The Stone Bridge example and IC

Right. So for example, we could explain an arch from a single part scaffold. First we begin with the scaffold, then we put two parts on top of it as our arch. Then we remove the original scaffold. Then we could put three parts on top of the two parts, then remove the two parts underneath…ad infinitum.

But here is the point: The more parts that we add in our higher layers, the more improbable it is for this to come about through a random arrangement.

1 Like

That is not the question. We are asking a technical question. Is Behe’s argument that they were designed valid? That, we can say with confidence, reliably leads to the answer “no.”

I work with probability for a living, as a computational biologist. There is no content in this sentence that could be valid in a way that challenges evolutionary science. It is not more “improbable” unless we invoke the marksmans fallacy. Avoiding that fallacy, there is no problem for evolutionary science.

1 Like

Really? Even if the probability was 1 in 10^40?

1 Like

That is a separate question. If the very first organism was created by an intelligence and then all life evolved through the mechanisms described by the theory of evolution then we wouldn’t have to change a word of the theory of evolution. So is ID an argument against evolution as described by the theory of evolution, or is it an argument against abiogenesis?

1 Like

I’m saying that Behe does not know much about how to compute these probabilities, or how to make a biological case based on mathematical models. He is not a computational biologist after all, and molecular biologists of his generation are notoriously bad at making (and therefore skeptical of) these arguments (with many exceptions of course). The 1 out of 10^40 can only be valid with the marksman’s fallacy in view. So either it is an incorrect calculation, or it is an estimate of the wrong number. Either way, his argument falls.

1 Like

You have it mostly right. Check your messages for the full paper.

Briefly, they disabled the protein and observed it re-evolving, a single step in a stepwise pathway. It’s been a while since I read it, but I think that’s right.

1 Like

Take a deck of cards and shuffle them thoroughly. Lay out the cards one by one. The order of those cards has a probability of 1 in 52!, or 1 in 10^67. According to you, it is impossible to shuffle cards and lay them out one by one.

2 Likes

To make the connection, @T_aquaticus is illustrating the absurdity of ignoring the marksman’s fallacy. It leads to absurd paradoxes like this. Behe’s math falls prey to this fallacy (among other errors too).

1 Like

To push the example even further, there is also the necessity of improbability. The way in which nature operates makes improbable events inescapable. At any point in the natural history of life there are billions and billions of possible paths that each lineage could take (at least a molecular level), and the existence of the arrow of time guarantees that one of those highly improbable paths will be taken. This happens over and over and over, multiplying improbabilities with each step.

A good illustration is our own singular existence. What are the chances of your parents meeting and making you? What are the chances of those exact two gametes with their unique mixture of chromosomes and cross over events meeting to make you at that specific microsecond in time? Out of the billions of sperm cells that could have made you, only one did. Each of these events is astronomically improbable, yet it happened. And those same improbable events happened in every generation before you in your family lineage. If you multiplied the probabilities of all these events happening in just that way it would annihilate any of the boundaries Behe puts on what is allowed to happen.

3 Likes

Controversial but true, this was the same fallacy we saw at play with the probability arguments against Resurrection offered by some. (@dga471)

1 Like

Certainly an argument against abiogenesis. But perhaps also an argument against much of random evolution. It depends upon how much random evolution can accomplish.

1 Like

No, the question is, can we randomly get 52 stones that interlock into an arch and fit on top of the 51 stones that are underneath?

1 Like

All we have from Behe is some bad math, bad logic, and no real life examples. For example, when has Behe pointed to differences between the human and chimp genomes that random mutations could not produce? I have yet to see him do it. Behe claims that random mutations and selection could not produce the bacterial flagellum, yet he never points to the genetic changes that were responsible for the emergence of the flagellum and showed how they could not be produced through random mutagenesis (as defined by biology).

1 Like

You tell me.

4 Likes

We need to bracket abiogenesis away from biological evolution, which is where Behe is focused.

Yes, and that is exactly the point. Behe has not make a valid argument that apparently random evolution can’t increase the IC1 complexity of biological systems. In fact, we have shown in the lab, time and time again, that evolution can increase the IC1 complexity of systems.

This would only matter if arches with with 52 stones was a valid analogy of biological systems. It is not. So we do not need to worry about this in any precise detail. It is merely a loose analogy to help understand the deeper point.

That is, also, why I do not really care about the Stone Bridge example. You appear to be correct at pointing out its error in demonstrating the Muller Two Step. That was an ad hoc example that fails because it does not actually demonstrate a Muller Two Step. It is not hard to imagine, however, another version of the story that would, in fact, be a Muller Two Step.

