Dear Discovery Institute,
Just thought you'd enjoy seeing a recent publication that yet again proves Behe's "irreducible complexity" argument for the bacterial flagellum wrong. Here's the links, hope you enjoy!!
http://www.newscientist.com/channel/life/mg19726431.900-uncovering-the-evolution-of-the-bacterial-flagellum.html
http://pandasthumb.org/archives/2008/02/flagellum-evolu-4.html#more
http://psom.blogspot.com/2008/02/evolutions-engine.html
As I have already touched upon this subject in a previous blog, I will not burden you with a full discussion of this information. The links above will be sufficient to show you some of the implications of the work.
Showing posts with label irreducible complexity. Show all posts
Showing posts with label irreducible complexity. Show all posts
Sunday, February 17, 2008
Saturday, February 16, 2008
Stephen Meyer teaches Wedge Strategy
Dear Discovery Institute,
Haven't written in a while. How have you been? I've been good, but am growing intriqued by the work of Stephen C Meyer, one of your Vice Presidents. As you know, Stephen Meyer is a proponent of the "teach the controversy" approach to evolution and Intelligent Design, and also a supporter of "On Pandas and People", which we have experienced in an earlier discussion. Lets investigate his article titled "The Origin of Life and the Death of Materialism".
First, we will return to a common theme in these blogs. Does this article remain consonant with Wedge Strategy? The answer is a resounding "yes", and as the following quote seems to imply, Intelligent Design is essentially a way to promote Wedge Strategy:
"Thus, for scientific materialists at the end of the nineteenth century, the whole history of the universe and life could be told as a seamless‚ or nearly seamless, unfolding of the potentiality of matter and energy. No longer could it be held that a pre-existent mind shaped matter. Rather, modern science showed that matter shaped and created the capacities of mind (and not the reverse). God did not create "the heavens and the earth." The heavens and the earth (i.e., matter) created (via evolution) the minds that created the concept of God.
By the turn of the twentieth century, this once shockingly materialistic approach to science had become the norm. Most twentieth century scientists have assumed no limits to the explanatory power of materialistic forces. Materialistic modes of thought and assumptions have spread from physics and biology to psychology, sociology, criminology, economics, educational theory, and even theology. Thus, Whitehead would in the end attempt to reconcile science and religion by asserting that even God himself evolves.
Yet now at the end of the twentieth century after many wars and genocidal policies pursued in the name of materialistic "science-based" ideologies, the scientific picture of the world is rapidly changing. From the microcosm of the cell and the quantum world, to the macrocosm of an expanding and finely-tuned universe, the materialistic vision of nature now seems incomplete. Even in biology where Darwin's theory, perhaps more than any other, inspired the possibility of a fully materialistic world view, materialism now seems to be failing as scientists have uncovered an awe-inspiring complexity in even the simplest of living cells. Indeed, nowhere is the inadequacy of materialistic science more evident than in the contemporary discussion of how life in its very "simplest" form might have first originated." (Meyer 1996)
So, as implied by this statement, the materialistic worldview is destined to fall; for those who haven't read my other blogs, in laymen's terms, the implication here is that the very definition of science is supposed to be due to be overthrown (or at least according to Meyer's comments here). But is this truly the case? As I have shown previously, the very structures paraded as "irreducibly complex" by the Intelligent Design movement have been shown to be evolvable. Therefore, this statement by Meyer is obviously outdated, and currently inaccurate. While
most groups would give up an argument once it becomes untenable, however, Discovery Institute still holds onto the "irreducibly complex" argument. Therefore, besides the point that this constitutes an extremely poor attempt at science, it is possible to still use Meyer's 1996 statement to day as a good explanation of Discovery Institute's views, mainly because it is still an accurate representation.
