Fearfully and Wonderfully Made: A Christian Perspective on the Molecular Foundation of Life

Michael J. Behe | Saturday, April 30, 2005
Copyright © 2005, Michael J. Behe

Professor of Biochemistry, Lehigh University

Edited transcript from a lecture given Saturday, April 30, 2005, 10:00 a.m. Grace Valley Christian Center, Davis, California As part of the Faith and Reason series sponsored by Grace Alive! and Grace Valley Christian Center

King David

Psalm 139:14 says, “I will praise thee; for I am fearfully and wonderfully made: marvellous are thy works; and that my soul knoweth right well’ (KJV). The psalmist was saying that we are wonderful creations, put together in a marvelous fashion. But who wrote this? The author of Psalm 139 was King David, who lived about one thousand years before Jesus Christ. The Jewish people of that time were not renowned for science; their medical knowledge was rather meager and obscure. As a matter of fact, the medical knowledge of much of the world was obscure at that time.

In this lecture I want to go through our knowledge of what the human body is like, and how that knowledge has developed, and show that the psalmist clearly had much more insight than existed generally when he wrote. I first want to clarify that I am not a pastor and nor a theologian; I am just a biochemist. But, strangely enough, at this time science and theology seem to have some points of intersection; we want to talk about those points today.

Hippocrates

Knowledge of how the human body is put together really did not get started until long after David’s time. The first person credited with making a small amount of progress in this area is Hippocrates, often called “the father of medicine,’ who lived about 500 years or more after King David, around 460-370 B.C.

When Hippocrates was alive, the prominent scientific theory was that four elements-earth, air, fire, and water-made up all matter. Associated with those were the four humors: with earth there was black bile; with air there was yellow bile; with water there was phlegm; with fire there was blood. These ancient scientists hypothesized that different combinations of the elements gave rise to “qualities’: for example, fire and earth was dry, earth and water was cold, water and air was wet, and air and fire was hot.

Clearly, the “father of medicine’ lived in a time that we would consider as exceedingly primitive scientifically. But Hippocrates took the first steps towards trying to figure out how the body works and how medicine should be used. He came up with a number of good ideas. For example, in Hippocrates’ Aphorisms he wrote, “Art is long and life is short’; “Desperate diseases need desperate remedies’; “Sleeping too much is as bad as waking too much’; and “One man’s meat is another man’s poison.’ Many of these sayings have the ring of truth about them. But they are not really science, as we would define it.

Nonetheless, Hippocrates is considered to be the father of medicine. Why is that? One of the main reasons is that he wanted to understand how nature worked. Even if he could not figure out too much, he at least wanted to understand how natural things worked. For example, in some of his writings, he talked about an illness called the “sacred disease,’ because people who had it were considered to have run afoul of the gods of ancient Greece and been struck down by them. But Hippocrates did not think this illness was due to Zeus or Poseidon. He wrote, “It appears to me nowise more divine nor more sacred than other diseases, but has a natural cause that originates like other affections. Men regard its nature and cause as divine from ignorance and wonder, because it is not at all like to other diseases.’ Hippocrates did not think this disease was due to direct supernatural intervention, and that people should try to understand this illness as a problem of the workings of the human body.

He went on to say, “They who first referred this malady to the gods appear to me to have been just such persons as the conjurers, purificators, mountebanks, and charlatans now are, who give themselves out for being excessively religious, and as knowing more than other people. Such persons, then, using the divinity as a pretext and screen of their own inability to afford any assistance. . . .’ In other words, people who pretended to know the cause of this disease ascribed it to the pantheon, and then tried to profit from their knowledge. Hippocrates was saying, “No, we have to understand the disease as it is.’

He went on to say that these people who purported to be able to cure the disease through special knowledge were, in fact, relying on physical cures: “But if these things, when administered in food, aggravate the disease, and if it be cured by abstinence from them, godhead is not the cause at all; nor will purifications be of any avail, but it is the food which is beneficial and prejudicial, and the influence of divinity vanishes.’ Again, his point was that some people were trying to profit from this, but we really should be studying nature as it is. So although Hippocrates did not make much progress, he was considered the father of medicine.

