DNA and Information
(Feature Article - Part 2 of 3)
then click here to read Part 1 first! See link at bottom of page for Part 3.
From the beginning of the universe to the present day, we must ask... wherein is the origin of information?
Information specifies our existence and lays the foundation of the universe before us ...
... If the universe had zero information before 10-43 seconds, how did it acquire its subsequent high information state without the input of an intelligent, personal Creator? A personal Creator seems to be required, too, to explain the existence of the primeval radiation field. Such an effect, like everything else in the universe, requires a cause. Ross (CH) Page 155
Dr. Ross has a particular spin on his statement ... isn't this rather an inappropriate suggestion coming from a scientist? Hold on to this question as you read on.
Long after the beginning, there is today evidence for the "workings" of biological information all about us. It's everywhere and we've become so accepting as to forget the exceptional nature of this fact — we accept the presence of nature's information base without thinking further.
Yet scientists think, research, and then write complex reports that fill hundreds of scientific journals. The commonly employed logic is that the fit and 'design' of nature comes from a material source ... yielding an exceptional high order of specified complexity ... without batting an eye the conclusion is all this appears as an intricate design arising from a material field with no will, choice, direction, or concept of an end product.
Look at the published examples ...
three-dimensional complex diagrams of biological proteins that routinely appear in Science and Nature magazines - each one a specific molecular machine or unique cell structural components
a schematic of how a simple virus is composed and infects a host - each embodies a strategy for success and mechanisms geared for adaptation (this is a common example for evolution)
mammalian cellular mechanics and integration of cellular systems at the macromolecular level - all together a cell is an architectural prize, incredibly efficient factory of life, wired to the specifics of atomic details (we illustrate this a bit better elsewhere for an article on cells and another on molecular machines)
... there are numerous other examples to cite ... all are specified, complex, the details so eloquent in their workings. We really have to step back to look at this before it hits us ... its not easily assembled simply by chance. This all requires information.
Critical thinking leads us to ask — where does this information come from? How is this inserted into the universe and thereafter captured in biological forms and expressed by each successive generation?
Information in a Code
One of the greatest scientific stories of the twentieth century concerns the elucidation of DNA's structure and the discovery of the genetic code. Bradley and Thaxton (CH) Page 204
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Where does the code begin? As with the universe, do we start with nothing (but a few random chemicals)?
Even if it could be demonstrated that the building blocks of essential molecules could arise in realistic prebiotic conditions, the problem of assembling those building blocks into functioning proteins or DNA chains would remain. This problem of explaining the specific sequencing and thus the information within biopolymers lies at the heart of the current crisis in materialistic evolutionary thinking. Meyer (MC) Page 119
Remember in Part 1, we noted a difference between material and efficient causes. While we'll leave these terms somewhat undefined at this point, the latter cause is an open avenue for our considering the full extent to what biological information delivers!
Molecules characterized by specified complexity makeup living things. These molecules are, most notably, DNA and protein. By contrast, nonliving natural things fall into one of two categories. They are either unspecified and random (lumps of granite and mixtures of random nucleotides) or specified but simple (snowflakes and crystals). A crystal fails to qualify as living because it lacks complexity. A chain of random nucleotides fails to qualify because it lacks specificity. No nonliving things (except DNA and protein in living things, human artifacts and written language) have specified complexity. Bradley and Thaxton (CH) Page 207
So, it's possible to begin separating how order might appear to us, yet order in atoms or molecules alone is not specified complexity. And even when we take the molecular subunits that make up the types of molecules that can exhibit biological specificity, there needs to be another level of organization to embody the specificity. Just having a similar type of molecule doesn't get us to the biological level as exhibited by life today.
The discovery of the complexity and specificity of protein molecules has raised serious difficulties for chemical evolutionary theory, even if an abundant supply of amino acids is granted for the sake of argument. Amino acids alone do not make proteins, any more than letters alone big words, sentences or poetry. In both cases this sequencing of the constituent parts determines the function or lack of function of the whole. In the case of human languages and the sequencing of letters and words is obviously performed by intelligent human agents. In the cell this sequencing of amino acids is directed by the information—the set of biochemical instructions—encoded on the DNA molecule. Meyer (MC) Page 121
Without a detailed review of the composition of DNA (for some detail see diagrams below), simply think of a set of blocks with letters. DNA's 'blocks' are quite like an alphabet and the way the blocks (sets of chemical 'bases') are arranged makes a big difference. If arranged like letters in words and words in sentences, there is the potential for 'sense' to be present in the DNA molecule's code. But again, what guides the initial arrangement?
