1) Protein-protein binding sites must be produced by multiple, simultaneous mutations in a specific sequence.
2) There are lots and lots of protein-protein binding sites in modern organisms, far more than could be produced during the lifetime of any given species. To take the second claim first, note the slight of hand involved. Humans do have lots of protein-protein binding sites, but we didn’t develop them de novo. The vast majority we inherited from our common ancestor with the chimpanzees. That hominid in turn inherited most of its protein binding sites from its ancestors, and so on. Indeed, the majority of the most impressive protein-protein complexes evolved in single celled organisms over hundreds of millions, if not billions, of years. The populations of these organisms far exceed the measly 1020 that Behe invokes. But reading “EoE” Behe certainly gives the impression that all these protein-protein complexes must have evolved relatively recently, without a deep history. Take the proteasome, it didn’t evolve in some slow reproducing, lumbering multicellular organism, it evolved in bacteria back in the deep Precambrian. For someone who claims that he accepts evolution and natural selection, Behe certainly ignores it when considering protein-protein binding. He also ignores a very important aspect of the evolution of binding sites, exemplified by the proteasome. I’ll amplify this later, but for the moment, hold this thought, Behe ignores known details of protein evolution. Now, after that roundabout introduction, I’ll return to the first point. Behe implicitly assumes that there is no simple, step by step selectable path to strong protein-protein binding (he also implicitly assumes that there is no step by step path to any multiprotein complex). But is his assumption true? In the paper I introduced at the beginning of this essay, Grueninger et al. were trying to engineer binding sites into proteins. They were able to produce strong protein-protein binding in many cases with a single mutation. Not only that, the proteins produced multimers of a variety of sizes. Let’s repeat that again, a single mutation produced strong protein-protein binding which resulted in protein complexes. And the researchers hadn’t exhaustively tested all possible mutations and binding sites. Now, these complexes were composed of identical proteins, but this is actually quite important and I will elaborate on this momentarily. But buried away in the references was a paper that was even more illuminating. This paper was looking at the basis of the binding of bovine seminal ribonuclease. Ribonuclease is an enzyme that, as its name suggests, breaks down ribonucleaic acid. These enzymes are typically monomers, but bovine seminal ribonculease is a modified duplicate of standard ribonuclease which is a dimer. The question that researchers were interested in was which mutations were responsible for binding. At stake was a particular model of how proteins bind to each other. To explain this, I have to briefly diverge into a discussion of protein folding. When proteins are synthesized in a cell, they have to fold up into their final, three dimensional shapes. In this process, loops on the protein chain fit into pockets in the protein chain. Sound familiar? It’s the same process the produces protein-protein binding. One of the simplest ways for two proteins to bind to each other is if the loop of one binds into the pocket of the other (see the diagram). You can see that it would be very simple to set this up. In the end the researchers found there were multiple ways to get ribonulcease to dimerise. One mutation was all it took. So we have evidence that in nature, single mutations are all it takes to produce important protein-protein complexes. And we have had this evidence for sometime. Why didn’t Behe address this? Evolution of homodimer binding, there are two rapid paths to forming homodimers, using internal structures of the protein. Both paths appear to be used, and it takes only a single mutation to generate strong homodimer binding. Diagram taken from Canals et al., 2001. We can ask how relevant these results are. Are dimers and multimers of the same protein at all useful? Certainly the bovine seminal ribonuclease is. And indeed, dimers and multimers of the same protein play very important roles. For example, the nicotinic receptor composed solely of five α7 subunits is important in brain function, and there are many similar examples. As well, these homomultimers are raw material for more complex systems. Duplication and subsequent mutation of the nicotinic a subunit produced beta subunits, in the same way that monomeric haemoglobin became a tetramer of α and β subunits (something Behe accepts). The key issue here is that a mutant α subunit that becomes a β subunit retains the protein-protein binding site, it doesn’t have to reinvent the whole thing again. And the whole process can be repeated several times. There are several crucial nicotinic receptors composed of variant αb complexes. Subsequent duplication and divergence produced the complex αβγδ nicotinic receptor of the skeletal muscle. Duplication of the genes for homomultimeric proteins, with subsequent mutation and divergence, can generate large families of interacting proteins without having to generate new binding sites. This process can produce significant complexity, remember the 28 subunit proteasome? Well, in the many primitive organisms, it is constructed solely out a αβ dimer. The dimer is the result of duplication of a simple monomer (and many eubacteria