Revolutionary Worker #1220, November 23, 2003, posted at rwor.org
In the last 10 years or so there has been an important shift going on in the creationist world. The standard and more traditional old-school "scientific creationists," centered around the ICR (Institute for Creation Research) and people like Duane Gish are still doing their thing: they still try to get people confused about whether or not evolution is really a proven fact; they still argue that divine creation is a legitimate "alternative theory" to evolution and should be given "equal time" in the science classrooms; they still try to take over local school boards and change textbooks and state laws setting criteria for science education; they still launch courtroom challenges to try to get the government to order public school science teachers to teach a set of religious beliefs (so-called "creation-science") in clear violation of the constitutional separation of church and state, etc. But while this is all still going on, these Biblical literalist promoters of so-called "creation- science" (the ones who insist that every word in the Biblical story of Genesis is literally true) have been increasingly discredited in recent years, especially as scientists from all fields of science have increasingly stepped forward to expose and denounce so-called "creation-science" as pseudoscience (phony science) and to explain, over and over again, why the scientific evidence for evolution is rock solid, how the methods of the Creationists are not at all scientific and how they are promoting not science but religion.
Although the Biblical literalist Creationists who were trying to get "creation science" taught in the public school science classrooms were very active throughout the 1980s and 1990s and made some gains, they also suffered some significant setbacks, especially in the wake of their defeats in a number of the more high-profile court cases during those years. For instance, in a very important case in 1982 known as McLean et al. vs. Arkansas Board of Education , many prominent scientists from a number of different fields of science (including a number of Nobel Prize winners and some well-known evolutionists such as Stephen Jay Gould and Francisco Ayala) got together to explain to the court why evolution is such a well-established fact of science and once again to make the case that there is absolutely nothing scientific about so-called creation science. In addition to the testimony from the scientific community, a number of religious scholars and philosophers of science also joined in to further explain the differences between science and religion and to make clear why so-called "creation science" does not belong in the science classroom. The result was a setback for the creationists. Then in the 1987 Louisiana case known as Edwards vs Aguillard,the Supreme Court ruled that it would be unconstitutional to order that "creation science" be taught in science classrooms alongside the science of evolution (a law the Creationists had managed to get the state of Louisiana to adopt) because this would require that students be taught a particular religious belief in state-run schools (including the belief that a supernatural power created human beings) and this would clearly be unconstitutional. Despite all these setbacks, the traditional Biblical literalist Creationists are far from down and out, and to this day they are spreading a lot of confusion at the grassroots level, where they continue to try to get local school boards and legislatures to force teachers to teach anti-science creationism and have had some success in getting some school textbook publishers to insert little evolution "disclaimers" into high school biology textbooks, encouraging kids to think that evolution is not a settled question and to keep their minds open (!) to (obviously religious) alternative theories.
The Creationists are not satisfied with the successes they have had (taking advantage of many people's ignorance and gullibility) at the local and state levels. They want to impose the teaching of their religious dogma on the country as a whole. And to be successful at doing that --especially in the wake of those high profile courtroom losses and widespread denunciations of Creationism by an increasingly outraged scientific community-- they need a new strategy: they need to find some new arguments to get over with a general public which has become a bit more aware and suspicious of the anti- scientific nature of their "creation science" claptrap in recent years; and they also need a revamped legal strategy if they hope to get U.S. courts to give a green light to the forcible teaching of a religious viewpoint and agenda in the public schools.
The Intelligent Design Creationists are increasingly in the forefront of trying to undermine the science of evolution and smuggle faith-based theories of life into the high school science classrooms. And they are even making some beginning inroads into some college campuses! These new Creationists are much more slick than their Biblical literalist brethren and they therefore have the potential to create a great deal more confusion and harm, including among people who are relatively well educated.
Philip Johnson, a Berkeley professor of law, is generally recognized as the leading ideologue of their movement. A believer in divine creation, Johnson knows enough about the law and the U.S. Constitution to realize that the legal strategy of the so-called "scientific creationists" of the '80s and '90s (who promoted the Biblical creation story as literal truth) is unlikely to succeed in changing the laws at the national level. So he is revamping the terms of the creationist argument: no more talk about the Bible, Genesis, Adam and Eve, Noah, or the idea that God made everything in six days. This kind of talk makes it too easy for the theory of divine creation to be barred from the classrooms on the basis that it is teaching a specific religious viewpoint (duh). Johnson realizes that the Biblical literalist Creationists centered around things like the Institute for Creation Research (ICR) have been hurting the creationist cause by coming off too much like fanatically irrational religious dogmatists.
What to do? Well, why not make it look like it's the other way around? Yeah, that's it... make it look like it's the evolutionists who are stubbornly close-minded and dogmatic and that they have turned the science of evolution, and "scientific naturalism" in general, into what amounts to a new state religion ! And then make it look like your breed of new Intelligent Design Creationists are by contrast much more open-minded and reasonable people, who are pretty much open to any possibilities, but who simply "feel" that evolution is far from proven, and that in addition there are good and rational reasons to think that it is more likely that a divine power created biological life. You can do this, Johnson basically argues, without explicitly promoting the Biblical story of Genesis, and if you handle it that way you'll have a much better chance of being able to convince Congress and the Supreme Court that it would be "viewpoint discrimination" (and therefore unconstitutional) to keep the "alternative" scientific theory of Intelligent Design out of science classrooms or any other public venue.
