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Abiogenesis anyone?


IrishEyes
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Ok, as this question is not getting answered in any other thread right now, and there are no other topics that cover this right now that I can find, I'd like to open up this can of worms in a brand new topic.

 

dictionary.com

a·bi·o·gen·e·sis n. - The supposed development of living organisms from nonliving matter. Also called autogenesis, spontaneous generation.

 

So can someone please give a plausible explanation for the development of living organisms from non-living matter? Without it degenerating into the "What is life, anyway?" debate? (life: #4 The physical, mental, and spiritual experiences that constitute existence ; also the first definition listed that did not contain 'life' or a derivitive in its definition - UGH!)

 

I want you guys to play fair, ok? I don't want this boiling down to a "abiogenesis didn't happen because God made everything" fight. I don't want "Abiogenesis happened because there is no God". And I don't want endless lists of links with nothing to explain the links. Frankly, though I'm sure most of you post very informative links, my time on the computer is very limited. I'd rather YOU tell me YOUR opinion, and also tell me WHAT is on the link you provide. A basic synopsis will suffice, but I want the gist of the site. Don't post a link and expect me to go there and search the whole site in order to figure out what your opinion is, ok?

 

FreeT, Unc, TeleMad, Bo, island, and any others... please share your opinions, and support them with facts if you have them. I'm still interested in your opinions without 'supporting facts', but please understand that it will be regarded only as your opinion, not as a fact. with 'proof' of some sort. I'm really intersted in seeing what you all consider 'proof' of abiogenesis, and which of you 'accept' it because it is 'scientifically accepted', without knowing the reasons. Telemad, I'm sure you have done extensive research on this, and I hope I'm not asking you to duplicate your efforts if you've already posted this info in another thread, but please copy it to here as well, if it's not too much of a problem.

 

Thanks to all, and I look forward to your posts.

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As far as I'm concerned both ideas seem improbable; there is no Direct evidence of either.

 

However, life had to come from somewhere didn't it? Given the predicted age of the universe and the unpredictible size of it, I'd go with a slightly truncated view of Abiogenesis. I'd put the first life in a different basic chemical makup and theorise it came together by chance in an intersteller gas-cloud. Intelligence? Responsive behavior and memory? Evolution in process.

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As far as I'm concerned both ideas seem improbable; there is no Direct evidence of either.

 

What are the BOTH to which you refer?

 

Given the predicted age of the universe

 

Not trying to nitpick, but please don't assume we all know what you mean. What is the 'predicted age of the universe'?

 

I'd put the first life in a different basic chemical makup and theorise it came together by chance in an intersteller gas-cloud.

 

Again, I just want to be able to understand what you mean. can you please explain what "different basic chemical makup" means, and explain how the interstellar gas cloud theory contributes to life on earth?

 

Maybe I wasn't clear in my initial question though. I would like your answers to somehow relate to the formation of life on this planet.

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Originally posted by: IrishEyes

As far as I'm concerned both ideas seem improbable; there is no Direct evidence of either.

What are the BOTH to which you refer?

Originally posted by: IrishEyes

...I don't want this boiling down to a "abiogenesis didn't happen because God made everything" fight. I don't want "Abiogenesis happened because there is no God"...

 

Originally posted by: IrishEyes

Given the predicted age of the universe

Not trying to nitpick, but please don't assume we all know what you mean. What is the 'predicted age of the universe'?

 

Greater than ten billion years( >10^9 years if you want scientific notation). Combined with the 'unknown' size of the cosmos that's a lot of space and a lot of time for things to be randomly interacting.

 

http://www.astro.ucla.edu/~wright/age.html

 

In summary, he goes over several methods of determining an approximate age for the universe, some of them going as high 12.8+/- billion. References are given in context.

 

Originally posted by: IrishEyes

I'd put the first life in a different basic chemical makup and theorise it came together by chance in an intersteller gas-cloud.

Again, I just want to be able to understand what you mean. can you please explain what "different basic chemical makup" means, and explain how the interstellar gas cloud theory contributes to life on earth?

Maybe I wasn't clear in my initial question though. I would like your answers to somehow relate to the formation of life on this planet.

