This is the third in a series about the debate between Darwinian evolutionists and advocates of Intelligent Design. In part 1, I used President Bush's statement that the debate should be "properly taught" to point out that no one (at least, no leading figure in the debate) is presently advocating that ID be taught with the same weight as Darwinian evolution. Rather, the case that is being made is that it should be introduced and taught fairly so that students can understand the controversy. In part 2, I pointed out that statements to the contrary notwithstanding, the central hypothesis of Darwinian evolution has not actually been tested. That doesn't mean that there isn't a lot of evaluating of the evidence and placing the evidence into the Darwinian evolutionary framework. The fact that the evidence fits so nicely (much of the time) into that framework provides evidence that the framework is true. But the problem is that the framework itself remains untested and unproven. In this part, I want to elaborate on the second part by using two analogies. First, however, I want to use a comment from part 2 to try to clarify what I was saying.
Testing, Conclusions and Reasonableness
I found it interesting that in response to my last entry, one reader named "a hermit" commented with respect to evolution that "there is no way to do one single test that confirms the theory as a whole, but the accumulation of many smaller tests which each confirm different aspects of the theory make for an even stronger case for confidence in the theory as a whole." I mostly agree. I don't know that there is no way to do one single test that confirms the theory as a whole, but I certainly believe that to be true. And I agree that smaller tests would build confidence that the theory as a whole is true.
Nevertheless, I have a problem with the implications of the comment: there are not that many smaller tests that can and have been run. In reality, the vast majority of Darwinian evolutionary "testing" consists of looking at the evidence that is uncovered and shoe-horning it into the evolutionary framework. Sometimes (most of the time, in fact) the new evidence slides in quite nicely. But on occasion the framework has to be adapted because the facts don't meet what is expected. The fact that the evidence can fit into the framework does lend credence to the idea that Darwinian evolution is true --- in fact, as I pointed out, I am not in these posts asserting that Darwinian evolution isn't true. A person can reasonably conclude from the evidence that Darwinian evolution is true. But merely because someone can rationally arrive at a conclusion that something is true doesn't make it true in actual fact.
After all, at one point in time a person examining the evidence could reasonably conclude that the universe had alwasys existed (the steady state theory) while others were concluding that the universe began with a big bang. It wasn't possible that both could be true, but the evidence was such that scientists, based on the evidence available, could reasonably conclude that either could be correct. However, more recently new discoveries have made it much more difficult to believe that the steady-state theory of the universe has merit. I would argue that the Darwinian evolution is very much like the steady state theory -- it is an framework for understanding the evidence that is consistent with what can be observed and which it is rational for people to accept. However, it may turn out that Darwinian evolution is as wrong as the steady state theory when tests are developed that can actually test the central hypothesis of Darwinian evolution.
Allow me to give two analogies that may help explain what I mean when I am talking about the testing the central hypothesis. But before I do, let me explain something about how analogies should be evaluated. (A fuller discussion of analogies, their use and limits, from which the following has been taken can be found here.) First, look at the context in which the analogy occurs. In other words, what is the purpose of the analogy. What is the main point that the analogy is intended to make or illustrate? Once that purpose or point is identified, then the second step is to see whether the analogy differs in any substantive respect from the analog that would make the intended analogy inapplicable. Simply pointing out differences between the analog and the analogy that don't go to the point of the analogy is nothing more then pointing out that an analogy isn't an identity.
The Blind Men and the Elephant Analogy
To give an analogy (keeping in mind that no analogy is an identity and no analogy will be an exact parallel the original), consider the old Indian fable of the blind men and the elephant. In the story, the blind men are all feeling a different part of the elephant and concluding different things about the elephant based on what they happen to be feeling. Thus, one blind man feels the trunk and says, "the elephant is like a snake." A second man feels the tusk and concludes that the elephant "is like a spear." Ultimately, none of them knows what the elephant is really like.
