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Author | Topic: Abiogenesis | |||||||||||||||||||||||
RAZD Member (Idle past 1426 days) Posts: 20714 From: the other end of the sidewalk Joined: |
fair enough (only an A???) ahahahaaa
While I agree that abiogenesis has not been accomplished experimentally, I will not be surprised when it happens.
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Loudmouth Inactive Member |
quote: Even if life is created in the lab, it is still not PROOF (as in ultimate proof) that life arose via a precise mechanism. 3.5 billion years is a long time ago, and any models that we create are tentative and will not tell us the specifics of how life arose on Earth. On the other hand, if self replicators do form spontaneously, then the possibility of life arising naturally is possible. Current research is getting closer and closer, but questions will remain. What it comes down to for me is the God of the Gaps fallacy. Natural mechanisms have been found for almost every natural phenomena previously ascribed to dieties. Hanging your faith on a dieties presence in natural phenomena is probably not the best route to take, because that gap in knowledge may be closed and your faith with it. I don't see how abiogenesis lowers the wonderment of life on the planet, but to some it may. Oh well, at least we live in a world where we can discuss these lofty questions.
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One_Charred_Wing Member (Idle past 6177 days) Posts: 690 From: USA West Coast Joined: |
"Even if life is created in the lab, it is still not PROOF (as in ultimate proof) that life arose via a precise mechanism. 3.5 billion years is a long time ago, and any models that we create are tentative and will not tell us the specifics of how life arose on Earth."
That's a really good point: Just because something can happen doesn't mean it did. Guess that's something that both sides of the debate need to keep in mind. As for when (and if) we can create life from non-life, keep in mind that using a bunch of instruments and setting everything just right to prove that abiogenesis can occur naturally, without intelligent intervention is... kind of redundant. I'm NOT saying that such a success would invalidate natural abiogenesis, it's just that it wouldn't guarantee that its too often. But then again I guess one could argue that given enough time anything happens and so on. Either way, it won't effect my faith because I believe God plays by his own rules(chemical rules in this case) and created us through MOSTLY non-miraculous means. Then again, the materials would probably gather near or on the surface of the soil, and we were created from the 'Dust of the Earth'... but that's another speculation, and a whole other thread. Wanna feel God? Step onto the wrestling mat and you'd be crazy to deny the uplifting spirit.
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RAZD Member (Idle past 1426 days) Posts: 20714 From: the other end of the sidewalk Joined: |
hmmm
"Even if life is created in the lab, it is still not PROOF (as in ultimate proof) that life arose via a precise mechanism. 3.5 billion years is a long time ago, and any models that we create are tentative and will not tell us the specifics of how life arose on Earth." It would be proof that life can originate when the conditions of the experiment occur in the real world. Of course it will not be proof of how it actually happened, as there is (still) a lot of debate about what the conditions were like on earth at that time. What I would expect to see, is that once a self replicating element has been achieved, that a number of similar experiments would follow using different conditions --- if for no other reason than to see how easily life could evolve on other planets: what are the limiting factors? And as the number of extra-solar planetary systems has sky-rocketed since the discovery of the first one, I would expect to see many successful experiments using many varieties of conditions. That is a prediction based on the way science works and the innate inquisitiveness of humans. Enjoy.
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Loudmouth Inactive Member |
quote: If we have to intelligently measure the distance from the Earth to the Sun, does this mean that that distance was intelligently made? Nope. With respect to abiogenesis, even if the CONDITIONS were intelligently controlled, the resultant self replicators would be considered natural and not the product of intelligence. Another example, is ice intelligently created because you stick water in your freezer? Obviously not. If conditions and reactants set up by an intelligence is reasonably close to what we would expect in a natural early earth environment then the results can be considered indicative of what we would expect in nature. This type of rule is adhered to throughout science, and in the biological sciences especially. An example of possible intelligently made self replicators would be a step by step synthesis. An analogous procedure is drug manufacturing where each step in the synthesis is controlled to such a degree that the chances of this compound naturally occurring in the quantities seen in synthetic manufacturing is quite low. It is the step by step procedure that is the problem. Equating this to self replicators, it would be like creating a 3 million base genome and controlling the sequence base by base. Non-intelligently produced self replicators must have a large dose of randomness, and this must be reflected in the methodology. Argh, turned 30 last month and already I am getting long winded. I'll probably start repeating myself any minute now. And I'll probably start getting long winded too.