In fact, as we will show, Intelligent Design is just as lacking in scientific basis as all those older versions of "scientific creationism." It can however be more confusing (and to a broader variety of people) for the following reasons:
The more traditional old-style Biblical Creationism has often been promoted by relatively unsophisticated people who more often than not end up coming off like irrational zealots and who are obviously deeply ignorant of even the most basic scientific principles and practices. But the Intelligent Design people are generally a mild-mannered bunch that includes a number of highly educated scholars and college professors. Some of them even have multiple graduate degrees in fields such as law, philosophy, mathematics, engineering and even a few have degrees in biochemistry and molecular biology. And while they generally do admit to believing in a supernatural higher power and divine creation as a matter of religious background and ongoing faith, they also insist that they are the ones who are being truly scientific, because, unlike the evolutionists, their minds are supposedly not clouded by the institutionalized secular prejudices of modern American science. Philip Johnson in particular strenuously argues that secular science (science which seeks to understand the natural mechanisms of natural processes without reference to any supernatural power) needs to be replaced with a theistic science --a method of doing science which would actively incorporate the idea that God exists into the scientific process itself! With this broader philosophical broadside, the Intelligent Design Creationists aligned with Philip Johnson show themselves to be even more profoundly radical (in a reactionary sense) than the old-school proponents of so-called "creation science" who falsely argue that they have "scientific evidence" that evolution is wrong, but who don't go so far as to make the case that a belief in god has to guide how science is done.
But not many people realize the full scope of what some of the Intelligent Design Creationists are trying to do. They "debate" evolutionists in polite academic exchanges, they often sound like they know something about science, and in general they try very hard not to come off like irrational religious nuts. In fact, most of the proponents of Intelligent Design hate even being called "Creationists," precisely because they don't want to be confused with the kind of crude Bible- thumping Creationism that insists that every single word in the Bible has to be taken absolutely literally. (In general the IDCs claim to value the Bible mainly as a religious moral and ethical guidebook of sorts, and many of them would agree that much of it should only be taken as metaphor.) So the IDCs do not pretend to believe, for instance, that God created all life in just six 24-hour days and only a few thousand years ago; they also don't literally believe in the story of Adam and Eve or in the story of Noah and the Great Flood. Most would readily agree that it is completely ridiculous to imagine that all the millions of species we see on earth today are the direct descendants of however many breeding pairs of animals Noah might have been able to pack into a single boat. The IDCs are, after all, educated people, and they understand full well that human beings wrote down these Biblical stories some 2,000 (or more) years ago in an attempt to make some sense of what they didn't yet understand.
But, despite this, there is absolutely no doubt that the people who put forward "Intelligent Design Theory" are, in fact , Creationists, whether they like to be labeled that way or not: Like all other varieties of Creationists, the proponents of Intelligent Design believe that it is impossible to account for all the features of life on this planet simply by the workings of completely unconscious natural evolutionary processes, spread out over millions and billions of years. They think that, one way or another, a supernatural higher power had to be involved.
For one thing, while most IDCs would admit that they cannot definitively prove it, they have convinced themselves that life is just "too complex" to be accounted for simply through such natural processes as evolution. Therefore, they reason, the only possible alternative is that some higher force, some kind of "intelligent designer"-- one who remains by definition completely undetectable in the natural world and who is by definition not subject to merely natural laws and limitations --must have been involved in making life into what it is today, at least at some point in the process. If that's not a religious viewpoint, I don't know what is.
Intelligent Design Theory is actually not new. In fact, the so-called "argument from design" is a very old argument--for instance, in England at the beginning of the 19th century, the Reverend William Paley famously argued that only a divine designer could have brought into being something as complex as a human eye. Charles Darwin himself was very aware of such arguments, which were popular throughout the 19th century. In The Origin of Species Darwin paid a lot of attention to explaining how, given enough time , complex features of living things (including something like the human eye) could in fact have been brought into being and shaped by nothing more than the simple and entirely natural mechanism of natural selection. Modern evolutionary biologists today know Darwin was in fact correct, and can trace and map out the likely series of step-wise evolutionary modifications involved in something like the evolution of mammalian eyes in much greater detail than Darwin could ever have imagined. But, even back in the 1860s, Darwin had grasped the basics, which is a lot more than can be said about the modern-day Intelligent Design people who are resurrecting William Paley's tired old argument.
At the same time, today's IDCs are finding some new ways to "modernize" the Creationist "argument from design": Not only do these IDCs seem perfectly willing to cut their losses and accept that the Bible is not the literal Word of God (this of course infuriates the old-style Biblical literalist Creationists who accuse them of "selling out" the Bible) but they generally also go even further, and accept the fact that lifeforms on this planet have undergone some amount of biological evolution, and even that some amount of biological evolution continues to occur (this, of course, also lands them in trouble with some of the more traditional anti-evolution Creationists, with whom they'd still like to maintain some kind of united front on basic religious grounds).1
These modern-day IDCs don't all speak with a single unified voice, but in general their opposition to the theory of evolution could be summarized as follows:
The Intelligent Design people (and in particular their head ideologue Philip Johnson) basically argue that modern scientists have fallen into a fundamental error by adopting the methods of " scientific naturalism " through which science traditionally seeks to understand natural phenomena by investigating exclusively natural processes (the only kind of processes that can be investigated!). They say that modern scientists are wrong not to make room for an operating assumption that an overarching supernatural force could be overseeing and guiding these natural processes and the universe as a whole. "Scientific naturalism," which concerns itself only with natural phenomena, is how all modern science is actually done, and it is how all modern scientific advances are actually accomplished. Despite this, IDCs like Johnson insist the modern scientific community is prejudiced and closed-minded for not allowing for God and building this possibility right into the scientific process itself. But most scientists (even the ones who are religious) will tell you that if scientists abandoned the secular methods of science and attempted instead to investigate the workings of the material natural world under the guidance of an outlook and method which takes as its fundamental point of departure the idea that there exists a supernatural realm (which, by definition, is not subject to the laws of change and development of the material world and which cannot itself be investigated or verified), this would end up completely destroying the scientific process and would cause modern scientific advances and the overall development of human knowledge to grind to a halt!