Next, Meyer goes on to attempt to deny the evolvability of DNA (after discussing origin-of-life research, which is not my area of expertise). See, for example, the following quote:
"Second, in nature every amino acid has a distinct mirror image of itself, one left-handed version or L-form and one right-handed version or D-form. These mirror-image forms are called optical isomers. Functioning proteins tolerate only left-handed amino acids, yet the right-handed and left-handed isomers occurs in nature with roughly equal frequency. Taking this into consideration compounds the improbability of attaining a biologically functioning protein. The probability of attaining at random only L-amino acids in a hypothetical peptide chain 100 amino acids long is again (1/2)100 or roughly 1 chance in 10^30. The probability of building a 100 amino acid length chain at random in which all bonds are peptide bonds and all amino acids are L-form would be (1/4)100 or roughly 1 chance in 10^60(zero for all practical purposes given the time available on the early earth). " (Meyer 1996).
While to some readers, this may seem like a valid argument, it is not. In April 2001, Robert Hazen published an article titled "Life's Rocky Start", which discusses geology-based research that accounts for the left-handed bias in amino acids. In this article, Hazen shows that if mineral facies are used as a point of growth for amino acids, then biases in "handedness" will occur. One of the most "useful" minerals for a left-handed bias is Calcite. While research is still ongoing on this possibility, it shows promising results thus far.
It is also worth noting that Meyer goes on to claim that Intelligent Design is the only known explanation for the creation of "information" in organic systems. Let's see the claim, however:
"since intelligent design is the only known cause of information-rich systems, the presence of information--including the information-rich nucleotide sequences in DNA--implies an intelligent source. Scientists in many fields recognize the connection between intelligence and information and make inferences accordingly. Archaeologists assume a mind produced the inscriptions on the Rosetta Stone. Evolutionary anthropologists try to demonstrate the intelligence of early hominids by arguing that certain chipped flints are too improbably specified to have been produced by natural causes. N.A.S.A.'s search for extra-terrestrial intelligence (S.E.T.I.) presupposed that information imbedded in electromagnetic signals from space would indicate an intelligent source. As yet, however, radio-astronomers have not found information-bearing signals coming from space. But closer to home, molecular biologists have identified encoded information in the cell. Consequently, a growing number of scientists now suggest that the information in DNA justifies making what probability theorist William Dembski and biochemist Michael Behe call "the design inference." (Meyer 1996).
To disprove this statement would severly undermine Meyer's credibility, and the credibility of the Discovery Institute as a whole. So, lets consider the following question: Is Intelligent Design the only explanation for the evolution of biological information? No. But don't take my word for it; let's see some of the technical literature!! First, here's an experiment showing the evolvability of information. I will quote the abstract, then link the entire article under works cited:
"How do genetic systems gain information by evolutionary processes? Answering this question precisely requires a robust, quantitative measure of information. Fortunately, 50 years ago Claude Shannon defined information as a decrease in the uncertainty of a receiver. For molecular systems, uncertainty is closely related to entropy and hence has clear connections to the Second Law of Thermodynamics. These aspects of information theory have allowed the development of a straightforward and practical method of measuring information in genetic control systems. Here this method is used to observe information gain in the binding sites for an artificial ‘protein’ in a computer simulation of evolution. The simulation begins with zero information and, as in naturally occurring genetic systems, the information measured in the fully evolved binding sites is close to that needed to locate the sites in the genome. The transition is rapid, demonstrating that information gain can occur by punctuated equilibrium. " (Schneider 2000)
There's one source showing that information is evolvable. Is this conclusion repeatable? Adami et al show that it is, in fact reproducable.
"To make a case for or against a trend in the evolution of complexity in biological evolution, complexity needs to be both rigorously defined and measurable. A recent information-theoretic (but intuitively evident) definition identifies genomic complexity with the amount of information a sequence stores about its environment. We investigate the evolution of genomic complexity in populations of digital organisms and monitor in detail the evolutionary transitions that increase complexity. We show that, because natural selection forces genomes to behave as a natural "Maxwell Demon," within a fixed environment, genomic complexity is forced to increase. " (Adami et al 2000)
Thus, the claim that Intelligent Design is the only explanation for biological complexity is proven false. Yet another blow to the coffin of Intelligent Design, and also the Discovery Institute's Wedge Strategy. Let us conclude with a final quote from Meyer's 1996 article:
"Other work promises to reshape our conception, not only of living things but of our science and ourselves. If the simplest life owes its origin to an intelligent Creator, then perhaps man is not the "cosmic orphan" that twentieth century scientific materialism has taught. Perhaps then, during the twenty first century, the traditional moral and spiritual foundations of the West will find support from the very sciences that once seemed to undermine them. " (Meyer 1996)
Here we see more of Discovery Institute's Wedge Strategy at work. This is a telling quote, because it shows that Intelligent Design advocates are appealing to religion as a source of legitimacy to some degree; see, for example, how the above quote attempts to show that Intelligent Design proves the validity of religion. As shown by the blogs on this site, however, Intelligent Design does not itself have scientific validity as a theory. However, ID proponents keep attempting to undermine the definition of modern science in attempt to give their "theory" scientific validity. Until they can provide compelling evidence in favor of this action, their attempts to gain scientific validity will consistently fail.
