This week, the Veritas foundation, a Christian apologetics group, is holding a series of talks at Stanford, which I found out about last Thursday. Yesterday, two of the talks were by Dr. Michael Behe, a professor of biochemistry at Lehigh University, and the author of DarwinÃ¯Â¿Â½s Black Box, in which he advances his claim of intelligent design in biological systems and that certain biochemical systems are irreducibly complex and could not have evolved by natural selection. As an evolutionary biologist, I felt the need to attend his talksÃ¯Â¿Â½and since IÃ¯Â¿Â½m BrendanÃ¯Â¿Â½s unofficial science correspondent, I figured IÃ¯Â¿Â½d take the opportunity to report on what happened, and my take on the issue as a whole. Be warned, this is an extremely lengthy post, as IÃ¯Â¿Â½m trying to balance the desire to be technically precise (always a strong drive with me, as some may have noticed) with the desire to make my points understandable to people without substantial background in biology and chemistry.
In the interests of full disclosure, I have significant objections to both the substance of the claims made by Intelligent Design proponents, as well as the classification of this movement as either science or a theory. IÃ¯Â¿Â½ll explain why later, but I figure itÃ¯Â¿Â½s best to be up front with my biases. When I heard about the talk, I decided to read BeheÃ¯Â¿Â½s book over the weekend, and later read some of the scientific criticisms and responses to his book.
There are several reasons why I donÃ¯Â¿Â½t feel ID qualifies as either a theory or a science. I feel that word meanings are very important, so I need to define some words here. First off, as a friend and I explained to someone sitting next to us at the first talk, science is a systematic attempt to make positive, falsifiable predictions about future events based upon a synthesis of past and present knowledge gained by empirical testing of previous predictions. Science seeks to explain how natural forces can account for observations. It does not say that those natural forces are the only ones which exist, but merely that they’re sufficient. Science is NOT an attempt to explain everything in every area of thought and/or life. The criticism that science classes don’t teach about anything beyond natural forces is true, but it’s only as valid as the criticism that science classes don’t teach modern dance. There are other fields of study out there. Secondly, the word theory has a different meaning in science than it does in daily usage. Theories in science are explanations of a large body of data collected from a variety of sources under a unifying idea which is supported by a solid framework of predictions and tests carried out.
ThereÃ¯Â¿Â½s been a great deal of debate about whether evolution is a theory or a fact. IÃ¯Â¿Â½ve written about this before, but the simplest explanation is that itÃ¯Â¿Â½s both. When someone refers to evolution as a fact, what they mean is that populations change over time. Biologists define evolution as a change in a measureable trait (either morphologicalÃ¯Â¿Â½relating to the structure of the bodyÃ¯Â¿Â½or genetic, such as a change in the relative frequencies of alternative copies of a gene) from one generation to another. This is the fact which really canÃ¯Â¿Â½t be disputed, given that there are species around now that didnÃ¯Â¿Â½t used to be, there are others which used to be here which arenÃ¯Â¿Â½t, and we can see a steady change in a number of features over geological time scales. The theory of evolution by natural selection with common descent is the idea that gradual changes could have accumulated to cause the differentiation of organisms into the great variety of life we can see today. Note the word Ã¯Â¿Â½couldÃ¯Â¿Â½ thereÃ¯Â¿Â½science doesnÃ¯Â¿Â½t say that supernatural intervention never occurred, but evolutionary theory posits that it isnÃ¯Â¿Â½t necessary to explain the present.