I will discuss some of these philosophical issues more a bit later on.
The IDCs go on to claim that any scientist who frees his or her mind of the supposed prejudice of "scientific naturalism" and is willing to be "open" to the idea of God will come to realize that there is actual evidence in the world around us that life was designed by a higher power, a conscious intelligence. Today the Intelligent Design claims that attempt to masquerade as science seem to center on William Dembski's idea of a "design filter" (also known as the "design inference") and, even more so, biochemist Michael Behe's argument about "irreducible complexity" in natural systems.
To briefly summarize these two pseudo-"scientific" arguments:
William Dembski, a mathematician and philosopher associated with Intelligent Design's Discovery Institute, argues that people should simply apply a "design filter" to any feature or phenomenon in nature and then ask themselves a series of questions: first, can you explain this feature through our existing understanding of natural laws and processes? If not, then can you explain it as just a random chance event, the occasional chance departure from the regular laws of nature? If the answer to that is also no, then, says Dembski, you really have no choice but to conclude that what you are looking at is something that had to have been designed by some form of conscious intelligence.
This reasoning just doesn't hold up. For one thing, just because we might not yet understand all the steps involved in some natural process doesn't mean that we won't later come to understand them (our knowledge of natural processes--including natural evolutionary processes--is continually expanding).
Second of all, as has been stressed many times in this series, evolution is not "just a chance process." Many of the well-known and well-demonstrated mechanisms which generate evolutionary change (natural selection in particular) are not random (or "chance") processes: while chance processes (such as randomly occurring genetic mutations) are involved in producing the genetic variation that is found in all living populations of plants or animals and which serves as the raw material of evolutionary change, the ways in which natural selection then "sorts out" this genetic variation over many generations take place in very tight relation to different particular environments and so this part of the evolutionary process is very much not random.
Again, while a new feature may at first appear in a population through "just a chance process" (such as a mutation or "copying error" in the DNA), natural selection will spread it to more and more individuals over the next generations only if it provides individuals who have that new feature with some kind of "reproductive advantage" (if it helps them in some way to produce more offspring, which in turn produce more descendants, and so on). But whether a new feature does or does not provide individuals with such a reproductive edge is not a "chance" occurrence--it very much depends on the specifics of an organism's environment and how the organisms are interacting with the physical features of that environment as well as with other individuals in its own and other living species. Depending on the particular circumstances, a new feature might provide a reproductive edge and be "favored" by natural selection or it might not. That's why this part of the process cannot be described as "chance."
Dembski (and creationists in general) never seem to really understand that evolutionists do not claim that natural evolution is "just an accidental chance process." Evolutionists simply claim that evolution is a basic property of all of life; that it occurs over the generations in any reproducing population of genetically variable individuals through a combination of randomly generated changes in inheritable material and highly selective (non-random) processes such as natural selection; that at any given point the changes that can occur are limited and channeled by the history of past evolutionary changes, but future evolutionary change is never "bound" to proceed in any predetermined or predestined directions; and that evolutionary change will in any case proceed automatically and on its own, without any outside "intelligence" needing to be involved.
So Dembski's so-called "design filter" turns out to be completely useless: a particular feature or process of the natural world could easily a) not yet be fully explainable through our current understanding of natural processes, and b) not be explainable as only chance processes, without this in any way constituting evidence that we will never be able to better understand the natural evolutionary processes involved, including how they have been shaped by significant non-random components. And Dembski's "design filter" certainly doesn't provide a shred of evidence, or any logical reason to conclude, that some kind of conscious intelligence had to have been involved.
Michael Behe is a biochemist (at Lehigh University) whose particular interest has to do with the kinds of biological processes that happen at the molecular level, inside of cells. Behe is the kind of Creationist who does not reject all of Darwinian evolutionary theory--he is willing to accept, for instance, the evidence of the kind of smaller scale evolutionary changes which are continually taking place over the generations in living populations of any plant or animal species on the basis of a certain amount of natural sorting out of naturally occurring genetic mutations and recombinations. But he nevertheless has a problem with the theory of evolution down at the level he is personally most familiar with--the level of molecules at the sub-cellular level. He is frankly amazed by the multi-part complexity of some of the molecular systems which function inside of cells to produce such things as, for instance, the chain of biochemical reactions which allow the flagellum (tail) of a sperm cell to move, or the cascade (chain reaction) of coordinated chemical steps which all have to work together in just the right ways for blood to be able to clot. He argues that these kinds of highly complex molecular systems could not have been shaped merely by natural evolutionary processes (which, like Dembski, he also incorrectly refers to as "chance" processes--more on this later); therefore, he concludes, the very fact that such complexity even exists is itself concrete "evidence" of "intelligent design"- -i.e., that some kind of conscious intelligence (basically a divine supernatural power) must have stepped in at some point to bring such complex processes into being.
