A badly designed argument

3 03 2007

This is likely to be brief as I don’t think I have the cognitive ability to do a 10-page discussion at the moment, but I don’t particularly like the “This [organ, system, organism] is badly designed, hence there is no designer (and if there was he was surely incompetant)” argument. While this can lead to some interesting discussion over the how certain organs or systems are put together and were evolved, focusing on the “good design, bad design” aspect isn’t very fruitful and will likely hurt those arguing for evolution in the end. Arguing that something was badly designed takes the question out of the scientific realm and into the philosophical/theological realm (Was there a designer? When was the structure designed/created? How was it done? What was the intention?), creationists ultimately saying that God could’ve done things anyway he wanted, or that when an engineer is designing something he has to take into account space requirements, end-use, output, input, etc. Hence, they argue that organs like the eye really are well designed because they function well for what they have to do given the amount of space they have to do it.

I’m all for discussing how organs, systems, organisms, populations, etc. work and have evolved, but arguing whether something is badly designed or not, to me, seems to open the door a crack for the creationists to jam their foot in. There’s nothing scientific about arguing bad design, and while some may view it as a good rhetorical tactic, it doesn’t seem to be especially effective or convincing, and may even have the potential to backfire. If we’re going to contemplate a designer and their intention, we need a lot more information unavailable through nature (and possibly unavailable at all), so the argument for and against “good design” is fruitless, the only real benefit I’ve gotten from reading such arguments being how the eye works, how it evolved, etc. Arguing for “bad design” is almost giving creationists an allowance as it’s stepping outside of science into more abstract (and probably unknowable) realms of thought where absolute truth is more like a bluff than something tangible, hence I believe scientists would do well to abandon the argument for bad design.


Thinking about this a little further, when the “bad design” argument is used, is it really about evolution or is it about the existence of a designer? It seems to me that often it’s not so much about evolution being a reality as the non-existence of a designer. In this respect it’s difficult to separate arguments for atheism from arguments for evolution, and if we are to contemplate “bad design” it should be in terms of how evolution has shaped organisms and extinction rather than the plausibility of a designer, however incompetant.




4 responses

3 03 2007
Chris Harrison

I’ve actually seen an evolution denier use the flaws of our own eyes as evidence against evolution. I asked him to make sense of these flaws from a design point of view, and he did exactly what you said they would do. There were limits to our eyes when God was making them etc. If you can follow this up with an evolutionary explanation for the vertebrate eye, one that accommodates known flaws, it should give them pause at least.
I think pointing our bad “design” does chip away at the design argument fairly well, and often bolsters evolution.
Take bipedalism. Honestly, the problems that arise from it are huge. Bad backs, bad knees, narrow birth canal etc. You can’t make sense of this from a scientific perspective unless its from an evolutionary point of view. So as long as you can keep your evolution/creation discussion within the scientific realm, pointing out bad design should be an easy touchdown for evolution.
And then you can run up the score with whale legs and endogenous retroviruses.

Have you ever discussed “bad design” with an IDer/creationist?

3 03 2007

Hi Chris, I actually have discussed “bad design” with creationists and it usually doesn’t go very well. When on the topic of science, i.e. the structure, function, and history of a structure things go well, but once I step over into the realm of “bad design” it becomes a subjective argument that doesn’t have a scientific basis. Once we start going into the “bad design” argument, however, it’s more of a rhetorical device and creationists usually say “Well, God could have done it anyway he wanted” and even though it may be apparent that a structure is badly designed, the existence, intent, and methods of a designer are not scientific, so unless we’re prepared to take a philosophical/theological stand for an incompetant designer I think we’re better off sticking to the science.

3 03 2007
Darwin's Beagle

When considering the merits of intelligent design versus modern evolutionary theory, I see the bad design argument as THE thing that shows modern evolutionary theory to be superior. Especially to someone espousing a Behe-type of ID.

Behe, at least publically, accepts common descent. This allows him to say that arguments for common descent are not arguments for modern evolutionary theory. According to him ID accommodates common descent as well as modern evolutionary theory does.