Intelligent Design is basically a critique of some aspects of evolutionary theory. Its central concept is that there are systems which are irreducibly complex (a phrase coined by Behe), which is to say that they are made up of multiple interacting parts and the removal of any one of these parts would cause the system to stop functioningÃ¯Â¿Â½not function to a lesser extent, but stop altogether. The conceptual analogy most often used within the movement is that of a mousetrap. The type of mousetrap in question is a spring-loaded one, and is comprised of 5 essential parts: a platform, a spring, a hammer, a holding bar, and a catch. When the mouse takes the bait, it causes the catch to release the holding bar, which allows the tension in the spring to snap the hammer onto the platform, either immobilizing the mouse (by catching an appendage), or killing it outright. If any one of these parts is removed, the mousetrap fails to catch or kill the mouse. Therefore, ID proponents say that such systems are a challenge for Darwinian evolution. Some take the position that irreducibly complex structures are inherently unable to evolve, but in his book, Behe takes the more moderate position that they are unlikely to arise because itÃ¯Â¿Â½s difficult to see how such systems could be put together and improved upon by slight modifications over time.
The Darwinian response to this can be boiled down to two basic themes: 1) the system that is said to be irreducibly complex actually isnÃ¯Â¿Â½t irreducibly complex, or 2) the pieces were already there, just not working together for this purpose beforehand. Argument 1 takes longer to explain, so IÃ¯Â¿Â½ll address argument 2 first. The concept here is something known in the field as exaptationÃ¯Â¿Â½something which used to be used for one function now serves another. Feathers are proposed to be an exaptation, under the idea that their original purpose was for insulation, but theyÃ¯Â¿Â½ve been coopted for use in flight. Closer to my own area of research is the idea that the original purpose of mitochondria was to detoxify oxygenÃ¯Â¿Â½oxygen is actually toxic to many organismsÃ¯Â¿Â½but that the processing of oxygen was later used as a way to generate energy for the cell. Exaptation at the molecular level would be seen in proteins that used to be used for one thing now being used for something else. There are numerous technical examples of thisÃ¯Â¿Â½e-mail me if youÃ¯Â¿Â½d like me to point you to a few of them.
The other argument is that something which is seen as irreducibly complex really isnÃ¯Â¿Â½t. Many of the claims of irreducible complexity are based upon the idea that removing any one component in the present destroys the system. The problem with this is that evolution is a process. The simplest analogy I have to offer is the game of Jenga. For those unfamiliar with it, Jenga is a game played with a set of wooden rectangular prisms, each with a width equal to 1/3 its length. A tower is made out of these blocks, aligned such that alternating layers switch the orientationÃ¯Â¿Â½the length runs north-south on one layer, then east-west on the next, and so on. Each turn, the player must remove one of the blocks from a layer other than the topmost and place it to either start a new layer on top of the tower, or continue such a layer if one is already being formed. The goal is to not knock over the tower. Over the course of the game, the forces traveling through the tower change; previously required pieces are suddenly able to be removed, and ones which were unimportant become essential as holes develop around them. At any given time point in the game, the existing pieces can be categorized as either essential or removable, but which pieces are in which list can change over timeÃ¯Â¿Â½some pieces can become permanently required (such as the center block on a layer which has had both of the side blocks removed), but others can be freed up as the balance changes. In an analogous way, the essentiality of proteins can change over time, either because the proteins it interacts with change, or because the environment changes. ItÃ¯Â¿Â½s therefore very difficult to say that a given biochemical network could not have evolved, as you have to deal with the possibility that there used to be another gene involved which produced some other protein which would allow ancestral versions of the current proteins to be removed and yet have the system retain some function.
Having set the stage of the debate, I can now move on to what Behe actually said during his talks.
