Download Intelligent Design has no evidence to support its positive

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Cody Cobb
ENG 1304
Geoffrey Reiter
25 April 2006
Unintelligence Denied: Why ID Has No Place in a Science Classroom
Charles Darwin and Alfred Russell Wallace’s theory of evolution via natural
selection has been the best explanation for the origin of species for the past century and a
half because it explains so much and is corroborated by many observations of natural
phenomena. The processes of inheritable mutation and natural selection are the
mechanisms which best explain the evidence for evolution. However, a new group of
scientists and philosophers have, in recent years, sought to replace or at least supplement
the theory of evolution via natural selection with a new theory, which they call intelligent
design. Writing in Intelligent Design: The Bridge between Science and Theology, Dr.
William Dembski states, “its fundamental claim is that intelligent causes are necessary to
explain the complex, information-rich structures of biology and that these causes are
empirically detectable” (Dembski 106).
Supporters of intelligent design think their theory and criticisms of evolution –
both of which are rejected by nearly all major institutions of scientists – warrant inclusion
in public science classrooms. However, such changes would be misguided and potentially
damaging to the students’ education, because intelligent design theory and the criticisms
of evolution that are derived from it can be shown to be scientifically vacuous. On these
grounds, no science curriculum should include the theory of intelligent design or
unfounded critiques of current evolutionary theory.
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For intelligent design to gain acceptance among the scientific community, and
therefore be taught in science classrooms, the theory which it seeks to replace (evolution
via natural selection) must first be shown to be seriously lacking in both explanatory
power and evidence. Currently the theory lacks neither, which is why the
overwhelmingly vast majority of life scientists continue to support it. Additionally, even
if the theory was lacking significant explanatory power in one field of application, it may
still be useful in other fields.
For instance, Einstein’s theory of general relativity can explain everyday physical
experience (as can Newtonian physics) in addition to large scale planetary and
cosmological physics (which Newtonian physics cannot adequately explain). Yet, physics
classes continue to use Newtonian physics today for everyday applications, because
Newtonian physics adequately explains everyday physical phenomenon. Likewise,
quantum mechanics best explains small-scale physical interactions – something that
general relativity cannot accomplish. Yet all are still taught in science classes, because,
while they may be incomplete theories, they still offer a wealth of explanatory power and
are all observationally verified in their fields of application. Likewise, small-scale
evolution (microevolution) explains the shifts in genetic frequencies of populations,
while large-scale evolution (macroevolution) explains the emergence of differentiated
organ structures and the inter-relatedness of all life. It should be noted that almost all
proponents of intelligent design accept microevolution and only take issue with certain
aspects of macroevolution.
For the theory of intelligent design to gain mainstream scientific acceptance, it not
only needs to offer greater explanatory power of natural phenomena than evolution, but it
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must also be empirically testable. There must be a mechanism by which intelligent design
functions that can be either directly or indirectly observed and be verified by all available
evidence. For evolution that mechanism is the combination of inheritable mutation and
natural selection (along with a handful of other processes, like genetic drift and gene
flow), and it has been verified by discoveries in genetics, paleontology, ecology,
anthropology, and geology. Currently, intelligent design offers no such mechanism that
would explain the emergence of differentiated structures or the inter-relatedness of all
life.
In Darwin’s Black Box, Dr. Michael Behe illustrates a concept that he calls
irreducible complexity, by which he means, “A single system composed of several wellmatched, interacting parts that contribute to the basic function, wherein the removal of
any one of the parts causes the system to effectively cease functioning” (39). In what
some consider a hurdle over which evolutionary explanations cannot jump, Behe places
certain restraints on his concept:
An irreducibly complex system cannot be produced directly (that is, by
continuously improving the initial function, which continues to work by the same
mechanism) by slight, successive modifications of a precursor system, because
any precursor to an irreducibly complex that is missing a part is by definition
nonfunctional. (39)
Such a system could pose a serious problem to evolutionary thinking if, in fact,
the evolution of certain systems relied only on direct, gradual changes that improved
upon the same function. But evolution does not rely exclusively on such pathways, and
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Behe is quick to point this out. However, he argues that the alternative indirect
evolutionary routes to an irreducibly complex system are prohibitively implausible (40).
Behe’s concept of irreducible complexity echoes the arguments of William Paley,
which were advanced over a half a century before Darwin published Origin of Species.
