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Brian Nelson
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Brian's
comments will be in upper case CAPITAL LETTERS to give you more to think
about.
Objectivity
results from the use of the scientific method without philosophic or
religious assumptions in seeking answers to the question:
Where do we come from?
We believe objectivity
in the institutions of science, government and the media will lead not only
to good origins science, but also to constitutional neutrality in this
subjective, historical science that unavoidably impacts religion.
YOU HAVE A RELIGIOUS FAITH BELIEF
WHEN YOU WAKE UP THAT YOU ARE ALIVE. YOU MAY NOT THINK IT IS A
RELIGION BUT YOU HAVE TO BELIEVE IN SOMETHING.
THE
AUTHORS, http://www.intelligentdesignnetwork.org/ promote the
scientific evidence of intelligent design because proper
consideration of that evidence is necessary to achieve not only scientific
objectivity but also constitutional neutrality.
WHO IS GOING TO DECIDE THAT YOU ARE
RIGHT IN PROVING WHAT YOU FEEL IS THE TRUTH.
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Intelligent Design
http://www.intelligentdesignnetwork.org/
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The theory of intelligent design (ID)
holds that certain features of the universe and of living things are
best explained by an intelligent cause
WELL WHAT CAUSED IT.?? rather than an undirected process such as
natural selection. ID is thus a scientific disagreement with the core
claim of evolutionary theory that the apparent design of living systems
is an illusion.
In a broader sense, Intelligent Design is simply the science of
design detection -- how to recognize patterns arranged by an intelligent
cause IS THE CAUSE A PERSON? for a purpose. Design detection is
used in a number of scientific fields, including anthropology, forensic
sciences that seek to explain the cause of events such as a death or
fire, cryptanalysis and the search for extraterrestrial intelligence (SETI).
An inference that certain biological information may be the product of
an intelligent cause can be tested or evaluated in the same manner as
scientists daily test for design in other sciences.
NOT CLEAR TO ME.
ID is controversial because of the implications of its
evidence, rather than the significant weight of its evidence. ID
proponents believe science should be conducted objectively, without
regard to the implications of its findings. This is particularly
necessary in origins science because of its historical (and thus very
subjective) nature, and because it is a science that unavoidably impacts
religion. |
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Positive evidence of design in living
systems consists of the semantic, meaningful or functional nature of
biological information, the lack of any known law that can explain the
sequence of symbols that carry the "messages," and statistical and
experimental evidence that tends to rule out chance as a plausible
explanation. THIS IS
GETTING WORDY. Other evidence challenges the adequacy of natural
or material causes to explain both the origin and diversity of life.
FROM THE SCIENTIFIC POINT OF VIEW YOU ARE GOING TO HAVE A TOUGH TIME
PROVIDING THAT INFORMATION. |
 |
Intelligent Design is an intellectual
movement that includes a scientific research program for investigating
intelligent causes WHO IS TO
JUDGE THAT THE CAUSES WERE INDEED INTELLIGENT.? and
that challenges naturalistic explanations of origins which currently
drive science education and research. |
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3/3
Brian's comments will be in upper case
CAPITAL LETTERS to give you more to think about.
Natural History magazine is the voice of The American Museum of
Natural History. Its April 2002 issue featured the special report
"Intelligent Design?" which is reprinted here by permission.
more on
contributing authors |
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evolution:
science and belief
Intelligent Design?
a special report reprinted from
Natural History magazine |
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reporthighlights
Three proponents of
Intelligent Design (ID) present their views of design in the
natural world. Each view is immediately followed by a response
from a proponent of evolution (EVO). The report, printed in its
entirety, opens with an introduction by Natural History
magazine and concludes with an overview of the ID movement.
The authors
who contributed to this Natural History report are: |
- Richard
Milner and Vittorio Maestro, ed. (introduction)
- Michael J.
Behe, Ph.D. (ID) and Kenneth R. Miller, Ph.D. (EVO)
- William A.
