Figure 1: An artist’s
rendition of a flagellum as it appears on William Dembski’s blog Uncommon Descent. A similar
image appears on the dust cover of Dembski’s book No Free Lunch.
by Mark Perakh
In 1996 a
professor of biochemistry at Lehigh University named Michael
Behe published Darwin’s Black Box1,
in which he presented his concept of “irreducible complexity” (IC).
Behe and his Intelligent Design (ID) colleagues claim that IC is
strong evidence of “design” of biological systems, and ever since
his book IC has acquired the status of one of the main pillars of
the Intelligent Design platform.
The concept of irreducible complexity was in fact known for many
years before Behe’s book. The Nobel Prize winning biologist Hermann
J. Müller had already discussed it (under the slightly different
name of “interlocking complexity”) in 1918.2
Some 10 years before Behe’s book the same idea was explored by A.
Unlike Behe, however, these pioneers did not claim that the concept
in question was a great discovery on a par with those by “Newton and
Einstein, Lavoisier and Schroedinger, Pasteur, and Darwin” (as Behe
asserted in Darwin’s Black Box).
Neither did they claim that “irreducible complexity” was a “marker”
of a supernatural design. To the contrary, according to Müller,
development of interlocking complexity in biological systems is to
be expected from Darwinian evolution. Therefore the concept in
question, as such, evoked no resistance from mainstream science.
As an example of an allegedly irreducibly complex system Behe
suggested a mousetrap. Soon afterwards, in multiple publications by
various Intelligent Design advocates, images of a mousetrap were
endlessly reproduced. The mousetrap, however, was not accepted by
the mainstream scientific community as a genuine example of IC. For
example, professor of biology John McDonald suggested4
an animated illustration of how, starting with just a piece of a
hook-shaped wire serving as a primitive mice-catching device, a
full-fledged mousetrap can be gradually built up via two-part, then
three-part, etc. contraptions, improving its mice-catching ability
at each step in a Darwinian fashion.
Apparently finally realizing that a mousetrap was not a very
successful choice for illustrating Behe’s IC concept, ID advocates
switched to another example — a bacterial flagellum, a “device” used
by bacteria for motility.5
By 2002, the image of a flagellum had become a ubiquitous
accompaniment to ID advocates’ books, papers, lecture slides, etc.
According to one of the main advocates of ID, William Dembski, the
flagellum had become the “mascot” of ID. The image of the flagellum
appeared on the cover of Dembski’s book
No Free Lunch6,
on creationist blogs, etc.
(above article title) shows an image of a flagellum as it appears on
Dembski’s blog named Uncommon Descent.
Notice the smooth surface of the depicted contraption, its perfect
symmetry, its tightly fitting components — features we usually see
in man-made machinery. This image is a product of an artist’s
imagination of how a flagellum “must” look. Does this image
truthfully represent the real flagellum? No.
Figure 2: A schematic model
of a flagellum. From Yonekura, K., S. Maki, D. G. Morgan, D. J.
DeRosier, F.Vonderviszt, K.Imada, and K. Namba, 2000. “The
Bacterial Flagellar Cap as the Rotary Promoter of Flagellin
Self-Assembly”, Science 290: 2148–2152.
Flagella are tiny organelles that can’t be seen directly by the
unaided human eye. Their dimensions are measured in nanometers
(billionths of a meter). Modern versions of cryogenic electron
microscopy and of X-ray techniques have, though, enabled scientists
to form a pretty good understanding of flagellum’s structure and
shape. Figure 2 shows a schematic model of a flagellum’s structure.7
This model (one of several published in scientific literature) is a
theoretical interpretation of the data obtained via electron
microscopy, and mainstream scientists construe it more as an
idealized schematic than a true-to-life representation of a
flagellum’s actual structure. ID advocates, however, happily treat
such images as if they are real replicas of the tiny flagella,
usually providing no disclaimers as to the degree of idealization
inherent in such images.
Figure 3: A composite
electron micrograph of flagella. It has been obtained by a
superposition of multiple photographs shot from various angles,
of a number of flagella. From Francis, N. R., Sosinsky, G. E.,
Thomas, D. and DeRosier, D. J., 1994. “Isolation,
characterization and structure of bacterial flagellar motors
containing the switch complex.” J Mol Biol. 235 (4), 1261–1270.
