EDITOR'S NOTE: The following is an excerpt from Intelligent Design Uncensored: An Easy-to-Understand Guide to the Controversy by William A. Dembski & Jonathan Witt. This chapter is written by John Mark Reynolds (IVP).
Chapter Three: The World's Smallest Rotary Engine
In chapter one the captain and pilot in our voyage into the cell argued over the tiny outboard motor called the bacterial flagellum. The characters were fictional, but they were rehashing a real scientific debate, one that has spilled onto the pages of the world's most prestigious science journals and into newspapers like the New York Times, Washington Post and USA Today. Let's consider exactly what the two sides are saying, boiling it down into everyday language.
The most prominent design theorist in the debate is Lehigh University biochemist Michael Behe, author of the bestselling Darwin's Black Box. His most visible opponent is Brown University biologist Kenneth Miller. Miller is coauthor of a high school biology textbook and perhaps intelligent design's most capable opponent. Some ID critics try to dismiss intelligent design simply by labeling it "religion" or "bad philosophy." Miller attempts this as well, but he deserves credit for also trying to address Behe's actual arguments.
Miller makes three main objections. He says Behe's case is based on what the scientific community doesn't know, whereas it should be based on what we do know. His second and closely related objection is that Behe improperly invokes God to explain scientific mysteries. Instead, Miller says, scientists should keep looking for a natural explanation. And finally Miller insists that the bacterial flagellum motor actually can be built up one small step at a time through random variations and natural selection.
Miller's arguments look good from a distance, but they fall apart on close inspection.
Miller Objection 1: A Gee-Whiz Argument
Miller claims that the problem with design theorists like Behe is a failure of the imagination. As he says, design theorists can't "imagine how evolutionary mechanisms might have produced a certain species, organ, or structure," so they dismiss the possibility. But Miller is mistaken. It isn't that design theorists can't imagine how those machines arose. Part of Behe's argument (and only part of it) is that no one has imagined how they might have arisen naturally, much less demonstrated an evolutionary scenario for them in the lab.
To really imagine something means to see it in rich detail. In this full sense of imagine, the Darwinists haven't imagined an evolutionary pathway for the bacterial flagellum motor, much less tested it in the lab and shown it to be sound. Theirs is a tale as vague as it is implausible.
Miller Objection 2: The God of the Gaps
Miller reminds us that science would never have gone anywhere if it had attributed every natural mystery to divine action. For instance, science might never have discovered the natural cause of lightning if it had gone on assuming these were bolts flung down by the gods. As primitive and superstitious as that attitude sounds, Miller says this is just the sort of god-of-the-gaps reasoning that modern design theorists use. He claims that we reason straight from the premise "Shucks, no one has figured out how the flagellum arose" to the conclusion, "Gee, a cosmic designer must've done it."
Miller is debating a straw man. What follows is the actual argument.
Certain biological systems have a feature called irreducible complexity. That's a fancy phrase for a simple idea. Think of a mousetrap. It needs all of its parts before it can so much as bruise a mouse. Intelligent agents (engineers) build irreducibly complex things all the time. In fact, any time we discover this sort of machine and can trace it back to its source, we always arrive at a mind or minds (Thomas Edison, Alexander Graham Bell, the Wright brothers). But we also find irreducible complexity in living things, and that's a problem for Darwinists. Darwinists don't have a clue how biological systems with this feature first arose (Miller disputes this, but we'll come back to that). In fact, humankind has no direct experience of any purely mindless cause ever producing a new kind of irreducibly complex system or device.
At this point, Darwinists insist that everyone must maintain faith in modern evolutionary theory, must go on looking for a way to make the evidence fit their model of mindless evolution. But there is another way to respond to the evidence, one that has deep roots in the history of scientific progress.
A geologist might try to explain where a layer of lava ash in someone's garden soil came from. An archaeologist might try to explain how that ancient and imposing structure on the Salisbury Plain of England, known as Stonehenge, came to be. An astronomer might try to figure out why the universe is expanding. Each of these researchers is doing what's called historical science. They are trying to identify causes in the distant past that we can't observe. If they can't observe the cause directly, what can they do? Charles Lyell, one of the founders of modern geology, said that historical scientists should seek to explain past events "by reference to causes now in operation." He meant that they should search for a type of cause, active in the present, with the demonstrated power to have caused the past event.