Intersteller space is chaulk-full of the basic ingredients for life from the ejected masses of ancient stars. As stars get older they 'burn' the composing elements within them into ever dencer elements(this is known as fusion ), ejecting all of it continuously throughout their lifespan. In any area sufficiently dence(or even sparcely populated) with such steller bodies the cosmos are peppered with the ejected molecules. Should these moleculs collide(as is likely to happen once in a while over a few billion years) they have a chance each time of forming a stable and complex molecule, such as the base-pair chromosomes. Should these then combine(again, billions of years causing a relative googolplex of chances) in complementary fasions a primitive form of order/life would begin to evolve in the cosmic chaos.

 

When I said a different chemical makup, I was referring to other 'life' based on lighter elements than carbon which would have been more plentiful in the earlyer days of the universe when everything was much more dencely packed together and the likelyhood of interaction was greater. Indead the original 'soup' could have been thae wash-out from the plasmatic mass predicted for the era after the BB. Given the possibility of an ambient temperature close to that which could enable 'life' to exist as likely to have occured in those steller spaces away from the first forming stars once things had 'settled down' a bit, and in my estimate an era of a few millenia where those temperatures and semi-dence 'atmosphere' permiated the cosmos, the chances of interactions with 'favorable outcomes' in that time period are far greater than those 'now' comically speaking.

 

It is not too far of a leap to envision this life prospering in what is now a 'void' and then being locked in its mutitude of forms within the rock and ice that resulted from the expansion of the universe. It is then not too far of a leap to see Earth being pepp

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Originally posted by: IrishEyes

So can someone please give a plausible explanation for the development of living organisms from non-living matter? Without it degenerating into the "What is life, anyway?" debate? (life: #4 The physical, mental, and spiritual experiences that constitute existence ; also the first definition listed that did not contain 'life' or a derivitive in its definition - UGH!)

So you want us to ignore the problem that even dictionary.com can't solve? They can't provide a def of "life" without using the word itself or REQUIRING cogniscence of [/i]"experiences that constitute existence"[/i].

 

In order to use the def of life you provide we need to accept INTELLEGENT life. This is way out of the scope of Abiogenesis.

 

What we have basically is a combination of existing natural elements in a particular combination. We have decided to draw a line and say this side of the line we call "life". We can model a number of processes to explain how any particluar molecular combination developed. I am willing to acknowledge that we do not have any strong singular such process promoted as the leading theory for Abiogenesis.

 

However logic and reason, and especially Scientific Methodology does not allow the leap from "We don't know" to "therefore god".

I want you guys to play fair, ok? I don't want this boiling down to a "abiogenesis didn't happen because God made everything" fight. I don't want "Abiogenesis happened because there is no God".

The only FAIR and SCIENTIFIC approach lacking a strongly supported specific theory is the application of Ockham's Razor.

 

We have seen that in lab test, basic building blocks of life do spontaneously develop under the numerous conditions which represent those we find are most likely to have existed at that point in time we find "life" developing.

FreeT, Unc, TeleMad, Bo, island, and any others... please share your opinions, and support them with facts if you have them. I'm still interested in your opinions without 'supporting facts', but please understand that it will be regarded only as your opinion, not as a fact.

And for now that is my personal opinion.

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08/24/2004 05:05 PM - FreeT

We have seen that in lab test, basic building blocks of life do spontaneously develop under the numerous conditions which represent those we find are most likely to have existed at that point in time we find "life" developing.

 

Thanks for chiming in, FreeT. As hard as you may find this to believe, i do value your opinion.

 

However, can you please clarify who "WE" is, and which documented 'lab test' has shown that the basic building blocks of life have spontaneously developed?

 

And thanks, Gahd, for clarifying your statements. I will have to do some looking over and pondering, but you have given me some incredible food for thought.

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FT beat me to it - Irish, you limit life to "beings with awareness", which I would say still implies a roundabout definition (all beings that are aware are also alive).

 

Maybe we should agree on a definition of life first. But then again I'm not listed in your exclusive list of VIPs so I'll shut up now.

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Originally posted by: IrishEyes

However, can you please clarify who "WE" is,

Anyone interested enough to do simple Google search to find out what SCIENCE is up to.

and which documented 'lab test' has shown that the basic building blocks of life have spontaneously developed?