Dembski, Ph.D. (ID) and Robert T. Pennock, Ph.D. (EVO)
- Jonathan
Wells, Ph.D. (ID) and Eugenie C. Scott, Ph.D. (EVO)
- Barbara
Forrest, Ph.D. (overview)
ActionBioscience.org has added "learn more links" to this report
which consist of author-recommended links to online information to
help readers learn more about each author's views. An "educator
resources" section has also been created by ActionBioscience.org
that includes additional links and an original class lesson for
high school students through college undergraduates to accompany
this report. Links can be accessed at the end of each author's
comments or by scrolling to the bottom area of this web page.
introduction
Behe/Miller Dembski/Pennock
Wells/Scott
overview
learn more links
educator resources |
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April 2002 |
Brian's comments will be in upper
case CAPITAL LETTERS to give you more to think about.
Intelligent Design?
A special report reprinted from Natural
History magazine |
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Darwin's evidence convinced
scientists that natural selection can better explain life's
complexity than intelligent design (ID).
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Introduction
Prepared by Richard Milner & Vittorio Maestro, senior editors of
Natural History
The idea that an organism's
complexity is evidence for the existence of a cosmic designer was
advanced centuries before Charles Darwin was born. Its best-known
exponent was English theologian William Paley, creator of the famous
watchmaker analogy. If we find a pocket watch in a field, Paley
wrote in 1802, we immediately infer that it was produced not by
natural processes acting blindly but by a designing human intellect.
Likewise, he reasoned, the natural world contains abundant evidence
of a supernatural creator. The argument from design, as it is known,
prevailed as an explanation of the natural world until the
publication of the Origin of Species in 1859. The weight of
the evidence that Darwin had patiently gathered swiftly convinced
scientists that evolution by natural selection better explained
life's complexity and diversity. "I cannot possibly believe," wrote
Darwin in 1868, "that a false theory would explain so many classes
of facts."HOW DID HE KNOW IT
WAS A FALSE THEORY? |
ID proponents accept that
some species do change and that Earth is much more than 6,000 years
old but reject that evolution accounts for the array of species.
|
In some circles, however, opposition to the concept of evolution has
persisted to the present. The argument from design has recently been
revived by a number of academics with scientific credentials, who
maintain that their version of the idea (unlike Paley's) is soundly
supported by both microbiology and mathematics.
WHAT PAPERS ARE THEY
REFERRING TO AND WHO HAS JUDGED THEM?. These
antievolutionists differ from fundamentalist creationists in that
they accept that some species do change (but not much) and that
Earth is much more than 6,000 years old. Like their predecessors,
however, they reject the idea that evolution accounts for the array
of species we see today, and they seek to have their concept --
known as intelligent design -- included in the science curriculum of
schools. |
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ID is getting a hearing in
some political and educational circles.
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Most biologists have concluded that the proponents of intelligent
design display either ignorance or deliberate misrepresentation of
evolutionary science. Yet their proposals are getting a hearing in
some political and educational circles and are currently the subject
of a debate within the Ohio Board of Education. Although Natural
History does not fully present and analyze the
intelligent-design phenomenon
WHO SAID IT WAS A
PHENOMENON? in the pages that follow, we offer, for the
reader's information, brief position statements by three leading
proponents of the theory, along with three responses. The section
concludes with an overview of the intelligent-design movement by a
philosopher and cultural historian who has monitored its history for
more than a decade. THAT IS
ONLY 10 YEARS. |
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author bios suggested
links
educator resources
introduction
Behe/Miller
Dembski/Pennock Wells/Scott
overview
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| |
Brian's comments will be in upper
case CAPITAL LETTERS to give you more to think about.
Intelligent Design
position statement
The Challenge of Irreducible
Complexity
Every living cell contains many ultrasophisticated molecular
machines.
By Michael J. Behe |
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Black box: a system whose
inner workings are unknown. |
Scientists use the term "black box" for a system whose inner
workings are unknown. To Charles Darwin and his contemporaries, the
living cell was a black box because its fundamental mechanisms were
completely obscure. We now know that, far from being formed from a
kind of simple, uniform protoplasm (as many nineteenth-century
scientists believed), every living cell contains many
ultrasophisticated molecular machines.
SO WHERE DID THESE COME
FROM? |
Does natural selection account for complexity that exits at the
molecular level? |
How can we decide whether Darwinian natural selection can account
for the amazing complexity that exists at the molecular level?
