible wouldn't it?

Keith, your presumption that abiogenesis would be "impossible" without self assembly of a particular chemical doesn't make sense. It simply means that those aren't the ones that would have been the very first step in a probably chain of steps leading to something we would finally be able to recognize as alive.If you want to know how that happened -- well, I don't know and I don't think anyone does right now. There seems to be a lot of focus on the unknowns in there. Why are you interested in that at all?

The simplest living things that we know of would have to have some way of replicating themselves. Most of the research I have seen tends to think DNA is too complicated because it needs more than 50 products of itself to replicate. (otherwise impossible) The newest research is attempting to show an RNA world is more plausable. My intrest is that if robose and deoxyribose can't self assemble then they must be produced in living things in a similar matter as glucose through the Calvin cycle in plants. If they have to be produced by plants or other living things then they obviously couldn't be part of making the first living organism.

Thats huge. If you can't account for the self-assembly of a ribose or even self assembly of ribose pre-cursors then where did they come from? Are they only made as a product of some living thing?Also, did the first cell also randomly have a cell wall assembled around the cell memberane? Without it, wouldn't the osmotic pressure cause the cell to burst in those "ancient seas"? If there was a cell wall then it must have randomly appeared at the same time as the membrane and DNA and protein molecules that are necessary for the simplest cell.

RNA and DNA were NOT the first replicators. DNA is nothing more than luggage for RNA in the first place, and given the existence of dsRNA, it's pretty easy to see how selection could have gotten DNA its start. More likely is that PNA or an equivalent was the first true replicator, especially since PNA can catalyze its RNA homolog (and which also eliminates the stereochirality problem).It might be really interesting if you actually cited the "research" you claim to have read. That way, it would be possible to correct your misapprehensions. For example, Zhang B, Cech TR, 1997, "Peptide bond formation by in-vitro selected ribozymes", Nature 390:96-100 which discusses the formation of a 196-nucleotide self catalytic ribozyme. A zillion nucleotides aren't necessary. Further, Reader JS, Joyce GF, 2002, "A ribozyme of only two different nucleotides", Nature 420:841-4 shows pretty conclusively that even uncomplicated ribozymes can be formed naturally AND self-catalyze.Now, if you want to insert your God of the Gaps, the chemistry of ribose isn't a bad place to do it - the sugars haven't been shown to form in sufficient quantities in the lab without purification. However, there are some tantalizing hints in some of the current research that a "two-fer" might have been the way things got organized initially. David Deamer, for example, proposes that metabolism (specifically phospholipid bi-layer vesicle) and replication were linked by synthesizing RNA inside a membrane naturally. (I don't have a journal article to hand, but he wrote up his idea on line at How did it all begin? The self-assembly of organic molecules and the origin of cellular life. Since lipids, nucleic acids, etc can all arise spontaneously - as can simpler sugars - there's no reason to assume that anything precludes a "multiple origin" hypothesis is wrong. Insert GOTG here.

There are a number of self replicators out there - SunY, GL, etc - that are a lot simpler than DNA or RNA. GL is only (32?) amino acids long. Would one of these be the first self replicator? No. For two reasons.1) We've examined such a miniscule percentage of possible proteins even at such a short length as 32 amino acids, that we're probably not even close yet. It probably was "a similar style self replicator", but not one of these exact ones2) There was likely no true first "self replicator". The first "self replicators" were probably molecules that produced broken copies of themselves - i.e., encouraged molecules "similar" to themselves to form, but not exactly the same. However, increasing the percentage of the pool that is "similar" molecules increases the odds that one, or one that has undergone some random changes from other reactants in the area, will be the same. From the incomplete replicators came complete replicators that produced exact copies when given precisely the right subunits, and broken copies otherwise (which fell under the rules of step 1). From these came ones that could either help produce their subunits, or would produce chemicals that would in turn help produce their subunits. Etc. Eventually you have a full-fledged hypercycle operating. Competition between parts of the hypercycle leads to regionalism and the first "walling off" of individual components, producing the first ur-cell.------------------
"Illuminant light,
illuminate me."

Keith, theman: As Quetzel notes you seem to be playing "god of the gaps". Is this true?That is, are you saying that God is "proven" in some way when there is something that we don't know about the natural world?I must say that this appears to be your whole arguement. Is there something else you are trying to say? If that is actually your argument what happens to God when the gap closes?

I don't think we are playing God of the gaps. What we are saying is that the more we learn about cells the more complex they become. It's mind boggling to even understand what we know now. As I said before we are simply using a different theory on the evidence we see. Remember a theory is the best explanation of the evidence. You seem to think that the cell in all its complexity and its micro machinery could have assembled itself without any guidance whatsoever. I look at the evidence and think that something that is more complex than a computer couldn't possibly happen by accident. If you told me or anyone that your computer assembled itself and used the evidence that it was made of the same materials you find in the earth people would say you were insane. So what makes you think that something even more complex could assemble itself?What's more, if you took your computer and tried to assemble it you could probably do it with a lot of work. No one has even come close to assembling a living organism from scratch. And if we can't do it with all our intelligence, what makes you think nothing at all can accomplish this.