I know you are asking what you expect to be a loaded question. As you already know we have the original Miller-Urey test which produced basic amino acids in a lab jar. It is considered flawed now, not because of errors in the test, but in assumptions made of early earth conditions. But "Miller Tests" continue as we learn more about possible early earth conditions. This in fact becomes one of the stumbling points in solving Abiogenesis. We still do not have a strong grasp on what early earth was like. So while one group is dealing with early earth research, another is working with other possible "Miller Tests" based on various early earth models. One such is Sidney Fox's spontaneously formed microspheres. It is based on volcanic reactions, one of the strongly held early earth models. Fox later found proteinoids similar to those he had created in his laboratory in lava and cinders from Hawiian volcanic vents and determined that the amino acids present polymerized due to the heat of escaping gases and lava. Other catalysts have since been found; one of them, amidinium carbodiimide, is formed in primitive Earth experiments and is effective in dilute aqueous solutions. Such as might be found on early earth. It is just another step in the path.

 

Creationists like to try to reject Sidney Fox's work out of hand because it, as WOULD be expected, is just another step along the way. They like to pretend that unless everything is laid out in front of them in total, none of it counts. But it is a very valid advancement in the "Miller Tests" sequence. It has since been performed at even lower temps. They were able to form protein-like chains from a mixture of 18 common amino acids at only 70°C in the presence of phosphoric acid.

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Anyone interested enough to do simple Google search to find out what SCIENCE is up to.

 

Thanks, but the sarcasm isn't really necessary. I was actually asking if you've ever worked in any type of lab environment that has studied this. I'm seriously not trying to be a pain, I was just wondering. Thanks for answering, and I will google "science" later to try to get some more info.

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I know you are asking what you expect to be a loaded question.

 

Actually, I was asking a sincere question. I'm not trying to trick you into saying or admitting anything, ok? I'm not asking you to show me proof that God doesn't exist, or to explain things that have anything to do with creationism or religion. I'm just asking for you guys to explain abiogenesis, as you understand it, and give supporting proof if you have it.

 

And please don't give me more credit than I deserve. I would really like for you to explain things to me as if you think I have never been exposed to the ideas before, if you can do that without being condescending. Try to explain it to me the way you might explain it to an intelligent 8 year old. Easy on the HUGE words, but you can skip the "see spot run" rhetoric.

 

Also, before I forget, the information that you have presented thus far is really interesting, and I appreciate you taking the time to walk me thorugh this. As intelligent as I like to pretend I am, some of the things that you discuss on this site are not only way beyond my comprehension, but also way out of the realm of what I would ever even consider considering, if that makes sense. I know we go round and round about religion, but this has nothing to do with that. You, and many others, amaze and astound me on a fairly regular basis. I appreciate your input in this thread, as it has been very educational so far.

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FT beat me to it - Irish, you limit life to "beings with awareness", which I would say still implies a roundabout definition (all beings that are aware are also alive).

 

Ok, I see your point. I don't know how to get around that though. Any suggestions on how to word it better? I'm trying to avoid this turning into a debate about what life is or is not. If we can come to a quick concensus of 'life' without it taking over this thread, I'd be willing to go there. Can you give us a definition that would work for the purpose of this thread?

 

All beings that are aware are also alive? But does that imply that anything that is not aware is not alive? I don't think I said this, but maybe it was implied. I just don't want the 'life' debate on tis. I really want to hear what you guys think is the best explanation for abiogenesis.

 

Maybe we should agree on a definition of life first. But then again I'm not listed in your exclusive list of VIPs so I'll shut up now.

 

Gee, you sound almost jealous! You silly silly, of COURSE I'm interested in what you have to say. As for it being a list of VIPs, don't be that way. You are THE VIP here, and we all know it. In all seriousness, I was asking for the people I mentioned to respond because I'm sure that the first 4 on the list will probably have very strong opinions that are probably supported by facts. That's not to imply that your opinion would not also be supported by fact, of course. Aw shucks, Tormod, I'm SORRY your name wasn't on the list, I messed up, can you please forgive me?????

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FreeThinker: One such is Sidney Fox's spontaneously formed microspheres. It is based on volcanic reactions, one of the strongly held early earth models. Fox later found proteinoids similar to those he had created in his laboratory in lava and cinders from Hawiian volcanic vents and determined that the amino acids present polymerized due to the heat of escaping gases and lava.

 

Concerning Fox's proteinoid microspheres, from my personal notes (haven't looked at this for some time)...

