Watch from this point until about 15 minutes it. Right around 14, 14 and a half, after a little bit of poking and prodding, we get to an actual clear statement of what IC means in terms of whether or not something can evolve. Behe says that if a system meets the criteria for IC, it cannot evolve by any “undirected” process - including all the stuff we’ve figured out since 1859.
And that, I think, was one of the two big takeaways, at least for me. Because that is a clear, testable prediction. And any number of directly observed examples refute it.
This is exactly what is said:
At about 13 minutes in Dan takes about one minute to list things he considers non-Darwinian mechanisms and causes of change. He mentions (among other things) neutral theory, exaptation, horizontal gene transfer, epigenetics, then says:
Dan: The reason I harp on this is I wanna make sure I have this crystal clear. Dan: When we say a system has irreducible complexity - does it preclude evolution by all these mechanisms - just the ones from 1859 - just the ones from the 1940s…? Behe: Well - I, I’m glad to say it precludes them by all those processes you just mentioned… Dan: Okay. Behe: …I just wanna say that, in my mind, I consider them all random changes, remember Darwin didn’t know about mutations or anything - he said random changes plus natural selection - and you got look at each of them carefully - I think neutral mutation fits happily into Darwinian evolution except that the mutation has a selection coefficient of 0 instead of a negative or a positive one - uh, so… so that doesn’t strike me as a big deal. Behe: And gene duplication - meh that’s fine that’s one event though. Ahh so, yeah - any unguided processes. Dan: Alright, any unguided pro…(?) Behe:Nods Dan: Okay, any unguided processes! Behe: Right.
Your typing in the PPT seemed to be very effective at limiting his wiggle room. It was sad that the first thing Behe went to was quote-mining Darwin. That he would demand that someone show him neutral evolution, instead of bothering to learn about it himself, was truly pathetic.
And his claim that Darwin talked about “random changes” is not consistent with my memory. Didn’t Darwin only talk about existing heritable variation?
Hi DS
First I believe it is helpful to think of ID as a method vs a hypothesis. In his discussion with @swamidass he described design detection as having a stronger signal depending on the arrangement of parts you are observing. This is discussed below in the debate they had about 15 minutes in.
First, yes, as Behe indicates, it shows that Darwinism is capable of getting 2-3 changes to occur before selection. I certainly don’t have a hard with this. But my understanding is that these were 1) a gene duplication, and 2) a few point mutations (correct me if I’m wrong). Again, to me it’s a stretch to call those three events occurring before selection a “2-3 component system.”
Here are some observations:
Applying the cit+ modification to IC is painting with a pretty broad brush.
The LTEE is a package deal. You have to take the good with the bad: devolution. As Behe has pointed out, the majority of beneficial mutations were loss-of-function, and the overall size of the genome is smaller. If, as you implied, you extend that experiment out a million years, that devolution will have an adverse impact.
I feel like I followed your logic just fine. I just want to give a perspective from a creationist “in the stands.” Here’s how I ‘see it’:
You’ve become convinced that the cit+ modification allows you dismiss Behe’s challenges to things like blood clotting & flagellum, which fall under the category referred to as IC. With Behe, you went through a series of debates over definitions, dividing lines and falsifiability in order to get Behe to either agree to something, or perhaps say something that justifies your counter-hypothesis. To me I can’t help from thinking this sounds like quibbling over wordings in search of some “loop-hole” (again, my perspective). And not surprisingly, Behe wasn’t compliant to that.
You may win some quibble over the definition of IC, the lack of “dividing lines” or lack of falsifiability, but those do nothing to convince me that IC has been ‘refuted’. It just sounds like you really want to refute it, which is admirable. You certainly have the freedom to come to your own conclusion of ‘refutation’. But don’t be surprised that others aren’t convinced.
Additionally (again, my “view from the stands”), I feel like this phrase reveals what I’m saying:
BTW I’d have to disagree. And this is the really important part. For me it’s not about ‘framing’, it’s about the fact that large ‘leaps’ exist, call them what you want. Not just flagellum, but also things like single-celled to multiple-celled, asexual to sexual, various steps along the way to a working eye. Some of these are significant. And a chain is only as strong as its weakest link.
It only takes one link, so here’s one: blood clotting. It’s covered in Behe’s “A Mousetrap for Darwin”, which I recently read about. After reading that, I concluded that blood clotting cascade IS a serious challenge that no-one has refuted.