Aristotle

Hippocrates was succeeded by Aristotle (384-322 B.C.); their lives overlapped a few years. Although he is best known for being one of the great philosophers of Western thought, Aristotle was also considered the father of biology. He was interested in a great many things, including the study of life, and took science beyond what Hippocrates discovered. Aristotle realized that to understand the way the world worked, one had to study it closely. For example, he wrote the following observations on the octopus: “The octopus breeds in spring, lying hid for about two months. The female, after laying her eggs, broods over them. She thus gets out of condition since she does not go in quest of food during this time. The eggs are discharged into a hole and are so numerous that they would fill a vessel much larger than the animal’s body. After about fifty days the eggs burst. The little creatures creep out and are like little spiders, in great numbers. The characteristic form of their limbs is not yet visible in detail, but their general outline is clear. They are so small and helpless that the greater number perish. They have been so extremely minute as to be completely without organization, but nevertheless when touched they move.’

Aristotle’s innovation of closely observing nature and writing down what he saw had not been done before. That is the first step in explanation. We must observe what is going on before we can try to understand and explain it. But also notice that, as closely as he watched, he got some things wrong. He said that the eggs are “so numerous they would fill a vessel much larger than the animal’s body.’ That would imply that the volume of the eggs was greater than that of the octopus, which is not possible. Also, he noted that the little octopi are so small that they are “completely without organization.’ To Aristotle, they looked like little dots or small spiders, so he thought they must be simple little things. He could not see closely enough to understand how in fact they were organized.

So the first point I want to make is that one of the important steps in learning about nature is observation. We have to look at it, and then we have to write down what is going on. The other point is that sometimes we cannot see what is going on. And if we can’t see what is going on, we have no hope of making much progress.

Pliny the Elder

A few hundred years after Aristotle, another scientist named Pliny the Elder observed blood in animal bodies. He wrote: “The arteries have no sensation, for they even are without blood, nor do they all contain the breath of life; and when they are cut only the part of the body concerned is paralyzed. . . . the veins spread underneath the whole skin, finally ending in very thin threads, and they narrow down into such an extremely minute size that the blood cannot pass through them, nor can anything else but the moisture passing out from the blood in innumerable small drops which is called sweat.’

Pliny was intelligent, and he tried his best to describe what was going on, but he just could not see what was going on. Veins go into capillaries, and we cannot see them with the naked eye because they are too small. Pliny had to more or less guess at some observations and tried to put together a coherent expression of what was going on. But because he could not see what was going on, he failed.

Galen

Another person who tried to describe what was going on with the blood was the physician Galen, a Greek who lived in Rome. He believed that there were two distinct types of blood-nutritive blood, thought to be made by the liver and carried through the veins to the organs, where it was consumed; and vital blood, thought to be made by the heart. Galen essentially believed that the heart pumped out blood to the tissues, and the blood “irrigated’ the tissues and was consumed. Since the blood was continually pumped out to irrigate the tissues and was consumed, he thought blood was continuously produced.

Galen was a very influential figure, so his ideas on blood and other things were taught to medical students for a thousand years. So for a thousand years this mistaken idea about what blood does was held, mostly because Galen had taught it and Galen could not be wrong.

In the early Middle Ages, attitudes started to change. The History of Biology by Charles Singer contains a drawing of the basil plant from a textbook on herbs written in 1200A.D. In this very stylized drawing, the plant is depicted with several wolves’ heads coming from the leaves. For quite some time, people imbued mythical qualities into plants and animals, and drew them, not as they were, but as idealized types. But then, somewhere around the 1200s, things began to change. People became more and more interested in drawing plants and animals exactly as they were. Thus, when we look at a stone carving from a church (circa 1260 A.D.), we see a number of species of plants carved in close representation to what they look like in nature. For a thousand years, science had lost Aristotle’s insight that we have to look closely at nature in order to understand it. But eventually this understanding was recovered, and it was the precursor of modern science.

