Well, since nucleotides form a natural polymer (they inherently link to one another) they are far, far, far more likely than scrabble pieces, which only assort randomly, don't polymerize, and don't have the complex properties that a polymer has, to form meaningful arrangements.
What's the meaning? Initially it's only, "how well do I reproduce myself." Probably some sequences will be more easily reproduced than others. If that's the case, you're off from there with few limitations. Every time some slight change improves reproduction fecundity and fidelity, it will be preserved in future copies, and subject to further improvement.
So the problem is not the origin of information. Information is there once you have a polymer with a definite primary sequence that gets copied accurately. Meaningfulness is there so long as some sequences copy better than others, at that's certain to be the case because different primary sequences will have different secondary (bonding) and tertiary (3-D) structures.
The problem is how do you get an accurately reproducing bio-polymer in the first place. In fact it can't be DNA because DNA can't reproduce by itself. It needs RNA and proteins to reproduce. So, the original reproducer was certainly something other than DNA, and DNA latter piggybacked on it. For instance RNA, which can have enzymatic properties, and therefore could conceivably facilitate it's own reproduction, almost certainly preceded DNA. There may well have been one or more reproducing molecules (or molecular systems) which preceded RNA, but haven't been retained by organisms the way RNA was.
Whatever. I don't know the answer. But I do know the question. It's not, "how do you get information?" That's easy. It's, "how do you get reproducing bio-polymers?" That's the hard part.
So, we are left with asking ourselves, what is the only known source of information? The answer is, of course, an intellect. It is beyond the realm of empirical science to determine the identity and nature of that intellect. Even so, an intellect is the best explanation by far of the origin of the information embedded in DNA.
Again, I disagree.
Funny, however, that I agree there are significant difficulties with the naturalistic origin of life. It's just that the part you think is hard is actually very easy, and happens as a matter of course once given reproduction, while the part that's really hard you pass over.
More specifically, it's simply not true that "an intellect ... is the only known source of information." Any time you have nonrandom structure you have information, and the world is full of nonrandom structure created naturally without "intellect". For instance the various layers of sand, gravel and rock in a river bed contain information. They tell you actual things about the river. When sand was deposited it means the river was flowing slowly. Gravel means faster flow, and rocks mean the flow was torrential. There are innumerable examples. The size of hail pellets, and the number of ice layers, for example, record information about the thermal layers in the clouds that produced them. Um, O.K., it's early and I'm caffeineless, so I'm not thinking of more examples right now, but you must realize on refelction that they are endless.
"The "origin of life" (OOL) is best described as the chemical and physical processes that brought into existence the first self-replicating molecule. It differs from the "evolution of life" because Darwinian evolution employs mutation and natural selection to change organisms, which requires reproduction. Since there was no reproduction before the first life, no "mutation - selection" mechanism was operating to build complexity. Hence, OOL theories cannot rely upon natural selection to increase complexity and must create the first life using only the laws of chemistry and physics.
If the origin of life took place in the pre-biotic soup, then it took place in an aqueous (i.e. water-based) solution of pre-biotic monomers. According to Le Chateliers Principle, one of the basic laws of chemistry, the presence of a product (in this case, water) will slow the reaction. If one tries to polymerize monomers into polymers in an aqueous solution (one where water is the solvent), it not possible to obtain any appreciable amount. The bottom line, the polymerization step in the chemical origin of life could never take place in water—this step is impossible in the primordial soup.
Step 3: Pre-RNA World: Getting A Sufficient Self-Replicating Molecule
Though the OOL appears to be dead in the water, because of the lack of evidence for a "primordial soup" and the problems facing polymerization, let’s assume that those hurdles could be overcome. What would happen next? Many researchers have hypothesized that once polymers somehow formed, some of them came together to form the first self-replicating molecules. Somewhere within this step--the Pre-RNA world--the true origin-of-life occurred. However, nothing even close to a complete scenario by which polymers can naturally form a self-replicating molecule has ever been put forth. Chemists can artificially synthesize some self-replicating molecules in the lab, but they are not synthesized under conditions resembling the early Earth. Essentially, this is an appeal to a miracle.
