Australia is right near Antarctica.
Is Abiogenesis Scientific?
- Thread starter Prince_James
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Australia is right near Antarctica.
Oh. Maybe it was Antarctica. A- something.
well besides Antarctica there are many martian meteorites found around the globe: http://www2.jpl.nasa.gov/snc/
The famous martian meteorite that sorta has some life marks is: ALH 84001
http://www.lpi.usra.edu/lpi/meteorites/The_Meteorite.html
http://www.lpi.usra.edu/lpi/meteorites/The_Meteorite.html
Draqon:
Yet until there is data to support the hypothesis fully, one cannot concede to acceptance of it. That is to say, it is not yet a theory or law, but remains a hypothesis.
Fraggle Rocker:
Actually, don't we have panspermia to account for? Of course, that has just as scanty evidence...
But basically, one cannot reason from one signs to all signs.
Spidergoat:
Yet not synthesized yet.
Are you certain that life "originated in the ocean"? For according to the primordial soup, life didn't develop in the ocean proper, but in a pre-ocean (or what we'd call an ocean today) which was rich in various materials.
Yet until there is data to support the hypothesis fully, one cannot concede to acceptance of it. That is to say, it is not yet a theory or law, but remains a hypothesis.
Fraggle Rocker:
Actually, don't we have panspermia to account for? Of course, that has just as scanty evidence...
But basically, one cannot reason from one signs to all signs.
Spidergoat:
Yet not synthesized yet.
Are you certain that life "originated in the ocean"? For according to the primordial soup, life didn't develop in the ocean proper, but in a pre-ocean (or what we'd call an ocean today) which was rich in various materials.
The difference was that space is subject to strong radiation, and the ocean was protected by water. The UV would tend to destroy complex molecules.
but maybe...premordial Earth had lotsa clouds repelling the radiation.
Right! So now with this addition you have all three postulates that satisfy your initial post that lead towards abiogenesis. Trivial point. No problem. It happened.
The only thing that the poster of this thread is not taking into account is the 4.5 billion years of Earth's evolution and history.
I'm not finding anything relating to the RNA and the clay issue. Might anyone have anything on the topic off hand?
It goes like this: The Universe began with The Big Bang or something that had essentially the same effect, ie a large expansion of the space available to do stuff in, at first at ginormous temperatures which forged the first protons and electrons. There was no life (as we know it) in this primordial universe. Eventually one solar system was formed with a planet around it that was at molten rock temperatures. There was no life (as we know it) on this planet because conditions were inimicable to life.
Now, however, there is life.
Logic dictates that if there is life now when there was no life before, some natural sequence of events gave rise to self-replicating molecules out of non-self-replicating molecules. I brought up the Big Bang to emphasise that we cannot simply postulate life from lifelessness in a large old Universe in which the process may have begun elsewhere. In any case, even if I did not point out that at some time in the past the Universe was lifeless, it is pointless to talk about life having come to Earth from somewhere else, because you are still left with how the process got going in the first place.
Life comes from lifelessness. The scientific viewpoint is that all extraneous actors are disallowed and whatever it is that caused life is a natural phenomenon which requires explanation. Abiogenesis simply defines the fact that the Universe is known to have been lifeless, and is now known to have life in it. What is then hypothesised is the precise mechanism for the generation of life. Having made hypotheses about the precise mechanism we set up experiments to test the possibility or impossibility of those mechanisms. The first of these was the classic Miller-Urey experiment of 1953 which showed that the elements of organic molecules could, without any life processes infecting the procedure, be spontaneously synthesised into the simpler amino acids that form the building blocks of proteins. Since then, by creating more and more organic chemicals spontaneously and then using those as building blocks for other experiments, we can move towards something like the processes that took place on the primordial Earth.
My point is this: Life exists. It did not always exist. Those are scientific facts. Abiogenesis is therefore a scientific fact. The investigations into what the actual process might have been are undertaken under conditions of scientific rigour. Despite Michael Behe's fantasies there is no point at any part of the investigation of life processes, either the bottom up ones starting with Stanley Lloyd Miller and Harold Urey, or the top down ones that investigate the processes of living creatures and the fossils of their ancestors, that cause any scientist to say at any point, "Life is impossible without a sapient external agency".
In another 20 years maybe, we'll have synthesised spontaneously the first DNA molecule, and that will replicate itself. Then we will have proved that what we thought happened is a) not intrinsically impossible and b) reproducible under lab conditions. On the other hand, maybe it simply isn't reproducible under lab conditions, but that does not mean that it is intrinsically impossible.
One side-effect of the hypothesis probably being the right one is that not only do you demonstrate results that are consistent with the final answer being the right one, but you simultaneously learn a great deal of new stuff that you never knew before.