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One_Charred_Wing Member (Idle past 6177 days) Posts: 690 From: USA West Coast Joined: |
Agreed. However, I did state just after the end of that quote that it doesn't make the experiment irrelevant in the least.
Wanna feel God? Step onto the wrestling mat and you'd be crazy to deny the uplifting spirit.
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DNAunion Inactive Member |
quote: So far so good...
quote: Which requires DNA. The host cells wouldn't be alive without their DNA, and without living host cells viruses couldn't "replicate". Second, there's no consensus as to whether or not viruses are alive.
quote: But since prions are not living, they're an irrelevant example.
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RAZD Member (Idle past 1426 days) Posts: 20714 From: the other end of the sidewalk Joined: |
" Which requires DNA. The host cells wouldn't be alive without their DNA, and without living host cells viruses couldn't 'replicate'." Do we know the mechanisms of viruses outside a host environment re survival and replication? Are there conditions that would allow replication? " Second, there's no consensus as to whether or not viruses are alive." the definition of life is a tough one indeed. Do a google on [definition life] and there is a lot of reading with no clear end in sight. Morales gives it a pretty good whack (but too much about too little) at: Psychozoan: The Definition of Life "But since prions are not living, they're an irrelevant example. " Again they are able to replicate within a system. The [bottom up] question of abiogenesis is not life but the first replicator. The [top down] question of abiogenesis is what is the absolute simplest possible form of life. Dissecting DNA down to an absolute minimum for bacteria to still qualify as life brings us very close to virus type stuff at this point though controversy ensues. A professor at school mentioned the difference between practical and theoretical:Take a boy and a girl and stand them 10 feet apart. Every second, halve the distance between them. theoretically they never touch, but they get close enough for all practical purposes. the [top down] and [bottom up] approach is like that. we are limited in our ability to understand by our ability to understand
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DNAunion Inactive Member |
quote: quote: Yes we know them, and not they cannot. Here's a bit on viruses.
quote: quote: quote: quote: Also, see my long quote in the next part.
quote: quote: Here are some statements that directly address the question of are viruses living.
quote: quote: quote: And on to prions...
quote: quote: A printed page is also able to replicate within a system : just put it into a photocopier. Of course, we realize that the paper is not what is doing the replication. Same with a prion. A prion CANNOT replicate itself. It absolutely relies upon normal cellular processes to produce a specific protein — only then can the prion come along and simply convert that normal, preexisting protein into a prion. Without DNA, RNA, ribosomes, tRNA, enzymes, etc. there would be no normal protein for the prion to then simply convert. There is no clear consensus as to whether or not viruses are living, but there is a clear consensus that prions are not. [This message has been edited by DNAunion, 03-20-2004]
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RAZD Member (Idle past 1426 days) Posts: 20714 From: the other end of the sidewalk Joined: |
Yes we know them, and not they cannot. Here's a bit on viruses.
Here are some statements that directly address the question of are viruses living.
I don’t think you are looking at this with a fully open mind. The evidence to date is that viruses do not replicate on their own within the environments that we know about. The absence of evidence is not evidence of absence however, and does not rule out that a certain environment may exist wherein viruses could replicate. That environment could be something closer to a primordial environment or one of the extremophiles type or depend on a random input of energy in a pre-bio soup. It is also possible that the viruses have lost mechanisms where they have found easier mechanisms to use from cells than from their [original development], even though that [original mechanism] may have differed significantly from modern cell biology. This would mean that they are not devolved bacteria but a separate form of life, perhaps one entirely based on RNA. ... we don't know.
And on to prions...
A printed page is also able to replicate within a system : just put it into a photocopier. Of course, we realize that the paper is not what is doing the replication. Same with a prion.