In Natural Theology, Paley formulated what is known as the teleological argument for the
existence of God. He envisioned himself finding a watch on the ground and, noting the
finely constructed details and obvious function the watch displayed, correctly inferred
that such an intricately crafted object could not have arisen by blind, natural forces;
instead, it must have been designed with purpose (Paley 3). For Paley the purpose evident
in nature was made by the grace of God. For the modern intelligent design theory, that
purpose can only be supplied by some sort of unspecified intelligent agent.
Curiously, proponents of intelligent design insist that knowledge of the designer’s
identity or nature is not necessary when inferring whether or not a system was designed
by said designer. Moreover, intelligent design theory does not explain when or how a
irreducibly complex system could have come into existence, whereas within the context
of evolution there can be possible scenarios for the gradual change of a system into an
irreducibly complex one. If there exists a system that can be appropriately identified as
irreducibly complex, then the only way it could have arise via evolutionary processes
would be an indirect, circuitous route – the kind Behe dismissed out of hand immediately
after defining irreducible complexity. But such early dismissal is unfounded, since there
are systems and structures that exhibit functions markedly different than their
evolutionary forbearers. When Behe asserts that in irreducibly complex system would
present a serious problem to evolution, he means to imply that the problem is too great to
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overcome. In fact, the problem facing scientists is not, “How could we possibly believe in
evolution in light of Behe’s concept of irreducibly complex structures,” but is rather,
“How could evolution possibly explain the existence and origins of these structures?”
In Why Intelligent Design Fails, Alan Gishlick gives a quick overview of the
gradual evolution of the wing of a bird (Young 66-70). Such a structure is irreducibly
complex in Behe’s original definition of the term, because if the wing lacked a single part
it would not function and the bird would not be able to fly. However, the evolutionary
pathway presented by Gishlick is indirect in the sense that the bird’s wing did not always
function as a system designed for flight. For instance, one rather conspicuous property of
a wing is the presence of feathers. Granted, an individual feather cannot be considered a
“part” the way Behe uses the term (remove one feather and chances are the bird can still
fly), but that only reflects Behe’s poor word choice when defining irreducible
complexity, since feathers are obviously essential for bird flight. Using cladistic analysis
and observing the available evidence from the fossil records, one can see that filamentous
feathers existed as far back as 150 million years ago, such as those found on
Sinosauropteryx. Early filamentous feathers were likely used for thermal regulation and
not flight. Likewise, the bipedal nature of early theropods allowed for the forelimbs to be
used for purposes other than walk, such as grasping. Several more developmental
changes followed, each step beneficial to the organism, and eventually an irreducibly
complex bird wing was formed.
This is just one case where one or more structures began with their own
respective functions and which additional developments followed that greatly modified
the original functions of the original structures beyond recognition. Only later did
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evolution select for feathers that were more aerodynamic or forelimbs with greater
surface area. This co-option of structures that results in an overall different function of
the system is what biologists and paleontologists call “exaptation” – a term that existed
well before Behe’s book was ever published!
Gishlick concludes his chapter by noting, “Irreducible complexity would be
biologically significant if . . . it meant ‘unevolvable’” (Young 71). But irreducible
complexity does not automatically equate to “unevolvability,” as the evolutionary history
of the avian-flight system shows. Behe’s offhand dismissal of indirect routes as highly
implausible can itself be dismissed in light of the evidence presented above.
Behe, however, is a molecular biologist, and every irreducibly complex system he
mentions is a molecular system composed of proteins and other cellular structures. His
argument has become nothing more than stating, without any positive evidence, that one
may legitimately infer design of an irreducibly complex molecular structure (e.g., the
bacterium’s flagellum) in the absence of a detailed evolutionary history, since the
probabilities of such structures occurring by chance are said to be greater than the number
of atoms in the universe. Yet what does the answer “the designer did it” explain? The
origin of a bacterium’s flagellum can at least be speculated about and various alternative
pathways to the structures we observe today can be hypothesized within an evolutionary
context. As a scientific theory, evolution via natural selection offers far more (if still
incomplete) explanatory power for natural phenomena than intelligent design. There have
been no serious proposals from proponents of intelligent design theory that suggest how
the designer designed an irreducibly complex structure, when the designer designed an
irreducibly complex structure, or even who or what the designer is. Evolution,
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meanwhile, is fully capable of answering the how and when questions, and to a lesser
extent the last question as well. In evolution’s case, as argued by Richard Dawkins in The
Blind Watchmaker, the designer is actually the blind forces of known physical laws and
natural selection (5).