By all these criteria, abiogenesis is a scientific theory. You don't have to accept it, but you can't deny that it is fully scientific. Something is not withheld from being "scientific" just because it cannot yet be proved as true. Only this morning there is a report about the Large Hadron Collider in CERN (you know, the particle lab run by the Illuminati who own a stealth aircraft :bugeye: ) and their hopes for finding the Higgs Boson (the God Particle). They don't know that they'll even find it using this device. They don't know the details of how the Higgs Boson imparts matter with mass, and finding the particle may not ultimately help them with deciding that. But none of these "known unknowns" (as Donald Rumsfeld would have said) makes any part of this process "unscientific".
Silas:
This actuallly hasn't been established fully yet. It is the best working hypothesis, but this has -not- been demonstrated as of yet.
Actually, that isn't necessarily so, so long as the hypothesis is falsifiable.
As far as I know, no process of sponteneous chemical creation has produced things more complicated than amino acids. THat is to say, there is no experimental proof that the "next step" can be so made in that manner.
Certainly, a lack of evidence for these mechanisms of abiogenesis does not imply that abiogenesis is categorically false.
Yes. Certainly.
It isn't a theory - it is a hypothesis. Until we have hard scientific evidence that points to the mechanics of abiogenesis, how can one justify calling it a "theory" when the essence of theory is empirical justification?
Actually, isn't that the essence of something being a scientific theory? You have to prove it is true before it becomes one?
This actuallly hasn't been established fully yet. It is the best working hypothesis, but this has -not- been demonstrated as of yet.
Actually, that isn't necessarily so, so long as the hypothesis is falsifiable.
As far as I know, no process of sponteneous chemical creation has produced things more complicated than amino acids. THat is to say, there is no experimental proof that the "next step" can be so made in that manner.
Certainly, a lack of evidence for these mechanisms of abiogenesis does not imply that abiogenesis is categorically false.
Yes. Certainly.
It isn't a theory - it is a hypothesis. Until we have hard scientific evidence that points to the mechanics of abiogenesis, how can one justify calling it a "theory" when the essence of theory is empirical justification?
Actually, isn't that the essence of something being a scientific theory? You have to prove it is true before it becomes one?
Clay is a catalyst that is helpful in polymerizing proteins from amino acids and nucleic acids bases, sugar, phosphoric acid to nucleic acids (DNA, RNA)s; thus forming macromolecules. Amino acids and nucleic acid bases are attracted and bind to clay minerals forming membranes. Clay contains zinc & iron (metal catalysts) and collects energy from radioactive decay and releases it with temperature and/or humidity change. In macromolecule cellular research, much of which focuses on self-replicating lipid vesicles. David Deamer (Univ. of California, Santa Cruz) and Pier Luigi Luisi (ETH Zurich) describe the production of lipids using light energy, and the template-directed self-replication of RNA within a lipid vesicle. They demonstrated the polymerization of amino acids into proteins on the vesicle surface, which acts as a catalyst for the polymerization process. The principal hurdle remains the synthesis of efficient RNA replicases and related enzymes entirely within an artificial cell. Martin Hanczyc (Harvard Univ.) showed how the formation of lipid vesicles can be catalyzed by encapsulated clay particles with RNA adsorbed on their surfaces. This suggests that encapsulated clay could catalyze both the formation of lipid vesicles and the polymerization of RNA.
This is the view supported by the research of James P. Ferris at Rensselaer Polytechnic Institute. Nucleotides assemble into polymers and the polymers could replicate on clay minerals that catalyze the joining of reactive nucleotides into polymers. A common clay called montmorillonite catalyzes the synthesis of RNA oligonucleotides.
Ferris has found that irregularities in the structure of a clay - for example, an irregular distribution of cations (positively charged ions) - can be used as repository of genetic information. Replication would be achieved in this example if any given arrangement of the cations in a preformed layer of clay directed the synthesis of a new layer with an almost identical distribution of cations. Selection could be achieved if the distribution of cations in a layer determined how efficiently that layer would be copied. So far no one has tested this daring hypothesis in the laboratory.
