Actually, they’re not, they purport to address different concepts.
Paley’s watchmaker apologetics purports to present human design as allegedly supporting the idea that a supernatural magic entity poofed the universe into existence, which fails on several grounds that I’ve already covered. The version of “irreducible complexity” peddled by Behe purports to be evidence that evolution could not have produced certain features, which is patently false.
“Irreducible complexity” wasn’t even defined by Behe in the first place, he just found a nice soundbite to describe the phenomenon, as part of the process of propagandising for a supernaturalist doctrine. The evolutionary biologist Hermann Joseph Müller alighted upon the concept sixty years before Behe was born, and his deliberations on this phenomenon were published in a scientific paper in 1918. I’ve cited this paper repeatedly elsewhere whenever this topic as arisen, but, for your benefit, I’ll spare you the horrors of the forum’s non-functioning search facility and provide not only the citation, but the relevant quote. The paper in question is:
Genetic Variability, Twin Hybrids and Constant hybrids in a Case of Balanced Lethal Factors by Hermann Joseph Müller, Genetics, 3(5): 422-499 (1918) [Original paper downloadable in full from here]
I shall quote directly from that paper for your convenience, highlighting the relevant parts in blue (bottom of page 464 to top of page 465 in original paper):
In other words, “irreducible complexity” was arrived at by Müller before Behe was born and was posited by Müller not as a problem for evolution, but as a natural outcome of evolutionary processes. The so-called “Müllerian Two Step” is summarised succinctly as follows:
[1] Add a component;
[2] Make it necessary.
This was placed upon a rigorous footing by Müller himself, along with others such as Fisher, by the 1930s, and so Behe didn’t even find a gap for his purported god to fit into. Biologists have known that Behe’s “irreducible complexity” nonsense has been precisely that - nonsense - for a minimum of six decades. Indeed, the community of evolutionary biologists have a term to describe the Müllerian Two Step in more formal language, namely ‘bricolage’, which is defined as the temporary appearance of supporting structures, followed by the disappearance thereof when they are no longer needed. I have 15 papers on the bacterial flagellum alone (which Behe erected as his “poster child” for his canard) that drive a tank battalion through his assertions.
In short, biologists knew Behe was wrong six decades before he was born.
The most hilarious moment of Behe’s undoing came, of course, at the Dover Trial, where he asserted pompously that not only did evolutionary biology have an explanation for the vertebrate blood clotting cascade, but that it never would. At which point the cross-examining counsel produced fifty-eight peer reviewed scientific papers, and nine university textbooks, containing the solution evolutionary biologists alighted upon, that Behe arrogantly asserted they would never find.
Indeed, it’s illustrative to look at Behe’s cross-examination in detail. Let’s turn to the Dover Trial transcripts, which can be downloaded in full from here, and check Michael Behe’s evidence, you can see him being systematically dismantled over his canards. In particular, referring to:
Behe Evidence In Chief Day 10 AM Session
Behe Evidence In Chief Day 10 PM Session
Behe Evidence In Chief Day 11 AM Session
Behe Evidence In Chief Day 11 PM Session
Behe Evidence In Chief Day 12 AM Session
Behe Evidence In Chief Day 12 PM Session
Notice that in the following, I provide precise page and line numbers, so that the instances of Behe being completely owned by the cross examining counsel can be located with ease.
Good places to look are:
Day 11, PM session, where Behe is forced to admit under cross examination that his attempt to widen the definition of “science” to admit “intelligent design” would also result in astrology being admitted as a “scientific” discipline. Scroll down the PDF document to Page 36, Line 18 - all pages and lines are conveniently numbered - and read on to Page 39, Line 19 … take note where he says that “incorrect theories are nonetheless theories” at the end … then continue reading to Page 41, line 17, where the cross-examining lawyer quips that he didn’t taken Behe’s deposition in the 16th century :lol:
Day 12, AM session, where Behe is taken apart slowly over flagella and blood clotting. Scroll to Page 101, Line 7, read on, and see Behe admitting that no one in the ID movement ever bothered to put the “irreducible complexity” of the bacterial flagellum to empirical test. He was also forced to accept that 3½ billion years was ample time for the bacterial flagellum to evolve by natural processes at Page 108, Line 23, followed by being forced to admit that the “test” he proposed for invalidating “irreducible complexity” in the case of the bacterial flagellum was as unreasonable as asking a scientist to grow a bird wing in a petri dish. Likewise, Behe is also forced to admit that any demonstration that the flagellum could arise by natural processes would be “a real feather in the cap of people who think Darwinian theory is correct” at Page 112 Lines 13-15. Additionally, Page 112 Line 16 moves on to the blood clotting cascade, and the fact that various Puffer Fishes manage to do without some of the “irreducibly complex” components of Behe’s description of the cascade - Page 120, Line 16.