Dr. William Dembski states, “The world contains events, objects and structures
that exhaust the explanatory resources of undirected natural causes and that can be
adequately explained only by recourse to intelligent causes” (107). A skeptical reader
who has just finished Dawkin’s Blind Watchmaker may think Dembski is advancing an
argument from personal incredulity, which is another form of argument from ignorance
(38), but Dembski reassures the reader in the following sentence, “This is not an
argument from ignorance.”
Dembski has developed what he calls an explanatory filter that can be used to
detect and infer design. The explanatory filter, in effect, asks three questions about an
event or object, “Is it contingent? Is it complex? Is it specified?” (Dembski 133). If
something is contingent, then it can be explained by necessity, or natural law. The second
possible cause of the event is due to chance, which could result in complex, if
unspecified, structures. The third separate possible cause is one of design, which refers to
complex events that are specified. All three possibilities are said to be “mutually
exclusive and exhaustive” (Dembski qtd. in Perakh 23). Yet no justification is given for
why all three possibilities should be mutually exclusive. Chance and law are arbitrarily
separated by Dembski, neglecting the body of mathematics and physics devoted to
statistical analysis of random events, the results of which are determined by certain
statistical laws. A good demonstration of an essentially random event that is nevertheless
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governed by law is the Gaussian distribution of a Galton board (Perakh 33). With this in
mind, Dembski’s explanatory filter is in need of a serious reworking before it can
actually be of any use to anyone.
However, accepting for the moment that what Dembski said earlier is true, and
that there are indeed events, objects, and structures that must be explained by intelligent
causes, the obvious response to Dembski’s assertion is a demand for clarity. What kind of
intelligence does he mean? Are we to assume that the intelligent causes are of
supernatural origin? Dembski’s personal answer to the second question is yes, but he
makes an interesting distinction between the location and actions of intelligent agents:
Undirected natural causes can explain how ink gets applied to paper to
form a random inkblot but cannot explain an arrangement of ink on paper
that spells out a meaningful message. To obtain such a meaningful
arrangement requires an intelligent cause. Whether an intelligent cause is
located within or outside nature (i.e., is respectively natural or
supernatural) is a separate question from whether an intelligent cause has
acted within nature. Design has no prior commitment to supernaturalism.
(259)
So to Dembski, the possibility that intelligent causes may be supernatural in
origin is ultimately irrelevant to the theory of design. Here Dembski is perched perilously
on the fence of science and theology. But he also offers as an example in his passage a
type of intelligence that can be detected in the natural world, namely the meaningful
placement of letters on a piece of paper. Although Dembski purposefully leaves open the
possibility that a supernatural intelligent agent could interfere with the natural world by
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arranging objects and instilling within them some sort of informational meaning or
significance, Dembski’s vague model of intelligence and information cannot be
accurately applied to biological systems in the first place.
Alphabetical letters represent an arbitrary set of symbols to which humans have
attached specific meanings. A vertical line with a semicircle drawn from the opposite
ends of the line and extending to right of it represents the letter known as “D.” One could
conceivably, and without any change to the meaning of the words that would form,
replace the letter D with another arbitrary symbolic representation. Since this keyboard is
capable of displaying a limited number of characters, however, a pre-existing symbol
must be chosen for sake of argument; in this case the character will be “#.” So if one
were to rewrite “DOG” as “#OG,” the physical manifestation of the word would be
different on paper, but the meaning would remain the same, since it was already decided
arbitrarily in the beginning that D would equal #.
However, in DNA, the fundamental instructions for all life, the function
(meaning) of the different genetic “letters” (nucleotides) is tied intrinsically to the
molecular structure of the “letters.” In the same way, the manner in which individual
nucleotides join together to form a strand of DNA also dictates the function of the entire
DNA strand. If one were to arbitrarily assign a chlorine atom in place of a hydroxyl
group on a molecule of cytosine, a type of nucleotide, then the strand would not function
properly. The crucial point missed by Dembski is that the molecular structures of DNA
cannot rightly be considered “information” in the same sense as letters printed on paper,
since molecules are subject to well understood natural laws, including physical and
chemical interactions, in ways that printed letters are not. While not completely
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understood, the sciences of self-organization and abiotic genesis are generating
fascinating results and answering questions among a plethora of different, competing
theories. The famous Urey-Miller experiment in the fifties demonstrated that organic
molecules essential for the functions of life are able to form in an environment free of any
detectable intelligent guidance or design. Without an appropriate application to biological
systems, the intelligent design theory, as currently formulated, is again scientifically
vacuous in this regard.
