I’m just a layman but it sounds to me like you are playing with words?
I’m mostly interested in Behe’s material and criticism of his material that I can understand.
Regarding fitness, it sounds to me like a strawman version of what Behe would claim.
Isn’t complexity what Behe would refer to.
As an analogy, and I know some people hate analogies - I think I recall somewhere Behe using the example of a city without resources to repel an enemy military advance, so they blow up a bridge to their own city.
This city may be more fit in the way you are using the term, but less complex, or to use more of Behe’s phraseology, it has devolved.
Or, to use another example from Behe, this time not an analogy, a person with sickle cell disease in certain environments may be considered in very specific ways to be more ‘fit’ to deal with the vicissitudes that present, but it is a stretch to call this ‘more fit’.
No, it isn’t. When the terrestrial ancestors of whales evolved to live in the water, they lost the ability to live on land. Articulated, load-bearing limbs, the ability to run, and fur were “lost” in favor of a streamlined body. They became more fit for life in water, but less fit for life on land. In this view it is entirely sensible to speak of fitness relative to the circumstance you find yourself in. This is just how evolution works.
It doesn’t make a species continuously better towards all possible challenges it will face in the future, it adapts the species to the environment it finds itself now.
No, it’s a definition.
That strikes me as a contortion of reality, since Behe’s “material” (rhetoric with zero empirical component) is merely a criticism of a straw man of evolutionary biology (science with a massive empirical foundation). It appears to me that you are actively avoiding any attempt to understand evolutionary biology with that stance, as well as ignoring the fact that Behe is the critic, lobbing rhetorical bombs at those who actually do the work.
Indeed, but never defined with any rigor.
I only hate analogies that are falsely presented as arguments. I like them very well as explanatory devices.
So what? What does that have to do with the evidence for evolution? Why did you just describe an invalid analogy as an “example”?
Not at all. Fitness only has meaning in the context of the environment. The three sickle-cell genotypes, SS, AS, and AA, have different fitnesses in the presence vs. absence of endemic malaria.
No. It happens that I reread what Behe wrote and it is clear that you have misinterpreted what he said.
Indeed, according to you, Behe essentially said that biochemists are better equipped to understand evolution than evolutionary biologists. But this is not what he said, not at all. Rather, his point is that biochemistry is prominent over evolution to understand organic life and that consequently, just as an engineer cannot contradict a physicist on fundamental principles of life, similarly, evolutionary biologists can’t contradict biochemists on fundamental principles of life. I am pretty sure that if you carefully reread what Behe wrote, you will acknowledge the point.
For the record, here is what Behe wrote:
As it struggles to comprehend nature, science sometimes has to completely rethink how the world works. For example, Newton’s laws apply to everyday objects, but they can’t handle nature’s tiny building blocks. Propelled by this discovery, quantum mechanics overthrew Newton’s theory. Revolutions in biology have included the cell theory of life in the nineteenth century, as well as the slow realization in this century that cells are composites of enormously complex molecular systems.
Newton’s theory remains very useful, and we can still learn many things by studying whole animals or cells. When explaining the nuts and bolts of the world, however, those views must yield to more basic descriptions. A mechanical engineer can’t contradict a physicist on fundamental principles of life. It’s not a question of pride – that’s just the way the world works.
Curiously, some people seem offended by the way the world works. In his review of my book, Darwin’s Black Box: The Biochemical Challenge to Evolution , evolutionary biologist H. Allen Orr unexpectedly attempts to claim priority for his field. He grouses that pre-med students are required to take biochemistry but not evolutionary biology. He plaintively asks, “Why is everyone an expert witness when the topic is Darwinism but not when it’s biochemistry?” The obvious reply is that the evolution of biochemical systems is itself biochemistry . When a protein sequence changes, when DNA mutates, those are biochemical changes. Since inherited changes are caused by molecular changes, it is biochemists—not evolutionary biologists—who will ultimately decide whether Darwin’s mechanism of natural selection can explain life. No offense—that’s just the way the world works.
The things you (and Behe) think cannot evolve naturally include many things the rest of us have no problem with. So it’s not an objective conclusion at all.
No, that isn’t just playing with words. “Fitness” has a specific definition. Instead of insisting on using the wrong definition, creationists should make the affirmative case that we shouldn’t bother with fitness and instead should care about…something else. Of course, when they do that, you get problems like this, where they end up saying the quiet part loud in the conclusion.
Part of the problem is he keeps changing his definition in response to the refutations of his claim. That definition is quite different to the one you quoted earlier.
It is actually true that there probably are hypothetical structures or systems that will never evolve because the mutations it requires are so specific they are unlikely to arise over a reasonable timescale thru evolution. This seems to be what he is getting at in the other definition you quoted, though he speaks of mutations being “beneficial” rather than being rare and specific.
Behe’s task is to show that these abound among structures and systems that actually exist.
He has so far failed at this task.
In my defense, I was trying to briefly summarize the arguments, not recapitulate the whole drama. 
Discussing gains or loses in fitness is always relative to a given environment. That’s why homeostasis in cells is so important, because cells cannot remain fit if their internal environment changes very much (others here know far more).
I prefer to describe changes in fitness as being “differently fit”, which avoids the implication that changes can only be good/neutral/bad.
By ananolgy, the city that destroys the bridge will suffer from the loss. But the city’s shipbuilders may do windfall business, leading to the city becoming a major center for industry and trade. The city may become differently fit.
OK, so let’s go with that analogy.
Instead of blowing up the bridge, they modify parts of it, making some larger or smaller, changing the shapes of others, so that it now serves as a fort that will prevent intruders from entering the city.