There is no chemical restriction on the order of the bases along a strand of DNA; the order can be anything at all. The order of the bases is then free to carry information.
How did that message get written in the first place? The standard answer of the biologist today is that the message got written by itself, through evolution, and that evolution works the way the neo-Darwinian theory says it does. But I shall show that evolution cannot work that way. Spetner (NBC) Page 29
The last sentence of the preceding quotation was left to remind you that we encourage further readings in the sources cited in the WindowView feature articles. Thus, we'll leave you to read Dr. Spetner's discussion for his explanation on the way he thinks evolution works. To restate the main concept in this portion of the discussion:
Proponents of an intelligent origin of life note that molecular biology has uncovered an analogy between DNA and language, giving rise to the sequence hypothesis. The sequence hypothesis assumes that an exact order of symbols records information. The basic sequences in DNA spell out in coded form the instructions for how a cell makes proteins, for example. It works just the way alphabetical a letter sequences do in this article to give information about origins. The genetic code functions exactly like a language code—indeed it is a code. It is a molecular communications system: a sequence of chemical "letters" stores and transmits the communication in each living cell. Bradley and Thaxton (CH) Page 205
Again, we are asking: how was life's information base initiated? Aside from a possible discussion on life being the product of a Creator's action, and thus a creation, we are faced with a question that science cannot answer. We are left to marvel at the dimensions of the information that are held in all forms of life!
Remarkable Dimensions to Life's Information Storage
... The genome of a bacterium, for example, is a string of a few million symbols. ... of a mammal ... two to four billion. If you were to print those symbols in a book in ordinary type, the book for a bacterium would have about a thousand pages. ... for a mammal ... two thousand volumes—enough to take up a library shelf the length of a football field! All this information is in the tiny chromosomes of each cell.
... the DNA in the nucleus of a single human cell would be more than a meter long. If all the copies of the DNA in all the cells of your body were straightened and laid end to end they would be about 50 billion kilometers long! That's long enough to reach from the earth to beyond our solar system! Light would take about two days to travel the length of all the DNA molecules in your body! Spetner (NBC) Page 30
The long chains of DNA's bases are a solution to the problem of how life stores information. Unique chemical properties to the nucleic acid molecule itself provide a most versatile storage system. Not only is the system effective in storage, this is part of the mechanism that passes copies from generation to generation — making heredity's pathway through time.
... It is a superbly economical solution. The capacity of DNA to store information vastly exceeds that of any other known system; it is so efficient that all the information needed to specify an organism as complex as man weighs less than a few thousand millionths of a gram. The information necessary to specify the design of all the species of organisms which have ever existed on the planet, a number according to G. G. Simpson of approximately one thousand million, could be held in a teaspoon and there would still be room left for all the information in every book ever written. Denton (ETC) Page 334
If we are not careful, we slip into the assumption that a random process of evolution somehow selected the information storage system in use today. Why would that necessarily be so uniform a system? Why is it necessary to think the uniform application of the code system itself—across all life forms—is necessarily evidence that demands evolution as an explanation?
Why should this system, if evolved from a randomness, be as efficient as it is? This is mere understatement in the face of the powerful DNA replication, repair, and error detection mechanisms that each cell maintains. These mechanisms are guardians to the information in the code. Yes, mutations occur. Yes, errors sneak in. But errors are far less the case otherwise chaos would freely reign over all the aforementioned processes. Errors are routinely detrimental causing lethal conditions, loss of information, and problems.
It is astonishing to think that this remarkable piece of machinery, which possesses the ultimate capacity to construct every living thing that ever existed on Earth, from a giant redwood to the human brain, can construct all its own components in a matter of minutes and weigh less than 10-16 grams. It is of the order of several thousand million million times smaller than the smallest piece of functional machinery ever constructed by man. Denton (ETC) Page 338
So we can reflect on how awesome the system is ... in its efficiency and intricate scale. An ancient system that it is ... rivals and surpasses our most modern of data storage technologies of today. We are tempted to ask how could that have ever come about? Remarkably ...
The information storage density of DNA, thanks in part to nucleosome spooling, is of several trillion times that of our the most advanced computer chips (Gitt 1989, 4). Meyer (MC) Page 120
There may be any number of ways to demonstrate that life's existence relies on remarkable features. We may wear out the window metaphor by insisting that time at the window really offers a unique view. Again, we think moments of awe too often yield to the routine responses and mechanistic biological explanations ... and so much of what is special about life really takes some effort to see clearly. But wait! We aren't done mentioning interesting aspects to DNA and the information it represents!