Most disturbing about the intelligent design movement is its paucity of credible
research publications about the theory. Even the most visible supporters of intelligent
design agree that “without solid scholarship, research and argument, the project would be
just another attempt to indoctrinate instead of persuade” (Wedge 14). In The Wedge
Strategy, published by the Discovery Institute sometime in 1998, the goals for the
intelligent design movement were made clear. When reassessing the strategy in 2003, the
framers of the original document acknowledged that the “five-year plan . . . is now out of
date. Many of its goals were reached or exceed, but some were not” (Wedge 12). Indeed,
arguably the most important goal of the movement has failed to be realized: peerreviewed publication. Of the list of peer-reviewed academic papers that support
intelligent design maintained by the Discovery Institute, very few are found in credible,
impartial scientific journals, and even fewer actually offer original research. Most of the
papers consist only of criticisms of evolution, and criticism of evolution cannot be
automatically counted as support for intelligent design.
One highly embarrassing inclusion on the list is Jonathan Wells’s paper in Rivista
di Biologia. Rivista is no longer a credible scientific journal, as evidenced by its inclusion
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of young earth creationist papers. Additionally, the actual content of Wells’s paper does
not say much that is new: “Wells assumes that centrioles are designed to function as the
tiny turbines they appear to be . . . He then formulates a testable hypothesis . . . that—if
corroborated by experiment could have important implications . . .” (Peer-Reviewed 3) In
other words, Wells simply assumes from the start a function for a cellular structure that is
not well understood, claims without any evidence that such a structure would be
irreducibly complex, and formulates a testable hypothesis that he has not bothered to test.
This is hardly evidence for intelligent design.
More credible, however, is Michael Behe and David Snoke’s paper that was
published in Protein Science, a legitimately peer-reviewed science journal. Behe and
Snoke tried to demonstrate that a particular type of evolutionary mechanism could not
offer an adequate explanation for the appearance of new protein structures in a
moderately sized population (2651). However, their paper does not rule out other
evolutionary mechanisms, only the mechanism that is simplest to test; they say nothing at
all in their paper that supports intelligent design; and their model has since been disputed
in a later issue of the same journal (Lynch 2217).
And finally, although not every scientist listed supports intelligent design theory,
the Discovery Institute released a list of one hundred scientists who are skeptical of
evolutionary explanations for the complexity of life. The list was designed to give the
impression that there exists a legitimate scientific controversy and promote the idea that
“careful examination of the evidence for Darwinian Theory should be encouraged”
(Schaefer). To illustrate how ridiculous the Discovery Institute’s approach is, the
National Center for Science Education began Project Steve. Compared to the Discovery
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Institute’s list of one hundred scientists, the majority of whom are not biologists, Project
Steve currently lists over 700 signatories who agreed to a statement that only evolution
should be taught in science classrooms, while creationism and scientifically bankrupt
theories such as intelligent design should not be taught. The only other difference
between the Discovery Institute’s list and Project Steve is that signatories of Project
Steve are restricted by one additional criterion: they must be named Steve, or some
variant thereof. Steven Weinberg, a Nobel-winning scientist, explained the purpose of
Project Steve in a press release from the National Center for Science Education: “science
isn't decided by manifesto; this statement pokes fun at such efforts. If you want to know
whether scientists accept evolution, you should look in the scientific literature”
(Weinberg qtd. in Evans 1-2).
In order for science classes to teach the theory of intelligent design there must be
an actual theory to teach. Claiming to be able to infer design of biological systems on
questionable mathematical probability sets and precious little else does nothing to
advance human understanding of the natural world. Evolution, on the other hand, has
proven to be well-established by all available evidence. For a classroom to abandon or
denigrate such an elegant theory and replace it with another that has no apparent
scientific basis is just not intelligent.