William Harvey

Many people attribute the beginning of modern science to William Harvey, an Englishman who lived in the early seventeenth century. Harvey revisited the question, thought to be resolved by Galen, of what happens to blood. He did something very special, something that had not been done before: he reasoned about the situation. His reasoning was as follows: Suppose the heart pumps two ounces per beat. There are seventy-two beats every minute in the average pulse, and sixty minutes in an hour. Harvey multiplied those all together, and then reasoned that, since there is one pound per sixteen ounces, the body would be producing 540 pounds per hour! Clearly, that is not what happens. That would be triple the weight of a large man. No one can make that much blood; we cannot eat that much in a day.

This seems simple to us. Why, then, were people stumped on this question for a thousand years? Were they not as smart as Harvey was? Think about this: Suppose instead that William Harvey had been forced to reason this way: There are II ounces per heart beat, and LXXII beats per minute, and LX minutes per hour, and I pound per XVI ounces. How many is that? That is a much tougher question to answer.

The European world did not have Arabic numerals until the sixteenth century. Up until then, Roman numerals were used throughout the region, and it is very difficult to calculate with Roman numerals. In the sixteenth century, modern math notation came to Europe from the Hindus by way of the Mesopotamian Arabs. Only then did they get such things as plus (+) and minus (-) signs; only then did they begin to use positional notation and fractions (3/4 = 0.75) and so on. Before this, their ability to calculate numerical problems had been severely limited, and this in turn limited their understanding of what was going on in biology.

After William Harvey made his calculations and showed how reasonable it was to think that the blood circulated-deducing that it had to circulate because the blood simply could not be made at a sufficient rate to keep up with what would be needed if it was consumed-many others opened their eyes and said, “If we reason about these other questions, maybe we can make more progress.’ So people got back to observing things, doing so in greater and greater detail than had ever been done in the past. For example, vivisectionists began to take out veins from animals and started looking closely at human veins. They noticed little bumps, which turned out to be valves in the veins. These valves are exactly what one would expect if the circulatory system were designed to pump blood in only one direction.

Biologists started looking in greater detail at all living systems, dissecting animals and illustrating the lymphatic and circulatory systems. Yet the actual connection between capillaries and arteries was still not seen. People knew it must be there, due to Harvey’s calculations, but they could not observe it directly.

Robert Hooke

At this point, scientific progress had advanced greatly, but scientists were still stymied, because much of what goes on in biology occurs at a level too small to be seen with the naked eye. In order to make more progress, a technical advance needed to be made. That technical advance was the invention of the microscope. Robert Hooke used the first microscope in 1665. It was extremely crude, compared with our best microscopes these days, but it was an astounding advance in Hooke’s day, for it allowed people to see things that they had not been able to see before. For example, one of the first things that Hooke used the microscope to look at were feathers. To the naked eye, feathers look like fluffy little things, but when observed closely, one notices intricate structures of branches with little barbs sticking out from them. The barbs are wrapped around the branches sticking out from another part of the feather on the opposite side and give feathers the strength that they need to fly.

Scientists also examined insects using microscopes. At the time, insects were thought to be so simple that they could arise spontaneously from decaying matter. They were thought to be so simple as to have no internal organs. But when insects were examined by microscope, incredible details became visible. Details of the anatomy of bees and wasps and other insects were also studied. Hooke himself, upon examining a small mite, was astonished to see that the mite had tiny mites on top of it! Such activities had never before been imagined, and led others to imagine that there was a progression of infinitely smaller and smaller life forms who preyed on each other.