Behe and other IDCs have extended this reasoning even further, arguing that some biological systems can be described as "irreducibly complex." They define a multi-part biological system as "irreducibly complex" if it appears it would collapse and stop being functional if it were missing even just one of its interlocking parts. Using examples from his field of biochemistry, Behe points to a number of systems (in this case biochemical reactions) which would in fact be unable to perform their current functions if they were missing even one of their components. He then declares that he considers this proof of design by some kind of conscious intelligence (in other words, god). Why? Why would it necessarily be the case that, if a particular biochemical system can't perform its particular (current) function unless it has all its parts up and running, this is automatically proof of "intelligent design"? Because, argues Behe, natural biological evolution couldn't possibly have brought all those necessary parts into being (and into such complex coordinated functioning) all at once , in one fell swoop. Even if this were true, say the evolutionists, we know that natural evolution is perfectly capable of bringing complex systems into being through a step-by-step process spread out over a very long period of time, rather than all at once. But Behe simply doesn't believe evolution could have built up complex biochemical processes one step at a time. Why not? Because, argues Behe, a system still missing some of its parts would be non-functional (and even likely to collapse) and so it could never provide organisms with a reproductive advantage and therefore natural selection would never favor such piecemeal evolutionary development and allow such incomplete and non-functional systems to spread over the generations.
But as we will see, the only reason Behe and his fellow IDCs can't understand how relatively simple and well-known evolutionary processes could have brought such genuinely complex features and processes into being without any supernatural powers having to be involved is that a) they don't actually understand how evolution works, and b) they don't even understand the nature of biological complexity very well. But, since Michael Behe is one of the most influential of the current crop of Intelligent Design Creationists, and since the fact that he is a trained biochemist is probably enough to mislead some people into thinking that he must know what he's talking about, it is worthwhile examining, and refuting, his arguments in some detail.
Behe's influence does not stem from any major new discoveries in his field, but from the simple fact that, as a trained biochemist, he can obviously speak in knowledgeable terms about the intricacies of some of the molecular processes which take place inside of cells. Behe really adds nothing new to the old argument about "complexity"--he has simply shifted the focus to the sub-cellular level. The problem with Behe is that he may know a lot about how different kinds of molecules are organized and how they interact in various ways to perform complex functions (such as the clotting of blood, for instance) but he really doesn't know much about evolution. He knows his biochemical parts and processes well enough, but he doesn't actually understand the mechanisms whereby evolution can build new parts and processes out of pre-existing genetic variation. He even has some significant misconceptions about some of the most basic aspects of the theory of evolution: for instance, he refers to evolution as just a "chance" process when just about any basic biology textbook will explain that evolutionary change occurs through random (chance) events which alter the genetic variation available in a reproductive population (through such things as random mutations, genetic recombinations, genetic drift, etc.) combined with non-random selective mechanisms (such as natural selection) which, over the generations, serves to "sort out" evolutionary modifications, differentially spreading those that give organisms a reproductive advantage in relation to a particular environment (so this part of the process is very much not random ). Like Dembski and most (or perhaps all) Creationists, Behe just doesn't seem to "get" that natural selection in particular is the furthest thing from a random chance event.2
It is important to understand that no biologist would disagree that the sub-cellular molecular systems Michael Behe discusses are, in fact, complex --but any trained evolutionary biologist will tell you that natural evolutionary mechanisms are perfectly capable of generating plenty of complexity, at any level of organization, and that there is absolutely no valid reason to suppose that the observed complexity of molecular systems functioning inside of cells came about through anything other than those by now well- known and purely natural evolutionary processes, without a "Designer" of any sort having to be involved.
Behe may be able to put fancy chemical formulas up on a blackboard, but that's basically all smoke and mirrors. His methods really aren't all that different from those of the crudest Biblical literalist Creationists: through either gross ignorance of basic evolutionary principles, or because he turns a blind eye to anything that runs counter to his preconceived notions about supernatural involvement, Behe first of all distorts and misrepresents what most biologists know about how evolution actually works; and then he also makes the standard methodological error common to all types of Creationists: unable to "imagine" how some of the wonders of the natural world can have been brought into being without god, he turns around and tries to impose his preconceived notion of a "conscious intelligent designer" on reality, looking specifically for features or processes of life that have not yet been fully described or understood in complete detail, and then basically acting as if what is not yet completely understood (by him or by scientists in general) is automatic proof of god's involvement in the matter.
If this sounds familiar it should: it's basically no different than the reasoning of the more old- fashioned Biblical literalist Creationists who try to discredit evolution by pointing to some "gaps" in the fossil record (or "gaps" in human understanding more generally), only to turn their attention to something else that has not yet been found or understood as soon as those particular "holes" get filled by the advances and development of science.
But let's look a bit more closely at Behe's specific arguments.3
In his book Darwin's Black Box and in his various presentations, Behe often likes to start off by making the point that: " for the Darwinian theory of evolution to be true, it has to account for the molecular structure of life. " This is in fact very true, and any evolutionary biologist will readily agree with this. But then Behe goes on to say that the "purpose" of the book he has written is " to show that it does not ."
This is a bold claim, but the reality is that Behe has ultimately failed in his mission: the examples of complex sub-cellular biochemical systems he claims represent "evidence" of Design are nothing of the sort, and there is nothing which legitimately would cause one to think that they can't be accounted for by standard principles and mechanisms of evolution.
Let's look at this a bit:
Behe's basic argument is that evolution may account for the features of life at every other level of organization, but not at the sub-cellular molecular level. Unlike the Young Earth Creationists, for instance, Behe is at least willing to acknowledge that the universe is billions of years old, and even that living species are biologically related to each other through lines of common descent. "I find the idea of common descent (that all organisms share a common ancestor) fairly convincing," Behe writes, "and have no particular reason to doubt it."