have a simple 12 subunit proteasome composed of a simple monomer which appears ancestral to the dimeric proteasome (Gilles et al, 2003, Valas & Bourne 2008). Subsequent duplication and divergence of the dimer genes produced the 28 subunits that are found in vertebrates, but it all started with a very simple multimer. Again, although Behe says he accepts evolution and natural selection, he ignores the role of evolution in generating structures such as the nicotinic acetylcholine receptor family, the sodium channel family, the potassium channel family, the proteasome, GABA receptors, AAA+ ATPases, NMDA receptors, glycine receptors, histamine H3 receptors … you get the idea. Vertebrate proteasomes are complex barrel like structure of 28 subunits. These evolved by duplication and divergence of a structure made of simple αβ dimers. The α subunit (yellow) itself is a duplicate of the β subunit (red) . The E. coli proteasome is made of a single subunit (red), which shares a common ancestor with the β subunit. Image from Groll et al., 2003 So, a large proportion of protein-protein binding is due to structures that started out as homomultimers, which we have seen can evolve very easily indeed. That’s all very well, but not all protein complexes began as homomultimers. For example, in the voltage-operated calcium channel family each channel is a complex of unrelated proteins. Now, one of Behe’s assumptions is that proteins in protein-protein complexes have no function unless they are in a complex, but in fact this is often not the case. The α subunit of the voltage operated calcium channel is in fact a fully functioning ion channel. The α subunit complexed with either the β subunit alone, or the β and γ subunits modify the characteristics of ion flow through the channel. Again, multiple forms of voltage gated calcium channels are formed by duplication and divergence of the subunits. Again, there is no need to develop entirely new binding sites, these are carried over with the duplicated proteins, and again there are multiple classes of proteins that follow this pattern. For example the NADPH oxidase family are diverged duplicates, which exists as simpler systems in simpler organisms. Even in these kinds of heteromultimeric complexes, some of the elements will be internal duplicates as well, making things simpler. The scope of this inheritance of binding sites can be illustrated with the G-protein coupled receptor family. The receptor protein is in a complex with the eponymous G-protein [1], through which it signals. The repertoire of vertebrate G-protein coupled receptors are modified duplicates of the original G-protein coupled receptor in single celled organisms. How big is that repertoire? In vertebrates there are around 500 G-protein coupled receptors, that represents a big chunk of the approximately 10,000 protein-protein binding sites that Behe cites that don’t have to be evolved from scratch. Now consider that most protein complexes are parts of families, even before we consider the huge families of protein complexes that evolved from homomultimers, and Behe’s big numbers begin to melt away like snow at Arakarula[2]. We have up to now considering simple point mutations. But there is another way proteins can gain binding sites. That is through gene fusion or crossover, where segments of genes containing binding sites can be swapped into other genes. Indeed, in the protein kinases, new targeting binding sites have been produced in just this way. Duplication, divergence, crossover, fusion and inheritance; once again, Behe is unacquainted with the evolutionary history of the systems he claims to describe. However, while there is lots of experimental evidence that single mutations can easily produce high affinity homodimers and homomultimers (which then, by duplication and divergence, result in the protein complexes that we see today), can such simple, one amino acid mutations produce binding between entirely different proteins (say the α and β subunits of the voltage gated calcium channels)? The answer is yes. Once again, we turn to bovine seminal ribonuclease. The simple mutation that made it dimerise has also lead it to bind to a variety of other, unrelated proteins (without any harm to cows). This emphasises the messy, contingent nature of biology, and also illustrates that protein-protein binding is a lot easier to evolve than Behe claims. Summary Behe claims that there are a huge number of protein-protein binding sites, and that even one protein-protein binding site is extraordinarily difficult to evolve. However Behe greatly overestimates the difficulty of developing a binding site, ignores the fact that the majority of 10,000 binding sites in modern vertebrates are duplicate copies of each other, with there being only a much smaller number of basic binding motifs and ignores the fact that most of these basic binding motifs were developed in rapidly dividing single celled organisms with very large populations. Far from protein-protein binding pointing to an unknown designer, protein binding sites point directly to descent with modification and the “tinkering” of natural selection. [1] Strictly speaking, G-proteins bind to the G-protein-coupled receptors only when the receptors are activated, rather than permanently, as in voltage gated calcium channels. However, G-protein receptor binding involves the same issues of selective interaction of “bumps” and “holes” as with all other protein complexes. [2] Arkarula in the Flinders Ranges is on the edge of the great Australian Desert, and boy, is it hot!
