by Lenny Flank
(c) copyright 2006
According to this argument, the complex molecules of life, DNA or amino acids or proteins, are, "too complicated" and "too improbable" to have arisen on their own through random chance or chemical interactions, and therefore they must have been deliberately strung together by a creator with supernatural powers. Some creationists illustrate their claim by pointing out that the odds of an intact strand of DNA forming all at once from chance are the same as the odds of a tornado sweeping through a junkyard and assembling a functional Boeing 747.
"Since random changes in ordered systems almost always will decrease the amount of order in those systems, nearly all mutations are harmful to the organisms which experience them. Nevertheless, the evolutionist insists that each complex organism in the world today has arisen by a long string of gradually accumulated good mutations preserved by natural selection. No one has ever actually observed a genuine mutation occurring in the natural environment which was beneficial (that is, adding useful genetic information to an existing genetic code), and therefore, retained by the selection process. For some reason, however, the idea has a certain persuasive quality about it and seems eminently reasonable to many people—until it is examined quantitatively, that is! For example, consider a very simple putative organism composed of only 200 integrated and functioning parts, and the problem of deriving that organism by this type of process. The system presumably must have started with only one part and then gradually built itself up over many generations into its 200-part organization. The developing organism, at each successive stage, must itself be integrated and functioning in its environment in order to survive until the next stage. Each successive stage, of course, becomes statistically less likely than the preceding one, since it is far easier for a complex system to break down than to build itself up. A four-component integrated system can more easily "mutate" (that is, somehow suddenly change) into a three-component system (or even a four-component non-functioning system) than into a five-component integrated system. If, at any step in the chain, the system mutates "downward," then it is either destroyed altogether or else moves backward, in an evolutionary sense. Therefore, the successful production of a 200-component functioning organism requires, at least, 200 successive, successful such "mutations," each of which is highly unlikely. Even evolutionists recognize that true mutations are very rare, and beneficial mutations are extremely rare—not more than one out of a thousand mutations are beneficial, at the very most. But let us give the evolutionist the benefit of every consideration. Assume that, at each mutational step, there is equally as much chance for it to be good as bad. Thus, the probability for the success of each mutation is assumed to be one out of two, or one-half. Elementary statistical theory shows that the probability of 200 successive mutations being successful is then (½)200, or one chance out of 1060. The number 1060, if written out, would be "one" followed by sixty "zeros." In other words, the chance that a 200-component organism could be formed by mutation and natural selection is less than one chance out of a trillion, trillion, trillion, trillion, trillion! Lest anyone think that a 200-part system is unreasonably complex, it should be noted that even a one-celled plant or animal may have millions of molecular "parts." . . . All this means that the chance that any kind of a 200-component integrated functioning organism could be developed by mutation and natural selection just once, anywhere in the world, in all the assumed expanse of geologic time, is less than one chance out of a billion trillion. What possible conclusion, therefore, can we derive from such considerations as this except that evolution by mutation and natural selection is mathematically and logically indefensible!" (Henry Morris, ICR Back to Genesis, #179)
"The fact is that the remarkable DNA molecule provides strong evidence of original creation (since it is far too complex to have arisen by chance) and of conservation of that creation (since the genetic code acts to guarantee reproduction of the same kind, not evolution of new kinds)." (Henry Morris, ICR Impact #107)
"What was the incredibly powerful force operating within the naturalistic world that managed to overcome the fantastically impossible odds against getting the first living cell? There simply was none, and thus the origin of life by naturalistic, mechanistic process is totally impossible." (Gish, ICR Impact #43)
There are a number of things wrong with the creationist "probability" argument, however. The first and most obvious is that wildly improbable things happen all the time. How improbable must a thing be before it is "too improbable" to have happened without Divine Influence? The odds of any human being being struck by lightning are enormously improbable, yet every year at least a dozen people are killed in the United States by lightning bolts. Is the chance of any particular person being struck by lightning "too improbable" to have happened by chance? Have they all been struck down by God?
Another example: in an ordinary deck of playing cards there are 52 cards. If I deal these out face up, the odds of that particular combination arising in order, by chance, are 52-factorial; that is, 52 x 51 x 50 . . . x 3 x 2. That is one heck of a big number, and the odds are astronomically against dealing that particular hand at that particular time. Yet there it will be, staring us right in the face. If I were to take ten decks of cards and deal them all out, face up, the odds against that particular combination arising by chance are higher than the number of electrons in the universe. Yet again, there it will be. Is it therefore impossible for that particular combination to have arisen by chance? Is the appearance of this particular combination "too improbable" to have happened by chance? Do I witness a Divine Miracle every time I deal out ten decks of playing cards? I very much doubt it.
Even more fatal to the creationist "probability" argument, however, is the simple fact that the odds they are talking about are irrelevant, since neither biomolecules nor living cells are formed "randomly" or "by chance". Life is a chemical process, and like all chemical processes it is governed by the deterministic laws of chemistry and physics. These laws are not "random".
If we have a number of amino acids in solution, for instance, they do not combine "randomly"---they combine according to their chemical properties. Thus, any given mixture of amino acids will always combine in the same ways, in accordance with the laws of chemistry. The idea that there are an astronomical number of possible combinations is simply wrong. The laws of physics narrow the possible chemical combinations to a very much smaller number --the possible number of electron configurations in the outer shell of those atoms. All of the other "possible" combinations are forbidden by the laws of chemistry and physics.
Thus, in their "probability" argument, the creationists conveniently neglect to mention that the combination of the components of those biomolecules is not "random"--they are precisely determined by the laws of chemistry and nuclear physics. Put a group of amino acids in proximity and they will combine in the same basic ways every single time, due to the chemistry of carbon atoms. This makes the "probability" that a collection of amino acids will combine to form a particular protein very near 100%. The laws of chemistry and physics drastically reduce the number of "possible" chemical combinations -- and in many cases leave only one possible chemically stable configuration.
The creationist contention that a cell or a strand of DNA arose "all at once" is a straw man. No one has ever suggested that an entire living cell or biomolecule "poofed" into being all at once, intact. Instead, the appearance of the first replicating molecule (as well as the first living cell) was a steady process of step-by-step building, beginning with a proteinoid and adding bits and pieces from there. No evolutionary biologist has ever asserted that biomolecules or living cells must have arisen all at once, in complete and final form. Since a whole series of intermediate chemical steps preceed their formation, the creationist argument that intact biomolecules could not have arisen by chance is completely irrelevant.