According to the biochemist and evolutionist Ken Miller, who has personally debated Michael Behe on a number of occasions, Behe even goes so far as to say that he has absolutely no problem with the idea that humans and apes shared a common ancestor . (OK, now he's really distanced himself from the Biblical literalist breeds of Creationists!) But if Behe accepts so much of the concrete evidence of evolution and common descent, then what is it about the theory of evolution that Michael Behe doesn't agree with? Well, it seems that it's only the complex biochemical systems operating inside cells which he thinks are evidence of divine design--he simply doesn't believe they could have come about simply through the known mechanisms of entirely natural biological evolution.
As a biochemist, Behe knows many of these systems well.
Actually part of his problem seems to stem from his being too narrowly focused on just his particular patch of the biological universe (sub-cellular biochemical reactions) and not reflecting enough on how "complex biological systems" also exist at all the other levels of organization of matter, including the ones for which he makes no explicit claims of "design."
So Behe highlights some of the complex molecular systems that make up the internal working machinery of living cells--such as systems through which cells manufacture enzymes, antibodies, blood clotting agents and so on, through a multitude of chemical "steps"--and then he basically says: "Look, these systems are just too complex! Natural biological evolution can't possibly have brought them into being!" He just can't imagine how evolution could have produced such complex multi-part reactions all on its own. Therefore, argues Behe, we just have no choice but to conclude that some kind of "conscious intelligent designer" (might as well say god) must have designed these molecular systems to be just the way we see them today.
But just because Behe personally "can't imagine" how evolution could have produced these systems doesn't mean he's found evidence of design (some evolutionists aptly and humorously describe this type of argument as the "argument from incredulity"!)
As a kind of sidepoint, I have to say that I think it's fine for Behe to be impressed and even "amazed" by the wonderfully integrated intricacies of the multi-part biochemical reactions he is examining--and I suspect that even after biologists finish deciphering every essential aspect of these processes, most of us will still find these well-oiled sub-cellular machineries duly amazing! But just because something is "amazing" (and we don't yet understand exactly everything about them or about how they came to be the way they are) doesn't mean that we should jump to conclusions about how a supernatural power must have been involved. Throughout human history and to this very day people claim to have witnessed a "miracle" when they observe something they can't yet fully explain or place in a proper context in light of ordinary experience. For instance, because they didn't know any better, people also used to think lightning strikes were miraculous and signs from the gods (and some people probably still do), but that didn't make it so.
You start realizing that Michael Behe actually doesn't understand a lot about evolutionary processes as soon as he gets into his explanation of how he supposes a "conscious intelligent designer" might have designed those complex biochemical reactions. He proposes that the designer may have taken the first living cells some four billion years ago, and packed them right at the start with all the necessary molecular information which, over time, would turn out to be needed to produce all the complex biochemical systems we can see in different kinds of living cells today. This is preposterous, and it is really bad science! In fact it is so bad that I doubt very much that other biologists would ever even bother to respond to Behe's silly arguments if it weren't for the fact that he has been built up as something of a poster-boy for the larger Intelligent Design movement.
How could it be possible for all of the molecular information needed for all the "later" complex biochemical processes--the ones operating in organisms that even Behe admits had not even evolved until hundreds of millions of years after the first appearance of life--to already have been contained in the very first living cells (the ones that didn't even use these processes), billions of years ago? Behe says he can't prove it of course, but he speculates that a lot of " preformed " genetic information (which would not be called into action for hundreds of millions of years) must have been kept dormant thanks to the control of a regulatory gene (the kind of biochemical "on-off switch" that we find in many sub-cellular systems today) that Behe imagines must have remained "turned off" for hundreds of millions of years.
Again, this is really, really bad science! Of course we know that there are regulatory genes in today's living cells which sometimes keep certain molecular functions temporarily "turned off." But it is completely ridiculous to suggest that genes coding for all the sub-cellular molecular functions which "later" appeared could have already been present in a dormant ("turned off") state in the very first living cells and then been passed on from generation to generation, completely intact and unchanging , for hundreds of millions or billions of years. As Ken Miller justly points out, Behe's vision is "an absolutely hopeless genetic fantasy of `preformed' genes waiting for the organisms that might need them to appear gradually"!
For one thing, any geneticist will be quick to point out that "turned off" genes would never have remained unchanged over hundreds of millions of years--all sorts of random mutations ("copying mistakes") would have accumulated and eventually changed the basic genetic instructions as these "turned off genes" passed from generation to generation over all that time. This would be true of any collection of genes. But, in addition, it has been shown in the lab that genes that are in fact "turned off" (inactive) generally tend to accumulate mutations over time at an even greater rate than currently active genes.If you think about it, this actually makes sense in light of evolutionary theory: for one thing, natural selection has no way to sort out, or weed out, genetic changes that occur in dormant systems that aren't yet having any functional effects on living organisms, since such changes would provide organisms with neither reproductive advantages or disadvantages-- therefore, in non-active genes that are "turned off," there isn't much that can happen to prevent or restrict the accumulation over time of genetic mutations. This explains why inactive genes seem to change even faster than active genes.
In short, even if some supernatural "intelligent designer" had somehow packed the first cells nearly four billion years ago with all the chemical instructions which would ever be needed, and then simply "allowed" natural evolution to take place for the next hundreds of millions of years (which seems to be Behe's view) there's simply no way the genetic information needed for those later molecular systems (such as the mammalian blood clotting mechanism) would have remained unchanged and in its original state all that time. And yet it is the way complex molecular systems are structured today inside living cells that Behe claims is "evidence" of the initial "intelligent design" which supposedly occurred billions of years ago. There is therefore an enormous logical inconsistency in Behe's basic argument, and it is one for which he has no answers.