For example, what carved out the Royal Gorge in Colorado? Was it an earthquake that split the rock? Or did the Arkansas River carve it? Assembling all of the available evidence, geologists have concluded that only the second option, a river, has the demonstrated power to have caused the set of features that make up the Royal Gorge.
Keep in mind that when Lyell talked about "causes now in operation," he meant types of causes now in operation. Even if the Arkansas River had been dry since before the first Indians came to Colorado, geologists could still determine that one type of cause, erosion caused by flowing water, was the best explanation for the Royal Gorge. They wouldn't need to produce a particular flowing river right in front of our eyes in order to make their case that a river of some sort did it. They would just need to point to the telltale signs of river erosion and demonstrate that their explanation was better than the competing explanations.
Return now to machines like mousetraps that need all of their parts to work. What around us has the demonstrated power to produce these kinds of machines? We know of only one type of cause that produces such machines: intelligent design. Examples are all around us—mousetraps, motorcycle engines, the integrated circuits in computers. So what is the best explanation for the origin of biological systems with this same characteristic of irreducible complexity? Intelligent design. This is the positive evidence for intelligent design.
Despite Miller's claim to the contrary, intelligent design isn't an argument from ignorance but an argument based on our common knowledge. When we attribute intelligent design to complex biological machines that need all of their parts to work, we're doing what historical scientists do generally. Think of it as a three-step process: (1) locate a type of cause active in the present that routinely produces the thing in question; (2) make a thorough search to determine if it is the only known cause of this type of thing; and (3) if it is, offer it as the best explanation for the thing in question. Here the task is helped along by the fact that there is only one type of cause known to produce irreducibly complex machines—intelligent design.
Miller Objection 3: The Bacterial Flagellum Motor Isn't Irreducibly Complex
But Miller has a more direct objection to Behe's argument. Miller insists that the bacterial flagellum motor isn't irreducibly complex, and the Darwinian mechanism could have built it one small step at a time.3 To illustrate, he takes Behe's mousetrap illustration and turns it on its head, noting that three of the mousetrap's components could make for a dandy tie clip and two could work as a clipboard. This is how evolution arrived at a sophisticated rotary engine, Miller argues, by taking a series of biological machines from other systems on the way to the bacterial flagellum. Nature is a scavenger, he says, cobbling together parts from existing machines for new purposes.
But Miller has only illustrated the obvious: just about any complex machine we find contains parts that a good mechanic could use for some other purpose. It's why born mechanics hate to discard broken-down machinery. They never know when they might be able to scavenge a part from it for some new project. But notice who's doing the scavenging and the building. Not the parts. Not the grease. Not the garage or the wind whistling through the garage. No, it's the mechanic in the garage. What is the one thing in our experience that co-opts irreducibly complex machines and uses their parts to build a new and more intricate machine? Intelligent agents.
So Miller's illustration actually works against his own position. Mike Gene points out another flaw in Miller's logic:
What is interesting about this logic is that we already know that the mousetrap was intelligently designed. We also know that it did not first exist as a clipboard, then a tie clip. Thus, while it is logically possible to see the mousetrap as Miller does, that is, as a modified clipboard and tie clip, such perceptions are not tied to history nor the origin of the mousetrap. Thus, coming up with imaginary accounts . . . is rather meaningless. If we can successfully come up with such explanations where they are known to be false (the mousetrap), how do we know that our ability to do likewise with things like the flagellum are not also inherently flawed?
Worse, Miller's proposed evolutionary path to the flagellum is even sketchier than his mousetrap evolution scenario. Miller bases it on a microscopic syringe that pokes holes in passing cells, and then it squirts some nasty stuff in that hijacks their machinery.6 The technical name for this biological machine is the type III secretory system (or TTSS). Here we'll just refer to it as a microsyringe. About ten different proteins are needed to code this mean little machine, and each of these proteins is similar to proteins in the bacterial flagellum motor. Miller argues that nature could have selected this microsyringe as an ancestor on the evolutionary path to the flagellum, but his argument has big problems.