Darwin himself set the standard when he acknowledged, "If it could
be demonstrated that any complex organ existed which could not
possibly have been formed by numerous, successive, slight
modifications, my theory would absolutely break down." |
Irreducibly complex systems:
systems that seem very difficult to form by successive
modifications. |
Some systems seem very difficult to form by such successive
modifications -- I call them irreducibly complex.
THINGS ARE ONLY COMPLEX WHEN
YOU DON'T UNDERSTAND THEM. An everyday example of an
irreducibly complex system is the humble mousetrap. It consists of
(1) a flat wooden platform or base; (2) a metal hammer, which
crushes the mouse; (3) a spring with extended ends to power the
hammer; SO THE SPRING GIVES
THE HAMMER POWER? (4) a catch that releases the spring;
and (5) a metal bar that connects to the catch and holds the hammer
back. You can't catch a mouse with just a platform, then add a
spring and catch a few more mice, then add a holding bar and catch a
few more. All the pieces have to be in place before you catch any
mice. SOMEONE HAS TO CONTROL
THE MICE. DO MICE DO WHAT THEY WANT TO DO?
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Natural selection can only
choose among systems that are already working so irreducibly complex
biological systems pose a powerful challenge to Darwinian theory.
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Irreducibly complex systems appear very unlikely to be produced by
numerous, successive, slight modifications of prior systems, because
any precursor that was missing a crucial part could not function.
Natural selection can only choose among systems that are already
working, so the existence in nature of irreducibly complex
biological systems poses a powerful challenge to Darwinian theory.
We frequently observe such systems in cell organelles, in which the
removal of one element would cause the whole system to cease
functioning. THEN IT IS NOT
THE ORIGINAL WHAT EVER IT WAS AND WE HAVE ALTERED IT'S STRUCTURE.
The flagella of bacteria are a good example. They are outboard
motors that bacterial cells can use for self-propulsion. They have a
long, whiplike propeller that is rotated by a molecular motor. The
propeller is attached to the motor by a universal joint. The motor
is held in place by proteins that act as a stator. Other proteins
act as bushing material to allow the driveshaft to penetrate the
bacterial membrane. Dozens of different kinds of proteins are
necessary for a working flagellum. In the absence of almost any of
them, the flagellum does not work or cannot even be built by the
cell. OBVIOUSLY THE ITEM HAS
CHANGED SO WE CAN NO LONGER TREAT I AS THE ORIGINAL.
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Constant, regulated traffic
flow in cells is an example of a complex, irreducible system. |
Another example of irreducible complexity is the system that allows
proteins to reach the appropriate subcellular compartments. In the
eukaryotic cell there are a number of places where specialized
tasks, such as digestion of nutrients and excretion of wastes, take
place. Proteins are synthesized outside these compartments and can
reach their proper destinations only with the help of "signal"
chemicals that turn other reactions on and off at the appropriate
times. WHO DO YOU THINK IS
DESIGNING THESE THINGS? This constant, regulated traffic flow
in the cell comprises another remarkably complex, irreducible
system. All parts must function in synchrony or the system breaks
down. Still another example is the exquisitely coordinated mechanism
that causes blood to clot. |
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Molecular machines
are designed.
|
Biochemistry textbooks and journal articles describe the workings of
some of the many living molecular machines within our cells, but
they offer very little information about how these systems
supposedly evolved by natural selection.
THAT IS WHERE FAITH COMES IN. Many scientists frankly admit
their bewilderment about how they may have originated, but refuse to
entertain the obvious hypothesis: that perhaps molecular machines
appear to look designed because they really are designed.
HOW ELSE COULD THEY BE BUT
TO BE CREATED BY SOMETHING. |
Advances in science provide
new reasons for recognizing design. |
I am hopeful that the scientific community will eventually admit the
possibility of intelligent design, even if that acceptance is
discreet and muted. My reason for optimism is the advance of science
itself, which almost every day uncovers new intricacies in nature,
fresh reasons for recognizing the design inherent in life and the
universe. WE HAVE A LONG WAY
TO GO TO REALLY UNDERSTAND A TINY BIT OF WHAT HAS BEEN CREATED.
