[Republished from Homologous Legs, from October 2010 - I think this topic is particularly relevant at the present moment]
You hear it a lot, the claim that bad design is evidence against intelligent design. Jerry Coyne and Richard Dawkins, two of the most well-known educators about evolutionary biology, regularly mention it in their books and other writings, and so do numerous other defenders of evolution, striking back at the apparently growing intelligent design (ID) movement that is threatening science education in the US and across the globe.
The argument from bad design is as follows. If life were designed by an intelligence, particularly a supernatural intelligence, organisms wouldn’t be observed to have redundant organs, clumsily constructed systems and life-threatening faults with the ways their bodies work. Vestigial structures, like the tiny hind leg bones of whales or the flimsy wings of flightless ratites, wouldn’t exist, and the vast portions of genomes that do nothing, such as the broken remains of ancient retroviruses, wouldn’t be there. Life looks nothing like it was designed by an intelligence.
Fortunately for intelligent design, some ID proponents have an answer to this problem, as expressed here by Robert Crowther, the Director of Communications for the Discovery Institute’s Center for Science & Culture:
All a response…this [bad design argument] really requires is to post a few photos of clearly designed items that have had amazing, spectacularly bad problems. (The Hindenberg for instance. Or any Toyota apparently.) How stupid, yes I said stupid, do you have to be to equate bad design with no design?
In other words, bad design is not a problem for intelligent design because, while many objects have problems associated with them, these problems don’t take away the fact that the objects were designed. Intelligent design is compatible with a spectrum of the Designer’s possible competence, so pointing out a biological system that has flaws does not constitute evidence that the system was not designed.
This is a powerful and intuitive argument to defend “pure ID”, a strain of ID I’ve defined previously. Pure ID does not identify any qualities or characteristics of the Designer, and as such does not, within itself, allow for the distinction between a natural designer (an extraterrestrial intelligence) or a supernatural designer (a deity). Bad design is not a problem for pure ID because the vague nature of the Designer encompasses any and all levels of competence, disassociating itself from the necessity of perfect design. It is probably because of this fact that the Discovery Institute puts forward the “pure” strain of ID:
…the scientific theory of intelligent design does not claim that modern biology can identify whether the intelligent cause detected through science is supernatural.
Unfortunately for pure ID, its refusal to identify the Designer renders it unable to make predictions about any designs it is purported to explain. Pure ID proponents, like those at the Discovery Institute, cannot produce a list of attributes that an organism would have if it were designed, besides the presence of “complex and specified information” (CSI). However, this is not a positive prediction made by ID itself, but a veiled, direct argument against evolutionary theory, which they maintain cannot explain CSI. Their reasoning continues, often hidden in the background of the argument, that as evolutionary theory and ID are the only two options for explaining the characteristics of life, the presence of CSI must support ID. This argument is neither logically valid nor sound, but this is rarely acknowledged by ID proponents.
With pure ID unable to make predictions, it wouldn’t be a stretch to assume that the Discovery Institute doesn’t try to mislead the public into thinking that it does. However, this is not the case. Casey Luskin, the Program Officer in Public Policy and Legal Affairs for the Discovery Institute and one of its most prolific bloggers, often writes about new discoveries in biology, mostly to do with “junk DNA” (DNA that does not appear to have a biological function) that he claims are predicted by intelligent design.
In “The Positive Case for Design” (PDF), Casey claims that ID predicts:
Intelligent agents typically create functional things (although we may sometimes think something is functionless, not realizing its true function) [therefore] much so-called “junk DNA” will turn out to perform valuable functions.
Ignoring for the moment the properties of pure ID, this runs contrary to the claims made by Robert Crowther, above. Either intelligent agents are required produce things that are functional, as claimed by Casey, or intelligent agents are not required to produce things that are functional, as claimed by Robert. Since neither of these ID proponents have ever critiqued each other and they write on the same blog, one must assume they are in agreement.
But how can this be so? For Casey’s ID prediction to be useful and scientific, intelligent agents (ie. the Designer) must always produce functionality. However, Robert puts forward his claim that intelligent agents do not have to produce functionality (ie. that bad design is acceptable) in order to counter the claim that bad design in biological systems is not evidence against ID. Both cannot be correct - either ID makes a prediction and is open to scientific criticism, or it does not make a prediction and is immune from scientific criticism.
Whoever is right depends on what definition of ID is being used. If pure ID, then Robert is correct and bad design is acceptable. But if it is “ID creationism”, a strain of ID that claims the Designer is an infallible, supernatural deity, Casey is correct and bad design is predicted to not occur at all.
The problem is that the Discovery Institute explicitly states that intelligent design cannot identify whether or not the Designer is supernatural, thereby forcing them to promote pure ID over ID creationism. This works well from a defensive perspective, as they are now safe from the obvious “design flaws” in many organisms, but it has the undesirable effect of rendering their idea completely unscientific - it cannot make predictions and it cannot be falsified, two important properties that it lacks when compared to properly scientific hypotheses.
What this means is that ID proponents cannot use scientific discoveries about the functionality of “junk DNA” to support intelligent design while at the same time claiming that ID is not affected by the existence of suboptimal systems and structures in organisms. The fact that the Discovery Institute continues to make both claims is evidence that they are not applying rigorous thought to their own ideas.
The next time an ID proponent mentions either functional “junk DNA” or bad design, inform them about the conflicting nature of the two ideas, and see how they react.