Works Cited:
Adami, C., Ofria, C., Collier, T. "Evolution of Biological Complexity". PNAS, April 25, 2000. Vol. 97, no. 9. 4463-4468. http://www.pnas.org/cgi/content/full/97/9/4463
Hazen, R. "Life's Rocky Start". Scientific American, April 2001.
Meyer, S.C. "The Origin of Life and the Death of Materialism". The Intercollegiate Review 31, no. 2. April 1, 1996.
http://www.discovery.org/a/98
Schneider, T. "Evolution of Biological Information" Nucleic Acids Research, 2000. Vol. 28 No 14. 2794-2799. http://nar.oxfordjournals.org/cgi/content/full/28/14/2794
Haven't written in a while. How have you been? I've been good, but am growing intriqued by the work of Stephen C Meyer, one of your Vice Presidents. As you know, Stephen Meyer is a proponent of the "teach the controversy" approach to evolution and Intelligent Design, and also a supporter of "On Pandas and People", which we have experienced in an earlier discussion. Lets investigate his article titled "The Origin of Life and the Death of Materialism".
First, we will return to a common theme in these blogs. Does this article remain consonant with Wedge Strategy? The answer is a resounding "yes", and as the following quote seems to imply, Intelligent Design is essentially a way to promote Wedge Strategy:
"Thus, for scientific materialists at the end of the nineteenth century, the whole history of the universe and life could be told as a seamless‚ or nearly seamless, unfolding of the potentiality of matter and energy. No longer could it be held that a pre-existent mind shaped matter. Rather, modern science showed that matter shaped and created the capacities of mind (and not the reverse). God did not create "the heavens and the earth." The heavens and the earth (i.e., matter) created (via evolution) the minds that created the concept of God.
By the turn of the twentieth century, this once shockingly materialistic approach to science had become the norm. Most twentieth century scientists have assumed no limits to the explanatory power of materialistic forces. Materialistic modes of thought and assumptions have spread from physics and biology to psychology, sociology, criminology, economics, educational theory, and even theology. Thus, Whitehead would in the end attempt to reconcile science and religion by asserting that even God himself evolves.
Yet now at the end of the twentieth century after many wars and genocidal policies pursued in the name of materialistic "science-based" ideologies, the scientific picture of the world is rapidly changing. From the microcosm of the cell and the quantum world, to the macrocosm of an expanding and finely-tuned universe, the materialistic vision of nature now seems incomplete. Even in biology where Darwin's theory, perhaps more than any other, inspired the possibility of a fully materialistic world view, materialism now seems to be failing as scientists have uncovered an awe-inspiring complexity in even the simplest of living cells. Indeed, nowhere is the inadequacy of materialistic science more evident than in the contemporary discussion of how life in its very "simplest" form might have first originated." (Meyer 1996)
So, as implied by this statement, the materialistic worldview is destined to fall; for those who haven't read my other blogs, in laymen's terms, the implication here is that the very definition of science is supposed to be due to be overthrown (or at least according to Meyer's comments here). But is this truly the case? As I have shown previously, the very structures paraded as "irreducibly complex" by the Intelligent Design movement have been shown to be evolvable. Therefore, this statement by Meyer is obviously outdated, and currently inaccurate. While
most groups would give up an argument once it becomes untenable, however, Discovery Institute still holds onto the "irreducibly complex" argument. Therefore, besides the point that this constitutes an extremely poor attempt at science, it is possible to still use Meyer's 1996 statement to day as a good explanation of Discovery Institute's views, mainly because it is still an accurate representation.