The first of the two talks he gave was in the afternoon. Titled Ã¯Â¿Â½The Empire Strikes Back: My Rejoinders to the Scientific, Theological, and Social Criticisms of Intelligent Design,Ã¯Â¿Â½ it was a much smaller audience than the eveningÃ¯Â¿Â½s lecture titled Ã¯Â¿Â½The Argument for Intelligent Design in BiologyÃ¯Â¿Â½Ã¯Â¿Â½60 or so people at the former, compared to roughly 400 at the latter. The afternoon talk was during the ecology and evolution groupÃ¯Â¿Â½s weekly departmental seminar, so it wasnÃ¯Â¿Â½t terribly well attended by the field most critical of ID, but there were about 7 of us from the biological disciplines present. This turned out not to be terribly important, as Dr. Behe chose to save the scientific criticisms for the evening session. Instead, much more time was spent on conceptual criticisms and social criticisms. In terms of conceptual criticisms, he addressed at length the scheme proposed by Dr. John McDonald of how BeheÃ¯Â¿Â½s irreducibly complex mousetrap could have one piece removed at a time and still function. BeheÃ¯Â¿Â½s counters are that 1) John McDonald is a smart man, and his mousetraps are therefore all intelligently designed; 2) that several components not listed in this mousetrap are essential, such as the staples to hold the spring to the platform, and 3) that more than one thing changes at a time. In the social criticism section, he spent an impressively long amount of time discussing a three day installment of the comic strip Funky Winkerbean mocking ID as an example of how people who express skepticism in regards to Darwinian evolution are mockedÃ¯Â¿Â½for instance, when the science teacher is told that ID is mandated by the state, he counters with the idea that science fiction is properly the realm of the English teacher (though phrased in a more humorous fashion, of course). This was followed by a article for a British magazine, with a reference I must admit that I didnÃ¯Â¿Â½t write down, which dealt with the issue much more seriously. He also quoted several criticisms of him that argued essentially that his own lack of imagination for how something could come to be in a multitude of small steps was not an indictment against it happening, but rather against his powers of imagination. The basic response to this was that too much imagination is a bad thing.
I have to say that I found the afternoon talk less than enthralling. Behe was obviously rushed; he came in out of breath and started a bit late, explained that he had thought he was going to be picked up at his room but wasnÃ¯Â¿Â½t so he hurried over as fast as he could (and, admittedly, this is a LARGE campus), and a big part of why I went to the afternoon session was to hear his response to the scientific criticism. He lacked much of the polish that his writings and his evening talked displayed. And while he kept saying he was short on time, he really belabored things like the mousetrap and comic strip. But what he did say has some interesting implications.
The mousetrap analogy is just thatÃ¯Â¿Â½an analogy. Dr. McDonald even states at the top of the page giving his response to the analogy:
Ã¯Â¿Â½It is not my purpose here to point out all of the philosophical flaws in Behe’s argument; this has been done thoroughly in many of the resources collected on John Catalano’s excellent web page Ã¯Â¿Â½BeheÃ¯Â¿Â½s Empty BoxÃ¯Â¿Â½ (Note: IÃ¯Â¿Â½ve fixed the linkÃ¯Â¿Â½McDonaldÃ¯Â¿Â½s is out of date) Instead, I wish to point out that the mousetrap that Behe uses as an analogy CAN be reduced in complexity and still function as a mousetrap. The mousetrap illustrates one of the fundamental flaws in the intelligent design argument: the fact that one person can’t imagine something doesn’t mean it is impossible, it may just mean that the person has a limited imagination. Behe’s evidence that biochemical pathways are intelligently designed is that Behe can’t imagine how they could function without all of their parts, but given how easy it is to reduce the complexity of a mousetrap, I’m not convinced. (Of course, the reduced-complexity mousetraps shown below are intended to point out the logical flaw in the intelligent design argument; they’re not intended as an analogy of how evolution works.Ã¯Â¿Â½
Further, while the staples are essential, theyÃ¯Â¿Â½re also essential in BeheÃ¯Â¿Â½s formulation of the mousetrap. So, for that matter, is the density of the atmosphere. Behe initially claimed that there were 5 parts to be arranged and modifiedÃ¯Â¿Â½and McDonald does that. To me, staples seem like a way of arranging things. I could be wrong on this, I suppose, but I donÃ¯Â¿Â½t see why I am.