 

Thermal Synthesis (Proteinoids)

One of the primary reasons that amino acids will not combine spontaneously to form dipeptides in a watery medium (which is where most origin of life scenarios place such processes) is that their bonding is a dehydration synthesis reaction (a.k.a., a condensation reaction). In such reactions, a molecule of water is formed from the atoms of the two amino acids and that water molecule must be introduced into the surrounding aqueous solution. This is against the thermodynamically favored reaction, which would be to take molecules of water from the sea, ocean, or lake and use them to hydrolyze dipeptides (break then back down into two separate amino acids). One solution to this problem is to drive off the water in the immediate surroundings so that a water molecule can be ‘plucked’ from the amino acids and inserted into the surroundings. Heating mixtures of dry amino acids has proven successful in creating polypeptide chains because it serves dual purposes – it supplies the energy for the polymerization and evaporates any water produced during polymerization.

 

“Could the primeval amino acids have joined into peptides under prebiotic conditions? What

looked like a simple positive answer to this question was found in 1958 by the American

biochemist Sidney Fox, long of the University of Florida, now at the University of South

Alabama. His recipe: Just heat a dry mixture of amino acids for three hours at 170o C (338o F).

Water comes out and you get a plastic-like solid that, when ground and mixed with water, yields

up to 15 percent of its weight as a water-soluble product made, on average, of some fifty amino

acids joined together. To this product Fox gave the name proteinoid, a cautious choice since

proteinoids are far from having the regular chainlike structure of peptides.” (Christian de Duve,

Vital Dust:Life as a Cosmic Imperative, Basic Books, 1995, p29)

 

But there are, of course, many problems with the thermal synthesis of “proteins”. First, objections to proteinoids themselves will be presented, followed by objections to the microspheres which they can form.

 

Proteinoids (objections to their relevance)

Another, this time more skeptical, background quote will be provided.

 

“’Biochemists knew that when a mixture of amino acids in the ratio found in proteins was heated,

the result was pyrolysis to a dark brown tar with a disagreeable odor,’ commented chemist

William Day. At this point Sidney Fox made a contribution. Fox set aside the usual recipes and

added extra amounts of any of three special amino acids. These mixtures, when heated in the dry

state well above the boiling point of water, gave clean preparations, in which amino acids had

united with one another. The products obtained were not natural proteins, however, even though

they were made from amino acids. The special amino acids mentioned above contained either an

extra amino or an extra acid group. In normal proteins, these extra groups do not take part in

chain formation, but this had occurred in the heating process. Unnatural chains, even branched

chains, had been produced. Further, some of the amino acids had been converted into their mirror-

image forms, so both types were present. Others had been converted to colored substances,

pigments, which were also built into the chai

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Hmmm...last post was too long...continued...

 

A further indication that proteinoid microspheres cannot synthesize their own protein is stated by Fox later in his book, in a section entitled Evolution from the Protocell to the Contemporary Cell:

 

“A more independent and adaptable cell arose, however, when some protocells acquired the ability to produce their own polyamino acids internally. These would have had to be a more contemporary type, in which the instructions from one generation to a descendant generation were channeled through the parents as individuals rather than being drawn from the monomers and their polymers in the environment.” (Molecular Evolution and the Origin of Life, Sidney W. Fox and Klaus Dose, W. H. Freeman and Co., 1972, p246)

 

One needs to keep in mind several points when he or she encounters a statement such as the following.

 

“Moreover, it is striking that amino-acyl adenylates yield oligopeptides when incubated with proteinoid-polynucleotide complexes, which thus have some of the characteristics of ribosomes.” (Biochemistry: Second Edition, Albert L. Lehninger, Worth Publishers, 1975, p1047)

 

First, the mentioned amino acids that join to form an oligopeptide are pre-activated – it is not the “protoribosome” itself that performs this task. In addition, the “protoribosome” was not composed simply of proteinoid – it also contained polynucleotides, which have not been synthesized under any plausible prebiotic conditions, let alone under those dry, high-heat conditions associated with proteinoid formation.

 

Cell-Like Membrane?

Cells have membranes in which phospholipids are the primary structural component, and in which membrane-spanning proteins transport materials across the barrier the membrane forms. However, the “membranes” of proteinoid microsphere are lipid-free and do not carry out the functions of cellular membranes.