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author bio
author-recommended links
educator resources |
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Brian's comments will be in upper
case CAPITAL LETTERS to give you more to think about.
Evolution response to Michael J. Behe
The Flaw in the Mousetrap
Intelligent design fails the biochemistry test.
By Kenneth R. Miller
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Michael J. Behe fails to
provide biochemical evidence for intelligent design.
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To understand why the scientific community has been unimpressed by
attempts to resurrect the so-called argument from design, one need
look no further than Michael J. Behe's own essay. He argues that
complex biochemical systems could not possibly have been produced by
evolution because they possess a quality he calls irreducible
complexity. Just like mousetraps, these systems cannot function
unless each of their parts is in place. Since "natural selection can
only choose among systems that are already working," there is no way
that Darwinian mechanisms could have fashioned the complex systems
found in living cells. And if such systems could not have evolved,
they must have been designed. That is the totality of the
biochemical "evidence" for intelligent design. |
Parts of a supposedly
irreducibly complex machine may have different, but still useful,
functions.
|
Ironically, Behe's own example, the mousetrap, shows what's wrong
with this idea. Take away two parts (the catch and the metal bar),
and you may not have a mousetrap but you do have a three-part
machine that makes a fully functional tie clip or paper clip. Take
away the spring, and you have a two-part key chain. The catch of
some mousetraps could be used as a fishhook, and the wooden base as
a paperweight; useful applications of other parts include everything
from toothpicks to nutcrackers and clipboard holders. The point,
which science has long understood, is that bits and pieces of
supposedly irreducibly complex machines may have different -- but
still useful -- functions. |
Evolution produces complex
biochemical machines. |
Behe's contention that each and every piece of a machine, mechanical
or biochemical, must be assembled in its final form before anything
useful can emerge is just plain wrong. Evolution produces complex
biochemical machines by copying, modifying, and combining proteins
previously used for other functions. Looking for examples? The
systems in Behe's essay will do just fine. |
Natural selection favors an
organism's parts for different functions. |
He writes that in the absence of "almost any" of its parts, the
bacterial flagellum "does not work." But guess what? A small group
of proteins from the flagellum does work without the rest of
the machine -- it's used by many bacteria as a device for injecting
poisons into other cells. Although the function performed by this
small part when working alone is different, it nonetheless can be
favored by natural selection. |
The blood clotting system is
an example of evolution. |
The key proteins that clot blood fit this pattern, too. They're
actually modified versions of proteins used in the digestive system.
The elegant work of Russell Doolittle has shown how evolution
duplicated, retargeted, and modified these proteins to produce the
vertebrate blood-clotting system. |
Working researchers see
evolution in subcellular systems.
|
And Behe may throw up his hands and say that he cannot
imagine how the components that move proteins between subcellular
compartments could have evolved, but scientists actually working on
such systems completely disagree. In a 1998 article in the journal
Cell, a group led by James Rothman, of the Sloan-Kettering
Institute, described the remarkable simplicity and uniformity of
these mechanisms. They also noted that these mechanisms "suggest in
a natural way how the many and diverse compartments in eukaryotic
cells could have evolved in the first place." Working researchers,
it seems, see something very different from what Behe sees in these
systems -- they see evolution. |
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Behe's points are
philosophical, not scientific.
|
If Behe wishes to suggest that the intricacies of nature, life, and
the universe reveal a world of meaning and purpose consistent with a
divine intelligence, his point is philosophical, not scientific. It
is a philosophical point of view, incidentally, that I share.
However, to support that view, one should not find it necessary to
pretend that we know less than we really do about the evolution of
living systems. In the final analysis, the biochemical hypothesis of
intelligent design fails not because the scientific community is
closed to it but rather for the most basic of reasons -- because it
is overwhelmingly contradicted by the scientific evidence. |
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author bio
author-recommended links
educator resources
introduction
Behe/Miller
Dembski/Pennock Wells/Scott
overview
|
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Intelligent
Design position statement
Detecting Design in the
Natural Sciences
Intelligence leaves behind a characteristic signature.