52 Comments
sparc · 13 April 2008
Did I miss this post or went something wrong with the date?
Ian Musgrave · 13 April 2008
No, something was wrong with the date. Stupid Movable type doesn't update the date when you have edited something over a couple of days.
David Stanton · 13 April 2008
So, for once I agree with Behe. I do not believe that it is possible for thousands of protein binding sites to arise simultaneously. Wait ... wasn't that the ID poof hypothesis? Why would this guy think that disproving his own hyothesis would somehow disprove evolution?
Behe has certainly heard the argument before. He certainly knows that he is ignoring all of modern biology when he makes his nonsensical claims. It has been pointed out to him so many times that by now he must surely know that hs is being deliberately deciteful.
What good is having a PhD if you don't use it to study the actual science? Why did he need to get a degree in order to ignore all of the scientific literature? Did he take the same approach in his previous career, or did he just adopt this strategy when he sold out to the ID nonsense? This tactic is very telling. If the only way that you can find to discredit science is to misrepresent it, on one is going to be fooled for a minute, unless they want to be.
Oh well, at least when he testifies under oath he always makes the evolution side look good. As long as he continues to ignore all of the evidence, the only thing he can be an expert in is his own delusions. I can't wait until the defense attorney in the California case puts this new stack of papers in front of him.
JGB · 13 April 2008
I'm not sure if anyone has pointed this out before, but there is a terrible math problem with the conception of the evolution of protein binding sites as requiring a pair of simultaneous mutations. He basically is trying to "model" the problem is if it took two unlikely events, so you simply multiply two small probabilities. Given the diversity of interactions that can lead to affinity the most accurate way is not by asking what are the odds of rolling double six. It is much more accurate to look at it as given the identity of this site, what are the odds of getting a favorable interaction at this other site. This is much more analogous to asking what are the odds of getting two numbers the same when you roll two dice (i.e. 1 out of 6 instead of 1 out of 36). As alluded to above given natural selections opportunistic nature as it were it is not even accurate to restrict yourself to a single site looking for a match in most cases. Similarly I would venture that in many cases restricting yourself to a single protein as being the only one that could possibly evolve the protein binding properties in question would also be fallacious.
Joel · 13 April 2008
Great post! Although all the ideas you call upon in your essay are familiar, you have a gift for putting them together in an interesting and compelling way. Thanks!
Venus Mousetrap · 13 April 2008
Behe is a liar.
There isn't really any other way to put it. It's been ten years since DBB. Ten years since he argued against a strawman kiddie version of evolution with all the evolutionary power removed from it. And here he's back with the same argument again, like it never happened. Like Dembski, he's only gonna do enough work to give the fundies stuff to quote, and go LA-LA-LA when anyone notes his deliberate mistakes.
I mean, I can understand what's wrong with Behe claiming that evolution only works by addition (it doesn't) or Dembski claiming that all fitness functions are equally likely (they're not), and I'm not a biologist or a mathematician. I have nowhere close to their education, and yet I can sit here and watch them pretend nothing is wrong, and know that they are lying. It's disgusting.
Flint · 13 April 2008
Infidel Michael · 13 April 2008
Flint: .. they are attempting to solve a very difficult problem: How can the evidence be interpreted in such a way as to require their god?
I don't think it is a very difficult problem (for them). Look, it is enough to take a quote from this article:
Grueninger et al. were trying to engineer binding sites into proteins. They were able to produce strong protein-protein binding in many cases with a single mutation.