Biological Information: Beyond the Reach of Chance
There is an incredible amount of information stored in DNA. In our other feature articles we considered chemical origins, thermodynamics, and a probabilistic approach to life's origin. Let's quickly review some of the points along these lines to revisit the difficulty in putting specificity (i.e., information) into molecules.
Since molecular biologists began to appreciate the sequence specificity of proteins and nucleic acids in the 1950s and 1960s, many calculations have been made to determine the probability of formulating functional proteins and nucleic acids at random.
... For the sake of argument these calculations have generally assumed extremely favorable prebiotic conditions (whether realistic or not) and theoretically maximal reaction rates among the constituent monomers (i.e., the constituent parts of the proteins, DNA and RNA). Such calculations have invariably shown that the probability of obtaining functionally sequenced biomacromolecules at random is, in Prigogine's words, " vanishingly small ... even on the scale of ... billions of years " (Prigogine, Nicolis, and Babloyantz 1972, 23). Meyer (MC) Page 124
Some of the examples we've run across describe what it takes to make a protein 100 amino acids in length. Actually, if there are hurdles to straddle here, we need note that typical proteins are made of many more amino acids, say 300 or more! And stringing together amino acid subunits of a protein requires just the right chemical bond (a peptide bond) which by the way is not the only bond that can exist between amino acids. So, immediately we are faced with a 50:50 probability that two amino acids will be joined by just the right bond (i.e., the probability roughly = 1/2).
So if we take a very simple example of linking a few amino acids together we can start calculating probabilities ...
The probability of attaining four peptide bonds is: (1/2 x 1/2 x 1/2 x 1/2) = 1/16 or (1/2)4. The probability of building a chain of one hundred amino acids in which all linkages involve peptide linkages is (1/2)100 or roughly one chance in 1030. Meyer (MC) Page 125
As we've discussed elsewhere, amino acids are of two types (three dimensionally either an L- or D-form; sometimes called a right and left-handed configuration or optical isomer). And again, biology ends up with the left-handed form being used in biological proteins. So, now we have another 50:50 proposition. In any mix of randomly produced amino acids there is roughly a 50:50 assortment of the two optical types.
The probability of attaining at random only L-amino acids in a hypothetical peptide chain 100 amino acids long is again (1/2)100 or roughly 1 chance in 1030. The probability of building a 100 amino acid length chain at random in which all bonds are peptide bonds and all amino acids are the L- form would be (1/4)100 or roughly one chance in 1060 (zero for all practical purposes given the time available on the early earth). Meyer (MC) Page 125
Here again we are tapping into the remarkable nature of circumstances associated with life! Once we get past the hurdle of the specific bond and specific isomer of amino acid, we next face the specific sequence ... because in that specificity is information.
Furthermore, there are 20 amino acids used in making biological proteins, but there exists in nature many other amino acids. While biological specificity requires the next amino acid in a growing protein be one in twenty, the nonproteineous amino acids complicate the picture and potentially reduce the probability to something even less than 1 in 20.
What we are saying, in a nutshell, is that computing the probability of getting just the right amino acid sequence reveals a very complicated scenario - in a word: improbable.
[Robert Sauer of MIT] His results have shown that, even taking the possibility of a variance into account, the probability of achieving a functional sequence of amino acids in several functioning proteins at random is still "vanishingly small," roughly 1 chance in 1065—an astonishingly large number (there are 1065 atoms in our galaxy; ...).
In light of these results, biochemist Michael Behe a has compared the odds of attaining a proper sequencing in a 100 amino acid length protein to the odds of a blindfolded man finding a single marked grain of sand in the Sahara desert not once but three times (Behe 1994, 68-69).
All these calculations thus reinforce the opinion that has prevailed since the mid-1960s within origin-of-life biology: Chance is not an adequate explanation for the origin of biological specificity. Meyer (MC) Page 126
Not only is DNA's information storage capacity wonderfully efficient, but getting information into molecules is not likely to have come by chance. Summed up briefly: biological information is not the result of chance.
Some scientists would agree with the conclusion stated above. Okay, we also agree there are characteristics exhibited by molecules and matter that leave open other possible avenues to explore. We might next ask: Might biological information be inherent in chemicals?
Poke around and you'll find scientists saying that the laws of nature and chemical properties are likely responsible for the informational content in DNA and protein. The way atoms and molecules behave sometimes reveals some degree of self-organization, but these self-ordering properties come with limits. Such discussions lead one to think protein, DNA, and RNA exhibit molecular arrangements based on their physical properties alone. One needs to extrapolate, to stretch what is known, to make this an information bearing relationship.
A number of rebuttals provide insight and counterpoint. Let's take a look at a few examples ...