...One commentator noted that these self replicating molecules contain vastly less information compared to what is necessary for even the most primitive cell:
"This system carries very little information, in contrast to even the simplest cell. Mycoplasma gentalium has the smallest known genome of any living organism, which contains 482 genes comprising 580,000 bases. This organism is an obligate parasite. A free-living organism would need many more genes."19
Step 4: RNA World
Some time after the first "self-replicating" molecule formed, according to the story, RNA came along. Today, RNA is a genetic molecule in all cells, similar to DNA, but more versatile within the cell. The "RNA World" is essentially a hypothetical stage of life between the first replicating molecule and the highly complicated DNA-protein-based life. The chief problem facing an RNA world is that RNA cannot perform all of the functions of DNA adequately to allow for replication and transcription of proteins. OOL theorist Leslie Orgel notes that an "RNA World" could only form the basis for life, "if prebiotic RNA had two properties not evident today: a capacity to replicate without the help of proteins and an ability to catalyze every step of protein synthesis."41 The RNA world is thus a hypothetical system behind which there is little positive evidence, and much materialist philosophy:
"The precise events giving rise to the RNA world remain unclear … investigators have proposed many hypotheses, but evidence in favor of each of them is fragmentary at best. The full details of how the RNA world, and life, emerged may not be revealed in the near future."41
The best claimed evidence of an "RNA World" includes the fact that there are RNA enzymes and genomes, and that cells use RNA to convert the DNA code into proteins.42 However, RNA plays only a supporting role in the cell, and there is no known biochemical system completely composed of RNA.42
RNA experts have created a variety of RNA molecules which can perform biochemical functions through what is commonly termed "test tube evolution." However, "test tube evolution" is just a description for what is in reality nothing more than chemical engineering in the laboratory employing Darwinian principles; that does not imply that there is some known pathway through which these molecules could arise naturally.
The most interesting RNA molecule synthesized is perhaps an RNA "polymerase" which can replicate 14 base pairs of RNA.42 Yet, the polymerase itself is 200 pairs long.42 As Gerald Joyce noted, OOL theorists are thus 14 / 200 towards achieving a possible model molecule for the RNA World. $2 However, Joyce also noted that the replication accuracy of this molecule is too poor to allow for it to persist as a functional form of life.42
These purely speculative scenarios aren't bad on their own merits, but they are just another reminder of the philosophical presupposition driving this research in the first place: naturalism. Only when scientists assume there must be a natural explanation do they turn to completely unfalsifiable unverifiable and incomplete speculatory hypotheses.
The theory then says that some unknown precursor of RNA turned into RNA through an unknown process. This "RNA-world hypothesis" states that life then arose from a population of self-replicating RNA molecules. RNA is a sister molecule to DNA, used when DNA breaks up to create proteins or replicate. Like a copy from the library, RNA has a complementary code to DNA and goes out to do the dirty work. A few types of RNA have been known to have auto-catalytic self-replicating abilities, however this scenario inevitably encounters a chicken and egg problem18.
But these molecules must be encapsulated within a "cell wall structure" or a small protective enclosure from the outside world. But, the protective cell requires replicating genetic machinery to be created. Thus, we now have a "chicken and egg scenario"--which came first? the self-replicating machinery (which needs a cell to operate), or the cell itself, which protects (and is created by) the cellular machinery? The answer is neither came first for both are required for self-replication. How could self-replicating RNA arise naturally when it essentially is an irreducibly complex system that cannot functionally replicate without other distinct components.
Step 6: Making Proto-cells
Leaving the "chicken-egg" problem aside for a moment, how would we get the first cell-walls for these early replicating sets of molecules? According to one major biology textbook:
"One of the earliest episodes in the evolution of life may have been the formation of a membrane that could enclose a solution of different composition from the surrounding solution, while still permitting the selective uptake of nutrients and elimination of waste products. This ability of the cell to discriminate in its chemical exchanges with the environment is fundamental to life, and it is the plasma membrane that makes this selectivity possible."46 [LINK]
Well, since nucleotides form a natural polymer (they inherently link to one another) they are far, far, far more likely than scrabble pieces, which only assort randomly, don't polymerize, and don't have the complex properties that a polymer has, to form meaningful arrangements.Just like the scrabble pieces being dumped out onto the parking lot, the nucleotide bases would, if the process was left entirely to mindless chance, not be arranged in any meaningful way.
--Stultis... there was nothing about either the backbone of the molecule or the way any of the four bases attached to it that made any sequence more likely to form than another. Later I found out that the noted origin-of-life biochemist Bernd-Olaf Kuppers had concluded much the same thing. As he explained,
"The properties of nucleic acids indicate that all the combinatorially possible nucleotide patterns of DNA are, from a chemical point of view, equivalent."In sum, two features of DNA ensure that "self-organizing" bonding affinities cannot explain the specific arrangement of nucleotide bases in the molecule:--Stephen C Meyer, Signature in the Cell
- there are no bonds between bases along the information-bearing axis of the molecule and
- there are no differential affinities between the backbone and the specific bases that could account for variations in sequence.