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Title: Natural selection
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Answers In Genesis
URL Source: http://www.answersingenesis.org/home/area/cfol/ch2-selection.asp
Published: Jun 29, 2006
Author: Dr. Gary Parker
Post Date: 2006-06-29 20:56:49 by A K A Stone
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Views: 1109
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Chapter 2: Darwin and biologic change
In spite of its revolutionary philosophic impact, Darwin’s concept of natural selection is quite easy to understand (and to misunderstand). It was based on observations of artificial selection, the results of selective breeding by farmers and animal fanciers. Darwin, for example, referred to all the different breeds of pigeons that had been produced by artificial selection. The ordinary one in Fig. 11 is the wild rock pigeon, the one you often find around city statues and country barns. But all the other birds pictured are just pigeons, too: the fan tail, the one with the neck pouch, etc. All these birds can be bred from the wild rock pigeon, and crossing among the different varieties can lead right back to the wild rock pigeon. Everyone knows, of course, about the results of selective breeding with dogs, cats, cattle, roses, and so on. Figure 11
Figure 11. By artificial selection, all the “fancy” varieties of pigeons above have been bred from the common wild rock pigeon, and they can be bred back to the wild rock pigeon (just as special varieties of dogs and cats can be bred from and to the “mongrel” types). Darwin used artificial selection, selective breeding by man, as a model for natural selection, survival of the fittest selected by nature in the struggle for life. But does natural selection lead to evolution, or point back to the Biblical concept of a corrupted creation?
Darwin’s argument certainly seems logical. Is there any evidence that Darwin was right? Can nature select as well as man? Answer: there is considerable evidence that Darwin was indeed correct about natural selection.
Perhaps the best example of Darwinian selection is the one that’s in all the biology textbooks: the peppered moths. Take a look first at the top photo in Fig. 12, which represents a camera close-up of tree bark with some moths on it. How many moths do you see? One is easy to see, and most people see two. (Some claim to see three, but I’ve never found the third!) At least we can agree that one moth stands out and one is camouflaged. Presumably that’s the way birds saw it, too, back in the 1850’s. The darker moth stood out, but the lighter one was camouflaged against the mottled gray lichen that encrusted the trees back then. As a result, birds ate mostly dark moths and light moths made up over 98% of the population. Figure 12
Figure 12. “Evolution going on today”: that’s what many people believe, and what I once taught, about the peppered moth. Because of a change in the color of their background, the light moths so common in 1850 (well-camouflaged in the top photo) lost out in the struggle for life to the more “fit” variety (camouflaged by the dark background in the bottom photo). By 1950, most of the moths were the dark (melanic) variety. Can you accept that as “proof of evolution,” or do you wonder if there are boundary conditions that limit the amount of change natural selection can produce?
When I was an evolutionist, sometimes an unsuspecting student (often a “religious type”!) would approach me and say, “Look, if evolution is true, why don’t we see it going on today?” And I would say, “Evolution going on today? Glad you brought that up! It just so happens that we have a perfect example of evolution in action.” Then I would launch into the peppered-moth story. Those moths are the showcase for evolution. Over twenty years after they first became famous, they were chosen, for example, as the frontispiece for Lewontin’s article on adaptation in the Scientific American book Evolution.
Well, the peppered moths do seem to provide strong evidence of natural selection. But is that evidence of evolution? Notice, I’ve changed the question. That’s a key point. First, I asked if there was any evidence that Darwin was correct about natural selection. The answer quite simply is, “Yes, there is.” But now I’m asking a radically different question, “Is there any evidence for evolution?” Many people say, “Isn’t that the same question? Aren’t natural selection and evolution the same thing?” Answer: no, absolutely not!
When someone asks if I believe in evolution, I’ll often say, “Why, yes, no, no, yes, no.” The answer really depends on what the person means by evolution. In one sense, evolution means “change.” Do I believe in change? Yes, indeed—I’ve got some in my pocket! But change isn’t the real question, of course. Change is just as much a part of the creation model as the evolution model. The question is, what kind of change do we see: change only within kind (creation), or change also from one kind to others (evolution)?
Take a look again at the peppered-moth example (Fig. 12). What did we start with? Dark and light varieties of the peppered moth, species Biston betularia. After 100 years of natural selection, what did we end up with? Dark and light varieties of the peppered moth, species Biston betularia. All that changed was the percentage of moths in the two categories: that is, just variation within kind. (For details, see the master’s thesis by one of my students, Chris Osborne.3)
According to the Biblical framework of history, struggle and death began when man’s rebellion ruined God’s perfect creation. Natural selection is just one of the processes that operates in our present corrupted world to insure that the created kinds can indeed spread throughout the earth in all its ecologic and geographic variety (often, nowadays, in spite of human pollution).