ID comment: See?! They've designed these mutations and they tell us it somehow proves evolution? That's ridiculous! Only what they've shown is this process required intelligence.
---
Of course this kind of argument is stupid and misses the whole point, but for the creationist audience this is an elegant rebuttal. It is so easy for them, because they don't need to understand the biochemistry behind the experiment, all they have to know is there was SOMEBODY involved in this process. They'll dismiss the whole scientific work with god-did-it-the-similar-way conclusion.
Flint · 13 April 2008
PvM · 13 April 2008
slang · 13 April 2008
So next trial it won't be a stack of books and papers but just 2 papers that will demolish his testimony. Things are looking up!
Flint · 13 April 2008
raven · 13 April 2008
Chris Lawson · 13 April 2008
Flint,
I agree that Behe is sincere in his *beliefs* (but then, who isn't?), but I disagree that he's sincere about the arguments he puts forwards. His arguments and evidence have been shown over and over again to be wrong. Yet he keeps putting them forward. After being demolished in Dover, you'd think that Behe would have read some of that stack of papers, but judging by his recent statements, apparently not. Even when he has engaged in direct communication with Ian Musgrave about his mistakes about malaria, he only made superficial concessions without ever conceding that the errors in the evidence were not trivial, they completely blew his conclusion. So, sorry, I could agree with your assessment back when Behe wrote Darwin's Black Box. That book could have been the result of a sincere effort by a poorly-informed and blinkered writer. But now his work can only be the result of a writer who is willfully ignoring the evidence against him and sees nothing wrong with disseminating misinformation.
Behe's Backer · 13 April 2008
Your disagreement isn't with Behe, it's with Galileo, Newton, Einstein - possibly with Darwin, himself, and certainly with mathematics, physics, and reason. It's also a disagreement with the man in the street. Every time this brand of 'Evolution' comes out with this self-evident impossibility, the people at AIG rub their hands together.
Mainstream scientists almost to a man have long accepted the findings of geology - an unfolding/unrolling of living forms, over time. I suspect most scientists, just quietly, have left it at that.
We have had the junk yard converting to a cadillac by blind chance, so repeatedly, I won't belabour anyone by pursuing it. But since we here claim the technical truth for evolution, and since there was a sequential unrolling of species, let's stand a few facts up and test theories. Before we start, a note on the quite professional and totally relevant presentation at the head of this page: it tells us that changes can, at least theoretically, occur in the incredibly sophisticated information carriers/controls within cells. What it conveniently neglects to mention, are the remarkable recent advances in nanotechnology, quantum physics, quantum computation, etc., especially the hints that are coming through, of the possibilities in relation to complex organic molecules. It turns out that dull old carbon, is anything but dull, when you get down to the atomic level. Every technical fact presented above, testifies in some way to information technology; and the information technology - a natural phenomenon - points the way to overcoming the entropy hurdle and to an explanation of the unfolding of life within the parameters set by physical chemistry.
Darwin & co. championed selective breeding in response to environment. Owen and many others saw purposeful pre-programming as the governing factor in evolution. (Owen coined the term, LAW OF PROGRESSION. He mentioned the Deity: his theory stands, without overt reference to religion.) Which of these two proposals - chance selective breeding on the one hand, and information- driven pathways on the other, is supported by the following?
Arrival of gymnosperms and other vegetation some hundreds of millions of years ago, giving fossil fuels.
Arrival of flowering plants less than 100 mil. yrs ago - many species even more recent - hence, pastures, edible foods etc..
Manifestation of domestic animals mostly immediately prior to Man. Animals such as horses and dogs, seemingly made for man.
Series of theoretically genetically distinct species in the geologic column - hence, a conduit down which life was passed, right back to the first in the series.
Information technology devices in every cell, theoretically capable of scanning in environmentally relevant information and of working in concert with (presumably quantum category) signals permeating the biosphere, to trigger species transformation and re-programming.
Discovery that 'toolkits' for 'building' organic structures in future species, were present in other species long before the 'building' was triggered. (E.g, HOX genes in paddlefish, seemingly waiting to be activated by some future trigger. See SCIENCEDAILY on this topic.)
Perhaps some basic analytical investigation is appropriate?