MY CONCLUSION: Hearing “refuted” from evolutionists has been losing its meaning. It becomes a trust issue. I hear “IC has been refuted.” Oh really? Then I hear “I see lots of phylogeny signals.” Interesting. “Overwhelming evidence!” I see…
[/viewFromTheStands]
Behe is still making the same mistake you always make… He assumes a PURPOSEFUL arrangement when all we have evidence for is a FUNCTIONAL arrangement. Purposeful assumes conscious intent which has never been demonstrated. Conscious intent in creating a “design” is the thing Behe is supposed to be showing. On the other hand natural processes are empirically observed to produce function arrangements since such arrangements aid in reproductive success.
It’s not really clear what you mean by “before selection”? At no point during the LTEE was selection removed.
A second point is your use of the term “Darwinism”. I want to make sure I understand how that term functions(what it refers to) in a sentence you use.
Are we to take it you are referring to everything that is part of modern evolutionary theory with that term, including things like neutral theory, mutation bias, horizontal gene transfer, constructive neutral evolution, and so on? That similar to Behe, “Darwinism” is really just another word for everything mainstream science considers part of the modern theory of biological evolution?
That’s true yes.
But you’re not telling me why. The system has at least two components, does it not? And they both are necessary for the function, aren’t they?
So what is the “stretch” here?
You call them “events” as if that is somehow an argument against the evolution of irreducibly complex systems, but how else would something evolve but by a series of mutational events having phenotypical effects?
I can’t make sense of this point you’ve raised here.
That doesn’t appear to be an observation, but more like a subjective characterization. You appear to be suggesting(if I understand you correctly) that someone has gone beyond the definitions, but you don’t seem to have explained how exactly it was violated or overstepped.
It’s a stretch(why?). They’re events(what else would they be?). We’re painting with a broad brush. These are basically the essence of your complaints and I don’t understand them as they are.
Perhaps this can help clarify.
Pick one sentence here you think is factually incorrect and explain why:
A) If a system consists of multiple interacting parts that contribute to it’s essential function where if you remove any of these parts and the system stops functioning, then the system is irreducibly complex.
B) There is the function in question(aerobic citrate transport) that is performed by a system of multiple interacting parts.
C) If you remove any of these parts the system stops functioning.
D) The system is therefore irreducibly complex.
E) The system evolved by mutational events.
I’m happy to agree that I think this experiment will continue showing fitness increases because genes with functions that were adaptive in the ancestral environment of the mammalian gut are gradually purged by selection as they constitute a slight metabolic cost to carry around now that most of the challenges faced in nature are removed.
That said, I don’t think this is actually relevant to the subject matter of irreducible complexity (or the cit+ function specifically).
In a way I think this is a sort distraction that doesn’t make sense. To see what I mean, just dial up the knobs on both prongs of our respective arguments (more complexity in the system, but loss of much more ancestrally functional genome).
Suppose this experiment had run for a million years and during this span of time the total genome size had been reduced by 50% so we had ended up with a bacterium with a roughly 2.25 mb genome. Half as many total genes, half as much genome size is the net result after a million years.
But during this interval of time an irreducibly complex system consisting of 15 different parts (instead of 2 or 3) had evolved, with each of these parts deriving from duplications of genes that performed other functions in the genome. So here the complexity of this particular system had increased further, while the overall genome size had decreased by the loss of many other unnecessary genes. Could I still not then say that evolution can produce an irreducibly complex function, because it has occurred simultaneously with the loss of many other functions?
Where does the line cross for you? If a 4 component system evolves concomitant with a 1% loss in genome size, is that too much? What if it’s only a 0.5% loss of genome size and a 5 component IC system? Why must genome size expand or stay constant simultaneously with elaboration of the system in question? That was clearly not part of the original definition of irreducibly complexity, so why are you invoking it here as a sort of “packaged deal” argument against it?
Yes, it depends. Heh. I wish he would just come and hash this out on the forum, because to me, it seems like this all boils down to his understanding of the probabilities and mutation rates involved, with a heaping tablespoon of denying the principle of inference. IC just appears, to be his pet hypothesis that, like tissue paper, that must inevitably give way to the what his actual argument is.
But here’s the thing: you’re basically making the same argument as Behe: that there are systems SO complex that OF COURSE they have to be beyond some evolvability threshold.