As a matter of fact, 24 years before Darwin’s Origin, a scientist named Edward Blyth published the concept of natural selection in the Biblical context of corrupted creation. He saw it as a process that adapted varieties of the created kinds to changing environments after sin brought death into God’s world. A book reviewer once asked, rather naively, if creationists could accept the concept of natural selection. The answer is, “Of course. We thought of it first.”
But if natural selection is such a profound idea, and Blyth published it before Darwin, then why isn’t Blyth’s name a household word? Perhaps because he was a creationist. It was not the scientific applications of natural selection that attracted attention in 1859; it was its presumed philosophic and religious implications.
Evolutionists were not content to treat natural selection as simply an observable ecological process. Darwin himself was a cautious scientist, painstaking in his work. But others, especially T. H. Huxley and Herbert Spencer, insisted on making natural selection the touchstone of a new religion, a “religion without revelation,” as Julian Huxley later called it. For them, as for many others, the real significance of the Darwinian revolution was religious and philosophic, not scientific. These early evolutionists were basically anti-creationists who wanted to explain design without a Designer.
But in spite of what might be claimed, natural selection has been observed to produce only variation within kind, merely shifts in populations, for example, of moths to greater percentages of darker moths, of flies resistant to DDT, or of bacteria resistant to antibiotics. But evolution means more than change from moth to moth, fly to fly, or bacterium to bacterium. Any real evolution, “mega- or macro-” evolution, means change from one kind to another: “Fish to Philosopher,” as the title of Homer Smith’s book puts it, or “Molecules to Man,” the subtitle of the government-funded BSCS “blue-version” high-school biology textbook.
Still, I must admit that there is a potential connection between observed natural selection within kind and hypothetical evolution from one kind to another. That connection is called “extrapolation,” following a trend to its logical conclusion. Scientists extrapolate from population records, for example, to predict changes in the world population. If world population growth continues at the rate observed in the ‘60’s, statisticians said, then the world population by 2000 A.D. would be over 6 billion. Similarly, if natural selection continues over very long periods of time, evolutionists say, the same process that changes moths from mostly light to mostly dark forms will gradually change fish to philosophers or molecules to man.
Now there’s nothing wrong with extrapolation in principle. But there are things to watch for in practice. For example, simple extrapolation would suggest a population of a “zillion” by 3000 A.D. But, of course, there will come a point when the earth is simply not big enough to support any more people. In other words, there are limits, or boundary conditions, to logical extrapolation.
Consider my jogging (or should I say “slogging”) times. Starting years ago at an embarrassing 12 minutes per mile, I knocked a minute off each week: a mile in 11 minutes, then 10, 9, 8, 7, 6, 5, 4, 3, 2, 1. Wait a minute! As you well know, I reached my limit long before the one-minute mile! (Just where, I’ll keep secret!) This is an embarrassing example, but it makes an important point: no scientist would consider extrapolation without also considering the logical limits or boundary conditions of that extrapolation.
Evolutionists are aware of the problem. In their classic textbook, Evolution, the late Theodosius Dobzhansky4 and three other famous evolutionists distinguish between SUBspeciation and TRANSspeciation. “Sub” is essentially variation within species, and “trans” is change from one species to another. The authors state their belief that one can “extrapolate” from variation within species to evolution between species. But they also admit that some of their fellow evolutionists believe that such extrapolation goes beyond all logical limits, like my running a one-minute mile.
What does the evidence suggest? Can evolution from “molecules to man” be extrapolated from selection among dark and light moths? Or are there boundary conditions and logical limits to the amount of change that time, chance, and natural selection can produce?
The answer seems to be: “Natural selection, yes. Evolution, no.” As it turns out, there are several factors that sharply limit the amount of change that can be produced by time, chance, and Darwinian natural selection. (For exquisite detail on The Natural Limits to Biological Change, see Lester and Bohlin.5)
Perhaps the biggest problem for evolutionists is “the marvelous fit of organisms to their environment.” As I mentioned in the first chapter, many adaptations involve whole groups of traits working together, and none of the individual pieces has any survival value (“Darwinian fitness”) until the whole set is functioning together. Remember the woodpecker? Let’s look at another example.
Since death entered the world, there are many large, predatory fish that roam the oceans. But as they feed on smaller fish and shrimp, their mouths begin to accumulate food debris and parasites. Lacking recourse to a toothbrush, how is such a fish going to clean its teeth?