Next, Meyer goes on to attempt to deny the evolvability of DNA (after discussing origin-of-life research, which is not my area of expertise). See, for example, the following quote:
"Second, in nature every amino acid has a distinct mirror image of itself, one left-handed version or L-form and one right-handed version or D-form. These mirror-image forms are called optical isomers. Functioning proteins tolerate only left-handed amino acids, yet the right-handed and left-handed isomers occurs in nature with roughly equal frequency. Taking this into consideration compounds the improbability of attaining a biologically functioning protein. The probability of attaining at random only L-amino acids in a hypothetical peptide chain 100 amino acids long is again (1/2)100 or roughly 1 chance in 10^30. The probability of building a 100 amino acid length chain at random in which all bonds are peptide bonds and all amino acids are L-form would be (1/4)100 or roughly 1 chance in 10^60(zero for all practical purposes given the time available on the early earth). " (Meyer 1996).
While to some readers, this may seem like a valid argument, it is not. In April 2001, Robert Hazen published an article titled "Life's Rocky Start", which discusses geology-based research that accounts for the left-handed bias in amino acids. In this article, Hazen shows that if mineral facies are used as a point of growth for amino acids, then biases in "handedness" will occur. One of the most "useful" minerals for a left-handed bias is Calcite. While research is still ongoing on this possibility, it shows promising results thus far.
It is also worth noting that Meyer goes on to claim that Intelligent Design is the only known explanation for the creation of "information" in organic systems. Let's see the claim, however:
"since intelligent design is the only known cause of information-rich systems, the presence of information--including the information-rich nucleotide sequences in DNA--implies an intelligent source. Scientists in many fields recognize the connection between intelligence and information and make inferences accordingly. Archaeologists assume a mind produced the inscriptions on the Rosetta Stone. Evolutionary anthropologists try to demonstrate the intelligence of early hominids by arguing that certain chipped flints are too improbably specified to have been produced by natural causes. N.A.S.A.'s search for extra-terrestrial intelligence (S.E.T.I.) presupposed that information imbedded in electromagnetic signals from space would indicate an intelligent source. As yet, however, radio-astronomers have not found information-bearing signals coming from space. But closer to home, molecular biologists have identified encoded information in the cell. Consequently, a growing number of scientists now suggest that the information in DNA justifies making what probability theorist William Dembski and biochemist Michael Behe call "the design inference." (Meyer 1996).
To disprove this statement would severly undermine Meyer's credibility, and the credibility of the Discovery Institute as a whole. So, lets consider the following question: Is Intelligent Design the only explanation for the evolution of biological information? No. But don't take my word for it; let's see some of the technical literature!! First, here's an experiment showing the evolvability of information. I will quote the abstract, then link the entire article under works cited:
"How do genetic systems gain information by evolutionary processes? Answering this question precisely requires a robust, quantitative measure of information. Fortunately, 50 years ago Claude Shannon defined information as a decrease in the uncertainty of a receiver. For molecular systems, uncertainty is closely related to entropy and hence has clear connections to the Second Law of Thermodynamics. These aspects of information theory have allowed the development of a straightforward and practical method of measuring information in genetic control systems. Here this method is used to observe information gain in the binding sites for an artificial ‘protein’ in a computer simulation of evolution. The simulation begins with zero information and, as in naturally occurring genetic systems, the information measured in the fully evolved binding sites is close to that needed to locate the sites in the genome. The transition is rapid, demonstrating that information gain can occur by punctuated equilibrium. " (Schneider 2000)
There's one source showing that information is evolvable. Is this conclusion repeatable? Adami et al show that it is, in fact reproducable.