Day 12, PM session, in which the cross examination of Behe continues with respect to the blood clotting cascade, and on Page 6, Lines 5-7, Behe himself says that the Type 3 Secretory System might not be “irreducibly complex” (oh dear, because Nick Matzke later found homologies between the T3SS and - you guessed it - the bacterial flagellum). Behe is then introduced to a particularly awkward question by the cross examiner at Page 8 Line 24 that is well worth savouring. Then, on Page 10, comes the crunch about the immune system, where Behe’s statement “the scientific community has no answers to the question of the origin of the immune system” from his book Darwin’s Black Box is presented in open session in the court, and from the start of Page 11, the cross examiner begins listing the papers and textbooks that contain precisely the “answers” that Behe claimed didn’t exist … and also demonstrates that Behe, like so many IDiots before, has his knickers in a twist over the meaning of natural selection. On Page 16, line 17, we have the part where Behe claims that the peer reviewed literature on the molecular evolution of the immune system “isn’t good enough”, whereupon at Page 17, Line 6, the cross examiner reveals that he has fifty eight peer reviewed papers covering the subject, the earliest of which was written in 1971, with the list including new papers that were being prepared for publication at the time of the trial … then we reach Page 20, where college textbooks on the evolution of the immune system are presented, which Behe is forced to admit he hasn’t read, doesn’t know the contents of, but he still persists in trying to claim that these texts and these papers aren’t good enough because they don’t show the entire evolutionary process right down to the atomic level or some such nonsense. Then Behe is hoist upon his own petard on Page 25, Line 23 onwards, when his statement from his book that “if the natural mechanism is to be accepted, then its proponents must publish or perish” is displayed before the court … read on from this point for some pure comedy gold.
In short, when Behe was forced to defend his assertions about “irreducible complexity”, they were found to be worthless.
However, the whole “design” apologetics is a masterwork of duplicity and ignorance combined, even if we ignore the additional evidence for this supplied by the IDists themselves. “Magic man did it” isn’t a parsimonious explanation because [1] it isn’t an explanation, it’s a blind assertion, and one that constitutes the elevation of ignorance to a metaphysic, and [2] anyone who thinks that introducing the sort of supernatural entity beloved of design assertionists is “parsimonious”, really needs to look up what the word means. Especially when one factors into this, that the central assertion erected by IDists I mentioned above, is that complex entities purportedly cannot arise from simpler beginnings (despite the large body of scientific evidence refuting this assertion, but I’ll leave that to one side for a moment). If that assertion, which constitutes a central part of IDist attacks upon evolution, bore any connection to reality, then that assertion would alone destroy any idea that IDist assertions about “design” are parsimonious by definition. Because, that assertion would require their “designer” to be the most stupendously complex entity in existence. I’ve already covered the merely arbitrary nature of their assertion that the resulting infinite regress somehow doesn’t exist, and is purportedly brought to a finite halt by their merely asserted magic man above.
But of course, this isn’t the only problem that IDists have with their assertions. Leaving aside for a moment the fact that IDists only have assertions on their side, assertions that enjoy precisely zero evidential support from the real world (“it looks designed to me, therefore it is” doesn’t constitute evidential support in rigorous science), other problems arise with respect to those assertions.
Now of course, I’ve already covered in depth the duplicity of “design” apologetics, so I need not reprise that lengthy dissertation here. But the above should be sufficient to see just what sort of mess “intelligent design” is in with respect to proper, rigorously conceived concepts.
There is, of course, much more to be said on this subject, but the above should suffice for now.