This new knowledge had a profound effect on those who observed it for the first time. Charles Singer, a historian of science, wrote, “The infinite complexity of living things thus revealed was as philosophically disturbing as the ordered majesty of the astronomical world which Galileo had unveiled to the previous generation, though it took far longer for its implications to sink into men’s minds.’ People did not expect this complexity. They did not know how fearfully and wonderfully made nature was. They thought that things were simple enough that what they saw was all there was. It turns out there was much, much more to life than was commonly thought.

Discovery of the Cell

When Nehemiah Grew looked at beans with a microscope in the seventeenth century, he saw many tiny compartments. He did not know what they were, but they reminded him of the cells where monks lived. So he named these things cells, even though he did not have the slightest idea what a cell was. As science advanced and microscopes got better, scientists found these little compartments everywhere, even though they were not always as regular as Grew observed in the bean plant.

In the early nineteenth century, Theodore Schwann and Matthias Schleiden proposed the “cell theory of life,’ claiming that somehow cells are the basis of life. Schleiden wrote, “The question as to the fundamental power of organized bodies resolves itself into that of individual cells. Thus the primary question is, what is the origin of this peculiar little organism, the cell?’ Thus, people were beginning to realize that, as they tunneled down into life, there was a unit called the cell that somehow had much to do with life.

Further observations with microscopes showed that the cell was capable of doing many things, including mitosis and cell division. People started realizing that the cell was not just a simple glob of jello, as some scientists had though, but that it had active substructures within it.

Later, scientists noticed that prokaryotic cells, bacterial cells, had many different features, such as cell walls and membranes; hair-like things called flagella sticking out from them; a dense nucleoid; and more little hairs sticking out from the sides. Animal cells were even more interesting. Each one had a nucleus, as well as centrioles, endoplasmic reticulum, and all sorts of other substructures.

Thus, as we were able to see more and more, studies in biology went further and further down into life. As scientists could see more, they discovered that life, rather than the simple thing it looked like on the surface, was very complex.

Friedrich Wöhler

As biologists were going further and further down into life, chemists were starting at the bottom and working their way up. A major event linking chemistry with life occurred in 1828 when a German chemist, Friedrich Wöhler, went into his laboratory, mixed ammonium and cyanate together, heated it up and produced urea. When he did this, he was astounded; when he published his results, the scientific world was astounded.

Why was this so astonishing? Because ammonium and cyanate are inorganic chemicals not found in living systems. Yet even then urea was known as a biological waste product. This was the first demonstration that nonliving chemicals could give rise to a substance found in life. Until then, scientists thought that living things were made of some different materials than nonliving things, and that living things were entirely different from rocks and gases and so on, because they felt and acted differently. It was a reasonable conclusion. Wöhler’s work showed that we are made up of the same materials as everything else in the world. This may be the only chemical reaction with such philosophical implications.

Amino Acids and Proteins

So now chemists were getting into the act, and in the nineteenth century they discovered other chemicals called amino acids. All amino acids have a common structure with N, C, and COO. They just differ in the R1 and R2 side chains. Some examples are glycine, with an H in the side chain; alanine has CH3; valine has another side chain, and tryptophan has another. But amino acids have an interesting chemical property-when we take two of them, heat them up, and eliminate water from them, they join together into a bigger molecule that is two amino acids in length.

Chemists found out that in life there are just twenty different types of amino acids, and the things they called proteins were actually made from stringing these amino acids together. It turns out that the proteins of life generally consisted of one to two hundred or so amino acids strung together in a row in very specific sequences. So each protein has a specific sequence, just like words have specific sequences of letters and different sequences spell different words.

Later, biochemists discovered that these sequences of amino acids could fold themselves up into very specific shapes. They do so not by magic, but because some of the side chains have positive charges, and others have negative ones, and they attract each other. Other side chains are somewhat oily and band together to stay out of water. And when they are precisely positioned, the whole chain folds up into a special shape that gives the protein special powers. Just like the shape of a wrench or a hammer allows it to do its job, the shapes of proteins allow them to do their jobs. Some sequences of amino acids fold up into helical shapes, and the helices then fold over upon themselves to make bow-like structures. Sometimes a couple of these chains then associate to form larger aggregates of proteins.