One key falsification of IC1 is that the Muller Two Step is a clear mechanism for increasing IC1 complexity that Behe never considered when formulating IC1. Now that he knows about it, he never mentions this well known mechanism. With the the Muller Two Step in mind, it is no longer impaussible to imagine Biology evolving structures of increasing IC1 complexity. We also are now doubtful that IC1 complexity of the flagellum we se alive today has much at all to do with the simplest flagellum.

The other key error in reasoning is exaptation. There is no reason to think that all the parts must come together into flagellum to be useful. In the case of flagellum, there is strong evidence from several lines that different parts had different functions before they came together in a flagellum.

This means IC1 only appears like valid reasoning by:

  1. Ignoring clear examples of IC1 increasing in well understood experiments.

  2. Ignoring the Muller Two Step mechanism.

  3. Ignoring all possible prior functions for the constituent parts of an IC1 system.

Behe makes all these moves. To what extent he realizes he is doing this is another question entirely. Silence on these matters, however, is why people call IC1 an argument from ignorance. Just because Behe doesn’t know of a mechanism for evolving IC1 systems, does not some how evaporate the fact that biologists actually do know the mechanism by which IC1 increases.

Not that in Darwin Devolves there is NO MENTION of these difficulties in his argument. He just ignores them or dismisses them without reason.

In the public debate, as soon as it has become clear that IC1 fails, Behe switches to IC2, but without clarifying that IC1 failed. Of course, if you read him carefully, you will see that he does abandon it all the time, as merely useful to communicate with the masses, and not rigorous.

2 Likes

Hey, I do too!

Do you not see that his misrepresentation of evolution, deliberate or not, is a huge problem?

1 Like

Since TA brought up the 52 cards, I thought I would apply his analogy to my analogy of a stone arch.

But let’s go with the bacterial flagellum. If I recall, there are about 20 protein parts needed in the simplest flagellum. There is also the Type Three Secretory System that some people try (or tried? I think they might have given up) was a precursor to. If we allow that argument, we still need precursor(s) for the additional 10 or so proteins. Or at least some kind of plausible evolutionary pathway. Happen to have one?

As far as I can tell the Mullerian two-step merely proposes that if we have a complex system, we can somehow simplify it and get an IC system. So does that mean there was a more complex flagellum that was simplified into the present flagellum? Is that what you are suggesting? I somehow doubt it. So what is the relevance of the Mullerian two-step to the flagellum?

Remember, we dispute this. I think the actually number is far far lower.

We have seen other functions too, intermediate between the secretase system and the flagellum. There is no reason to think we have to jump from secretase to flagellum without having other functions in between.

Yes, we have a plausible pathway. Do you remember what Behe’s response was? “Please prove to me that is exactly what happened, the precise sequence of mutations, and the precise population sizes involved.” This an example of goal shifting. We do not need to prove that this pathway is the real pathway. In fact, we think there are a very large number of plausible pathways. The fact that one can easily be produced demonstrates that IC1 is an illusion. Whatever the IC1 complexity of a system, this tells us literally nothing about the difficulty of evolving it.

No. It says that if we have a complex system, we can always increase it complexity very easily. If you keep exapation in mind, it also means we can easily evolve new IC1 functions, because we do not need to start from scratch…

As stated above, it means that there is no reason to accept that an IC degree of extant (current observed) flagellum is the minimum IC degree of the simplest flagellum. With exaptation in mind, it also means that there is no reason to think that IC degree for a specific function (e.g. motility) has anything to do with evolvability.

3 Likes

Less than 20 parts? And precursor systems between TTSS and flagellum? No, I’ve haven’t heard of either.

Before we go farther, it is worth asking “why not?”

Behe’s book came out 22 years ago. Nothing I show you will be terribly new. All of it is freely available, and much of we can document that Behe has been presented with it. Should you have heard about it through him? Shouldn’t it be in his book as he explains the scientific response to IC?

Also, if you grant that an intermediate system would increase the plausibility, then you have tot also agree that IC1 is not a valid way to determine evolvability. IC1 doesn’t consider or say a single thing about intermediate step, except asset that they do not exist. If you grant that an pathway, if found, would show an IC1 system is evolvable, then you have abandoned entirely the IC1 measure as a measure of evolvability. Do you see why it follows thusly?

Remember, Behe, when formulating IC1 22 years ago, could not imagine any intermediates, nor did he eve know about the Muller Two Step. When presented these two things, he switched to a different argument, the IC2 argument, because the IC1 argument was no longer sustainable in dialogue with scientists. That would all be good and fine, and a normal revision of theory, except he does not clarify that to you. Which sends you on a poor wild goose chase with biologists like us, thinking we are ignoring his argument, when in fact he is not being upfront with you about what happened to IC1 over the last 22 years.

That is not fair to you @Bilbo. You deserve better from your leaders.

1 Like