For several kinds of fish, the answer is a visit to the local cleaning station. These are special areas usually marked by the presence of certain shrimp and small, brightly colored fish, such as wrasses and gobis. Often, fresh from chasing and eating other small fish and shrimp, a predatory fish may swim over to take its place in line (literally!) at the nearest cleaning station. When its turn comes, it opens its mouth wide, baring the vicious-looking teeth.
You might suspect, of course, that such a sight would frighten off the little cleaner fish and shrimp. But no, into the jaws of death swim the little cleaners. Now even a friendly dog will sometimes snap at you if you try to pick off a tick, and it probably irritates the big fish to have a shrimp crawling around on its tongue and little fish picking parasites off the soft tissues of the mouth. (Try to imagine shrimp crawling around on your tongue!) But the big fish just hovers there, allowing the cleaners to do their work. It even holds its gill chambers open so that the shrimp can crawl around on the gill filaments picking off parasites!
At the end of all this cleaning, the second “miracle” occurs. You might think the fish would respond, “Ah, clean teeth; SNAP, free meal!” But, no. When the cleaning is done, the big fish lets the little cleaner fish and shrimp back out. Then the big fish swims off—and begins hunting again for little fish and shrimp to eat!
The fantastic relationship just described is called cleaning symbiosis. Perhaps you have seen cleaner fish in a major public aquarium, or seen pictures of their behavior in television footage or nature magazines. Cleaning symbiosis is a well-known example of mutualism, an intimate relationship of benefit to both types of species involved, in this case, the “cleaner and the cleanee.”
Obviously, cleaning symbiosis has survival value for both types of species involved. But does survival value explain the origin of this special relationship? Of course not. It makes sense to talk about survival value only after a trait or relationship is already in existence. Question: did the survival value of this cleaning relationship result from time, chance and struggle, or from plan, purpose, and special acts of creation?
The major problem is using Darwinian fitness to explain traits with many interdependent parts when none of the separate parts has any survival value. There’s certainly no survival value in a small fish swimming into a large fish’s mouth on the hope that the big fish has somehow evolved the desire to let it back out! Sea creatures don’t provide the only examples of cleaning symbiosis, either. A bird, the Egyptian plover, can walk right into the open mouth of a Nile crocodile—and walk back out again, after cleaning the croc’s mouth!
The situation is even more dangerous for the famous “bombardier beetle.” The bombardier is an ordinary-looking beetle, but it has an ingenious chemical defense mechanism. Imagine: here comes a mean ol’ beetle-eater, a toad, creeping up behind the seemingly unsuspecting beetle. Just as he gets ready to flash out that long, sticky tongue, the beetle swings its cannon around, and “boom!” It blasts the toad in the face with hot noxious gases at the boiling point of water, and coats the toad’s tongue with a foul-tasting residue. Now that doesn’t actually kill the toad, but it surely kills its taste for beetles! Pictures show the toad dragging its tongue across the sand trying to get rid of the foul taste.
Successful firing of the bombardier beetle’s cannon requires two chemicals (hydrogen peroxide and hydroquinones), enzymes, pressure tanks, and a whole series of nerve and muscle attachments for aim and control. Try to imagine all those parts accumulating by time, chance, and natural selection. One crucial mistake, of course, and “boom!” the would-be bombardier beetle blows itself up, and there’s surely no evolutionary future in that! Trial and error can lead to improvement only if you survive the error!
Creationists and evolutionists agree that adaptations such as the woodpecker’s skull, cleaning symbiosis, and the bombardier beetle’s cannon all have survival value. The question is, how did they get that way: by time, chance, and the struggle for survival, or by plan, purpose, and special acts of creation? When it comes to adaptations that require several traits all depending on one another, the more logical inference from the evidence seems to be creation. Figure 13
Figure 13-A. Darwin said that, “To suppose the eye … could have been formed by natural selection seems, I freely confess, absurd in the highest degree.” He included other structures requiring many interdependent parts in a chapter titled “Difficulties With the Theory.”
Figure 13-B. Before it can have any survival value, every part of a bombardier beetle’s “cannon” must be in place, and the same is true for the woodpecker’s set of “drilling tools” and the “nerve wiring” for cleaner-fish behavior. Evolutionist Lewontin says such “perfection of structure was,” and I say is, “the chief evidence of a Supreme Designer.”
To suppose that the eye, [with so many parts all working together] … could have been formed by natural selection, seems, I freely confess, absurd in the highest degree.
“Absurd in the highest degree.” That’s Darwin’s own opinion of using natural selection to explain the origin of traits that depend on many parts working together.