Max Perutz

But what are these proteins, and how do we know their shape? In the 1950s a new breakthrough in technology allowed us to see the shapes of these single protein molecules. The first breakthrough was made by Max Perutz, who solved what is called the x-ray crystal structure of the protein myoglobin. He made a schematic model of the protein myoglobin showing the position of all the amino acids. It folds up, forming what is called a heme-group, something which allows myoglobin to bind oxygen. Myoglobin is a protein that is in our muscles. It binds oxygen and stores it in muscles so that when we exercise, oxygen is there to power the burning of food molecules in our muscle cells to give us energy.

When Max Perutz solved the structure of myoglobin and beheld it for the very first time-he was the first person in history to see the shape of one of the basic constituents of life-he was really disappointed. He later wrote, “Could the search for ultimate truth really have revealed so hideous and visceral-looking an object?’ Scientists of the time, at each stage, kept thinking that the bottom must be simple, yet pretty, like a salt crystal or some pleasing shape. When they saw the ugly structure of myoglobin, they were really disappointed.

It is interesting that in his quotation he called it “the search for ultimate truth.’ Perutz was looking for ultimate truth about how life worked, and he was disappointed. Nonetheless, in the past fifty years or so, scientists have grown accustomed to the way proteins look.

Myoglobin and Hemoglobin

The structure of myoglobin is similar in many respects to another protein, hemoglobin. Hemoglobin is found in red blood cells, where it binds oxygen in the lungs, circulates through the blood to the cells and delivers the oxygen to the cells, where it can be bound by myoglobin to be available to the muscles when needed.

The requirements for picking up oxygen in the lungs and then dropping it off in peripheral tissues are different than the requirements for a molecule like myoglobin, which just stores oxygen in the tissue. In other words, the ability of hemoglobin to bind oxygen is different from the ability of myoglobin to do the same. At a certain pressure of oxygen, myoglobin is almost totally oxygenated, meaning all the myoglobins in a solution have oxygen molecules bound to them. (GVCC) But at low oxygen pressures, hemoglobin does not have much oxygen bound to it. It is only when the pressure of oxygen gets pretty high that hemoglobin gets saturated with oxygen. Why is that?

It turns out that this little trick is crucial to hemoglobin’s ability to do its job. In the lungs, where we breathe in and where the hemoglobin comes around in the red blood cells, the pressure of oxygen is very high. Hemoglobin becomes saturated with oxygen in the lungs. Then the circulation of the blood takes it out to our fingers and toes, where the pressure of oxygen is pretty low. At low pressures, hemoglobin cannot bind much oxygen, so it drops off the oxygen.

The point is that in order to deliver something, we have to not only grasp it, but we also have to let it go where it is needed. It is no good to have a hunting dog retrieve the duck if the dog won’t let go when it brings it to you. Even so, hemoglobin not only has to bind the oxygen, but it also has to let it go. How does it do that? The key is the shape of the hemoglobin molecule. It has four units that are roughly the same shape as myoglobin, but the four units are all joined together. When hemoglobin does not have any oxygen bound to it, there is a certain distance from one side to the other. But when it binds oxygen, that distance is decreased. In other words, the shape of the molecule changes when it binds to oxygen. This happens because two of the subunits rotate with respect to the other two subunits.

How does this happen? We find the answer in the heme, which is the business end of the hemoglobin molecule, the site that actually binds the oxygen. Indeoxyhemoglobin, oxygen comes in and binds to one side of the iron atom and forms a chemical bond to the iron. Now it is called oxyhemoglobin. But when it binds, it pulls the iron down to one side. When it pulls the iron down into the plane of the porphyrin, that tugs on the histidine side chain to which the iron is attached. The histidine side chain is attached to a helical segment of the molecule, and that pulls the whole helical segment along with it. When that happens, the whole segment moves up one notch from where it was before. When it moves up like that, it has to break some other electrostatic bonds that other subunits made. But it turns out that that is very difficult to do unless there are a couple of oxygens binding simultaneously. So that means it can only happen in high oxygen environments. In a low oxygen environment, all these oxygens just spring off.