"To make a case for or against a trend in the evolution of complexity in biological evolution, complexity needs to be both rigorously defined and measurable. A recent information-theoretic (but intuitively evident) definition identifies genomic complexity with the amount of information a sequence stores about its environment. We investigate the evolution of genomic complexity in populations of digital organisms and monitor in detail the evolutionary transitions that increase complexity. We show that, because natural selection forces genomes to behave as a natural "Maxwell Demon," within a fixed environment, genomic complexity is forced to increase. " (Adami et al 2000)
Thus, the claim that Intelligent Design is the only explanation for biological complexity is proven false. Yet another blow to the coffin of Intelligent Design, and also the Discovery Institute's Wedge Strategy. Let us conclude with a final quote from Meyer's 1996 article:
"Other work promises to reshape our conception, not only of living things but of our science and ourselves. If the simplest life owes its origin to an intelligent Creator, then perhaps man is not the "cosmic orphan" that twentieth century scientific materialism has taught. Perhaps then, during the twenty first century, the traditional moral and spiritual foundations of the West will find support from the very sciences that once seemed to undermine them. " (Meyer 1996)
Here we see more of Discovery Institute's Wedge Strategy at work. This is a telling quote, because it shows that Intelligent Design advocates are appealing to religion as a source of legitimacy to some degree; see, for example, how the above quote attempts to show that Intelligent Design proves the validity of religion. As shown by the blogs on this site, however, Intelligent Design does not itself have scientific validity as a theory. However, ID proponents keep attempting to undermine the definition of modern science in attempt to give their "theory" scientific validity. Until they can provide compelling evidence in favor of this action, their attempts to gain scientific validity will consistently fail.
Works Cited:
Adami, C., Ofria, C., Collier, T. "Evolution of Biological Complexity". PNAS, April 25, 2000. Vol. 97, no. 9. 4463-4468. http://www.pnas.org/cgi/content/full/97/9/4463
Hazen, R. "Life's Rocky Start". Scientific American, April 2001.
Meyer, S.C. "The Origin of Life and the Death of Materialism". The Intercollegiate Review 31, no. 2. April 1, 1996.
http://www.discovery.org/a/98
Schneider, T. "Evolution of Biological Information" Nucleic Acids Research, 2000. Vol. 28 No 14. 2794-2799. http://nar.oxfordjournals.org/cgi/content/full/28/14/2794
Thursday, January 10, 2008
Reducing the Irreducibly Complex
Dear Discovery Institute,
Today I have been thinking about the work of Michael Behe of Lehigh University. Behe's concept of irreducible complexity appears sufficient to support Design theory, until it is critically considered at least. Today we will investigate exactly why the concept of irreducible complexity is flawed, and requires more support before it is accepted as a valid scientific concept.
First, we will critically consider some of "Darwin's Black Box", considered by many to be the seminal work (along with Philip Johnson's "Darwin On Trial") on Intelligent Design. First, Behe seems to confuse the definition of evolution (the diversification of life) with that of abiogenesis (the origin of life). Lets hear it in his own words:
evolution means a process whereby life arose from non-living matter and subsequently developed entirely by natural means. (Behe 2006 p.xi).
While the natural cause explanation clause is a major part of the definition of science (Behe has that statement correct),he is obviously confused about the very definition of Darwinian evolution, the theory which his entire book attempts to debunk. That fact raises major credibility questions. However, lets give Behe the benefit of the doubt for now. Let's consider his irreducibly complex structures.