The structure no longer functions as a bridge. You would not be able to drive a vehicle across it. So, in that sense, the bridge has been broken or destroyed. However, a new structure now exists that better meets the needs of the city.
This would similar to how, in evolution, the wings of birds or bats were obtained by modifying the structure of forelimbs. The original structures are now “broken”, in that they can no longer be used to run or grasp things. But they now serve a new function that better suits the organisms needs.
I don’t see how this invalidates evolution in any way, nor indicates the need for a “designer.”
Let’s return to the original analogy. Instead of modifying the original bridge, the citizens of the city build a second bridge right next to the original that is identical to it. They then modify this bridge as in the first example to produce a fort. It could even incorporate a gate that could be moved in front of the original bridge to block access.
The city now has one former bridge that was “broken” to create a fort. But they still have the original bridge, as well. So no function was lost.
This is similar to how, in evolution, a gene will be duplicated then one of the duplicates will undergo mutations to perform a new function, while the original gene remains available to perform the original function. There are many examples of this.
So, overall, I fail to see how Behe’s idea presents any challenge to evolution. Can you explain why you believe it does?
We have a fundamental disagreement on what Behe meant, and I don’t know how you can get your understanding out of it. “*The Biochemical Challenge to Evolution”, “the evolution of biochemical systems is itself biochemistry”, “it is biochemists — not evolutionary biologists — who will ultimately decide whether Darwin’s mechanism of natural selection can explain life”. Out of all that you get…what? How? The fundamental principles he’s talking about are in fact evolution and natural selection.
I sure do not acknowledge the point.
Judging by influence Claude Shannon, an engineer, contributed far more to a fundamental understanding of genetics than Behe ever has. And that is aside from the information theory which bears his name.
Recognition of formal qualification is only a platform. Credibility gains an audience, but ultimately, it is the merits of the argument which decides the case.
And as I posted above, the vast majority of biochemists contradict Behe. So what is his point?
i give that just as a theoretical situation. It has nothing to do with the experiment.
very relevant. if for the sake of the argument it takes 100 my to evolve two amino acids (which depend on each other), this can happen under the time limit of evolution. but if we are talking about 100 amino acids changes, it will takes far more than the age of the universe. thus, the level of complelxity is relevant to its stepwise evolution.
It will change something if we will talk about a motor such as the flagellum? you can even think about a watch which is made of amino acids.
no problem. but he also probably will agree that this isnt a complex IC. after all, even according to behe and snoke it will takes about 100-200 my to evolve such a simple IC. so it can happen at least few times in evolutionery history according to behe.
i dont think my definition will be so different from behe definition. i will just add the word “complex”, so i will call it a complex IC system.
see my question to dan.
For the sake of argument, the function can come first and complexity is added later. We had a recent discussion about that (will look for link).
You know from many previous discussions that it will not.
Hmmm. Orr is described as an evolutionary geneticist on his NAS page. Let’s see how that looks when we fisk Behe with that reality in mind:
No, he is not doing so. If one doesn’t accept Behe’s slight-of-hand with labels, Orr is merely pointing out Behe’s hypocrisy.
It’s also genetics, so Behe is not making sense, because both pre-med and med students are required to take genetics.
It’s also genetics, Orr’s field and not Behe’s, so Behe is not making sense. He’s blowing smoke at you, Gil.
That makes the hypothesis unfalsifiable, unless there is some objective and testable way to evaluate the differences between instance of IC that can evolve and those that can’t.
Speaking as a biochemist, I would take issue with this sentiment. There is no doubt that biochemistry happens in the cell, and that biochemical mechanisms are in operation. However, a biochemist like Behe who seems to focus on small systems, even single ones, misses far too much, including much of what will guide evolution.
I have to wonder if other ID proponents (@pnelson ?) have ever taken Behe to task behind closed doors. One of the directions that systems and synthetic biology is going is away from Behe’s simplistic notions, to an understanding of how large systems operate. One idea that comes up is how a systems - ne, an engineering - approach actually buffers or removes much of what a biochemist focuses on. Basically, how an interwoven collection of biochemical entities can yield simple, switch-like behavior that is a bit removed or independent of the biochemical properties of individual components of the system. Naively, I imagine that this sort of idea should be right up an ID proponent’s alley, and that such a person should take strong issue with Behe (or at least those who adhere to the sentiment being attributed to Behe here).
Of course, I also strongly disagree with the sentiment that biochemistry is in some way above evolutionary biology in the scientific pecking order. This is a ridiculous insinuation.
We are discussing Lenski’s work which produced an actual IC system. Your hypotheticals are just irrelevant.
Again we don’t need your hypothetical scenario, because in about 33 years one of the LTEE lines evolved the ability to utilize citrate as a carbon source. The ability was gained due to the effects of several mutations including the duplication of an entire gene.
AND there is the fundamental flaw with ID as a science. It’s not possible, even in theory, to have evidence that would contradict an unknown and unknowable Designer.
I’ve seen it (and Dan’s response), and it’s not relevant. Your conclusion is subjective, not objective.
It’s also wrong. But since you can’t even see that it’s not objective, I’ll pass on trying to convince you that i’s wrong.
And this isn’t even the only directly observe example! HIV-1 group M VPU and archaeal plasmids that transmit via liposomes are also crystal clear examples of complex traits, traits that meet Behe’s criteria, evolving before our eyes.
So if creationists are going to go with “well some IC systems can evolve, but other cannot”, then what’s the point of the the characterization anyway? The original point was to be able to identify systems that could not have evolved, but it clearly fails at that. So now the points is…? Could some creationists/IDers fill in the blank? And then what’s the new testable and falsifiable standard for identifying stuff that can’t evolve?