To state it more directly, the hemoglobin molecule is a machine that carries oxygen from our lungs to our tissues. It is so designed to be exactly what we need to pick up the oxygen where it is readily available, and to dump it off where it is needed.

Molecular Machines

Hemoglobin was one of the first molecules studied by biochemists because it is readily available in blood and easy to detect because it is red. So the study of hemoglobin became one of the first places where scientists appreciated that the molecular foundation of life is literally based on machinery. Since then, many more systems in the cell have been elucidated, and this machinery-based view of molecular life has been reinforced.

In 1998, the journal Cell published a special issue on molecular machines. Down in the corner of the cover was an illustration of something resembling a watch. It was a take-off on an argument that William Paley, an Anglican clergyman, made in the 1800s. Paley said that if we walked through a meadow and stumbled across a watch, which is a machine, we would realize that it was designed. The artist of the Cell journal cover was inferring that we have found such machines in the cell. So the table of contents shows these titles: “The Cell As a Collection of Protein Machines,’ “Polymerases and the Replisome: Machines within Machines,’ “Mechanical Devices of the Spliceosome: Motors, Clocks, Springs, and Things.’

This edition of Cell had a special editor, Bruce Alberts, president of the National Academy of the Sciences and a prominent biochemist. He wrote: “We have always underestimated cells. Undoubtedly we still do today. But at least we are no longer as naïve as we were when I was a graduate student in the 1960s. . . . The chemistry that makes life possible is much more elaborate and sophisticated than anything we students had ever considered. . . . Indeed, the entire cell can be viewed as a factory that contains an elaborate network of interlocking assembly lines, each of which is composed of a set of large protein machines’ (B.A. Alberts, The Cell as a Collection of Protein Machines. Cell, Vol. 93, 291-294).

Alberts wrote further: “Why do we call the large protein assemblies that underlie cell function protein machines? Precisely because, like the machines invented by humans to deal efficiently with the macroscopic world, these protein assemblies contain highly coordinated moving parts’ (Alberts, pp. 291-294). So he is emphasizing that the word machine is not just a fuzzy analogy; it is meant quite literally.

The Appearance of Design

When we look at proteins and hemoglobin molecules, they look like they were designed. Every scientist who studies these things has admitted as much. In fact, they have been overwhelmed by the sense of intricacy and design that they see. For example, Francis Crick, an atheist and famous scientist who discovered the shape of DNA along with James Watson, wrote, “Biologists must constantly keep in mind that what they see was not designed, but rather evolved’ (Francis Crick, What Mad Pursuit: A Personal View of Scientific Discovery [New York: Basic Books, 1988] 138). They have to close their eyes and scrunch up their teeth and say, “It was not designed; it was not designed; it was not designed’! Of course, the reason they have to try so hard is because the appearance of design is so overwhelming.

In fact, a man who is perhaps the foremost popularizer of Darwinian evolution in the world today is Richard Dawkins, professor of biology at the University of Oxford in England. His book, The Blind Watchmaker (New York: Norton, 1986), is a vigorous defense of Darwinian evolution. In it he tries to counter William Paley’s idea that if we stumbled across a watch we would know it was designed. Dawkins argues that natural selection, or evolution, is actually the blind watchmaker.

On the first page of the first chapter of that book, Dawkins writes: “Biology is the study of complicated things that give the appearance of having been designed for a purpose‘ (Dawkins, p. 1, italics added). That is what biology is-the study of these purposeful things. Dawkins agrees that life overwhelms us with a sense of design. Nevertheless, he also writes, “Natural selection is the blind watchmaker, blind because it does not see ahead, does not plan consequences, has no purpose in view. Yet the living results of natural selection overwhelmingly impress us with the appearance of design as if by a master watchmaker, impress us with the illusion of design and planning’ (Dawkins, p. 21, italics added).