Modern evolutionists continue to recognize these “difficulties with the theory” of evolution. Harvard’s Stephen Gould6 writes, for example, “What good is half a jaw or half a wing?” Gould also recognizes that many people (especially artists employed by museums and textbook publishers) have tried to present a hypothetical series of gradual changes from one kind to others. So he adds, “These tales, in the ‘Just-So Stories’ tradition of evolutionary natural history, do not prove anything. … Concepts salvaged only by facile speculation do not appeal much to me.” Even though Gould is an evolutionist, he recognizes that the classic textbook concept of gradual evolution rests on made-up stories and “facile speculation,” and not on facts.
In another article, Gould7 points out that the perfection of complex structures has always been one of the strongest evidences of creation. After all, he says, “perfection need not have a history,” no trial-and-error development over time from chance trait combinations and selection. So, Gould continues, evidence for evolution must be sought in “oddities and imperfections” that clearly show the effects of time and chance.
But creationists recognize imperfection, too. The Bible clearly indicates that “time and chance and struggle” have indeed corrupted what God originally had created in perfection. Imperfection, then, is not the issue; perfection is. And evolutionists from Darwin to Lewontin and Gould admit that “perfection of structure” has always been “the chief evidence of a Supreme Designer.”
Darwin’s theory also points us back to creative acts when it comes to the origin of traits. In spite of the title of his book, Origin of Species, the one thing Darwin never really dealt with was the origin of species. That is, he never explained the origin of the truly new traits needed to produce a truly new kind of organism, something more than just a variation of some existing kind. There are many other logical limits to extrapolation from natural selection to evolution, but the simplest is this: natural selection cannot explain the origin of traits. Figure 14
Figure 14. “Darwin’s Finches.” Darwin explained the location of finches with different beak types on the Galapagos Islands the same way a creationist would, by starting with a population of finches with variation in beak type. In fact, the creationist Edward Blyth published the concept of natural selection 24 years before Darwin did, and he used it to help explain how created kinds spread throughout different environments after sin brought struggle and death to the earth.
Natural selection works well: it helps us explain how and where traits survive—if we have adapted or adaptable traits to start with. In his article on “Adaptation” in the Scientific American book Evolution, Lewontin8 emphasizes this point over and over again:
… evolution cannot be described as a process of adaptation because all organisms are already adapted …
… adaptation leads to natural selection, natural selection does not necessarily lead to greater adaptation… .
That is, adaptation has to come first, before natural selection can act. Natural selection obviously cannot explain the origin of traits or adaptations if the traits have to be there first.
Lewontin recognizes that this simple (but crucial) point is often overlooked, so he gives an example. As a region becomes drier, he says, plants can respond by developing a deeper root system or a thicker cuticle (waxy coating) on the leaves, but “only if their gene pool contains genetic variation for root length or cuticle thickness.” (Emphasis added.) Here again, the genes for deep roots and thick, waxy coats must be present among the genes of a kind before natural selection can select them. And if the genes are already there, we are talking only about variation within kind: i.e., creation, not evolution. As creationists were saying even before Darwin’s time, natural selection does not explain the origin of species or traits, but only their preservation.
Lewontin is an evolutionist and outspoken anti-creationist, but he honestly recognizes the same limitations of natural selection that creation scientists do:
… natural selection operates essentially to enable the organisms to maintain their state of adaptation rather than to improve it. (Emphasis added.)
Natural selection does not lead to continual improvement (evolution); it only helps to maintain features that organisms already have (creation). Lewontin also notes that extinct species seem to have been just as fit to survive as modern ones, so he adds:
… natural selection over the long run does not seem to improve a species’ chances of survival, but simply enables it to ‘track,’ or keep up with, the constantly changing environment. (added.)
It seems to me that natural selection works only because each kind was created with sufficient variety to multiply and fill the earth in all its ecologic and geographic variety. Without realizing it at the time, Darwin actually discovered important evidence pointing both to God’s creation (the variation) and to the corruption of creation (struggle and death). References
3. Osborne, Chris D., A Reevaluation of the Engilish Peppered Moth’s Use as an Example of Evolution in Progress, Master’s Thesis, Institute for Creation Research, Santee, CA, 1985. Return to text. 4. Dobzhansky, Theodosius, F. Ayala, L. Stebbins, and J. Valentine, Evolution, W. H. Freeman and Co., San Francisco, 1977. Return to text. 5. Lester, Lane, and Ray Bohlin, The Natural Limits to Biological Change, Zondervan, Grand Rapids, 1984. Return to text. 6. Gould, Stephen Jay, The Return of Hopeful Monsters, Natural History, June/July 1977. Return to text. 7. Gould, Stephen Jay, Of Turtles, Vets, Elephants, and Castles, New Scientist, January 11, 1979. Return to text. 8. Lewontin, Richard C., Adaptation, Scientific American (and Scientific American book Evolution), September 1978. Return to text.