But leaving aside for now the total nonsense of Behe's idea that life somehow started off with simple cells designed by a supernatural power to contain preformed instructions for all later cellular functions, let's look at what's wrong with Behe's most fundamental argument: the idea that if a biological system is extremely complex it cannot have been brought into being by the known mechanisms of evolution.
This is simply not true. Again, all biologists would agree that many biological systems can in fact be described as highly "complex," whether you're looking inside of cells or at any other levels of organization, such as are represented by complex body parts, entire organisms, whole populations of organisms, or even larger-scale ecological communities. Something is "complex" when it has many interacting and interdependent parts or components (and many biologists and others will tell you that they find that much of the beauty and wonder of life resides in the great diversity of life, itself a form of complexity.) And one could even think of living cells as complex little "ecosystems" of biochemical molecules involved in all sorts of complex interactions. For instance, it is a fact that it takes many different distinct chemical "steps" for cells to do things like metabolize (process) energy sources, reproduce their genetic machinery, produce defensive mechanisms, repair themselves, interact with other cells to perform complex functions such as blood clotting, etc., etc. But to say that a system is "complex" really only means that it is "not simple"--that it has many (rather than only a few) different "parts," working together in some kind of larger integrated process. Complexity is not in and of itself "mysterious" or unexplainable by natural processes.
To illustrate another example of biological complexity, you can think, for example, of the difference between a piece of land that a lumber company has planted with just one single species of pine tree, and compare that to a piece of land on which grows a natural forest. The pine "plantation" designed by the lumber company for quick turnover doesn't have a whole lot going on--everywhere you look, you see row after row of just one species of tree, and such uniformity in turn produces little variety in food and other resources that other species can make use of. So the diversity of animal species occupying that environment tends to be very low as well (in fact, despite the number of trees, such a pine plantation is something of a biological wasteland). It is, in any case, a very simple system. By contrast, think of a tropical rain forest (or even a mixed deciduous forest in North America): there you will find a great many different species of trees, of shrubs, of fungi and flowering plants, and all this will create a whole complex patchwork of many different pockets of resources and habitats, which will be used in a near infinite variety of ways by thousands of different species of insects, birds, amphibians, reptiles, mammals, and so on.
And one way or another (directly or indirectly) the various components of this overall system-- including all these different species of plants and animals--interact and interconnect in complex ways. A great many species are actually directly inter-dependent in such systems: they are unable to be fully functional and to sustain themselves in a healthy state one without the other. This is true, for instance, of the two-way interactions that bind animal pollinators (insects, birds, bats, or even monkeys) with the flowering plants they pollinate, or bind predators with their prey. In fact, these kinds of complex interactions are often so integral to the healthy functioning of a larger complex ecosystem that if you take out some of these living links (by killing off too many insects and birds with pesticides or causing the extinction of a top predator, for instance) entire biological populations, and sometimes even entire ecosystems, have been known to collapse.
So any "complex" biological system, whether at the molecular level or at the level of a whole larger ecosystem, is made up of a web of many interlocking and interdependent links between different life-forms. The sheer number and variety of links often seem to provide complex systems with greater relative "steady-state" stability than can typically be found in much simpler systems. But if too many of the links in a complex system get disrupted (or even if just a particularly critical link gets disrupted, as might be the case when a top predator is eliminated from the system, for instance) then it is the case that even such complex systems can collapse, in which case they often "fall hard" (unfortunately this is exactly what has been happening to the vast bulk of the planet's richly complex rain forests--a human-engineered disruption and dislocation of crucially complex ecosystems which is taking place on a monumental scale).4
Why bring up this question of complex ecosystems in a discussion of Behe's Intelligent Design proposals which focus on the sub-cellular level? In part to make the point that the sub-cellular molecular world Behe talks about does not have a corner on biological complexity. And yet, as far as I know, Behe doesn't choose to argue that these other levels of biological complexity--such as the complexity of a rain forest, for example--are also "evidence" of a divine designer. This seems logically inconsistent. If Behe can understand how evolution could have brought about a high level of complexity at the ecosystem level, why is he having so much trouble imagining that evolution could have brought about a high level of complexity at the level of biological molecules?
Behe's "big objection" to evolution is that some biochemical systems are supposedly so complex that they can be said to be " irreducibly complex." Again, what Behe means by this is that such a system requires a certain minimum number of parts to function, and that if you were to remove any one of those parts it would just stop functioning altogether. Behe goes on to say that it is this supposed "irreducible complexity" that is the true evidence of Intelligent Design, because natural biological evolution could never produce all those necessary parts all at once, in one fell swoop. For instance, if a system needs all 50 of its chemical steps working in concert to be functional, it could not, argues Behe, have evolved out of a system with 48 or 49 of those necessary parts because such a precursor wouldn't have worked , and yet it is inconceivable that enough random mutations could happen at the same time to bring into being such a complex system "all at once." And evolution also couldn't have produced such "irreducibly complex" systems in stages over time, argues Behe, because natural selection would only favor a system that is "fully" functional. According to Behe, any system that is still missing some of its necessary parts wouldn't work, so natural selection would eliminate it. This is basically the heart of Behe's anti- evolution argument.5
But is there any truth to Behe's basic argument that the apparent "irreducible complexity" of some complex biochemical sub-cellular processes is evidence of design?
The short answer is: no. Let's look at why that is.