In 2004, when Dembski debated Professor Niall Shanks (at UCLA) he
a different image of a flagellum (Figure 3). Unlike Figures 1 and 2,
Figure 3 is neither an artist’s rendition, nor a schematic
theoretical model; it is a “real” electron-microscopic
photographically obtained image. While produced by scientists, such
images are often exploited by ID advocates who are fond of pointing
out their striking similarity to man-made machines. However, such
illustrations are misleading, picturing the flagellum in a
geometrically perfect shape, fully symmetric and consisting of
geometrically perfectly formed parts. The real flagellum is far from
having such a perfect geometric shape. Unlike machines, which may be
close replicas of each other (say, all Jeeps of the same year have
almost exactly the same shape) the real flagella, first, have shapes
with many deviations from a perfect geometric symmetry, and, second,
there are no two flagella exactly identical. Individual flagella
differ in various respects, just as biological organisms vary from
individual to individual.
Likewise, when I debated Behe on February 15, 2008 on a Larry
Kane’s TV show on the Comcast network, Behe supported his pro-ID
thesis by displaying the same images of a flagellum as shown in
Figures 1, 2 and 3. Behe’s argument essentially boiled down to the
stale asseveration that can be succinctly summarized as follows:
“You see — it looks like a man-made machine! If it looks like a
duck, then it must be a duck! All machines we are familiar with have
been designed. Therefore the flagellum must be a product of
intelligent design!” Oddly, Behe and his ID friends seem not to
realize that the “it must be a duck” argument is an obvious
non-sequitur: there are numerous examples of objects whose
appearance is deceptive. Just think of the mimicry, so common in
nature. For example, look up the article on “Mimicry” in Wikipedia
where examples are presented of animals looking like “twigs, bark,
leaves, or flowers” etc., thus negating the “it must be a duck”
Figure 4: The structure of
the hook—a part of a flagellum. From Samatey F.A., Matsunami,
H., Imada, K., Nagashima, S., Shaikh, T.R., Thomas, D.R., Chen,
J.Z., Derosier, D.J., Kitao, A., Namba, K. “Structure of the
bacterial flagellar hook and implication for the molecular
universal joint mechanism.” Nature. 2004, Oct 28;431(7012):1047. (In the online version
the image is animated, illustrating the flagellar hook’s rotation, see
this webpage. Reproduced in accordance with the blanket
permission granted in the referenced website, stipulating that a
reference to the above article as well as to
proteinexplorer.org is provided.
In fact the images that Behe, Dembski, and their ID colleagues
show are often not pictures of real flagella. Some of them are just
products of an artist’s imagination (Figure 1); others are
computer-generated images of imaginary machine-like contraptions.
The schematics like that in Figure 2, while reflecting many actual
features of flagella, are products of a modeling approximation which
likewise can’t pretend to reflect adequately the actual structure of
a tiny organelle. However, some other pictures of flagella may
indeed be “real” photographically obtained images (Figure 3). Are
the images in the latter category adequate representations of the
Look again at Figure 3. It is, at a glance, impressive. Indeed we
see here a contraption which is symmetric, its structure
machine-like, so it is easy to understand the satisfaction of
Dembski and Behe at the sight of this contraption so neatly fitting
in with their “design” hypothesis. There are, however, two important
details that must be noted. The first detail is that the image in
Figure 3 is a composite photo.
It is the result of a superposition of many photos, of several
flagella, made from various angles. This way the image in question
is eliminating from view various imperfections which, unlike in
man-made machinery, are inherent in every natural flagellum.
Moreover, the procedure of superposition of a number of photos
eliminates from view the inevitable individual differences between
various flagella, which radically distinguish flagella from
The second detail is that the resolution of this picture is
insufficient to see the flagellum’s intrinsic structure. To
appreciate the significance of this, recall, by analogy, the “face
on Mars,” or Lowell’s nonexisting Martian “canals.” When the
resolution is insufficient, we “see” nonexisting structures, which
on closer inspection look dissolve into natural patterns. This is
equally true for the images of very small objects perused under
insufficient magnification and/or resolution. The images of flagella
obtained at higher resolution, and assisted by other modern
sophisticated methods of investigation, reveal the actual
configuration of flagella, demonstrating that the seeming
machine-like appearance of the flagella in Figure 3 is deceptive.
Figure 5: The structure of
the flagellar filament. Side views showing the inner side (left)
and outer surface (right). The amino acid sequence of each
flagellin subunit is color-coded. From Yonekura, K., Maki-Yonekura,
S., Namba, K. “Complete atomic model of the bacterial flagellar
filament by electron cryomicroscopy.”