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“So,” Darwin said, in effect, “we see what artificial selection by man can do. I believe selection can also happen in nature. After all, there is a constant ‘struggle for survival’ because of population growth and limited resources, and certainly each kind can produce many varieties. Therefore, there will be ‘survival of the fittest,’ or natural selection, of those varieties of a population that fit best into their environments. Given enough generations [time] and the right trait combinations [chance], organisms that seem designed for their environment will simply result from natural selection [natural processes].” Apparent design in nature was not the result of creation, Darwin was saying, but of time, chance, and natural processes.
But then pollution killed the lichen on the trees, revealing the dark color of the bark. As a result, the dark moths were more camouflaged than the light ones. The moths themselves didn’t change; there were always dark moths and always light moths from the earliest observations. But the environment changed, and so the dark ones were better camouflaged. Thus, the dark ones had a better chance of surviving and leaving more offspring to grow into dark moths in succeeding generations. Sure enough, just as Darwin would have predicted, the population shifted. The “dark environment” just naturally selected the dark moths as more likely to survive and reproduce. By the 1950’s the population was over 98% dark, proof positive of “evolution going on today.” At least, that’s the way it’s stated in many biology books, and that’s what I used to tell my biology students.
Darwin himself was acutely aware of this evidence of creation and the problem it posed for his theory. His chapter in Origin of Species on adaptations was not titled “Evidence for the Theory” but “Difficulties With the Theory.” In it, he discussed traits that depend on separately meaningless parts. Consider the human eye with the different features required to focus at different distances, to accommodate different amounts of light, and to correct for the “rainbow effect.” Regarding the origin of the eye, Darwin wrote these words:
Take the famous example of “Darwin’s finches” (Fig. 14). On the Galapagos Islands about 600 miles (nearly 1000 km) west of Ecuador, Darwin observed a variety of finches, some with small beaks for catching insects, others with large beaks for crushing seeds, and one with the ability to use spines to pry insects from their tunnels. How did Darwin explain the “origin” of these various finches? Exactly the same way a creationist would. He saw finches with variation in beak type on the South American mainland and presumed these finches might have reached the islands on a vegetation mat or something similar. The ones with seed-crushing beaks survived where seeds were the major food source, and those with insect-catching beaks out-reproduced others where insects were the major source of food. Given finches with a variety of beak types, then, natural selection helps us to explain how and where different varieties survived as they multiplied and filled the earth. That, of course, is just what a creationist would say—except, that a Biblical creationist would add that the “struggle and death” part of migration did not begin until man’s rebellion ruined the world God had created without death. (Contrast Genesis 1–2 with the Fall in Genesis 3.)
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Ever since Darwin first published his theory of evolution, his defenders' favorite tactic against critics has been to attack their character and intelligence. Darwin himself used it against some of the greatest scientists of his day, accusing them of superstition and religious bias. Now that Darwinism rules the scientific roost, such charges against dissenters are widespread. Not even schoolchildren are immune. Indeed, California's science education guidelines instructs teachers to tell dissenting students, "I understand that you may have personal reservations about accepting this scientific evidence, but it is scientific knowledge about which there is no reasonable doubt among scientists in this field. . ." By today's rules, criticism of Darwinism is simply unscientific. The student who wishes to pursue such matters is told to "discuss the question further with his or her family and clergy." But is Darwinism so obviously true that no honest person could doubt it? Are alternatives like "intelligent design" so unscientific that no reasonable person could embrace them? The answer to both questions is a resounding no. Elegant . . . But Wrong The essence of Darwin's theory is that all living creatures descended from a single anscestor. All the plants, animals, and other organisms that exist today are products of random mutation and natural selection—or survival of the fittest. According to Darwin, nature acts like a breeder, carefully scrutinizing every organism. As useful new traits appear, they are preserved and passed on to the next generation. Harmful traits are eliminated. Although each individual change is relatively small, these changes eventually accumulate until organisms develop new limbs, organs, or other parts. Given enough time, organisms may change so radically that they bear almost no resemblance to their original ancsestor. Most importantly, all this happens without any purposeful input—no Creator, no Intelligent Designer. In Darwin's view, chance and nature are all you need. This all sounds very elegant and plausible. Problem is, it's never been supported by any convincing data. For example, consider the fossil evidence. If Darwinism were true, the fossil evidence should show lots of gradual change, with one species slowly grading into the next. In fact, it should be hard to tell where one species ends and another begins. But that's not what we find. As Darwin himself pointed out in his book, The Origin of Species: . . .