Nevertheless critics have called into question both the plausibility and the relevance of self-organizational models. Perhaps the most prominent early advocate of self-organization, Dean Kenyon, has now explicitly repudiated such theories as both incompatible with empirical findings and theoretically incoherent (Kok, Taylor, and Bradley 1988, 135-42). Meyer (MC) Page 129
To be fair, there are certain properties, such as affinities between various amino acids that lead to thinking about the potential for self organization. The chemical characteristics of DNA's subunits are indeed helpful to the functioning and stability of the biological information system.
... These bonds, which hold two complimentary copies of the DNA message text together, make replication of the genetic instructions possible.
In other words, the chemical constituents that are responsible for the message text in DNA do not interact chemically in any significant way. Meyer (MC) Page 130
DNA's two - stranded helix structure in three dimensions
DNA is a molecule of many marvelous properties. Not only does its structure hold information, its two stranded construction works to allow transmission of information and even error correction. Space prohibits a full discussion of a number of these features. We've only touched on several of the molecule's unique properties here.
DNA uses four nucleotide subunits (the four nucleic acid bases commonly abbreviated as: A, T, G and C). Like the 20 amino acids that could be bonded together in any order to make a protein, these four bases can link in any order to form a DNA molecule. All such sequences are equally probable.
We recommend further exploration in a library book, high school or college textbook to read more about the specifics of DNA structure and function.
Blueprint of DNA structure indicating the nucleic acid bases lay out a code along the length of the DNA molecule
Thus, "self-organizing" bonding affinities cannot explain the sequential ordering of the nucleotide bases in DNA because (1) there are no bonds between bases along the message-bearing axis of the molecule, and (2) there are no differential affinities between the backbone and the various bases that could account for variations in sequencing. Because the same holds for RNA molecules, researchers who speculate that life began in an "RNA world" have also failed to solve the sequencing problem—that is, the problem of explaining how information present in all functioning RNA molecules could have arisen in the first place. Meyer (MC) Page 13
The concept of an RNA world is considered in yet another feature article. Be it DNA or RNA, both are effective in their own abilities to hold information, the key issue is the source of the sequence. As we've noted before, evolution reduces this to trial and error. But here we are thinking in terms of highly specified information!
But biochemistry and molecular biology make clear that the forces of attraction between the constituents in DNA, RNA and proteins do not explain the sequence specificity of these large information-bearing biomolecules. Meyer (MC) Page 132
A hint made previously is that chemistry and physics will give us symmetry, the repetition exhibited (patterns) in nature (as in a crystal or other geometry characteristic of the physical world), but what is needed is an origin for information that in itself exhibits ...
... the highly improbable, aperiodic and yet specified sequences that make biological function possible. Meyer (MC) Page 133
Orderly organized molecules are no aperiodic! And in the unique pattern of coded molecules contains the specified information.
Conflating order and information (or specified complexity) has led many to attribute properties to brute matter that it does not possess. While energy in a system can create patterns of symmetric order such as whirling vortices, there is no evidence that energy alone can encode a functionally specified sequences, whether biochemical or otherwise. Meyer (MC) Page 134
Self organization based on atomic or molecular properties does not appear to provide the explanation we are seeking here.
So where does all this leave us ... what has come into view?
This article's key point is that of discerning the origin of information. Exploration of the literature reveals no property of matter that is sufficient to explain such an origin. Chance or self-organization can only get us so far, and not far enough to overcome the improbabilities associated with assembling molecules with a high degree of specificity.
The random selection and sequencing of Scrabble pieces out of a grab bag might occasionally produce a few meaningful words such as cat or ran. Nevertheless undirected selection will inevitably fail as the numbers of letters required to make a text increases. Meyer (MC) Page 135
Dr. Meyer suggests that when dealing with information-intensive systems, as with a code or language, we are left with the conclusion that such systems come from an intelligent source. But information in other forms also brings us to the same conclusion, for example, including:
... nongrammatical information (also describable as specified complexity) inherent in machines or expressed in works of art. Like the text of a newspaper, the parts of a supercomputer and the faces on Mount Rushmore require many instructions to specify their shape or arrangement and consequently have a high information content. Each of these systems is also, not coincidentally, the result of intelligent design, not chance or material forces.
Dr. Meyer further notes that the origin-of-life research itself fails to confirm that the cause of information arises from a natural (material) source.
During the last forty years, every naturalistic model proposed has failed to explain the origin of information. Thus mind or intelligence or what philosophers call "agent causation" now stands as the only cause known to be capable of creating an information-rich system, including the coding regions of DNA, functional proteins and the cell as a whole.