Behe's poster child for irreducible complexity is the bacterial flagellum. If this stucture can be shown to be "evolvable", then this raises major questions about the validity of irreducible complexity. NJ Matzke has done just that with his article "Evolution in (Brownian) space: a model for the origin of the bacterial flagellum". While I suggest reading his entire piece (cited and linked below), here is the abstract of Matzke's piece, which shows exactly why the words "irreducibly complex" fail to describe the bacterial flagellum:
"The bacterial flagellum is a complex molecular system with multiple components required for functional motility. Such systems are sometimes proposed as puzzles for evolutionary theory on the assumption that selection would have no function to act on until all components are in place. Previous work (Thornhill and Ussery, 2000, A classification of possible routes of Darwinian evolution. J Theor Biol. 203 (2), 111-116) has outlined the general pathways by which Darwinian mechanisms can produce multi-component systems. However, published attempts to explain flagellar origins suffer from vagueness and are inconsistent with recent discoveries and the constraints imposed by Brownian motion. A new model is proposed based on two major arguments. First, analysis of dispersal at low Reynolds numbers indicates that even very crude motility can be beneficial for large bacteria. Second, homologies between flagellar and nonflagellar proteins suggest ancestral systems with functions other than motility. The model consists of six major stages: export apparatus, secretion system, adhesion system, pilus, undirected motility, and taxis-enabled motility. The selectability of each stage is documented using analogies with present-day systems. Conclusions include: (1) There is a strong possibility, previously unrecognized, of further homologies between the type III export apparatus and F1F0-ATP synthetase. (2) Much of the flagellum’s complexity evolved after crude motility was in place, via internal gene duplications and subfunctionalization. (3) Only one major system-level change of function, and four minor shifts of function, need be invoked to explain the origin of the flagellum; this involves five subsystem-level cooption events. (4) The transition between each stage is bridgeable by the evolution of a single new binding site, coupling two pre-existing subsystems, followed by coevolutionary optimization of components. Therefore, like the eye contemplated by Darwin, careful analysis shows that there are no major obstacles to gradual evolution of the flagellum." (Matzke 2006).
There it is, right in Matzke's article. An allegedly "irreducibly complex" structure shown to be evolvable. Science once again trumps the Intelligent Design movement. Bad arguments in favor of supposed design do not qualify as science, especially when the "designer" in question, as well as the presence of "design" itself, remains inherently untestable.
But let's play Behe's game. The blood clotting mechanism in blood is Behe's other major "irreducible complex" structure. And as with the bacterial flagellum, it is shown to be evolvable. For example, check out the work of Kenneth Miller (a good rebuttal to Behe's blood clotting argument is available on the following site, which will not be cited because it is linked within the text: http://www.millerandlevine.com/km/evol/DI/Clotting.html )
On the site linked, Kenneth Miller does an absolutely beautiful job of refuting Behe's research on "irreducible complexity". It's sad that so many people have accepted Behe's concept of irreducible complexity when he has not even been able to provide an "irreducibly complex" structure that has withstood scrutiny. All of his examples have been shown to be evolvable. The argument from personal incredulity is not a valid argument to use to disprove Darwinian evolution. Strong evidence in favor of your viewpoint is provided. Behe has failed to provide this.
In conclusion, while scientists are still working to understand the exact nature of abiogenesis (the origin of life), that fact does not make Darwinian evolution false. Darwinian evolution does not attempt to explain how life arose; it only explains how it has subsequentially diversified. Those people claiming that evolutionary theory is sufficient to explain the origin of life are grasping at straws. Darwinian Natural Selection, by nature, requires reproduction to occur, which, in turn, requires life to be in existance. Darwin's black box? Not quite.
Works Cited:
Behe, MJ. "Darwin's Black Box: The Biochemical Challenge to Evolution". Free Press, NY. 2006. 10th Anniversary edition.
Matzke, NJ. "Evolution in (Brownian) space: a model for the origin of the bacterial flagellum". originally published 2003, updated 2006. http://www.talkdesign.org/faqs/flagellum.html
Today I have been thinking about the work of Michael Behe of Lehigh University. Behe's concept of irreducible complexity appears sufficient to support Design theory, until it is critically considered at least. Today we will investigate exactly why the concept of irreducible complexity is flawed, and requires more support before it is accepted as a valid scientific concept.
First, we will critically consider some of "Darwin's Black Box", considered by many to be the seminal work (along with Philip Johnson's "Darwin On Trial") on Intelligent Design. First, Behe seems to confuse the definition of evolution (the diversification of life) with that of abiogenesis (the origin of life). Lets hear it in his own words:
evolution means a process whereby life arose from non-living matter and subsequently developed entirely by natural means. (Behe 2006 p.xi).
While the natural cause explanation clause is a major part of the definition of science (Behe has that statement correct),he is obviously confused about the very definition of Darwinian evolution, the theory which his entire book attempts to debunk. That fact raises major credibility questions. However, lets give Behe the benefit of the doubt for now. Let's consider his irreducibly complex structures.
