Science is about evidence of occurrence, not mere possibility

Behe’s lack of scientific acumen is most glaring when he demands evidence of “possibility” of an evolution for which its actuality has hordes of evidence, and also when he treats “design” as the default because presumably just about anything could be designed–especially if it were designed to appear undesigned by some intelligence far beyond our own.  The trouble is that in science we have to produce evidence that something happened, not simply that it could have happened, for it really is the case that most phenomena could occur according to several different causal pathways–notably, by design, if one adopts Behe’s “design can do anything” nonsense.

Crucially, even though Behe makes stringent demands upon evolution to show that this or that biochemical pathway could evolve, actually showing that it could evolve would do nothing to show that it actually did evolve.  The actual evidence that a particular pathway evolved is dismissed by Behe, based on his hackneyed understandings of the issues of evidence, evolution, and what science is about.  Here is an example of his position, taken from an interview:

I claim, for example, that the bacterial flagellum could not be produced by natural selection; it needed to be deliberately intelligently designed. Well, all a scientist has to do to prove me wrong is to take a bacterium without a flagellum, or knock out the genes for the flagellum in a bacterium, go into his lab and grow that bug for a long time and see if it produces anything resembling a flagellum. If that happened, intelligent design, as I understand it, would be knocked out of the water. I certainly don’t expect it to happen, but it’s easily falsified by a series of such experiments.

Now let’s turn that around and ask, How do we falsify the contention that natural selection produced the bacterial flagellum? If that same scientist went into the lab and knocked out the bacterial flagellum genes, grew the bacterium for a long time, and nothing much happened, well, he’d say maybe we didn’t start with the right bacterium, maybe we didn’t wait long enough, maybe we need a bigger population, and it would be very much more difficult to falsify the Darwinian hypothesis.

More Behe on falsification

First off, on the relatively trivial matter of what would “falsify the Darwinian hypothesis,” sufficient evidence of rational design in non-engineered life would.  Apparently he doesn’t even think to turn his false dichotomy of “either evolution or design” around, because he has no conception of what actual evidence for design would entail.  Then, a lack of nested hierarchies–measured morphologically, via DNA, and through proteins (each is a fairly independent set evidence in certain aspects)–in the taxa which do not readily exchange genetic material is another possibility for falsification.  Many models can accommodate nested hierarchies, while only unguided evolutionary processes in our context actually predict the nested hierarchies we see.  Another test of “Darwinian evolution” which does not involve design is if life utilizes “physical precursors” and is devoid of “conceptual precursors,” a test for evolution that Behe himself brought up in DBB (and then fails to apply, for the obvious reason–it passes that test, along with the others).

Another fairly trivial issue that Behe gets laughably wrong is that any of this would constitute a test of design.  There are three reasons, one being that he knows very well that bacterial flagella are not in the least considered to easily evolve at all–and it is in fact possible that it is essentially impossible today due to bacterial specialization, when it was not impossible to do in the past.  He chose his “test” in order prevent any real testing, and perhaps to mislead the gullible.  A second, philosophical, problem is that this “test” would not show that the bacterial flagellum evolved at all, merely that it could evolve, as previously mentioned.  The third reason, another philosophical problem, is that it relies upon the false dilemma that if it did not evolve it was designed.

The more important matter is that falsification simply is not everything, regardless of what Popper said.  Suppose that a man is charged with shooting another man.  The judge is not going to be impressed with evidence that it is possible for men to shoot men.  Nor will the judge care that evolution cannot shoot men.  What is more, the court is going to demand evidence that the man actually was shot, and also that the accused was the one who shot him.

Let us suppose that the projectile that killed the victim turns out to be a piece of meteoric iron.  Behe, as the prosecuting attorney, will drone on and on about how it is possible for humans to hurl meteoric at lethal speeds, whether with compressed gases or, conceivably, with an electromagnetic impulse.  Another line he uses is that “anything might have been designed,” (DBB 193) including this death.  It really does not take very long for the judge to tell him to either deal with some actual evidence, or to sit down and be quiet.  Why?  Because saying that anything could be design, or that it is possible for a human to launch meteoric iron at great speeds, means nothing to the claim that anyone, let alone a particular person, actually was responsible.   Behe would have to demonstrate design behind the meteorite which struck the man even to “prove” that a murder was committed at all.