As mentioned regards prions, the development of a replicator is a relatively necessary first step whether it can be classed as [life by some definition or other] or not, even if that replicator uses a clay or crystal structure to form a molecular production [not so much Xerox as Widget building] machine. Perhaps "replicator" is the wrong word and we should be looking for "implicators" ("imps" for short?) first. Then one could look for how "imps" can be incorporated into proto-cell structures where they start to turn out product to maintain the proto-cells without necessarily replicating themselves.A prion CANNOT replicate itself. It absolutely relies upon normal cellular processes to produce a specific protein — only then can the prion come along and simply convert that normal, preexisting protein into a prion. Without DNA, RNA, ribosomes, tRNA, enzymes, etc. there would be no normal protein for the prion to then simply convert. There is no clear consensus as to whether or not viruses are living, but there is a clear consensus that prions are not. we are limited in our ability to understand by our ability to understand
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DNAunion Inactive Member |
quote: I don't think you are looking at this with a fully educated mind.
quote: Facts are evidence. Viruses do NOT and CANNOT replicate themselves. That's basic BIO101 stuff. Now YOU have an open mind and reread what I posted from the several undergraduate biology texts.
quote: Sure...inside of living host cells! A virus is analogous to a printed page: they both require something completely separate and far more complex to do the work necessary to "replicate themselves".
quote: So there were living host cells in the primordial environment to replicate the viruses?
quote: Extremophiles are living - they're cellular.
quote: A random input of energy in a pre-bio soup? Pretty naive. Besides, if you're switching to talking about a self-replicating RNA molecule then do so..don't try to call it a virus. [This message has been edited by DNAunion, 03-21-2004]
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DNAunion Inactive Member |
quote: Better would be to say that DNA is produced only in living cells (as someone already did, one could nit pick your statement and say that DNA can exist outside of living cells).
quote: How about using the other important nucleic acid, RNA? That’s one of the main theories: at some point RNA alone served both the informational and catalytic functions associated with life.
quote: A misuse of the term irreducible complexity (a term that seems to be assigned by someone to just about anything more complex than water!).
quote: A self-replicating RNA would be the organism. OOL researchers (and any rational and objective person) would be completely satisfied if a prebiotically plausible process were found that could produce a self-replicating RNA molecule able to undergo evolution.
quote: DNA is made by proteins, but is not made up of proteins. Nucleic acids (DNA and RNA) are made of individual units called nucleotides, which are linked together in a chain. Each nucleotide consists of three parts: 1) a nitrogenous base (adenine, guanine, cytosine, and either thymine (DNA) or uracil (RNA))2) a pentose (5-carbon sugar: deoxyribose (DNA) or ribose (RNA)) 3) a phosphate group OOL researchers have had success in making most or all of the individual components under prebiotically plausible conditions. The problems arise at higher levels (joining the three parts together to form nucleotides, getting the nucleotides to link together into polymers, and getting the particular polymers that could participate in some kind of mutation/selection process).
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keith63 Inactive Member |
I would like to know where you found information on the self assembly of ribose or deoxyribose. If the sugar glucose is assembled in living things and if ribose and deoxyribose, especially ribose, can't self assemble then you have a very difficult problem with abiogenesis. I think it is very ironic that something simple enough to happen accidently has baffled the scientific community for hundreds of years. I would think if life arrose on it's own with no help then it should be very easy to duplicate. Yet with all our intellegence and advancements it still remains tantilizingly out of reach.
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crashfrog Member (Idle past 1488 days) Posts: 19762 From: Silver Spring, MD Joined: |
I would think if life arrose on it's own with no help then it should be very easy to duplicate. Diamonds also arise on their own. Do you think that they are easy to duplicate? Don't conflate "natural" with "simple", please. The universe is quite capable of great complexity on it's own.
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DNAunion Inactive Member |
quote: In OOL-related experiments, ribose has been produced more than one way. There are some problems with these methods though: the prebiotic plausibility of the processes can be questioned, the wrong type of ribose is produced, or ribose is swamped out by many other sugars. Also, both enantiomers are formed in equal amounts (which leads to the problem of enantiomeric cross inhibition...but that's are the polymerization level).
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