[T]he number of intermediate varieties, which have formerly existed on the earth, [must] be truly enormous. Why then is not every geological formation and every stratum full of such intermediate links? Geology assuredly does not reveal any such finely graded organic chain; and this, perhaps, is the most obvious and gravest objection which can be urged against my theory. Darwin, of course, attributed this problem to the imperfection of the fossil evidence, and the youthful state of paleontology. As the discipline matured, and as scientists found more fossils, the gaps would slowly start to fill. But time has not been kind to Darwinism. Paleontologists have certainly found more fossils, but these fossils have only deepened the problem. As the fossils piled up, what paleontologists discovered was not gradual change, but stability and sudden appearance. It seems that most fossil species appear all at once, fully formed, and change very little throughout their stay in the fossil evidence. This poses quite a challenge for Darwinist paleontologists. One such paleontologist, Niles Eldredge, put it this way: Either you stick to conventional theory despite the rather poor fit of the fossils, or you focus on the [data] and say that [evolution through large leaps] looks like a reasonable model of the evolutionary process—in which case you must embrace a set of rather dubious biological propositions. Large jumps are anathema to good Darwinists because they look too much like miracles. You just can't have, say, reptiles giving birth to birds. Things get particularly bad with the Cambrian explosion, which paleontologists believe took place about 530 million years ago. In an instant of geological time, almost every animal phylum seemed to just pop into existence from nowhere. To understand just how big an "explosion" this was, it might help to understand what a phylum is. A phylum (phyla for plural) is the broadest classification of animals there is. As opposed to a single species, like a chimpanzee, a miller moth, or a crow, a phylum takes in a wide variety of organisms. The phylum that contains humans also contains elephants, squirrels, canaries, lizards, guppies, and frogs. Indeed, it contains every animal with a backbone— and then some. If the differences within a phylum are vast, the differences between phyla are really wild. As much as a chimpanzee may differ from a fish, it differs even more radically from a sea urchin or a worm. In fact, you could say it's built on an entirely different architectural theme. That's why the Cambrian Explosion is so troubling for Darwinists. What paleontologists find isn't just the sudden appearance of a few new species. What they find is the appearance of species so utterly distinct they have to be placed in completely different phyla. Even Oxford zoologist and arch-Darwist Richard Dawkins has remarked, "It is as though they were just planted there, without any evolutionary history." Worse yet, after the Cambrian Explosion, almost no new phyla appear in the fossil record—and many go extinct. By conventional dating, that's a 500 million year dry spell. This is exactly the opposite of what Darwin would have predicted. According to Darwinism, new phyla are produced by the gradual divergence of species. As species split off from each other, they eventually become so dissimilar as to constitute a whole new body plan. Over time, then, we should see new species slowly appearing, followed by the much slower appearance of new phyla—what Havard paleontologist Stephen Jay Gould calls a "cone of increasing diversity." Instead, the cone is upside down. Even by conventional timelines, the fossils look very non-Darwinian. Darwinists express confidence, of course, that future discoveries will clear up the mysteries. But so far, the research has only deepened them. A recent reassessment of the fossils has added perhaps 15 to 20 new phyla to the Cambrian zoo. Moreover, discoveries in 1992 and 1993 have shrunk the explosion's estimated duration from 40 million years to less than 10 million. Science or Philosophy? The fossil problem is just one of Darwinism's woes. Virtually every other area of research poses problems, too. But like the bunny in the Energizer battery commercials, Darwin's theory just keeps going. Why? Because Darwinism is perhaps more a matter of wishful thinking than fact. Professor Phillip Johnson is a professor of law at the University of California at Berkeley. While on sabbatical in England several years ago, he became fascinated with the serious problems in Darwin's theory. He was also struck by how Darwinists continually evaded these difficulties with tricky rhetoric and pulpit pounding. As he dug deeper into the scientific literature, he eventually became convinced that Darwinism wasn't so much a scientific theory as a grand philosophy—a philosophy whose goal is to explain the world in strictly naturalistic terms. "The whole point of Darwinism is to explain the world in a way that excludes any role for a Creator," says Johnson. "What is being sold in the name of science is a completely naturalistic understanding of reality." According to Johnson, the reason Darwinism won't die is that its basic premise is simply taken for granted: namely, that chance and the laws of nature can account for everything we see around us. Even living things. Once that assumption is made, Darwinism has to be true, because nothing else will work. Creation has been ruled out from the start, and the other naturalistic theories are even worse than Darwin's. So the argument that Darwinism is wrong can't even be heard. Design as Science If scientists are wrong about Darwinism, are they also wrong about the notion of intelligent design? Might not the notion of