By William A. Dembski
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Chance, necessity, or design
covers every eventuality in ordinary life. |
In ordinary life, explanations that invoke chance, necessity, or
design cover every eventuality. Nevertheless, in the natural
sciences one of these modes of explanation is considered superfluous
-- namely, design. From the perspective of the natural sciences,
design, as the action of an intelligent agent, is not a fundamental
creative force in nature. Rather, blind natural causes,
characterized by chance and necessity and ruled by unbroken laws,
are thought sufficient to do all nature's creating. Darwin's theory
is a case in point. |
Does nature require no help
from a designing intelligence?
|
But how do we know that nature requires no help from a designing
intelligence? Certainly, in special sciences ranging from forensics
to archaeology to SETI (the Search for Extraterrestrial
Intelligence), appeal to a designing intelligence is indispensable.
What's more, within these sciences there are well-developed
techniques for identifying intelligence. Essential to all these
techniques is the ability to eliminate chance and necessity. |
Complex, sequenced patterns
exhibit intelligence in their design.
|
For instance, how do the radio astronomers in Contact (the
Jodie Foster movie based on Carl Sagan's novel of the same name)
infer the presence of extraterrestrial intelligence in the beeps and
pauses they monitor from space? The researchers run signals through
computers that are programmed to recognize many preset patterns.
Signals that do not match any of the patterns pass through the
"sieve" and are classified as random. After years of receiving
apparently meaningless "random" signals, the researchers discover a
pattern of beats and pauses that corresponds to the sequence of all
the prime numbers between 2 and 101. (Prime numbers, of course, are
those that are divisible only by themselves and by one.) When a
sequence begins with 2 beats, then a pause, 3 beats, then a pause .
. . and continues all the way to 101 beats, the researchers must
infer the presence of an extraterrestrial intelligence. |
If a sequence lacks
complexity, it could easily happen by chance.
|
Here's why. There's nothing in the laws of physics that requires
radio signals to take one form or another. The sequence is therefore
contingent rather than necessary. Also, it is a long sequence and
therefore complex. Note that if the sequence lacked complexity, it
could easily have happened by chance. Finally, it was not just
complex but also exhibited an independently given pattern or
specification (it was not just any old sequence of numbers but a
mathematically significant one -- the prime numbers). |
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Specified complexity: the
characteristic trademark or signature of intelligence. |
Intelligence leaves behind a characteristic trademark or signature
-- what I call "specified complexity." An event exhibits specified
complexity if it is contingent and therefore not necessary; if it is
complex and therefore not easily repeatable by chance; and if it is
specified in the sense of exhibiting an independently given pattern.
Note that complexity in the sense of improbability is not sufficient
to eliminate chance: flip a coin long enough, and you'll witness a
highly complex or improbable event. Even so, you'll have no reason
not to attribute it to chance. |
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Specifications must be
objectively given. |
The important thing about specifications is that they be objectively
given and not just imposed on events after the fact. For instance,
if an archer shoots arrows into a wall and we then paint bull's-eyes
around them, we impose a pattern after the fact. On the other hand,
if the targets are set up in advance ("specified") and then the
archer hits them accurately, we know it was by design. |
Undirected natural processes
are incapable of generating the specified complexity in organisms. |
In my book The Design Inference, I argue that specified
complexity reliably detects design. In that book, however, I focus
largely on examples from the human rather than the natural sciences.
The main criticism of that work to date concerns whether the
Darwinian mechanism of natural selection and random variation is not
in fact fully capable of generating specified complexity. More
recently, in No Free Lunch, I show that undirected natural
processes like the Darwinian mechanism are incapable of generating
the specified complexity that exists in biological organisms. It
follows that chance and necessity are insufficient for the natural
sciences and that the natural sciences need to leave room for
design. |
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author bio
author-recommended links
educator resources |
| |
Brian's comments will be in upper
case CAPITAL LETTERS to give you more to think about.
Evolution response to William A. Dembski
Mystery Science Theater
The case of the secret agent.