Flint · 13 April 2008
Chris:
I suspect we have a misunderstanding here about what "sincerity" means in a religious context. What I intend to mean is, a plain flat psychological inability to set aside non-negotiable, a priori religious preconceptions. Maybe "deluded beyond redemption" would be a better term than "sincere"?
I read the Dover testimony carefully, and Behe was NOT trying to say that the stack of papers on his lap was relevant research he hadn't bothered to look at. He was trying to say that he KNEW it couldn't be relevant to his religious concerns, because he knows that his religious concerns cannot be researched. One either accepts that goddidit, or one needs to return to church and start praying harder.
Behe understands that if you do not start with religious conclusions, you will not reach religious conclusions. And that if you impose religious conclusions onto your data, why, there they are, right in the data! His data aren't "wrong" and his arguments are sincere, provided you know what you're looking for and are determined to find it, regardless of how you must interpret the data to do so.
raven:
Yes, I think you got it (perhaps you don't realize it). The immune system demonstrates the Hand Of God at work in real time, in each of us, every day. Certainly immune responses are compatible with magical explanations (what isn't?), and you can't prove it's NOT magic. You can only show that the system is also compatible with an atheistic model which might be far more useful for medical purposes, but that doesn't make it RIGHT.
Flint · 13 April 2008
Backer:
You make two arguments here. One is what I've also been saying - that NO natural phenomenon can, in principle, be incompatible with a magical explanation. No question about it, natural feedback processes continue to produce Cadillacs with thumping regularity, needing only our opportunistic ability to exploit what's available us to to be completely divine (though Cadillacs have suffered serious reliability issues...)
The second argument you make is straight post hoc ergo propter hoc, and you seem to have this one mastered. You repeat as many times as you see fit, that if X happened, therefore X was supposed to happen. Who could possibly deny it? Granted, it's a bit weak on the predictive end, needing as it does to wait for something to happen before we can adopt it to the purpose it "must have been meant for". But other than that, well done indeed!
Venus Mousetrap · 13 April 2008
David Stanton · 13 April 2008
Am I the only one who sees that Behe's Backer has a writing style that is creepy in it's similarity to the troll Philip? He was asked repeatedly to explain himself and answer questions and he refused. Now it appears he is back and thinks that he can fool everyone into thinking that his arguments are valid because he has chosen a different name.
Consider the metaphysical nonsense, the sentence fragments, the disjointed facts spewed out appropo of nothing, the question marks at the ends of noniterogative statements, the random use of capital letters, the almost incomprehensible mangling of idioms, the insistence on quantum computers of an organic nature, etc., etc. etc. One could go on at length, but why would one?
Please, if this guy is stupid enough to be using the same computer to make the same arguments, ban him according to the rules. The children will thnk you for it in the morning. If no evidence exists to support my contention, then never mind. Everyone should feel free to respond to his nonsense until he is banned, but I don't intend to dignify him with any more responses.
At least you can send him to TBW. His post is so wildly off-topic it would certainly be appropriate.
David Stanton · 13 April 2008
Man, I stopped reading that stuff half way through. HOX genes and SCIENCEDAILY, Now I know it's Phil.
Venus Mousetrap · 13 April 2008
forget my last sentence :)
Ian Musgrave · 13 April 2008
Mike Elzinga · 13 April 2008
SWT · 13 April 2008
Richard Simons · 13 April 2008
Mike Elzinga · 13 April 2008
David Stanton · 13 April 2008
SWT,
Good luck. Mike has been asking him to explain the "entropy barrier" for a week and for some reason he just doesn't want anyone else to understand it. That seems to be why he changed his handle, so he could avoid questions.
I guess he thinks that entropy somehow requires information in order to be overcome, rather than just energy. Hence the need for a quantum computer and photons that are processed by the magnetic field (however that is supposed to work). Anyway, since he refuses to explain what he means I guess we'll never know. Good bet that it is complete nonsense though.
Funny how he thinks that this stuff is necessaray to mention on every thread (no matter what the topic) but not important enough to explain. Oh, he doesn't know anything about hox genes either, so don't bother asking about that.