Here again Dawkins is echoing the words of William Paley, the Anglican clergyman from the 1800s, who said about mechanical objects: “When we come to inspect the watch, we perceive . . . that its several parts are framed and put together for a purpose, e.g. that they are so formed and adjusted so as to produce motion, and that motion so regulated as to point out the hour of the day; . . . The inference we think is inevitable, that the watch must have had a maker’ (William Paley, Natural Theology, 1802, Ch. 1). So whenever we see something so fearfully and wonderfully made, we realize that it must have been designed.

The Molecular Basis of Life

This, then, is the progress of science in the past several thousand years. Hippocrates and Aristotle could only see the external, visible parts of biology. But as science and technology progressed, we have been able to go lower and lower, to the fundamental molecular basis of life. As we have done that, we have seen more and more intricacy and sophistication. It is not an exaggeration to say that the view of the cell which modern science has discovered is like the engine control room in a ship. That is a fairly good analogy for what we find in the cell. Such machinery is the foundation of life.

Every step along the way, science was expecting to find that life would resolve into simplicity the further down we got. But we have reached the basement of life, and we find that that is not the case.

In 1996 I wrote Darwin’s Black Box: The Biochemical Challenge to Evolution (New York: The Free Press), in which I argued that Richard Dawkins and others are wrong because Darwinian evolution cannot explain what we have found in the cell, and that those who believe in it are essentially making an assumption that does not agree with the facts.

Briefly, I said that the reason that Darwinian evolution can’t explain these things is because much of the machinery that we find in the cell is what we call “irreducibly complex,’ which means that it needs a number of different parts in order to work. An example of irreducible complexity that we are all familiar with is a mousetrap. A mousetrap has a number of different parts-a spring, a hammer, a holding bar-and it turns out it needs all these things to work. If you take away any of the components, the mousetrap is broken.

Darwinian evolution works by having something that is functional, and very slowly improving it by natural selection and random mutation. But if we wanted to build something like a mousetrap by many small steps, each of which was functional, how would we do it? It turns out to be very difficult to figure out. In fact, many people have tried, but so far have been unable to even say how we could gradually build something as simple as a mousetrap by a process akin to natural selection.

The Bacterial Flagellum

Yet consider the incredible complexity of the cell, even when viewed in a cartoon-like diagram of a basic biology textbook. It has little hair-like things called flagella. Would they be a problem to make? After all, they are just simple little things flowing off the cell. But if we look very closely at the business end of the bacterial flagella, we find an entirely different story.

The structure of the bacterial flagellum has been pieced together by biochemistry, looking at the molecular level of life rather than the level of life we can see through a microscope. The flagellum is literally an outboard motor that bacteria use to swim, just like an outboard motor on a boat. It is a rotary engine with a propeller that spins around and pushes against water and propels the bacterium forward. The propeller is attached to the drive shaft by the hook region, which acts as a universal joint. The drive shaft is attached to the motor, which uses a flow of acid from the outside to the inside to power the turning. The drive shaft has to poke up through the bacterial membrane, so there are proteins that act as bushing material to allow that to happen. There is a wonderful schematic drawing of the bacterial flagellum in a popular biochemistry textbook that is used in many colleges around the nation (Biochemistry, Voet & Voet, 1995). When we see it, we very quickly apprehend that, yes, this is indeed a machine, a real molecular machine. That might give us an intuition about how we need to go about explaining it.

Recognizing Design I wrote in Darwin’s Black Box that, if we look at such molecular machines, there is a much better explanation for where they came from than Darwinian evolution. We could say that they were purposely designed by an intelligent agent. Critics of mine have said, “That is a religious conclusion, not a scientific one.’ But I disagree. I think the conclusion of design is completely empirical; it is a scientific conclusion based solely on the physical structure of the object. In other words, we are deducing design from the physical structure.