Everything we currently understand about evolution shows us that complex systems (including those that exhibit brand new functions) can evolve out of pre-existing material which was different, often less complex, and which may have fulfilled a different set of functions (see examples below). The reason Behe's argument (like that of his 19th-century predecessors) is wrong, is because the "earlier" evolutionary components of any biological system (those parts which evolved at an earlier time) could easily have been favored and preserved by natural selection with regard to different functions than those they would later assume as part of a more highly evolved system. Evolution produces new features by working with the genetic variation which already existed in prior generations of a population (generating novelty out of that pre-existing variation through chance "copying error" mutations and other assorted random genetic reshufflings, as discussed earlier in this series). But that doesn't mean that the pre-existing genetic variation in a population necessarily generated parts and features which were "less-functional" in a harmful way--the genetic variation at that earlier point may have given rise to some more limited but still reproductively advantageous functions for the organisms involved (such as a more simple or "primitive" version of what would later be further modified into a more developed and complex feature), or it may simply have generated features which performed entirely different functions.6
Behe seems to have difficulty conceiving of how a complex multi-part system can have evolved in a step-wise process of evolutionary modifications of pre-existing parts and systems which performed different (but not necessarily in any way harmful) functions. He often likes to illustrate what he calls "irreducible complexity" by showing people a five-part human-designed mousetrap (which has a platform, a spring, a hook, etc). Behe says the mousetrap is "irreducibly complex" because it requires all of its five parts to be present and functioning all at the same time in order to be functional (catch mice). A mousetrap missing any one of its parts would be completely useless and non-functional, says Behe (and he uses this as an analogy to say that a biological system which requires all its parts to function could not have evolved out of a system missing some of those parts because that incomplete system would have been harmfully non-functional and would have been eliminated by natural selection). But as the evolutionist Ken Miller often humorously counters, there are ways in which the mousetrap can be missing one or more of its parts and still be perfectly functional...though in a different way: he demonstrates this in front of audiences by removing a couple of the components of the mousetrap and showing everyone that it is still perfectly functional...but as a tie-clip! In this way Miller is humorously illustrating the fact that the evolutionary precursor of a now seemingly "irreducibly complex" biological system (at the biochemical level or any other level of organization) could indeed have been "functional" in ancestor lines even if it had fewer parts (or parts arranged or interacting in different ways)--as long as you understand that its function may have been significantly different in the ancestor lines.
Consider another of Behe's favorite examples of supposed "irreducible complexity": the series of biochemical reactions which allow bacterial or cellular cilia or flagella--microscopic hair-like or whip-like structures found on some living cells (including sperm cells)--to move through their environment. These complex series of chemical reactions take place inside tiny, microscopic tubes inside the cilia and flagella. Disrupt some of those chemical steps and the cilium or flagellum can't properly move any more. Is this biochemical system complex? Absolutely. Do we know every single last thing about these processes yet? No, not quite. But do biologists have very good reasons to think that even the most complex of these structures (ones Behe would actually consider to be "irreducibly complex") could have evolved naturally and without divine intervention out of simpler pre-existing structures, which were already present in earlier ancestor species? Yes. In fact Ken Miller (himself a biochemist) provides real-life examples of many such structures, which are made up of a smaller number of tubules (they are in this way "simpler") and which don't provide the full range of functions found in the more complex ones- -but they do have some of the structures and some of the parts and they do function (in more limited ways). These simpler systems still exist in living organisms where they have obviously not been eliminated, as somehow "faulty," by natural selection.
If genetic mutations appear in some of these simpler precursor systems, and they happen to provide some new functional capacities that end up giving organisms a reproductive "edge" in a given environment (better-swimming sperm, for instance), natural selection will typically spread these modifications over subsequent (following) generations. This happens automatically (without any divine intervention being required), and in this way evolution can "build" new structures and produce new (or enhanced) functions out of those simpler parts which were already present (and performing different or more limiting functions) in earlier generations and in pre-existing ancestor species.
Why isn't the great complexity of something like human and other mammalian eyes (camera eyes with stereoscopic vision) not "evidence" of divine design, as has been argued by many "intelligent design" types ever since the 19th century? Because there is no reason to think that standard evolutionary mechanisms wouldn't have been sufficient to build up such complex structures over time ( lots of time) through a series of step-wise evolutionary modifications involving the usual mix of chance genetic mutations and reshufflings (which we know are constantly occurring in any living population) coupled with non-chance natural selection. Once even a primitive and very limited ability to detect light (or crude shapes or motion) happened to emerge in an ancient line of organisms, it is not difficult to imagine that natural selection would likely have heavily promoted its spread.
Even the evolution of the very first simple and primitive "eye-spots," which are simple clusters of a few light-detecting cells with only very limited light-detecting capacities (and which can still be observed in various living organisms today) would have been likely to provide any animals which had them with a huge reproductive edge in any environment in which there is any light at all (just think of the kind of reproductive edge that an organism could gain from being able to even just crudely detect motion and shadows and in this way evade predators, for instance).
So in reply to the argument that Creationists have been making since the 19th century: "what good is half an eye?" --the short answer is: "plenty!" Later on, any genetic modifications which occurred among the descendants of these organisms, and which happened to cause further improvements in the ability to see in various ways, would also likely be heavily favored by natural selection (and this is clearly what has happened!), producing even more fancy eyes and expanded visual ranges.7
What these examples illustrate, once again, is that biological structures and systems can evolve from the more simple to the more complex (and sometimes the other way around, as in the case of the cave fish) in a step-wise evolutionary process spread out over a very long period of time. The evolution of increased complexity in any system doesn't have to happen "all at once": less complex and more limited "partial" systems and features present in older evolutionary lines can still be perfectly functional--to a different degree, or in a different way.
