Thursday, January 17, 2008

DI response to the NAS: It's all about Moving the Goalposts

The Discovery Institute's response to the National Academy of Sciences book about evolution, as so often is the case, reveals clearly what the Discovery Institute is really all about. Written by Casey Luskin, a lawyer of the type Shakespeare had in mind, leads us through a morass of rhetorical games and irrelevancies, as is typical of cranks.

Right out of the chute we get what one always gets in a paper about science: a poll.

"A 1982 poll found that only 9% of Americans believed that humans developed through purely natural evolutionary processes. Two years later, the U.S. National Academy of Sciences (NAS) issued its first Science and Creationism booklet, stating that science and religion occupy 'separate and mutually exclusive realms.' Public skepticism of evolution remained high—a 1993 poll found that only 11% of Americans believed that humans developed through purely natural evolutionary processes."

This of course is the mark of a PR firm. Scientists measure their theories by experimental data, not polls. Then our esteemed Mr. Luskin hits us with this inexplicable contradiction:

"The NAS accurately defines irreducible complexity — “If one component is missing or changed, the device will fail to operate properly” — but then promotes a false test of irreducible complexity, wrongly claiming that if one part of the flagellum can perform some other function, then irreducible complexity is refuted. "

One can be forgiven for rereading this several times trying to find what one is missing. It is as if Casey said "my firehouse cannot stand with even one brick missing", and upon being told "baloney, I can remove the entire third floor where the firemen sleep and not only does it stand fine, it makes a great garage", responding with "Yeah, but then it wouldn't be a firehouse." Luskin is trying to dismiss the existence of the Type III Secretory System (T3SS) which is made up of a subset of the components of the flagellum, and which is a glaring refutation of the claim that the flagellum is irreducibly complex.

This is typical of the kind of equivocation the IDers engage in, and why they cannot get even the most basic scientific foothold. One cannot do science with hypotheses that include weasel words like "properly" that allow them to move the goalposts any time the claim is refuted. Luskin spends a paragraph attacking the notion that the T3SS is a precursor to the flagellum, forgetting that there is nothing in the definition of irreducible complexity (IC) about precursors. Yet he can still unleash howlers like this:

"...Darwinists wrongly characterizes irreducible complexity as focusing on the non-functionality of sub-parts"

Excuse me, but YOUR OWN DEFINITION so focuses! Nevertheless, Casey continues the non sequitor and gives away the game in the process:

"[IC is properly tested] by assessing the plausibility of the entire functional system to assemble in a step-wise fashion, even if sub-parts can have functions outside of the final system.

But Casey, there is nothing in the definition of IC that says anything about step-wise assembly, and for good reason. This view has, at its core, an implicit assumption that evolution is a focused progression inexorably toward a finished product, instead of the messy, contingent, imperfect, never completed process it is. Evolutionary functional systems do not progress stepwise. They go forward, back, change function, co opt parts from other systems, and sometimes, die off entirely. The idea that one should study the evolution of a system and only consider step-wise solutions would be like studying successful football teams and only considering running plays.

There is also the size of the problem to consider. Systems like the flagellum evolved over millions of years, with likely tens if not hundreds of thousands of steps along the way. That makes claims like this one from Dembski completely absurd:

"At best the TTSS represents one possible step in the indirect Darwinian evolution of the bacterial flagellum. But that still wouldn’t constitute a solution to the evolution of the bacterial flagellum. What’s needed is a complete evolutionary path and not merely a possible oasis along the way. To claim otherwise is like saying we can travel by foot from Los Angeles to Tokyo because we’ve discovered the Hawaiian Islands. Evolutionary biology needs to do better than that."

On the contrary, the arguments via IC are akin to claiming one cannot travel on foot from New Orleans to Miami because the straight line path goes through the Gulf of Mexico, and refusing to consider any other pathway. Dembski's argument above is like insisting that we need a record of every single step along the way, despite the fact that it would take longer than a human lifetime to compile, or examine.

This is worth emphasizing, because it reveals a subtle intellectually dishonest tactic taken by IDers. When challenged to produce a falsifiable scenario to their claims, they always concoct something that is literally impossible. Always.

Casey Luskin is engaging in a long tradition of creationist rhetoric: ignore the facts, ignore the refutations, and keep repeating the same tired nonsense over and over again. Let's hope he, or some of the other leading lights of the ID movement, get a chance to espouse these views in the next court case, assuming they don't run away again.

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