Other investigators have also begun to take up the search for alternative genetic materials. In one intriguing example, Eschenmoser has created a molecule called pyranosyl RNA (pRNA) that is closely related to RNA but incorporates a different version of ribose. In natural RNA, ribose contains a five- member ring of four carbon atoms and one oxygen atom; the ribose in Eschenmoser's structure is rearranged to contain an extra carbon atom in the ring. Complementary strands of pyranosyl RNA can combine by standard Watson-Crick pairing to give double-strand units that permit fewer unwanted variations in structure than are possible with normal RNA. In addition, the strands do not twist around each other, as they do in double- strand RNA. In a world without protein enzymes, twisting could prevent the strands from separating cleanly in preparation for replication. In many ways, then, pyranosyl RNA seems better suited for replication than RNA itself. If simple means for synthesizing ribonucleotides containing a six-member sugar ring were found, a case could be made that this form of RNA may have preceded the more familiar form of the molecule. http://www.geocities.com/capecanaveral/lab/2948/orgel.html
The RNA World Hypothesis was first advocated by Leslie E. Orgel in 1965, but is also supported by the very respectable Carl R. Woese who has developed the most recent and best Tree of Life model based on rRNA research. The socalled Tree of Life is now considered to be more of a Ring of Life without any Least Most Common Ancestor (LMCA). See: http://tolweb.org/notes/?note_id=54
See "RNA World Hypothesis" http://en.wikipedia.org/wiki/RNA_world_hypothesis
"On The Origin of Life" http://evolgen.blogspot.com/2005/03/on-origin-of-life_09.html
"Origin of Life" http://originoflife.net/links/index.html
A team at the Howard Hughes Medical Institute and Massachusetts General Hospital in Boston said they had shown materials in clay were key to some of the initial processes in forming life. Specifically, a clay mixture called montmorillonite not only helps form little bags of fat and liquid but helps cells use genetic material called RNA. That, in turn, is one of the key processes of life. They were building on earlier work that found clays could catalyze the chemical reactions needed to make RNA from building blocks called nucleotides. They found the clay sped along the process by which fatty acids formed little bag-like structures called vesicles. The clay also carried RNA into those vesicles. A cell is, in essence, a complex bag of liquidy compounds.
"Thus, we have demonstrated that not only can clay and other mineral surfaces accelerate vesicle assembly, but assuming that the clay ends up inside at least some of the time, this provides a pathway by which RNA could get into vesicles. The formation, growth and division of the earliest cells may have occurred in response to similar interactions with mineral particles and inputs of material and energy. We are not claiming that this is how life started. We are saying that we have demonstrated growth and division without any biochemical machinery. Ultimately, if we can demonstrate more natural ways this might have happened, it may begin to give us clues about how life could have actually gotten started on the primitive Earth."
Among religious texts that refer to life being formed from the soil is the Bible's Book of Genesis where God tells Adam, (King James translation), "In the sweat of thy face shalt thou eat bread, till thou return unto the ground; for out of it wast thou taken: for dust thou art, and unto dust shalt thou return." http://www.cnn.com/2003/TECH/science/10/25/clay.life.reut/index.html
"There are several ideas for how large molecules such as RNA (and also early proteins) might have been generated out of the chemical raw materials that came from above or below or beyond. Two of the most persistent, though, are that clay was the catalyst, and that iron and nickel sulphides were the catalysts.
The clay theory is widely held. James Ferris of Rensselaer Polytechnic Institute, in New York state, explained to the meeting that his research on a type of clay called montmorillonite showed that it catalysed the formation of RNA molecules up to 50 units long. (A unit, in this context, is one of the four chemical bases that make up the alphabet of the genetic code, attached to some sugar and phosphate.) He also showed that the process was selective, with the same relatively small set of RNA molecules emerging every time. That is important, because if all possible permutations of the four bases were equally likely, none of them would ever become common enough for anything interesting to happen.
The iron/nickel/sulphur model is the brainchild of Günter Wächtershauser of Munich University. It, too, relies on catalysis, though in this case the best-tested chemical pathways generate amino acids and proteins, rather than RNA. Unfortunately, neither the clay route nor the iron/nickel route answers the breakout question. But a third, and novel, model described at the meeting might. this was devised by Trevor Dale of Cardiff University, in Wales. He has come up with a way that proteins and RNA might catalyse each other's production.
The protein involved would crystallise in the form of long, and easily formed, fibres called amyloid. (This is the form that proteins take in brain diseases such as Alzheimer's and Creutzfeldt-Jakob.) The amyloid fibres would then act as surfaces on which RNA molecules could grow. Crucially, RNA forming on a fibre this way would grow as double strands, like the DNA in a cell nucleus, rather than as the single strands in which the molecule normally comes. When the strands separated, each would act as a template for a new double-stranded molecule, just as happens when a DNA molecule divides. The protein, meanwhile, would grow because the protruding end of the RNA would act as a catalyst, adding amino acids on to the end of the amyloid fibre. When the fibre grew too long to be stable, it would break in two. Thus both RNA and protein would replicate. Such a system could be the ancestor of the ribosome and, if wrapped in a fatty membrane, of the cell, and such membranes will assemble spontaneously in certain conditions. http://www.economist.com/science/displaystory.cfm?story_id=5518892
Abiotic Synthesis of Polymers:
Polymers = chains of similar building blocks or monomers.
After the synthesis of the organic building blocks the next step in the chemical evolution of life would have been the linking of these building blocks into polymers. Polymers are synthesised by dehydrating reactions.