Now, take that same story and assume that the blind men have a theory about what the elephant is like -- they believe that the elephant is similar to a road-tractor with an attached semi-trailer. Now, the person grabs the trunk and feels that it is snake-like and assumes that he has grabbed some type of hydraulic hose. Another grabs the tusk and feels that it is spear-like and assumes that he has grabbed some bull's horns that someone has mounted as decorations on the front end of the truck. Someone else touches the side which feels wall-like and assumes that they are touching the flat, hard side of the semi-trailer. And on and on. Admittedly, they don't have all of the evidence, but the blind men are finding that by touching the elephant the evidence supports their hypothesis that it is like a road-tractor with attached semi-trailer.
What happens if someone shows that the trunk isn't quite the same as what would be expected if the elephant were a tractor-trailor? Does that disprove the theory? Not necessarily. The blind men, after all, only said that the elephant is like a tractor-trailer and admitted that they didn't have all of the details. So, when this is pointed out, the blind men simply note that the elephant is like the tractor-trailer, but that the hydraulic hoses are not as they originally hypothesized. The idea of what the elephant is actually like is adjusted and the belief that the elephant is a tractor-trailer is maintained despite the new evidence.
In effect, all the blind men have done is to demonstrate that the evidence can be manipulated in such a way that it fits into their belief framework. They haven't shown that their theory that the elephant is similar to a tractor-trailer is, in fact, true -- only that what they are touching is consistent with that central hypothesis. They have done little to prove that the elephant is actually a tractor-trailer in the first place, and new evidence that is inconsistent with the cental hypothesis changes but never disproves the central hypothesis.
The Evolving Cars Analogy
Allow me to give a second analogy (again, keeping in mind that no analogy is an identity and no analogy will be an exact parallel the original). Suppose that we are 10,000,000 years in the future, and we have somehow lost all records of what life was like in the 20th and 21st Centuries. Archaeologists dig up the remains of various automobiles. After a time, they put together a pretty good time-line for determining exactly how each car followed from the other. They are able to examine, for example, how the fuel-injection engines seem to build on the simpler carburator-based engines. Someone suggests that the remains of cars found are the remains of some metal-life creatures that evolved as the result of natural selection. This theory is widely accepted because these future scientists are able to track the evolution of the automobile over time.
Does the fact that it appears that some cars followed from other cars mean that the underlying idea that all cars evolved by natural selection has been proven? Of course, I recognize that some will argue that the analogy fails because cars, being inorganic, wouldn't evolve. I agree that cars, being inorganic, wouldn't evolve (although some seem to suggest that evolution of inorganic molecules is part of the whole evolutionary story), but the point of the analogy is not that scientists would make such a mistake, but rather to show that the fossil record only maps out what lived -- not why or how the changes occurred. Those are both speculations based on the assumption that the central pole is correct, and the speculations are applauded if they correspond with the overall framework created by the central hypothesis. However, the central hypothesis itself remains unproven.
My point is this: the majority of the evidence for Darwinian evolution is the fossil record. Darwinian evolution is the framework or central hypothesis that is used to explain the evidence discovered. I certainly accept that the evidence shows fossils starting with simple organisms at the earliest time which are followed in the record by more complex animals (although there are people who make a pretty good case that the dating of the fossils is also the result of the Darwinian evolutionary framework). Usually, these fossils fit into the framework quite easily. But occasionally, they don't.
The lastest example of not fitting so nicely is the ancient 20 pound frog named Beelzebufo or 'the frog from Hell' the fossils of which have been found in Madagascar. The article notes:
"The finding presents a real puzzle biogeographically, particularly because of the poor fossil record of frogs on southern continents," said Stony Brook University paleontologist David Krause, who led the research. "We're asking ourselves, 'What's a 'South American' frog doing half-way around the world, in Madagascar?'"
The answer? Well, it certainly isn't possible that Darwinian evolution is wrong, so the speculation is that there was a land bridge between Madagascar, Antartica and South America that allowed the biologically similar frogs to live so far away from each other. As a result, once a reasonable adjustment is made to the overall creation myth of Darwinian evolution by adding a land bridge to the continental drift theory, Beelzebufo is now going to be catalogued as further evidence of Darwinian evolution.
But that's the problem -- there is never any proof that evolution is wrong because the theory is infinitely malleable on the edges and the central core is never tested.
Next time: Counter-Example