Dale Husband · 13 April 2008
Since proteins, along with DNA, RNA, and carbohydrates are polymers (molecules made of repeating units) they could be of infinite length and could be combined in an unlimited number of ways. That alone discredits the concepts of "irreducible complexity" and "complex specified information" that Intelligent Design promoters like Michael Behe and William Demski made issues of many years ago. NOTHING can be irreducibly complex if its parts can be broken down and assembled differently! And specified complexity is such a subjective thing that it is scientifically meaningless.
fnxtr · 14 April 2008
Like I said: Phil's Timecube Lite.
Romartus · 14 April 2008
In fact, it is the outline I posted here and further expanding on it here using excerpts from his site.
Here are PBH’s “quantum computation” site and his “planetary magnetism” site .
I checked the links. I have noticed creationists have a method of writing in a very convoluted way which involves throwing a lot of "data" at you and then refer you to the Bible. It is like expecting that after reading Hamlet that somewhere buried in there is Shakespeare's thoughts about Dark Matter or something such like. Perhaps it is a writing style that is an attempt to bamboozle credulous people into thinking these guys might be on to something....
Mike Elzinga · 14 April 2008
Rick R · 14 April 2008
Like I said about PBH on another thread: a moron with a thesaurus is still a moron.
Ichthyic · 14 April 2008
Perhaps it is a writing style that is an attempt to bamboozle credulous people into thinking these guys might be on to something….
or maybe -just maybe-
they're in serious need of some mental health care.
Torbjörn Larsson, OM · 14 April 2008
Torbjörn Larsson, OM · 14 April 2008
paragwinn · 14 April 2008
A very enlightening post. Thank you and keep up the good work.
Nigel D · 14 April 2008
Ian, thanks for another very readable and informative post.
I deduce from Behe's ramblings that it is far too long since he tried to express and purify a protein in the lab. If he had done, he would know that protein-protein binding sites are cropping up all the time, and often present a barrier to purifying a mammalian protein from a bacterial expression system.
Sometimes, when expressing a mammalian gene in a bacterial system, a bacterial protein will purely by chance exhibit tight binding to the protein of interest. After all, since most of the surface residues on a soluble protein will be capable of participating in hydrogen bonding, it is not surprising that, from the thousand or so proteins expressed by E. coli, one occasionally sees one that possesses a pattern of residues that is complementary to a part of the surface of one's protein of interest.
Ian Musgrave · 14 April 2008
All the Phil Heyward stuff and comments has been moved to the Bathroom Wall, you can continue that conversation over there. (Please, don't feed the trolls here).
David Stanton · 14 April 2008
Thanks Ian.
David vun Kannon, FCD · 14 April 2008
Thank you for including the visuals in a very informative post. They really helped drive home the points.
The point that it is the shape, charge, etc. of the surfaces, rather than the linear codon sequences, that matter undercuts the argument from improbability very well. Is there a canonical version of this counter-argument?
Mike Elzinga · 14 April 2008
Ian Musgrave · 14 April 2008
Ian Musgrave · 14 April 2008
raven · 14 April 2008
Nigel D · 15 April 2008
ievolved · 15 April 2008
I think Behe has got a point.
ievolved · 15 April 2008
You mix alot of them green and red stringy things in a soup of stuff, add a bit of heat. Wait a zillion years and before you know it you have consciousness. Simple really.
Henry J · 15 April 2008
ie,
The first step in constructing an argument is to learn what the other side is saying. Think about it.
bigbang · 13 May 2008
Ian Musgrave says: “Behe claims that for even a simple binding site composed of two amino acids in specific locations that you would need a population of around 1020 organisms to evolve it.”
.
Well, not quite. As. Musgrave probably knows, Behe discusses in his EoE how a single mutation has indeed resulted in a change in the hemoglobin protein site causing sickle cell in humans which provides protection against malaria, but which is actually a degradation of hemoglobin making it less efficient and, unfortunately, also causing sickle cell disease in those individuals having two sickle cell genes, one from each parent.
Also, as many here don’t seem to appreciate, the 10^20 figure is not a probability calculation determined by Behe. Rather it’s a determination made from actual data. (Got that? Actual data.) It’s a determination made by Malaria expert N J White----he determined that it took a population of around 10^20 organisms b/f the Malaria parasite, via random mutation and selection, finally developed resistance to CQ, which required two mutations (apparently not by “simple step by step selectable paths)”.