By Robert T. Pennock
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|
Science requires positive
evidence that biological complexity is intentionally designed.
|
William A. Dembski claims to detect "specified complexity" in living
things and argues that it is proof that species have been designed
by an intelligent agent. One flaw in his argument is that he wants
to define intelligent design negatively, as anything that is not
chance or necessity. But the definition is rigged: necessity,
chance, and design are not mutually exclusive categories, nor do
they exhaust the possibilities. Thus, one cannot detect an
intelligent agent by the process of elimination he suggests. Science
requires positive evidence. This is so even when attempting to
detect the imprint of human intelligence, but it is especially true
when assessing the extraordinary claim that biological complexity is
intentionally designed. |
William A. Dembski has no
way to show that genetic patterns are set up in advance.
|
In this regard, Dembski's archery and SETI analogies are red
herrings, for they tacitly depend on prior understanding of human
intellect and motivation, as well as of relevant causal processes. A
design inference like that in the movie Contact, for
instance, would rely on background knowledge about the nature of
radio signals and other natural processes, together with the
assumption that a sequence of prime numbers is the kind of pattern
another scientist might choose to send as a signal. But the odd
sequences found within DNA are quite unlike a series of prime
numbers. Dembski has no way to show that the genetic patterns are
"set up in advance" or "independently given." |
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Antievolutionists claim that
evolution violates the second law of thermodynamics, but this
misunderstands how the law applies to biological systems.
|
Dembski has been promoted as "the Isaac Newton of information
theory," and in his writings, which include the books he cites in
the essay here, he insists that his "law of conservation of
information" proves that natural processes cannot increase
biological complexity. He doesn't lay out his case here, and a
refutation would require too much space. Suffice it to say that a
connection exists between the technical notion of information and
that of entropy, so Dembski's argument boils down to a recasting of
an old creationist claim that evolution violates the second law of
thermodynamics. Put simply, this law states that in the universe,
there is a tendency for complexity to decrease. How then, ask the
creationists, can evolutionary processes produce more complex
life-forms from more primitive ones? But we have long known why this
type of argument fails: the second law applies only to closed
systems, and biological systems are not closed. |
Random genetic variation is
subjected to natural selection by the environment. |
In the evolutionary process, an increase in biological complexity
does not represent a "free lunch" -- it is bought and paid for,
because random genetic variation is subjected to natural selection
by the environment, which itself is already structured. In fact,
researchers are beginning to use Darwinian processes, implemented in
computers or in vitro, to evolve complex systems and to provide
solutions to design problems in ways that are beyond the power of
mere intelligent agents. |
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Dembski's hypothesis of
design provides precious little that is testable.
|
If we really thought that genetic information was like the signal in
Contact, shouldn't we infer we were designed by
extraterrestrials? Intelligent-design theorists do sometimes mention
extraterrestrials as possible suspects, but most seem to have their
eyes on a designer more highly placed in the heavens. The problem
is, science requires a specific model that can be tested. What
exactly did the designer do, and when did he do it? Dembski's
nebulous hypothesis of design, even if restricted to natural
processes, provides precious little that is testable, and once
supernatural processes are wedged in, it loses any chance of
testability. |
Darwin followed the clues
given in nature to solve the mystery of origins.
|
Newton found himself stymied by the complex orbits of the planets.
He could not think of a natural way to fully account for their order
and concluded that God must nudge the planets into place to make the
system work. (So perhaps in this one sense, Dembski is the
Newton of information theory.) The origin of species once seemed
equally mysterious, but Darwin followed the clues given in nature to
solve that mystery. One may, of course, retain religious faith in a
designer who transcends natural processes, but there is no way to
dust for his fingerprints. |
| |
author bio
author-recommended links
educator resources
introduction
Behe/Miller
Dembski/Pennock Wells/Scott
overview
|
 |
Brian's comments will be in upper
case CAPITAL LETTERS to give you more to think about.
Intelligent
Design position statement
Elusive Icons of Evolution
What do Darwin's finches and the four-winged fruit fly really
tell us?