But how do we conclude something is designed? What reasoning do we use? We can say many things, but I think a good example of how we conclude design is captured in one of Gary Larson’s The Far Side cartoons in which there is a troupe of jungle explorers in a line. The lead explorer has been strung up by a vine and skewered by two apposing three-pronged bamboo forks. And the third fellow in line turns to the fellow behind him and says, “That’s why I never walk in front.’

Now, everyone who looks at this cartoon will immediately realize that this event was not accidental but intended. In fact, the humor of the cartoon depends on us recognizing the design. Are we making a religious conclusion? Probably not. We can say this is designed because we see a number of different parts interacting with each other to produce a function that the parts by themselves could not produce. This is essentially what we mean by the term “irreducible complexity.’ Like the mousetrap, the jungle trap needs all of its components in order to work. When we see how the parts of a trap fit together to perform its intended function of killing someone, we can conclude that it was designed. That is how we conclude design-when we see a system with a number of parts that are fitted to each other to perform a function.

Reacting to Complexity

This, then, is where science has taken us. As Charles Singer said, “The infinite complexity of living things thus revealed was as philosophically disturbing as the ordered majesty of the astronomical world which Galileo had unveiled to the previous generation, though it took far longer for its implications to sink into men’s minds’ (Charles Singer, History of Biology).

Science has uncovered this unexpected and enormous complexity. What are we to think of all this? People have reacted in various ways. Richard Dawkins wrote, “The universe we observe has precisely the properties we should expect if there is at bottom no design, no purpose, no evil and no good, nothing but pointless indifference’ (Dawkins, as quoted in Easterbrook, G. Science and God: A Warming Trend? Science, 1997, vol. 277, p. 890-893).

But there is another, and I think much more reasonable, point of view. I am going to illustrate it with quotations from a small book written by Cardinal Joseph Ratzinger (now Pope Benedict XVI) in the 1980s. In this book, Cardinal Ratzinger addresses the question of evolution, writing, “Let us go directly to the question of evolution and its mechanisms. Microbiology and biochemistry have brought revolutionary insights here. . . . They have brought us to the awareness that an organism and a machine have many points in common. . . . Their functioning presupposes a precisely thought-through and therefore reasonable design’ (J. Ratzinger, In the Beginning: A Catholic Understanding of the Story of Creation and the Fall [Grand Rapids: Eerdmans, 1986] 54). He goes on to say, “It is the affair of the natural sciences to explain how the tree of life in particular continues to grow and how new branches shoot out from it. This is not a matter for faith. But we must have the audacity to say that the great projects of the living creation are not the products of chance and error. . . .[They] point to a creating Reason and show us a creating Intelligence, and they do so more luminously and radiantly today than ever before’ (Ratzinger, p.56-57).

Cardinal Ratzinger makes the following three points in that excerpt: First, contrary to Richard Dawkins’ conclusion, life shows signs of design and purpose. What is more, to support his argument, Ratzinger points to physical evidence, that is, to the great projects of the living creation, which point to a creating Reason. He does not point to philosophical or theological or Scriptural arguments, as important as those might be, but to physical evidence. There is physical evidence to support the contention that life is designed. His third point is that biochemistry, which studies the molecular foundation of life, gives us the most insight into life’s design. For my money, I would say that Ratzinger has much the better point than Dawkins.

Conclusion

In the end, let us go back to Psalm 139:14: “I will praise thee; for I am fearfully and wonderfully made: marvellous are thy works; and that my soul knoweth right well’ (KJV). When the psalmist was writing this, he had none of the knowledge that we have now. Yet, perhaps through the grace of special insight, he realized that life is indeed fearfully and wonderfully made, extraordinarily intricate, and indicative of the wisdom and power of the Master Designer.