Similarly the specifically arranged nucleotide sequences—the encoded information—in DNA imply the past action of an intelligent mind, even if such mental agency cannot be directly observed. Meyer (MC) Page 136
The conclusion that follows this generalization is that intelligent design is the only known cause for the presence of information in systems such as that of information-rich DNA molecules.(see Meyer (MC) Page 137)
But if we cannot observe the source, are we left with a conclusion based on ignorance? Exactly where does this leave us?
While admittedly the design inference constitutes a provisional, empirically-based conclusion and not a proof (science can provide nothing more), it most emphatically does not constitute an argument from ignorance. Meyer (MC) Page 138
To be fair, some critical thinking lies ahead. Research conducted with the concept of intelligent design in mind is being proposed. The scientific community may not readily embrace such a research program because this runs against the main stream, but then this is not reason enough to prohibit such investigations.
To start our thinking, we see that the specificity in DNA, RNA and proteins simply exceeds solutions proposed by any materialistic means. It also seems like scientists thinking about the origin to life end up providing evidence to support Dr. Meyer's suggestions for an intelligent agency at work here:
The origin-of-life research community has generated a multiplicity of explanations involving either random and / or deterministic interactions of matter and energy. It has refused on principle to consider explanations that involve intelligent design.
Finding the best explanation, however, requires invoking causes that have the power to produce the effect in question. When it comes to information, we know of only one such cause. For this reason, the biology of the Information age now requires a new science of design. Meyer (MC) Page 139
We hinted earlier that just because DNA is in all cells does not mean that this uniform presence is a proof of evolution. Certainly we would expect the convenience of a common thread for evolution. DNA could be such a backbone element to an evolutionary process. Yet there are other problems with evolution. And why would an intelligence chose different information bearing systems as opposed to one core system?
... Since DNA is an essential molecular component of every form of life we know, we likewise conclude that life on earth had an intelligent cause. Bradley and Thaxton (CH) Page 206
The real thrust to what we are doing here is not so much focused on some final proof, but instead to get you thinking, looking, and exploring. But explore by looking at both sides of an issue. Look at the flip side of the coin, turn over the rock, poke beyond the standard assumptions. If we cannot tell you now what the absolute source of information is ... well okay ... but if you've read this article carefully and thought about all this ... then the materialists and evolutionists are even farther from the explanation than you now are!
Note: We have one more interesting notion to entertain before wrapping up a look at DNA & Information. What if all or most mutations effectively lose, not gain, information? What would that suggest about life, origins, and evolution? ...
FREE PDF of Mystery of Life's Origin (compliments of the authors) or purchase copy via link at the bottom of this page
also, consider reading Signature in the Cell ... see link below!
Consider This - Feature Article Part 3
Information In Motion - Do We See An Adding Of Specificity?
Generally, at this point in our feature articles conclude the Consider This portion of the discussion. In this case, the 'Consider This' portion is a bit longer than typically found in other articles. So, to access the next part of this special 'Consider This' section ... simply click here! [<<Future LINK. Part 3 is being drafted.]
Excerpts and links to Feature Articles:
Traditional approaches that fail to take account of new findings in molecular cell biology cannot survive the present day. Materialistic explanations for the origin of information have been systematically eliminated over the past forty years. Has origin-of-life research brought us to the brink of a new scientific revolution?: - Dr. Stephen Meyer on DNA and Information
A most significant text that is a must read for all readers. Follow the scientific explorations and the conclusions that tell why DNA is more than a molecule, but IS information by design and beyond mere chance product of an abiotic origin. Read the book for yourself (to consider obtaining a copy click on the image below):
Also, we recommend watching a video from yet another source that addresses the complexity of information in DNA. The original source is found at the web site on Programming of Life. Their site provides the video in Flash format ... and we provide viewing of the QuickTime and other versions for mobile devices or our WindowView visitors ... just click on this WindowView VIDEO LINK!
Quotations from Dr. Michael Denton's "Evolution: A Theory in Crisis" are used by permission of Adler and Adler Publishers Inc., 5530 Wisconsin Ave, Suite 1460, Chevy Chase, MD 20815
Quotations from "The Creation Hypothesis" (CH) edited by J. P. Moreland and "Mere Creation" (MC) edited by William A. Dembski are used by permission of InterVarsity Press, P.O. Box 1400, Downers Grove, IL 60515. www.ivpress.com All rights reserved. No portion of this material may be used without permission from InterVarsity Press.
Quotations from "Not By Chance" (NBC) written by L. Spetner, are used by permission granted by Dr. Lee Spetner.
Writer / Editor: Dr. T. Peterson, Director, WindowView.org