Imagine if all the protein parts just happened to be hanging around waiting to be assembled into a bacterial flagellum motor—not just the ten protein parts from the microsyringe but all forty necessary parts. Even if that unlikely event occurred, the parts would still have to come together just so. Each would have to be added to the emerging motor at just the right time and in just the right position in the way an automobile engine gets assembled. The car engine illustration is doubly helpful here because it gets us past thinking of the forty protein parts as akin to simple wooden blocks. In fact, they are far more intricate than many of the parts we find in a car engine. We may have all the parts on hand, but we still need some hands—one or more intelligent designers—to assemble them.
And this is only half the problem for Miller and his fellow design critics. Look at how a bacterial flagellum is assembled today. Sophisticated microscopes have revealed that the flagellum's cellular factory has an elaborate system of DNA instructions (the software) along with many protein machines to choreograph and build the sophisticated bacterial flagellum motor in just the right order for success. As researchers have noted, this tiny factory may itself be irreducibly complex.
The Darwinists need a credible evolutionary path to the bacterial flagellum and to the sophisticated factory that builds them. They don't have either.
At best, the microsyringe Miller points to represents one possible step in a Darwinian evolutionary path to the bacterial flagellum. But what's needed is a complete evolutionary path, not just one possible step along the way. To claim otherwise is like saying we can travel by foot from Los Angeles to the Philippine Islands because we've discovered the Hawaiian Islands in between. Evolutionary biology needs to do better than that.
There's another problem with Miller's scenario, and it's a big one. The best current evidence in biology suggests that the microsyringe appeared after the bacterial flagellum motor and not the other way around. That means the microsyringe doesn't provide even an isolated step in the supposed evolution of the motor. There's more. The motor doesn't even help explain the Darwinian evolution of the simpler syringe. After all, the syringe is much simpler than the bacterial flagellum motor. It contains about ten proteins similar to proteins in the motor. The motor requires an additional thirty or more proteins, which are unique. Darwinian evolution is trying to explain how complex life forms arose from simpler ones, beginning with a single-celled organism. But if the syringe developed from the motor, then all the Darwinists have done is explain the simpler in terms of the more complex.
Evolutionist Theodosius Dobzhansky once said, "Nothing in biology makes sense except in the light of evolution." In fact, Darwin's theory offers no insight into how the bacterial flagellum motor arose. If Darwinists had even an inkling how such systems arose by blind processes, Miller would not—more than a decade after the publication of Behe's Darwin's Black Box—still be lamely gesturing at a microsyringe, holding it up as a possible evolutionary ancestor to the bacterial flagellum. Instead, he would simply provide a detailed explanation of how a system like the bacterial flagellum motor arose by Darwinian means.
And it isn't as if the Darwinists haven't tried to find an evolutionary pathway for the bacterial flagellum. They've made a long, concerted effort to imagine a detailed, credible evolutionary pathway to this motor. Despite such efforts, their most detailed evolutionary stories remain hopelessly vague, and the few parts of the story that aren't vague are riddled with serious problems.
Darwinist Logic Meets the Mona Lisa
We've just waded through a bit of heavy scientific back-and-forth. So now for something completely different. Consider the grassy likeness of the Mona Lisa in figure 3.1.
Is it the product of design or blind evolution? Science writer Casey Luskin, tongue-planted-firmly-in-cheek, offers the following analysis:
Before you infer intelligent design, keep in mind that grass-cutting shears share an extremely high similarity with scissors which are used to cut paper. Since a paper stencil was apparently used in the origination of the grass-pattern, it's likely that a pair of scissors was used to cut the stencil. This makes it plausible to assume that the grass-cutting shears were co-opted from scissors, because both are clearly homologous structures based upon their similarity. Moreover, paper is made of plant material, and grass is a plant. This could account for the origin of the stencil itself. Finally, Virginia has metal resources which could account for the origin of the original scissors. Don't use a science-stopping explanation and infer design! We're "on our way" to figuring this out, so don't threaten the progress of science, medicine, and all of civilization by saying this was designed! You might as well reject round earth "theory" and the Periodic Table!
