OM 7-1: A Cellular Motor

The difficulties facing a theory of evolution can be more clearly seen when we consider a concrete example such as the cellular motors in the E. coli bacterium.8 This one-celled creature possesses flagella (corkscrew-shaped fibers) powered by rotary motors built into its cell wall. The turning of the flagella propels the E. coli through the water just like a ship's propeller, and by operating these motors in forward and reverse direction the bacterium can guide itself to its desired destination.

Now suppose we imagine a bacterium without this apparatus. The question is this: by what evolutionary steps could we arrive at a bacterium with the cellular motors? What is the sequence of intermediate stages? The requirement is that each stage would have to confer some definite advantage to the bacterium over the previous stage. Otherwise, the changes cannot be attributed to natural selection, which is said to govern the process of evolution.

It has been determined that 20 genes govern the structure of the motors. That means the development could not take place all at once because of a single mutation. An alternative is for the successive changes to come about gradually by random genetic mutations that affect a small number of genes. But if you just get part of a motor, how can that possibly benefit the organism? It would probably make it less likely to survive because it would be wasting its energy to produce a useless structure. Natural selection would therefore tend to prevent such changes.

Suppose then that one cell finally did somehow get a workable motor structure but didn't have the sensory system needed to control the motor. Then it wouldn't be able to properly use the motor, and thus the motor would be of no value. On the other hand, the sensory apparatus would be useless without the motor. What this means is that the sensory apparatus and the motors should develop simultaneously, which complicates the whole matter greatly.

In essence, the problem is this: the motor clearly involves a great number of interacting components, and for the entire motor to work, all the components have to be present together and assembled in the right way. It is very hard to imagine how you could produce such a complex mechanism unless you were suddenly able to bring together all of the components. Modern evolutionary theorists have no adequate explanation. But an intelligent designer would be able to do this, because the mind can go from an idea to a working design by a process of reasoning in which the intermediate stages do not have to survive in some natural environment. If a designer wanted to build a molecular motor, he could think about it and come up with a plan, slowly or quickly. It is possible to envision that, but it is difficult to imagine it could happen by a blind natural process.

The E. coli motor example is by no means unique. There are innumerable other instances of complex form ranging from sophisticated molecular machinery in cells (as described in the previous article) to remarkably developed organ systems in higher species of life. The problem of the origin of such structures is universal and remains unsolved by evolutionary theorists. In fact, since most of the structures in higher organisms are far more complex than the simple example from E. coli we have just considered, we anticipate that an honest attempt to explain their origin will involve correspondingly greater difficulties.

The recently developed science of molecular biology has made the task of the evolutionary theorist much more difficult. Followers of classical Darwinian theory customarily think of evolution in terms of what we might call plastic deformation. They tend to envision an organism as a plastic model and, for example, imagine one could gradually deform the plastic shape of a monkey until it by stages came to take on the appearance of a man. Most people still see evolution in this simplistic way.

But organisms are not plastic models. Physical bodies are extremely complex molecular machines, the workings of which are far more complicated than any machine of human manufacture. So it is practically impossible to see how you can change one machine into another type of machine by a process of plastic deformation. You can do body work on a car and change its shape somewhat, but if you want to rearrange the insides, that is an entirely different story. A new kind of engine, for example, is likely to require a whole new set of parts with a whole new set of interrelationships, and these cannot be produced by gradual continuous deformation of the parts of the original motor. If you start pulling wires and stretching metal in the motor and driveshaft, the machine is likely to break down entirely.

Some evolutionists have suggested that the characteristics that distinguish human beings from apes can be accounted for simply by an increase in brain size. This is another case of plastic deformation in operation-it sounds so simple, just like blowing up a balloon. But neurological studies of the brain have shown that it is not just a lump of flexible gray matter-it is composed of billions of neurons linked together in complex circuits.

So to go from an ape brain to a human brain is not as easy as blowing up a balloon. It would mean increasing the number of neurons and rewiring them so as to enable the brain to generate such complex human functions as speech. A human child, at a very early age, is able to spontaneously assimilate the symbolic structures and communication processes of a spoken language. Apes can't do this. This has led experts in linguistics, such as Naom Chomsky, to posit that the brain has a kind of grammatical software programmed into it.

Carrying the computer analogy a little bit further, we can understand that doubling the size of a computer memory and giving it a 16-bit processor instead of an 8-bit processor is not enough to increase its usefulness to the user. What's really required is new and more advanced software, programs that will let the user take advantage of the extra capacity. The same is true of the human brain-it may be bigger than the ape's, but the real difference is the more complicated programming it is able to run. The big question is how the new programs come into being. One thing is certain: it is difficult to add radically new capacities to a program by randomly modifying it in the hope that by gradual small changes it will improve. It is more reasonable and logical to suppose that a process of designing and engineering a completely new system of software is what's really involved.

Another example of the difficulties facing evolutionary theory may be found in the statocyst of a certain species of shrimp.9 The statocyst is a small, hollow, fluid-filled organ that helps the shrimp balance itself. Amazingly, its function depends upon the shrimp inserting a grain of sand into it through a tiny opening. By means of the pressure the grain exerts upon the sensitive hairs lining the inner walls of the statocyst, the shrimp can tell up from down. It is extremely difficult to imagine any series of gradual intermediate steps that might have led to the statocyst and the behavior associated with it.

At this point, when it becomes clear that a physical explanation of the origin of complex structures is out of reach, some scientists try to save the theory of evolution by appealing to blind chance. Although we have discussed this topic before in this magazine, the appeal to chance is so common in science that we feel it important to again dispel some of the misconceptions associated with it. Scientists making this appeal propose that somehow or other, everything comes together in just the right way by chance. But this involves a serious misconception. Chance is only meaningful when you can repeat an event and observe statistical patterns in the results.

For example, imagine you were the first person to ever flip a coin. If you could flip it only once, you really couldn't draw any conclusions about the chances of heads coming up rather than tails. Even if you flipped it five times, a pattern might not emerge-it might come up heads all five times. But if you flip it several hundred times, you are justified in making probability statements about the event.

Now how does all this relate to evolution? It is clear that the origin of a species is not something that can be repeatedly observed. Yet, as we have previously noted, the evolutionary theorist Theodosius Dobzhansky has stated that there is almost zero chance of human evolution being repeated. In general, when evolutionary theorists evoke chance they are talking about probabilities so small that you would not expect events with such probabilities to occur even once in the course of a span of time billions of times longer than the accepted age of the universe. (See "Could Life Arise by Chance?", p. 34.)

So in considering evolutionary events that are likely to occur only once in hundreds of billions (or even trillions) of attempts, it becomes useless to speak of them in terms of chance. It would be meaningful if you could repeat the events many hundreds of billions of times, but we are dealing with events that historically are supposed to have occurred but once. Therefore, if scientists can offer no acceptable physical explanation of the origin of the complex physical structures of an organism, then these structures become simply "unique events." We cannot say anything certain about their origin. All we can say is that they exist.

Some evolutionists have already been forced to draw similar conclusions. George Gaylord Simpson, one of the deans of modern evolutionary theory, says in his book This View of Life: "The factors that have determined the appearance of man have been so extremely special, so very long continued, so incredibly intricate that I have been able hardly to hint at them here. Indeed, they are far from all being known, and everything we learn seems to make them even more appallingly unique."10