Finally, as I believe Behe has already explained to Musgrave in one of their back-n-forths, and as noted in Chapter 8 of EoE, the HIV virus has undergone enough mutating in past decades to form all possible viral-viral binding sites, and as Behe originally (and mistakenly) commented in the book, that apparently none of them had been helpful . . . although he now realizes that one of them apparently did help after-all (apparently resulting in one new binding site) via random mutation and selection; but that, similar to the two mutations in the malaria parasite providing CQ resistance, random mutation and selection had to go through around 10^20 viruses to achieve that result.
(Again, this 10^20 figure is not Behe’s estimate or determination of the probability of two “simultaneous” mutations; rather it’s what actual data in he real world tells us that was actually required to get the two mutations that provided malaria with CQ resistance, and what was actually required for HIV to acquire the mutations to evolve the above mentioned viral protein-viral protein binding site; regardless of what anyone here happens to believe about simple step by step selectable paths to protein-protein binding.)
So based on actual available data, rather than just so stories, we conservatively estimate that random mutation and selection required around 10^20 organism to evolve one good protein binding site (which apparently requires at least two mutations----that apparently aren’t attained via “simple step-by-step selectable paths”----and also that is not ultimately a degradation), which means that two new sites would require 10^40 organisms (10^20 *10^20); and considering that it’s been estimated (by others, not by Behe) that there’ve been less than 10^40 cells in Earth’s 4 billion year history, and that most proteins in the cell operate as specific complexes of six or more chains, it looks like Behe’s two-binding-site rule is a reasonable estimate of the edge of evolution via random mutation and selection.
And BTW, as Behe has always maintained, the evidence for common descent is fairly convincing, so common descent isn’t and never has been an issue.
Although life certainly has and continues to evolve, or unfold as it were, the core issue is how much evolution can actually and reasonably be explained as being a result of random mutation and selection. It’s becoming more and more obvious that neo-Darwinian evolution by random mutation and selection is an incomplete theory at best, explaining little more than the microevolution that we can often observe.
Robb Massey · 19 June 2008
I believe Behe actually addresses this sort of phenomena in the footnotes in chapter 8. On page 152, he states: "With a couple of interesting exceptions,(6) protein-protein binding isn't the result of processes analogous to breaking a vase or water freezing around a complex shape. It arises either from searching a huge shape-space library, as the immune system does, or by some nonrandom mechanism".
Footnote 6 (page 293) states the following:
"Proteins sometimes take on the altered shapes of other proteins in neurological diseases such as Alzheimer's (Dobson, C.,M.2002. Protein-misfolding diseases: getting out of shape. Nature 418:729-30). Also, some proteins that bind copies of themselves are thought to have arisen by "domain swapping." That is, areas called "domains" that had been in contact in a single protein instead bind to the analogous region of a second copy of the protein. This scenario does not propose that new binding sites arose, just that pre-existing binding sites got mixed up (Rousseau, F., Schymkowitz,J.W., and Itzhaki, L.,S. 2003. The unfolding story of three-dimensional domain swapping. Structure 11:243-51).
Doesn't the ribonuclease example fall into the "domain swapping" category? Is what we see in this example sufficient enough to assemble new molecular machinery without relying on ANY of the types of protein binding that we see in sickle cell and HIV (VP1)? I could be missing something here but I don't find this to be all that threatening to Behe's thesis. I'm also not a biochemist (just interested in the topic) and I don't have much of a "biochemical imagination", but at face value I can't even begin to imagine how 'domain swapping' could be responsible for the raw material of nearly everything we see in biology (which, if Behe's claims that new protein-protein sites are correct, is necessarily true unless there is some other way). To me this would seem similar to trying to hand paint a colored picture when you only have black and white to mix with.
Regardless though, I think it's wrong to say that Behe does not address this in the book. Even if you disagree with the way he addresses it, he didn't ignore it altogether.
Ian Musgrave · 20 June 2008
Robb Massey · 9 July 2008