Okay…and the criteria for that are…? Not IC, since we can find any number of such systems with directly observed evolutionary histories, many of them more complicated than Cit+.
The problem is that if you’re going to make the affirmative claim that some stuff can evolve but other stuff can’t, you better have a clear answer to the question “how can I tell the difference?”
“It’s really complicated” isn’t going to cut it. “Irreducible complexity” doesn’t do it because you get false positives. “Irreducible complexity but like really complex, like a flagellum” is just “we-haven’t-literally-watched-it-evolve whack-a-mole”.
So if you want to say it’s okay for cit+ to evolve, but not a flagellum, then we have a problem, because IC catches both. So you need a different, objective way of telling them apart in this context, and empirical justification for that standard.
(I’ll also note that blood clotting is one of the examples for which a literal stack of research was provided for Behe on the stand at Dover, so to say that is an unevolvable system has a whiff of argument from incredulity to it.)
OK, let’s say this is correct. It isn’t ,but let’s say.
Does this lead to the conclusion that the clotting cascade was “designed”? If yes, how does it lead to this conclusion. Spell out the hypothesis clearly, and how this confirms it.
I would suggest that the larger problem is that you’ve let Behe convince you that science is advanced by rhetorical “challenges” instead of by testing mechanistic hypotheses. Case in point:
Behe’s claim that the clotting pathway is IC has been falsified for 20 years now.
Granted, that’s probably true if my objective was to get an evolutionist to concede that these things are beyond “some evolvability threshold” (and that’s certainly beyond my “pay-grade”). At the same I believe evolutionists have a difficult time convincing non-evolutionists that the cit+ modification “refutes IC”.
What really pulled me into this talk was that question “Isn’t it obvious?” Because I was thinking the same thing…
BTW, regarding:
Ok, I have to be honest, adding the old Dover-stack-of-books reference only reinforces my belief that blood clotting is a serious challenge to evolution. I’m actually surprised you used that reference.
I just recently finished Behe’s book “A Mousetrap for Darwin” The blood clotting section of that book had the biggest impact on me. He went through a great amount of detail about the current state of research and knowledge in that area (well beyond those books from many years ago). And yet it remains a significant problem to this day. It’s not like it hasn’t been looked into yet, as that stack of book indicates.
Mikkel, With my limited time constraint, I’ll just have to reply with the following:
First…
True. I will give you that. Size of the genome isn’t the issue.
Regarding the rest, I think I see one differing perspective we have that’s causing a disconnect. Perhaps it’s me not communicating well enough. I’ll phrase it this way: Regarding IC, I’m focused more on the ‘C’ than the ‘I’. I’m focused more on the complexity of things like blood clotting and flagellum, and less on the “framing of IC” as Dan put it.
I think I side somewhat more with this comment:
I absolutely believe there is a limit; clearly defined or not.
(BTW, the phrase “moving the goalpost” to me is almost always a indicating a really large problem, even after a small “move”)
Ultimately my answer to “isn’t is obvious” is simply “no”. What’s obvious to me is that there are still very significant problems, and cit+ modification doesn’t move very much towards that “goalpost”.
So, perhaps not the most robust answer, but that’s my take. I’ll let you have the last word…
My understanding is that (i) AMfD is simply a repackaging of Behe’s pre-existing arguments against his opponents (some of which may be decades old), so how “current” it may be is questionable, and (ii) Behe’s mastery of the underlying literature has proved at times to be less than comprehensive.
So can anybody up-to-date on the literature on the evolution of blood clotting weigh in on how current and comprehensive Behe’s understanding is?
Okay, but then do you agree that the Cit+ function is an irreducibly complex function that evolved, it’s just that it has low complexity?
Well in this case the really large problem appears to have been that Behe’s original argument had a huge weakness he had not considered. The possibility of existing components being coopted to serve other functions, and the possibility of exaptation changing the overall function of a system along the way. These meant Behe’s original focus on a cumulative-selection dominated chain of events(where the same original function just increased step by step as the system became more complex) did not undermine evolution’s power to explain the emergence of irreducibly complex structures. So he really did change his argument in response to critics. He saw a flaw in his argument and made up a new requirement of an IC system. That’s just a historical fact.
Yeah but you’re not telling me why. Your answer is no, but I don’t understand why it is no. I can only repeat myself. If we can see that two components can come together to yield an IC system in a matter of decades, why can’t such a thing continue to occur over longer timescales and the complexity of the system further increase?