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I look at the evidence and think that something that is more complex than a computer couldn't possibly happen by accident. If you told me or anyone that your computer assembled itself and used the evidence that it was made of the same materials you find in the earth people would say you were insane. So what makes you think that something even more complex could assemble itself?

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Computers don't reproduce or mutate, making a comparison between them and evolution incorrect (evolution being the change in frequency of alleles in a reproducing population over time). If you want an analogy concerning computers that does reproduce and mutate, you should check out genetic algorithms, such as Framsticks, Tierra & Avida, Polyworld, the various genetic artwork programs, and a whole host of other ones. I've even written some on my own, and we use them in our workplace.Also, I should add if there's one thing in common between almost all genetic algorithms, is that if it's possible to make something complex, they will It can take an hour to try and understand what's going on in a simple Avida self replicator after you've let it go on for a while. And also, regardless of the GA, they almost always produce better results than humans (the only cases where they aren't is if you design a system without much parallelism - I can go into this more if you'd like).------------------
"Illuminant light,
illuminate me."

I'll accept your point that a computer doesn't mutate but My point is that it would be ridiculous to think that something that complex didn't have someone create it.Also with your program on algorithm, didn't you create it? You even said the only cases where you don't get better results is when you "design" a system without much parallelism. So your analogy requires a creator or designer and that's what I am getting at.By the way. This is a side note but how do you take a quote from someone and insert it as you have done. I'm new to the forum and haven't taken the time to learn all those tricks yet.

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Also with your program on algorithm, didn't you create it? You even said the only cases where you don't get better results is when you "design" a system without much parallelism. So your analogy requires a creator or designer and that's what I am getting at.

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Yes, it requires a creator - but not a creator of life. All you program are the "laws of physics" - you're the creator of a universe instead, in which life develops or evolves (depending on where you start). Besides, if you accept your line of argument, then you accept evolution - just not abiogenesis, which is different. There are many christians who accept evolution, but not abiogenesis.

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By the way. This is a side note but how do you take a quote from someone and insert it as you have done. I'm new to the forum and haven't taken the time to learn all those tricks yet.

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I have to commend you for asking - most people just hack something together and go with it. First, the easiest way to learn how to do something that you're not sure how to do is to edit their post. It won't let you save it, but you can see what they typed. As for me, I either use the "quote" command or the "qs=name" command, depending on whether I feel like taking time to spell out the person's name. (edit: I just realized that I'm getting a bit off topic. We should probably try to move this back to discussion of the earliest self replicators; if this side topic wants to continue, we can move it to an existant thread, or start a new one).------------------
"Illuminant light,
illuminate me."[This message has been edited by Rei, 11-18-2003]

Actually, its closer to an argument from personal incredulity, you can't believe it so no one else should either. It's mind boggling to you, perhaps, but it starts to become understandable the more you study it. What used to be mysterious becomes more like a complex chemical reaction as you delve into the workings of a cell. There is nothing in the cell that can't be explained by chemistry or physics that I have seen, so it is probable that man can understand quite a bit more in the future. Supported by what evidence? Wrong, the first life was very simple. Subsequent mutation and selection masks the simplicity of the first life. It would be like comparing a wheelbarrow with a dump truck, as far as complexity goes. Again, the first life was simple. Besides that, it was put under selective pressure. A simple analogy to illustrate the point, why do we keep seeing faster and faster computers? This is because microchip producers (the organism) are put under pressure (natural selection) to improve the speed of their microchips. In this way, ENIAC (the first large computer) and a Dell look and behave quite differently, especially when looking at complexity and capability. This has happened with life on this planet. Natural selection culled improved versions of the first replicators and the subsequent time period has resulted in us and the species we see today.

It might be useful if you'd stop moving the goalposts here. Your original "question" concerned the self-assembly of complex sugars. Now you're arguing against (a strawman, btw) cellular self-assembly. Guess what? No one thinks cells spontaneously arose de novo, except creationists who proclaim cells were somehow poofed into existence ex nihilo. If you want to talk about early cellular evolution, or the SET hypothesis, or anything related to cells and cell "machinery" (vice original replicators, etc), then start a new topic. In the meantime, please respond to my refutation of your initial post - or admit that you cannot.

I think this particular argument needs a special name. Any suggestions?If we can't intelligently design something why on earth does that imply it's intelligently designed? Isn't that a quite spectacular non-sequiter?

my point is that if we can't design it intellegently, why would anyone think that it could happen by chance. It's amazing to me that scientists would look the the stars and accept any nonrandom signal, no matter how small, as proof of intellegence in the solar system. Yet we are confronted with every cell on earth that is filled with more nonrandom information, which would fill thousands of pages of books, and we try to expain it all away.My original point of this thread was to see if anyone knows research about the sugar ribose or deoxyribose. Since they are part of every living thing we are aware of, if they can only be produced in living things (like Glucose) then it presents a real problem.