 

“[stanley] Miller and [Leslie] Orgel also criticize Fox’s statements relating microspheres to living cells. They state that the microsphere’s bilayer membranes “… are not ‘biological-like’ membranes since they do not contain lipids or carry out any of the functions of biological membranes.” They conclude, “It seems unlikely that … the division of microspheres is related to the origin of cell division.”” (Charles B. Thaxton [Ph.D. in Chemistry], Walter L. Bradley [Ph.D. in Materials Science], Roger L. Olsen [bS in Chemistry, Ph.D. in Geochemistry], The Mystery of Life’s Origin: Reassessing Current Theories, Lewis and Stanley, 1984, p175).

 

“Folsome criticized microspheres in that they possess a “grossly thick” boundary layer that more closely resembles a nearly impermeable cell wall or spore coat than a cell membrane.” (Charles B. Thaxton [Ph.D. in Chemistry], Walter L. Bradley [Ph.D. in Materials Science], Roger L. Olsen [bS in Chemistry, Ph.D. in Geochemistry], The Mystery of Life’s Origin: Reassessing Current Theories, Lewis and Stanley, 1984, p175).

 

Communication?

It is also claimed that proteinoid microspheres communicate by exchanging information-containing molecules.

 

“Inasmuch as the endoparticles [that move from the interior of one microsphere into another through a connecting, hollow proteinoid junction] are composed of proteinoid, and the proteinoid has been shown to be informational (page 174), the phenomenon constitutes a model for the origin of communication. This model relates to either intercellular communication or intergenerational communication; in fact, the phenomenon suggests the simultaneous origin of both types of communication (Hsu et al., 1971).” (Molecular Evolution and the Origin of Life, Sidney W. Fox and Klaus Dose, W. H. Freeman and Co., 1972, p217)

 

Although this claim of microsphere “communication” may be technically true, i

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Thanks for all of that, TeleMad.

 

I know that there is some outstanding information in there, and I greatly appreciate you supplying so many facts. Would it be possible for you to clearly and succinctly state your opinion of abiogenesis now? I DO appreciate all of the time and effort that you put into these posts, and I will keep all of this information to go over more thoroughly at another time. But I guess what I'm looking for is a plausible explanation for the development of living organisms from non-living matter? If it is in your posts, PLEASE let me know, because it totally went right over my head.

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Would it be possible for you to clearly and succinctly state your opinion of abiogenesis now?

 

How about, "I don't know"?

 

The RNA World theory has several advantages, the most obvious being that it helps break the chicken-or-egg problem. In all extant cells, DNA stores genetic information, RNA carries that genetic information to ribosomes, which are also made of RNA, and the information is used to synthesize proteins. The problem is, DNA cannot replicate itself....it requires proteins to do that. In addition, RNA synthesis also involves proteins, so there's feedback and interconnections. So without DNA there's no proteins....without proteins there's no DNA...and without DNA and no proteins there's no RNA. If the three parts are interdependent and all are absolutely required, how did the system arise? Well, DNA is kind of uneeded in that RNA can store genetic information. It is possible to have RNA store information and have proteins made from that RNA and for proteins to make the RNA. But that still leaves us with 2 parts that each requires each other. But in the 1980s, scientists discovered evidence of what others had speculated: RNA can also catalyze chemical reactions (catalytic RNAs are called ribozymes)...that is, they can act like proteins (but are far less impressive catalysts). So proteins too are not actually required....RNA could serve both the informational and the catalytic roles. Thus was born the RNA World theory. The key molecule of the RNA World is a self-replicating RNA molecule. There's one big problem for the theory. No experiment has produced an RNA replicase and the closest thing to date was a whopping 180 nucleotides long...and it could copy only 14 of its own nucleotides. The problem with a 180-nucleotide replicator (assuming the molecule actually could) is the low probability of one arising by non-directed ordering of nucleotides...there are 4^180, or about 2.35 x 10^108, possible unique sequences of that length; and even if a trillion of them could function as an RNA replicase, the probability of hitting one of those in a single shot is only about 1 in 2.35 x 10^96. The numbers can be played with some, but even assuming that a trillion trillion of those sequences could function as RNA replicases, the probability would still be only about 1 in 2.35 x 10^84. The second major problem with the RNA World theory is getting RNA! No prebiotic experiment has yet to produce even 1 RNA nucleotide.

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