By Jonathan Wells |
|
Many features of living
things appear to be designed. |
Charles Darwin wrote in 1860 that "there seems to be no more design
in the variability of organic beings and in the action of natural
selection, than in the course which the wind blows." Although many
features of living things appear to be designed, Darwin's theory was
that they are actually the result of undirected processes such as
natural selection and random variation. |
Darwin's finches are one of the "icons of evolution." |
Scientific theories, however, must fit the evidence. Two examples of
the evidence for Darwin's theory of evolution -- so widely used that
I have called them "icons of evolution" -- are Darwin's finches and
the four-winged fruit fly. Yet both of these, it seems to me, show
that Darwin's theory cannot account for all features of living
things. |
Finch beaks appear to be
adapted to different foods through natural
selection. |
Darwin's finches consist of several species on the Galápagos Islands
that differ mainly in the size and shape of their beaks. Beak
differences are correlated with what the birds eat, suggesting that
the various species might have descended from a common ancestor by
adapting to different foods through natural selection. In the 1970s,
biologists Peter and Rosemary Grant went to the Galápagos to observe
this process in the wild. |
|
Direct evidence for this was
found in the 1970s. |
In 1977 the Grants watched as a severe drought wiped out 85 percent
of a particular species on one island. The survivors had, on
average, slightly larger beaks that enabled them to crack the tough
seeds that had endured the drought. This was natural selection in
action. The Grants estimated that twenty such episodes could
increase average beak size enough to produce a new species. |
|
Modern scientists did not
observe new species emerging. |
When the rains returned, however, average beak size returned to
normal. Ever since, beak size has oscillated around a mean as the
food supply has fluctuated with the climate. There has been no net
change, and no new species have emerged. In fact, the opposite may
be happening, as several species of Galápagos finches now appear to
be merging through hybridization. |
Natural selection works only
within established species. |
Darwin's finches and many other organisms provide evidence that
natural selection can modify existing features -- but only within
established species. Breeders of domestic plants and animals have
been doing the same thing with artificial selection for centuries.
But where is the evidence that selection produces new
features in new species? |
|
Major evolutionary changes
require anatomical as well as biochemical changes.
|
New features require new variations. In the modern version of
Darwin's theory, these come from DNA mutations. Most DNA mutations
are harmful and are thus eliminated by natural selection. A few,
however, are advantageous -- such as mutations that increase
antibiotic resistance in bacteria and pesticide resistance in plants
and animals. Antibiotic and pesticide resistance are often cited as
evidence that DNA mutations provide the raw materials for evolution,
but they affect only chemical processes. Major evolutionary changes
would require mutations that produce advantageous anatomical
changes as well. |
The four-winged fruit fly is
another "icon of evolution."
|
Normal fruit flies have two wings and two "balancers" -- tiny
structures behind the wings that help stabilize the insect in
flight. In the 1970s, geneticists discovered that a combination of
three mutations in a single gene produces flies in which the
balancers develop into normal-looking wings. The resulting
four-winged fruit fly is sometimes used to illustrate how mutations
can produce the sorts of anatomical changes that Darwin's theory
needs. |
This fly does not provide
evidence for evolution.
|
But the extra wings are not new structures, only duplications of
existing ones. Furthermore, the extra wings lack muscles and are
therefore worse than useless. The four-winged fruit fly is severely
handicapped -- like a small plane with extra wings dangling from its
tail. As is the case with all other anatomical mutations studied so
far, those in the four-winged fruit fly cannot provide raw materials
for evolution. |
|
Intelligent
design should be taught in school. |
In the absence of evidence that natural selection and random
variations can account for the apparently designed features of
living things, the entire question of design must be reopened.
Alongside Darwin's argument against design, students should also be
taught that design remains a possibility. |
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author bio
author-recommended links
educator resources |
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Evolution response to Jonathan Wells
The Nature of Change
Evolutionary mechanisms give rise to basic structural
differences.