Proteinoids are abiotically synthesised polypeptides. The first abiotically produced proteinoids were created in the lab by Sidney Fox, of the University of Miami. These amino acid polymers can be made by dripping organic monomers (amino acids) onto hot sand, rock or clay. When the water of these dilute solutions of organic monomers evaporated, the monomers could have concentrated to a point were polymerisation could have occurred.
Clay may have been an important substrate for abiotic synthesis of polymers since:
1. Monomers bind to charged sites in clay.
2. Metal ions could act as catalysts of dehydration reactions in clay.
3. The many binding sites on clay could have brought many monomers close together and assisted in forming polymers.
Pyrite may also have been important as it provides a charged surface and electrons freed during its formation could support bonding between molecules
The Formation of Protobionts:
Protobionts are aggregates of abiotically produced molecules able to maintain an internal environment different from their surroundings and exhibiting some life properties such as metabolism, excitability and self-replication (yet still not able to precisely reproduce). These protobionts were probably antecedents of first true cells.
Evidence to support this hypothesis:
1. When mixed with cool water, proteinoids self-assemble into microspheres surrounded by a selectively permeable membrane.
2. Liposomes can form spontaneously when phospholipids form a bilayered membrane similar to those of living cells..
3. Coacervates (colloidal drops of polypeptides, nucleic acids and polysaccharides) self-assemble.
The Origin of Genetic Information
Today's cells transcribe DNA into RNA, which is then translated into proteins. This chain of command must have evolved from a simpler mechanism of heritable control. One hypothesis proposes that before DNA, there existed a primitive mechanism for aligning amino acids along RNA molecules, which were the first genes.
Evidence to support this hypothesis:
1. Short polymers of ribonucleotides that can base pair (5-10 bases without enzyme, up to 40 bases with zinc added as catalyst) have been produced abiotically in test tubes.
2. RNA is autocatalytic, as indicated by ribozymes (RNA that acts as a catalyst to remove introns, or catalyse synthesis of mRNA, tRNA or rRNA).
3. RNA folds uniquely depending on sequence (unlike DNA), thereby providing a mechanism for natural selection to act on different molecular shapes varying in stability and catalytic properties.
The next step may have been the formation of a membrane that concentrated favourable reactions benefiting unique molecular aggregates. Following this, DNA may have replaced RNA as the genetic material since DNA is more stable. http://io.uwinnipeg.ca/~simmons/1116/16origin.htm
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I demonstrated that the Universe began without any life in it. There is life in it now. Please demonstrate how "life comes from lifelessness" can be ever disproved without invoking some external agency which for all practical and scientific purposes would be considered as Life. If you are promulgating some kind of Intelligent Designer, if that ID is part of our Universe, it is Life which itself must have arisen from lifelessness. If on the other hand you are promulgating a Creator God, then that is a mystical theory which, whatever its merits, cannot remotely be regarded as a "scientific theory".Prince James said:
Any theory which requires an extraneous agency is almost by definition not falsifiable. That is why "Goddidit" is not a valid scientific theory.Prince James said:
Once again, an area where a scientific theory does not require an actual demonstration to be regarded as true. Amino acids are the building blocks of proteins and consequently many life processes. Since we demonstrated that amino acids can form spontaneously, we demonstrated the first essential step in the spontaneous generation of life from non-life processes. That strengthened the theory. The theory is not equally as weak as, say, a theory that DNA came fully-formed out of the Big Bang. The consensus is that that is not a remotely probable eventuality. Finding that amino acids can form spontaneously is only the first step that strengthens the current theory of abiogenesis.Prince James said:
Apparently the meaning of English has changed since I learned it at the age of six.Prince James said:
I think you're thinking of a theorem, a mathematically proven proposition. In any case, the quesiton was "Is Abiogenesis Scientific?", and I certainly hope to have demonstrated that, since everything we know about it (whatever little that is) is derived from scientific endeavour, makes it a scientific theory.
Ah, but you see this time I didn't use the word "theory". I said that you can't disbar abiogenesis from being scientific simply because it has not been demonstrated. And that is the answer to the OP question. "Is it scientific?" Yes, assuming the opposite of "scientific" is "irrational" or "mumbo jumbo" or "mystical". It's the alternatives to abiogenesis which aren't scientific.Prince James said:
I hope I've demonstrated here that something doesn't necessarily have to be conclusively proved true to be counted as a scientific theory. I will now demonstrate that something that is wrong can still be a scientific theory. When Einstein formulated the General Theory of Relativity, he demonstrated that the Newtonian laws of motion are only approximations that work at low velocities. Newton had been "disproved". But when we sent rockets to the Moon, we "put Sir Isaac Newton in the driving seat", in other words exclusively used Newtonian mechanics to build the rockets and fly them, with no reference to Einstein. Newton's laws of motion are no less scientific for having been superseded.
(I started this post yesterday, because at the half way point I actually had to cite an alternative scientific theory to abiogenesis, and was stumped to even think of one!)