Part 7e continues next week
1 Readers of this series who want to look into the arguments of the Intelligent Design Creationists in greater detail could check out the following, who are among the most active, prominent and influential of the current crop of Intelligent Design types: Philip Johnson, a law professor; William Dembski, a mathematician who also holds degrees in philosophy and theology; Stephen C. Meyer, a philosopher; Jonathan Wells, a molecular biologist who also holds degrees in religious studies; and Michael Behe, a biochemist.
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2 As was discussed earlier in this series, a living population's overall gene pool goes through a lot of changes and overall genetic "reshuffling" over the generations, thanks to such things as mutations, genetic recombination and genetic drift, all of which affect the overall genetic variation present in a population at any given time and serves as a basis out of which evolution can produce brand new features. When individual plants and animals reproduce, their DNA strands (which contain the chemical information that can be passed on to descendants) pull apart, pair up with matching strands and reassemble yet again. But this is not a perfect system, and chance "copying errors" ( mutations ) can and frequently do occur in the course of this DNA replication (copying) process. Some mutations have little or no effect on an organism, some may be so harmful as to get eliminated from the population by natural selection, and some may turn out to provide an individual with a reproductive edge in a given environment (allowing it to produce more descendants than individuals who don't have that mutation), in which case non -random natural selection will cause this evolutionary modification to spread to a greater and greater proportion of the individuals in a population over the generations. Other random sources of new genetic variation besides mutations include things like genetic drift , which can occur simply due to individuals moving into or out of an area, thereby causing increases or decreases in the frequency of certain genes in a population. In addition, plants or animals that reproduce sexually (combining male sperm and female eggs) are continually in a position to contribute to changes in the overall genetic variation in a population since significant genetic reshuffling (or genetic recombination ) occurs when offspring inherit only part of each parent's DNA and blend or recombine these different bits of inherited chemical information in new ways. All this (chance genetic mutations, genetic recombinations, genetic drift) continually generates changes in the genetic variation found in the overall gene pool of reproducing populations of any species--and it is this constantly changing natural variation that serves as the raw material out of which genuine evolutionary novelties (brand new features) occasionally emerge and then get sorted out by non-random (non chance) processes such as natural selection.
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3 Anyone interested in a blow-by-blow refutation of Michael Behe's specific arguments about supposed biochemical "design" should check out the first part of the book Finding Darwin's God,written by another working biochemist, Ken Miller of Brown University. Miller tirelessly takes on the anti-evolution Creationists in his writings and in lively and entertaining debates, and he is good at popularizing many of the basic facts and mechanisms of evolution. And since most people know very little about how things work at the sub-cellular molecular level, the first part of his book can be particularly helpful in refuting Behe's specific design arguments, as Miller is able to examine some of the very same complex sub-cellular processes and systems that Behe claims are proof of design. Miller gives lots of examples of likely evolutionary precursors of these biochemical systems and explains in straightforward terms the errors in Behe's methods and why there is absolutely no reason to deduce from the structure of any of these systems that standard evolutionary mechanisms were not involved in bringing them into being. Unfortunately Miller--who is a staunch defender of evolution but who also believes in God--has devoted the whole second half of his book to trying to reclaim the concept of God from the Intelligent Design people and other anti-evolution Creationists. And in his attempts to reconcile the science he knows is true with the religion he believes in, Miller ends up making some unprincipled and completely unwarranted attacks on some very good evolutionists who happen not to share his belief in God. While I was quite disappointed by all this, it doesn't change the fact that there is still much we can learn from Ken Miller's critique of Intelligent Design as seen from the perspective of a working biochemist who also happens to understand biological evolution. (And, from a different angle, and more by negative example, we can no doubt learn much from examining the second part of his book as well, even if we come to diametrically opposed conclusions.
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4 While some partial "environmental restorations" have been attempted on a relatively limited scale (with mixed success) in recent years (especially in much "simpler" ecosystems), the sad fact is that human beings (so far at least) have absolutely no means to restore the innumerable interdependent connections between living species which make up any truly complex ecosystem once it has been fundamentally dislocated--and this is in large part because there is no way to recreate the biological processes through which these many connections evolved one in relation to the other over hundreds of millions of years . This is an aspect of the evolution of life on this planet we would do well to reflect on some more before we go around assuming that it would always be possible to at some later point repair what has been fundamentally damaged.
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5 Once again this goes back to the old 19th-century "argument from design" put forward by people like the Reverend William Paley who thought they saw evidence of divine design in the complexity, and apparent "perfection," of structures such as a human eye or the bird of a wing. Modern biologists now understand not only that such structures are not in fact "perfectly" adapted to their respective functions--for instance, mammalian eyes have blind spots, and the wings of bats and birds are not actually as efficient and aerodynamic as some of the wings human engineers can design--but also that such structures could have been built up in stages, through well understood evolutionary processes spread out over long periods of time.
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6 And the genetic reshufflings that go on as each generation reproduces can also bring forth some features which are basically just neutral and non-adaptive by-products of this process and of prior development, and which confer no particular reproductive advantage or disadvantage to the organisms having these features, and so are not particularly subject to being spread nor eliminated by natural selection. Such relatively "neutral" features (which Stephen Jay Gould and Richard Lewontin called "spandrels") do however sometimes end up becoming integrated as one component of some new evolutionary structure or feature at a later time, and in this way can end up contributing to building up more complex features performing entirely new functions, which, at that later time, may well become subject to natural selection.
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7 Conversely, the evolutionary process has reversed gears in many species of blind cave fish, which are descended from species of fish that had seeing eyes, but which now spend their whole lives in the dark, where continuing to produce such useless eyes would likely be energetically wasteful; it does turn out that natural selection has worked to eliminate sight in species of fish that live in these dark caves.
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