Behe has always been careful in his writings to maintain that ID doesnÃ¯Â¿Â½t say anything about the identity of the designerÃ¯Â¿Â½in fact, in his book he is very explicit that a noncellular form of life could have designed the first cell, or that perhaps humans will design it and send it back into the past with a time machine at some point in the futureÃ¯Â¿Â½yet there were a number of overtly religious comments in his speech. It is my impression that these were present for what he presumed would be their humor value to the audience, but when stating about one of his critics Ã¯Â¿Â½Atkins reviewed my book for a website called www.infidels.org, which shows you the company he keeps,Ã¯Â¿Â½ I think he displays rather worse humor than from more benign comments such as Ã¯Â¿Â½Darwinian evolution cannot invoke angels, because the angels are on our side. ThatÃ¯Â¿Â½s a jokeÃ¯Â¿Â½
Two of his statements in response to questions really caught my attention. The first was Ã¯Â¿Â½IÃ¯Â¿Â½m not convinced that ID is poorly received by the vast majority of scientists.Ã¯Â¿Â½ Well, thatÃ¯Â¿Â½s his business, but I have to say that I am. I think he may be referring to an often cited Gallup poll in which only 55% of scientists selected the choice Ã¯Â¿Â½Man has developed over millions of years from less advanced forms of life. God had no part in this processÃ¯Â¿Â½ over the alternatives of Ã¯Â¿Â½Man has developed over millions of years from less advanced forms of life, but God guided this process, including man’s creationÃ¯Â¿Â½ (40%) and Ã¯Â¿Â½God created man pretty much in his present form at one time within the last 10,000 yearsÃ¯Â¿Â½ (5%). As has been pointed out, though, this group of scientists most likely includes chemical engineers, computer scientists, and the likeÃ¯Â¿Â½people whose training and job have very little to do with the life sciences. As such, theyÃ¯Â¿Â½re probably not the scientists most relevant to the question. The second statement was Ã¯Â¿Â½If it [evolution] only had scientific implications, no one would care.Ã¯Â¿Â½ Well, IÃ¯Â¿Â½ll admit fewer people would care, but IÃ¯Â¿Â½m betting at least some of us still would, much as there are people who care about the degree to which various composers of the Baroque period influenced each other.
The evening talk occurred with much more fanfare. Several people had made posters reminiscent of picket signs decrying ID. Behe was polished and his jokes were far better prepared. In this talk, he laid out his views of irreducible complexity, how he sees evidence of design in virtually every aspect of biology, and how he doesnÃ¯Â¿Â½t feel that Darwinian evolution can explain the appearance of design. He also responded to some scientific criticisms, primarily a series of them which kept citing the same passage with a typo in it, and which showed misunderstand of a paper they refer to as showing an example of how blood clotting can work with several genes missingÃ¯Â¿Â½the actual paper does not demonstrate this finding. The person who originally misread the paper in question is an expert in vertebrate blood clotting, and his lab has produced a number of explanations of how the blood clotting mechanism arose in vertebrateÃ¯Â¿Â½a good overview can be found here, in an explanation by Ken Miller.
Both talks involved time for a limited number of questions. I didnÃ¯Â¿Â½t get a chance to ask mine over the microphone, but I did get to ask him in person. I wanted to know what positive predictions ID makes that arenÃ¯Â¿Â½t made by standard evolutionary thought. A negative prediction comes to mind easilyÃ¯Â¿Â½that an irreducibly complex biochemical system cannot evolve without intelligent intervention no matter what conditions and time are allowedÃ¯Â¿Â½but negative results are hard to use as the basis for science. One can always say that the conditions werenÃ¯Â¿Â½t right, or that not enough time was allowed, or whatnot. His response was that ID doesnÃ¯Â¿Â½t make any positive predictions, but predictive ability is not a requirement of science. This is really where Behe and I part company. For this reason above others, but for all of the ones listed above, I feel that ID is a philosophy. I disagree with parts of it, but I do with virtually all philosophies. It really irks me, though, when a philosophy claims to be a science. Science does not have the answers for everything, and those who confuse philosophy and science seem to overestimate the role of science and downplay that of philosophy, ethics, and other fields. Despite what popularizers like Richard Dawkins contend, views of atheism, agnosticism, or deism are not the only possibilities for an individual informed in regard to evolution.
Anyway, IÃ¯Â¿Â½ve babbled for long enough. I have no idea whether anyone actually found this interesting enough to read all of it, but it seemed worth the effort of writing.