Behe's poster child for irreducible complexity is the bacterial flagellum. If this stucture can be shown to be "evolvable", then this raises major questions about the validity of irreducible complexity. NJ Matzke has done just that with his article "Evolution in (Brownian) space: a model for the origin of the bacterial flagellum". While I suggest reading his entire piece (cited and linked below), here is the abstract of Matzke's piece, which shows exactly why the words "irreducibly complex" fail to describe the bacterial flagellum:
"The bacterial flagellum is a complex molecular system with multiple components required for functional motility. Such systems are sometimes proposed as puzzles for evolutionary theory on the assumption that selection would have no function to act on until all components are in place. Previous work (Thornhill and Ussery, 2000, A classification of possible routes of Darwinian evolution. J Theor Biol. 203 (2), 111-116) has outlined the general pathways by which Darwinian mechanisms can produce multi-component systems. However, published attempts to explain flagellar origins suffer from vagueness and are inconsistent with recent discoveries and the constraints imposed by Brownian motion. A new model is proposed based on two major arguments. First, analysis of dispersal at low Reynolds numbers indicates that even very crude motility can be beneficial for large bacteria. Second, homologies between flagellar and nonflagellar proteins suggest ancestral systems with functions other than motility. The model consists of six major stages: export apparatus, secretion system, adhesion system, pilus, undirected motility, and taxis-enabled motility. The selectability of each stage is documented using analogies with present-day systems. Conclusions include: (1) There is a strong possibility, previously unrecognized, of further homologies between the type III export apparatus and F1F0-ATP synthetase. (2) Much of the flagellum’s complexity evolved after crude motility was in place, via internal gene duplications and subfunctionalization. (3) Only one major system-level change of function, and four minor shifts of function, need be invoked to explain the origin of the flagellum; this involves five subsystem-level cooption events. (4) The transition between each stage is bridgeable by the evolution of a single new binding site, coupling two pre-existing subsystems, followed by coevolutionary optimization of components. Therefore, like the eye contemplated by Darwin, careful analysis shows that there are no major obstacles to gradual evolution of the flagellum." (Matzke 2006).
There it is, right in Matzke's article. An allegedly "irreducibly complex" structure shown to be evolvable. Science once again trumps the Intelligent Design movement. Bad arguments in favor of supposed design do not qualify as science, especially when the "designer" in question, as well as the presence of "design" itself, remains inherently untestable.
But let's play Behe's game. The blood clotting mechanism in blood is Behe's other major "irreducible complex" structure. And as with the bacterial flagellum, it is shown to be evolvable. For example, check out the work of Kenneth Miller (a good rebuttal to Behe's blood clotting argument is available on the following site, which will not be cited because it is linked within the text: http://www.millerandlevine.com/km/evol/DI/Clotting.html )
On the site linked, Kenneth Miller does an absolutely beautiful job of refuting Behe's research on "irreducible complexity". It's sad that so many people have accepted Behe's concept of irreducible complexity when he has not even been able to provide an "irreducibly complex" structure that has withstood scrutiny. All of his examples have been shown to be evolvable. The argument from personal incredulity is not a valid argument to use to disprove Darwinian evolution. Strong evidence in favor of your viewpoint is provided. Behe has failed to provide this.
In conclusion, while scientists are still working to understand the exact nature of abiogenesis (the origin of life), that fact does not make Darwinian evolution false. Darwinian evolution does not attempt to explain how life arose; it only explains how it has subsequentially diversified. Those people claiming that evolutionary theory is sufficient to explain the origin of life are grasping at straws. Darwinian Natural Selection, by nature, requires reproduction to occur, which, in turn, requires life to be in existance. Darwin's black box? Not quite.
Works Cited:
Behe, MJ. "Darwin's Black Box: The Biochemical Challenge to Evolution". Free Press, NY. 2006. 10th Anniversary edition.
Matzke, NJ. "Evolution in (Brownian) space: a model for the origin of the bacterial flagellum". originally published 2003, updated 2006. http://www.talkdesign.org/faqs/flagellum.html
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