The Clue That Isn't
If you enjoyed the grassy Mona Lisa illustration, consider another one on the whimsical end of the spectrum. A couple of kids are stargazing on the sidewalk in front of their houses. After a few minutes, the boy announces to the girl that one day he will climb to Jupiter because he's sure there's a natural ladder stretching from Earth to Jupiter. The girl points out that nobody on Earth has ever found such a ladder. She further notes that there are other good reasons to conclude it doesn't exist—the constantly changing distance between the planets, the sun occasionally coming between them and so forth. The boy shakes his head. "You say that nobody has found the ladder," he explains patiently. "What you have to understand is that's an argument from ignorance. Absence of evidence isn't evidence of absence. Scientists are finding all sorts of new things in our solar system all the time. Think about the asteroid belt out past Mars. That's one step along the way to Jupiter. You see, the evidence is gradually falling into place."
The girl would have every right at this point to roll her eyes. The boy's argument doesn't hold water in part because absence of evidence often is evidence of absence, especially when the absence comes after a long, broad and painstaking search of a limited area by many qualified investigators. In a classic Sherlock Holmes detective story, Silver Blaze, Holmes realizes that the key to the mystery is not the presence of something but the absence of it: nobody heard the guard dog bark. Similarly, in the case of the bacterial flagellum motor, an important clue to its origin is the absence of something after a long, assiduous search by numerous well-trained, highly motivated evolutionists—a detailed Darwinian pathway from simple ancestor to complex motor.
Is that absence meaningless? There are two ways to respond: (1) "Absence of evidence isn't evidence of absence! An unguided evolutionary pathway surely exists. Therefore, scientists eventually will discover it"; or (2) "Biologists should continue studying the bacterial flagellum motor to better understand its marvelous inner workings. But a growing body of evidence suggests that there simply is no unguided evolutionary pathway to the flagellum." The first answer illogically assumes the very question at issue. The second answer is reasonable since it follows the evidence. Nor must it stand alone. After noting that absence of evidence often does work effectively as evidence of absence, our fictional girl provided additional reasons for doubting the boy's ladder to Jupiter. Similarly, design theorists go beyond noting an absence of evidence for a Darwinian path to the flagellum motor. We also point to a common human experience. In the world around us, we encounter many complex machines that need all of their parts in order to work. Every time we can trace these machines back to their sources, we find intelligent agents. To borrow the language of the great geologist Charles Lyell, our "uniform" experience points to only one type of cause "now in operation" with the power to create new forms of such machines. The bacterial flagellum motor is a complex machine of this sort. Therefore, we have a positive reason to view intelligent design as the best explanation for its origin. Put simply, all of the available evidence suggests that this is how such machines get assembled—through intelligent design.
An Irreducible Pickle
The bacterial flagellum isn't an isolated problem for the Darwinists either. The scientific literature shows a complete absence of concrete, detailed proposals for how mindless evolution could have built complex biological machines that need all of their parts to work. One of the world's leading cell biologists, Franklin Harold, opposes inferences to intelligent design. He nevertheless concedes that "there are presently no detailed Darwinian accounts of the evolution of any biochemical or cellular system, only a variety of wishful speculations."
When one of us challenged Kenneth Miller with this quotation at the World Skeptics Conference, Miller didn't challenge the substance of Harold's claim. He just asserted that Harold had been retired a number of years. He was implying that Harold was old and out of touch with current biological thinking and therefore could be ignored. But if Harold is so out of touch, what were the science editors at Oxford University Press thinking when they agreed to publish his recent book The Way of the Cell? Oxford is one of the most respected academic publishers in the world. And if Harold made the assertion out of ignorance, why didn't Miller just point to a detailed evolutionary pathway to a complex biological system to prove Harold wrong? It appears Miller didn't because none existed.
Darwinists like to claim that there is no debate over Darwinism and intelligent design within the scientific community. The reality is quite the opposite. Not only is there a debate but design theorists have the evidence on their side.
Taken from Intelligent Design Uncensored: An Easy-to-Understand Guide to the Controversy by William A. Dembski and Jonathan Witt. Copyright(c) 2010 by Williams A. Dembski and Jonathan Witt. Used by permission of InterVarsity Press PO Box 1400 Downers Grove, IL 60515. www.ivpress.com.