Nature, 424: 643–650 (2003);
It should be noted that scientists often use such terms as
“machine” when describing various biological assemblies. This usage,
however, unlike in case of ID advocates, is purely metaphorical,
reflecting the superficial resemblance of certain biological
structures to man-made machinery. Scientists normally do not imply
that biological entities are intrinsically similar to man-made
machinery. Perhaps such a usage by scientists is not very fortunate
given ID advocates’ misuse of the superficial resemblance between
the designed man-made objects and natural biological entities. We
have to realize, though, that scientists by and large are not aware
of ID advocates’ misuse of such terminology, as only a small
minority of scientists pay any attention to ID advocates’ actions.
Let us look at a few selected illustrations of my thesis. The
detailed images of the flagella structure obtained via cryogenic
electron microscopy combined with sophisticated X-rays techniques
are exemplified in Figures 4, 5, and 6. These images, showing the
actual configuration of the flagellum, have been selected
practically at random from numerous similar images available in the
scientific literature. Instead of tightly-fit machine-like parts, we
see in these pictures convoluted garlands of protein molecules.
These structures look similar to typical bacteriophage viruses5,
and have nothing in common with any man-made machine. They vividly
illustrate that the image shown in Figure 3 is deceptive and owes
its machine-like appearance to the insufficient resolution (not to
mention the utter artificiality of the artist’s renditions of
flagella, whose variations serve as “mascots” of ID).
Figure 6: Partial structure
of the flagellar filament�s cross-section. By Keiichi Namba. See
ID advocates often point to the allegedly fraudulent “icons of
evolution” utilized by “Darwinists” for their nefarious purposes.9
One such “icon” are the illustrations of embryos made by the
19th-century German biologist Ernst Haeckel. In fact, the faults of
Haeckel’s embryological illustrations (dated 1874) were revealed not
by creationists but rather by the “Darwinists” themselves.10
On the other hand, creationists of various hues, including ID
advocates such as Dembski and Behe, incessantly reproduce images of
flagella that are often heavily doctored, without any disclaimers as
to the great degree of idealization inherent in these images.
Indeed, look again at the images of flagella’s actual molecular
structure, as shown above in Figures 4, 5, and 6, and it becomes
obvious that real natural flagella are far from looking like
An interesting question arises: Why ID advocates and other
creationists, who so eagerly and persistently display pictures like
those in Figures 1, 2, and 3, never deign to show much more
realistic representations of flagella structure such as those shown
in Figures 4, 5, and 6? If they are unaware of these better
pictures, perhaps they should try to educate themselves regarding
the entirety of the available information about flagella? If,
though, they are familiar with the images such as those shown in
Figures 4, 5, and 6 (which are freely available both in print and on
the internet) could it then be that they are less interested in
facts and truth and more focused on winning the “cultural war” by
We must conclude that the argument in favor of “design” of
biological entities based on their alleged similarity to man-made
machinery is not supported by evidence.
Acknowledgment: My thanks to Matt Young, Paul R. Gross, and Nicholas
Matzke for pithy advice.
- Behe, Michael, 1996.
Darwin’s Black Box. New York: Free Press.
- Muller, Hermann J. 1918. “Genetic Variability,
Twin Hybrids and Constant Hybrids, in a Case of Balanced Lethal
Factors.” Genetics 3:422–499.
- Cairns-Smith, A. Graham 1986.
Seven Clues to the Origin of Life: A Scientific Detective Story. Cambridge University
- MacDonald, John. Online:
- Luria, Salvador E., Stephen J. Gould, and Sam Singer. 1981.
A View of Life. Menlo Park, CA: The Benjamin Cummings Publishing Co.
- Dembski, William A. 2002.
No Free Lunch: Why Specified Complexity Cannot Be Purchased Without Intelligence.
Lanham, MD: Rowman & Littlefield Publishers.
- Yonekura, K., S. Maki, D. G. Morgan, D. J.
DeRosier, F. Vonderviszt, K. Imada, and K. Namba, 2000. “The
Bacterial Flagellar Cap as the Rotary Promoter of Flagellin
Self-Assembly.” Science 290: 2148–2152.
- Perakh, Mark. 2004. “Three SH’s and One D.” Online at Panda’s Thumb:
- Wells, Jonathan. 2002.
Icons of Evolution: Science or Myth? Why Much of What We Teach About Evolution is Wrong. New York: Regnery.
- Nic Tamzek (Nicholas Matzke). “Icon of Obfuscation”. In Talk Reason:
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