design be worthy of a second look? A new breed of young Evangelical scholars thinks the anwer to both questions is yes. They are arguing persuasively that design is not only scientific, but is also the most reasonable explanation for the origin of living things. And they're gaining a hearing. One such scholar is Stephen Meyer, a graduate of Cambridge University in the philosophy of science and now a professor at Whitworth College in Spokane, Wash. Like Johnson, Meyer believes that the prohibition of design has essentially stacked the deck in favor of Darwinism. "There's been a kind of intellectual rigidity imposed on the origins discussion," says Meyer. "It's only possible to talk about origins in a naturalistic vein, because people believe that the rules of science prohibit talking about intelligent design." But Meyer says this prohibition rests on a flawed view of science—one now rejected by many philosophers and historians of science. The basis for this rejection is an attempt to distinguish science from other forms of reasoning. Scientists and philosophers who hold this view employ certain criteria that allegedly set science apart from other disciplines, such as theology, history, or literary criticism. For example, someone might say that a scientific theory must explain everything in terms of observable objects and events, or that it must make predictions, or that it must capable of being proven wrong. These criteria are called demarcation standards. Although scientists and philosophers have proposed many demarcation standards, says Meyer, none of them do what evolutionists want them to—which is to exclude intelligent design as a scientific theory. "When applied even-handedly, demarcation standards either confirm that design is scientific, or they exclude evolution, too," says Meyer. For example, Darwinists like to argue that design is unscientific because it appeals to unobservable objects or events, such as a Creator. But Darwinism also appeals to unobservables. "In evolutionary science you have all kinds of unobservables," says Meyer. "The transitional life forms that occupy the branching-points on Darwin's tree of life have never been observed in the rock record. They've been postulated only because they help Darwinists explain the variety of life forms we observe today." When scientists are trying to reconstruct past events, appealing to unobservables is entirely legitimate, says Meyer. What's illegitimate is to say that design theorists can't do the same thing. Indeed, the concept of design is regularly used by scientists and non- scientists alike. William Dembski, another Evangelical scholar, is director of the Center for Interdisciplinary Studies at Princeton University. He holds a Ph.D. in mathematics from the University of Chicago and another in philosophy from the Chicago campus of the University of Illinois. He has also been a National Science Foundation doctoral and postoctoral fellow. Dembski argues that intelligent design, far from being a strange and exotic notion, is something we encounter and recognize every day. Dembski points to entire industries whose very existence depends on being able to distinguish accident from design: including insurance fraud investigation, the criminal justice system, cryptography, patent and copyright investigation, and many others. We do not call these industries "unscientific" simply because they look for evidence of design. Indeed, whole scientific disciplines could not exist without the notion of intelligent design. Anthropology and archaeology are two such disciplines. "How could we ever distinguish a random piece of stone from an arrowhead except by appealing to the purposes of primitive artisans?" says Dembski. According to Dembski, we recognize design in events or objects that are too improbable to happen by chance. Stones don't turn into arrowheads by natural erosion. Writing doesn't appear in sand by the action of waves. A fair coin doesn't come up heads a hundred times in a row. These things only happen when intelligence is allowed to determine the outcome. On the other hand, there's more to design than low probabilities. For instance, if you toss a coin a hundred times, any string of results will be extremely improbable. (If you don't believe that, try getting exactly the same string of results twice.) Still, if someone told us they flipped a penny a hundred times and got results like the following, we'd probably believe them: On the other hand, says Dembski, "Suppose this person comes to you and says, 'Would you believe it? I just flipped this penny 100 times, and it came up heads each time.' You would be ill-advised to believe that this person is telling the truth." So what's the difference between the first set of results and the second? If you look at just the probabilities, there's no difference at all. Yet the second sequence makes us suspicious, while the first one does not. We would also be suspicious if the tosses came up all tails, or if the first 50 tosses were heads and the next 50 were tails—or if the same sequence came up two times in a row. Thus, it's not just the low probability that makes us raise our eyebrows. It's also the kind of sequence we get. "Our coin-flipping friend who claims to have flipped 100 heads in a row is in the same boat as a lottery manager whose relatives all win the jackpot or an election commissioner whose own political party repeatedly gets the first ballot line," says Dembski. "In each instance public opinion rightly draws a design inference and regards them guilty of fraud." If detectives can use this kind of thinking to spot election and lottery fraud, if archaeologists can use it to spot arrowheads, why can't biologists use it to look for design in the living world? Currently, Dembski, Meyer, and Paul Nelson, a biologist and Ph.D. candidate in philosophy at the