The truth is that the justice system demands essentially the same kind of evidence that science does, only the courts often are intent upon “proof” that an individual was responsible (science often plays a part in this endeavor, however, as in forensic science) and science often is not focused on individual actions.  Falsifiability only matters with “entailed predictions,” that is to say, evolutionary theory is falsifiable because evolutionary processes actually must produce cladistic branchings such as we see, if it is true.  Finding those cladistic branches not only means that evolutionary theory was not falsified, it means that such evidence supports evolutionary theory.  Essentially the same obtains in the courtroom, where the interventions of gods, demons, and miracles cannot be ruled out entirely, but which are not taken seriously for the lack of evidence of these occurring within our sphere of existence.

Behe’s conception of “design” is completely unfalsifiable (I consider falsification a rule of thumb for scientific propositions, not an absolute rule), and not just because even demonstrating the evolution of the flagellum is possible would not actually indicate that the flagellum had evolved.  It is because for Behe (unlike for archaeologists and SETI researchers) “design” has no identifiable characteristics, and even if we found out that a god exists that knows everything and can do everything (so far as we can discern), that would be no indication that life was designed.  Crucially, life appears far too constrained by heredity and the possibilities for mutation to believe that any mind that can deal with life’s complexity would opt for designing within those constraints.

The important evidence is that which indicates what occurred.  Even Behe’s examples which supposedly cannot evolve frequently have such evidences, and the endosymbiotic events have such evidences in abundance.  The duplications, mutations, apparently slow adaptations of endosymbiotic and duplicated information, all point to the clotting cascade and P. falciparum’s plastid as having evolved over some time.  This is the evidence required by science, evidence of occurrence, not some proof of a mere possibility such as Behe mistakes as being a scientific test.

To be fair to the actual argument, it is worth noting that if we did have actual evidence that evolution is not and was never up to the task of producing the forms of life attributed to it, that would be important evidence.  But of course neither Behe nor anyone else is close to being able to show that evolution could not produce the complexities of life, any more than our ignorance of the causes of some of the dynamics on the sun can demonstrate that physics is unable to explain such dynamics, at least in theory.  Indeed, what we see in life bears all of the marks of the difficulty in evolving complexity, especially in a short time.

So it is that, just as with unexplained complexities of magnetohydrodynamics on the sun, we take our bearings from the evidence that we have of the origination of observed phenomena, and we follow that evidence to try to discover what remains unknown.  This is why the evidence of occurrence is so very important, because just as it would be a waste of resources to try to understand the origination of evidently rationally designed machines (like UFOs) according to evolution, it is equally useless to try to explain life according to rational design, when it turns out that there are no marks of rational design in non-GMO organisms. 

Nobody’s liberty is directly at stake in this matter, unlike in the hypothetical court case, however, the fate of human knowledge does depend upon properly interpreting the evidence of what actually happened, instead of chasing after the mere possibilities upon which Behe’s “case for design” relies.  Rather than bypassing the evidence that points directly to what happened, as Behe does, science relies upon that evidence in order to find out what was not only possible but truly did happen, through the course of evolution.  For it turns out that the possibilities which correlate with the data are the ones that matter, both in science and in prosecuting a case in court.

I decided to write this post on which evidence matters, and how it does, because I have recently written several posts about the evidence of what happened to make certain systems found in life, and I intend to write some more, regarding photosynthesis and at least on one or two more about Behe’s “examples” of what “cannot evolve.”  In his books he discusses “what is possible,” while ignoring all of the evidence for what actually did occur.  Empirically, that is almost completely backward, and is another in a long string of indictments against ID for being effectively opposed to science and its methods.

This is part of a series of posts that I am combining into one long post, which may be found at Darwin’s Black Box.

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Explore posts in the same categories: Darwin's Black Box, Science and Philosophy, The Edge of Evolution

3 Comments on “Science is about evidence of occurrence, not mere possibility”

  1. EastwoodDC Says:

    Nicely written Glen. This makes me want to pick up a (used!) copy of DBB and take a whack at Behe dismantling myself.


  2. […] wrote a post discussing the importance of evidence for actual occurrence vs. mere possibility here, in part to lead into the evidence for the evolution of oxygenic (oxygen-releasing) […]


  3. […] wrote a post discussing the importance of evidence for actual occurrence vs. mere possibility here, in part to lead into the evidence for the evolution of oxygenic (oxygen-releasing) photosynthesis. […]


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