Joined: May 2002
Reposted from ISCID thread:
Dr. Dembski has recently put up his introduction to a soon-to-be published anthology of Darwinism skeptics: Uncommon Dissent.
Therein, he writes of the Lenski et al. (2003) simulation of the evolution of a complex, multiple-parts-required system,
We will leave aside the irony of Dembski (author of the tornado-in-a-junkyard strawman for flagellar evolution, the closest thing to actual biology in No Free Lunch) accusing someone of not having any "actual biology" in their study. The question that Dembski raises here is, can "complex features exhibiting complex functions" be "decomposed into simpler features exhibiting simpler functions"? Dembski says that the simulation's validity "depends crucially" on this assumption, and further argues that Lenski et al.'s simulation is invalid because "There is no evidence that real-life irreducibly complex biochemical machines can be decomposed this way."
|This paper describes a computer simulation and thus contains no actual biology. Go to the discussion section, and you'll read: "Some readers might suggest that we 'stacked the deck' by studying the evolution of a complex feature that could be built on simpler functions that were also useful. However, that is precisely what evolutionary theory requires...." In other words, the computer programmers artificially built into the simulation what they thought evolution needed in order to make it work. The validity of this study therefore depends crucially on whether the simulation maps faithfully onto biological reality.|
Unfortunately, it does not, and the study therefore doesn't prove a thing about real-life biological evolution. By requiring of their simulation that complex features exhibiting complex functions can always be decomposed into simpler features exhibiting simpler functions, the authors of this article begged precisely the point at issue with irreducible complexity in real-life biological systems. There is no evidence that real-life irreducibly complex biochemical machines can be decomposed this way.
But, in responding to Ken Miller just a few months ago, Dembski conceded exactly this assumption about irreducibly complex systems: the Icon of ID, the flagellum, can in fact be decomposed into several subsystems with independent functions:
(Dembski then goes on to argue that the fact of functional subsystems doesn't disprove Behe's arguement, but that is not the point Dembski is contesting in his Uncommon Dissent critique of Lenski)
To this let me add: A system is irreducibly complex in Behe's sense if all its parts are indispensable to preserving the system's basic function. That an irreducibly complex system may have subsystems that have functions of their own (functions distinct from that of the original system) is therefore allowed in the definition. It seems that Miller is unclear about the distinction between a definition and an argument. Irreducible complexity is a well-defined notion that is appropriately and ascertainably applied to the bacterial flagellum. Miller's concern ultimately seems not over the definition but over its use as an argument to rebut Darwinism. Miller's point here generally is that if subsystems can be found with functions of their own (perforce different from that of the original system since otherwise the original system would not be irreducibly complex), then those subsystems and their functions can be grist for selection's mill and underwrite a Darwinian account of how the original system arose.
Source: Still Spinning Just Fine: A Response to Ken Miller
If that weren't enough, Dembski has been even clearer elsewhere:
And he even says in one place that such subsystems "always" occur:
You've charged me with moving the goalposts and adjusting the definition of irreducible complexity because I require of evolutionary biologists to "connect the dots" in a causally convincing way. The dots here are functional precursors that could conceivably have evolved into the final system of interest. You state that previously I claimed that the dots couldn't exist because they wouldn't be functional. Please show me in Michael Behe's writings or my own where we deny that IC systems can be made up of subsystems that can be functional in their own right. The point is not whether subsystems can be functional on their own but whether they can exhibit the same function in the same manner as the system in question. You misrepresent our position.
Source: ISCID thread, page 2: Organisms using GAs vs. Organisms being built by GAs
In other words, Dembski has already admitted that his own argument against the Lenski paper is wrong. He has *already* admitted in print, repeatedly, that "complex features exhibiting complex functions can always be decomposed into simpler features exhibiting simpler functions." And yet he criticizes Lenski for their assumption:
...even though it is -- even according to Dembski himself -- biologically *realistic* and therefore "actual biology".
|...the authors of this article begged precisely the point at issue with irreducible complexity in real-life biological systems. There is no evidence that real-life irreducibly complex biochemical machines can be decomposed this way.|
Dembski spends most of his introduction to Uncommon Dissent accusing scientists of adhering to evolutionary theory for all kinds of ideological reasons, rather than evidence. Perhaps Dembski would be more successful in convincing them if he spent more time making sure his own arguments were self-consistent (let alone well-supported by evidence, a topic for another thread), and less time calling them names.