University of Chicago, are writing a book that details precise scientific criteria for recognizing design, and applies them to biological systems. Irreducible Complexity Even without precise definitions, however, it's not hard for most of us to recognize design in the living world. The exquisite complexity of living organisms virtually proclaims the existence of a Creator. In fact, many Darwinists admit this—except they say it's only an illusion, produced by strictly natural forces. For Michael Behe, a Catholic biochemist at Lehigh University in Bethlehem, Pa., this complexity is just too extreme for Darwinism to be plausible. He argues that many systems in living organisms are irreducibly complex. They consist of several parts, all of which must be present for the system to work. "It's like a mousetrap," says Behe. "A standard household mousetrap has about five parts, all of which must be present for the trap to work. If you take away any of those five parts, you don't have a functioning mousetrap. You can add the parts one by one, but until you get to the full 5 parts, you have no function. It's an all or nothing kind of thing." This irreducible complexity exists even at the level of a single cell. "It was originally thought in Darwin's day that cells were very, very simple things—like little blobs of gel," says Behe. But as science has progressed, it's shown that cells are extraordinarily complex, more complex than anybody thought." One example is the system that transports proteins within the cell from where they're made to where they're used. As it turns out, the cells that make up most organisms have several compartments. For the most part, proteins and other molecules don't just float around loose in the cell, but must be moved from place to place to place. Enzymes are a class of protein that helps the cell digest other kinds of proteins. They are created in a compartment called the endoplasmic reticulum. But they do all their work in another compartment, called the lysosome. In order to get from the one compartment to the other, they have to be stuffed into a kind of bus (actually, a vesicle). The "bus" then travels to the destination compartment and eventually merges with it, spilling its contents into the compartment. Achieving this task requires several very specific proteins. You need certain proteins (along with certain fats) just to form the little capsule that contains the enzyme. You need others to help the capsule grab onto just the right protein, since the endoplasmic reticulum creates all sorts of proteins at the same time. Finally you need proteins that help the "bus" attach itself to the destination compartment and merge with it. "Now if you think about irreducible complexity," says Behe, "virtually all of these proteins have to be there from the beginning, or you simply don't get any function." That makes it tough for Darwinists to argue that design is simply an illusion produced by mutation and natural selection. "Darwin said one thing pretty strongly in the Origin of Species. He said that if it could be shown that any system or organ could not be produced by many small steps, continuously improving the system at each step, then his system would absolutely fall apart. "Now the thing about irreducibly complex systems is that they cannot be produced by numerous small steps, because one does not acquire the function until close to the end, or at the end. Therefore, with irreducibly complex systems, they cannot be produced by Darwinian evolution." So maybe design is not an illusion after all. Maybe it's the way things really are. Gaining Ground Of course, most scientists are far from throwing in the towel on Darwinism or accepting design. Nevertheless, it's getting easier to gain a hearing. In March 1992, a landmark symposium took place at Southern Methodist University in Dallas. At that meeting, Phillip Johnson, Stephen Meyer, William Dembski, Michael Behe, and other Christian scholars squared off against several prominent Darwinists. The topic of debate was "Darwinism: Science or Philosophy?" The proceedings of the meeting have since been published in a book by the same title. (See accompanying "resources" sidebar.) The remarkable thing about the meeting was the collegial spirit that prevailed. Creationists and evolutionists met as equals to discuss serious intellectual questions. Of course, few issues were resolved. But in today's climate, where dissent is frequently written off as religious bias, just getting the issues on the table was an accomplishment in itself. What's more, several months after the debate, one prominent Darwinist who participated in the symposium publicly conceded that one of the points Johnson made at the meeting was correct: namely that Darwinism is ultimately based as much on philosophical assumptions as on scientific evidence. This admission, which took place at a national meeting of country's largest science society, the American Association for the Advancement of Science, scandalized the Darwinist community, which likes to portray evolution as an indisputable fact. It was all the more scandalous because the speaker had specifically been invited to the meeting to denounce Johnson. So things are slowly beginning to change. Creationists are still far from winning, but things are getting better. As Johnson points out, creationist arguments are getting more sophisticated, while most Darwinists are still responding with cliches. Thus, it's now the creationists who come across as asking the hard questions, and demanding fair debate. But ultimately, says Johnson, it's not the debates or the arguments that will win the day. "It's reality that's doing it. It's just the way the world is. And sooner or later, scientists will have to acknowledge that fact."
Schoolin Since Birth
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