The problem with evolutionary theory, according to Behe is the blind undirected nature of natural selection. He says that the complexity of biochemical systems suggest that an intelligent designer did it. Evolutionary theorists say that there are plenty of mechanisms that can combine to produce such complexity, but natural selection is by far the most important for producing anything that is adaptive.

So how do you distinguish between the two claims. One way is to argue that Behe is wrong. Natural selection can create the complexity and give examples of what is known concerning the evolution of those biochemical pathways that Behe says is Irreducibly Complex.

We have done that. Every single system that Behe claimed could not possibly have evolved, scientists have gotten convincing evidence (at least to me) how it could have evolved. What did Behe do in response to this evidence? He moved the goal posts. Now he is demanding that we show every single mutation that occurred, the selective pressures that fixed it in the genome, and probably fossil evidence that ancestors actually had those intermediate biochemical pathways. Of course, this level of detail is unreasonable. It is also impossible to obtain. Behe knows this, but demanding it allows him to still claim that no one has yet demonstrated a COMPLETE pathway by which irreducibly complex biochemical pathways can evolve.

Another tact to take is to ask, “What differentiates Intelligent Design from modern evolutionary theory?” An intelligent designer will produce things that look designed. So will the combined processes of mutation and natural selection. So what IS the difference? Well, one process is intelligent the other isn’t.

What does that predict? Intelligence can foresee problems and avoid them. Mutation and natural selection cannot. Intelligent design is not necessarily limited by historical contingency. Mutation and natural selection is.

Those differences suggest that there should be detectable differences in nature if there was an intelligent designer involved versus mutation and natural selection. Which model does the evidence point toward?

Things like the recurrent laryngeal nerve which goes down into the chest cavity loops underneath the aorta and goes back up to the larynx are EXACTLY the type of things one would expect with a process that does not have the foresight to see obvious problems. It is EXACTLY the thing one should not expect in a process of intelligent design.

Same for Panda’s thumb. Same for the appendix. Same for the inside-out design of the retina. Same for wisdom teeth. Same for teeth in toothless whale embryos. Same for our lordotic spine. Same for hip bones in snakes and dolphins. Same for the wing-like halteres of insects. Same for shared endogenous retroviruses. Same for pseudogenes. Same for sickle-cell trait. Same for a whole host of traits.

I have found the argument VERY useful when I present instances of bad design by saying “Modern evolutionary theory explains this as being due to [whatever is appropriate for the example]; ID on the other hand says that for some strange reason designer happened to do it a totally bizarre way”.

After several examples of the designer being totally bizarre, the point generally gets across. It seldom gets accepted but it never gets refuted.

I think in conjuction with the first tact (showing the evidence that exists that biochemical pathways did indeed evolve) it makes a winning argument for people who lurk on the sidelines.

People can reject either argument alone, but if they reject both together then they are totally unconvincable no matter what. So I don’t think you have lost anything by using the poor design argument properly.


Darwin’s Beagle

3 03 2007
Chris Harrison

Brain, I understand your argument, and agree that evolutionary science in and of itself should not take a stance on anything from the metaphysical/supernatural realm(whatever that is).

The point that I was (poorly) trying to make, is that in order for a “bad design” argument to be effective, we should simply caution the creationist/IDer that we are here to explain the living world in terms of an empirical and thus scientific means. Arguing about the motivations and identity of the “intelligent designer” is obviously outside science, and thus it should be avoided in the discussion. If he cannot agree to these terms, then we should explain that his explanations are unscientific and then direct him to a philosophical/theological discussion.

Therein lies the rub. Evolutionists can explain vestigal structures (etc.) from a purely scientific perspective. The challenge for the IDer is to explain how ID makes sense of these structures while avoiding unscientific speculation like “We don’t know what the designer was thinking”. I’m betting that they cannot do this, and that they will be forced to concede that ID explanations are not scientifically valid, and surely not superior to evolution. What do you think?

Darwin’s Beagle,

Great post!

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