By Eugenie C. Scott
|
Darwin proposed a scientific
rather than a religious explanation of nature.
|
Without defining "design," Wells asserts that "many features of
living things appear to be designed." Then he contrasts natural
selection (undirected) with design (directed), apparently attempting
to return to the pre-Darwinian notion that a Designer is directly
responsible for the fit of organisms to their environments. Darwin
proposed a scientific rather than a religious explanation: the fit
between organisms and environments is the result of natural
selection. Like all scientific explanations, his relies on natural
causation. |
|
Modern science can now draw
on evidence from biological processes. |
Wells contends that "Darwin's theory cannot account for all features
of living things," but then, it doesn't have to. Today scientists
explain features of living things by invoking not only natural
selection but also additional biological processes that Darwin
didn't know about, including gene transfer, symbiosis, chromosomal
rearrangement, and the action of regulator genes. Contrary to what
Wells maintains, evolutionary theory is not inadequate. It fits the
evidence just fine. |
Darwin's conclusion that
Galapágos finches had a common ancestor is confirmed by modern
genetic analysis.
|
Reading Wells, one might not realize the importance of the Grants'
careful studies, which demonstrated natural selection in real time.
That the drought conditions abated before biologists witnessed the
emergence of new species is hardly relevant; beak size does
oscillate in the short term, but given a long-term trend in climate
change, a major change in average size can be expected. Wells also
overstates the importance of finch hybridization: it is extremely
rare, and it might even be contributing to new speciation. The
Galápagos finches remain a marvelous example of the principle of
adaptive radiation. The various species, which differ
morphologically, occupy different adaptive niches. Darwin's
explanation was that they all evolved from a common ancestral
species, and modern genetic analysis provides confirming evidence. |
|
The discovery of
Ubx
genes shed light on how body plans evolve.
|
Wells admits that natural selection can operate on a population and
correctly looks to genetics to account for the kind of variation
that can lead to "new features in new species." But he
contends that mutations such as those that yield four-winged fruit
flies do not produce the sorts of anatomical changes needed for
major evolutionary change. Can't he see past the example to the
principle? That the first demonstration of a powerful genetic
mechanism happened to be a nonflying fly is irrelevant. Edward Lewis
shared a Nobel Prize for the discovery of the role of these genes,
known as the Ubx complex. They are of extraordinary
importance because genes of this type help explain body plans -- the
basic structural differences between a mollusk and a mosquito, a
sponge and a spider. |
A very small
Ubx
change results in a big difference in the body plan of organisms.
|
Ubx genes are among the HOX genes, found in animals as
different as sponges, fruit flies, and mammals. They turn on or off
the genes involved in -- among other things -- body segmentation and
the production of appendages such as antennae, legs, and wings. What
specifically gets built depends on other, downstream genes. The
diverse body plans of arthropods (insects, crustaceans, arachnids)
are variations on segmentation and appendage themes, variations that
appear to be the result of changes in HOX genes. Recent
research shows that fly Ubx genes suppress leg formation in
abdominal segments but that crustacean Ubx genes don't; a
very small Ubx change results in a big difference in body
plan. |
These genes allow for
anatomical experimentation.
|
Mutations in these primary on/off switches are involved in such
phenomena as the loss of legs in snakes, the change from lobe fins
to hands, and the origin of jaws in vertebrates. HOX-initiated
segment duplication allows for anatomical experimentation, and
natural selection winnows the result. "Evo-Devo" -- the study of
evolution and development -- is a hot new biological research area,
but Wells implies that all it has produced is crippled fruit flies. |
|
Science only has tools for
explaining things in terms of natural causes. |
Wells argues that natural explanations are inadequate and, thus,
that "students should also be taught that design remains a
possibility." Because in his logic, design implies a Designer, he is
in effect recommending that science allow for nonnatural causation.
We actually do have solid natural explanations to work with, but
even if we didn't, science only has tools for explaining things in
terms of natural causation. That's what Darwin did, and that's what
we're trying to do today. |
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author bio
author-recommended links
educator resources
introduction
Behe/Miller
Dembski/Pennock Wells/Scott
overview
|
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Brian's comments will be in upper
case CAPITAL LETTERS to give you more to think about.
Overview
The Newest Evolution of
Creationism
Intelligent design is about politics and religion, not science.
By Barbara Forrest |
|
Intelligent
Design (ID) proponents put most of their effort in swaying
politicians and the public. |
The infamous August 1999 decision by the Kansas Board of Education
to delete references to evolution from Kansas science standards was
heavily influenced by advocates of intelligent-design theory.
Although William A. Dembski, one of the movement's leading figures,
asserts that "the empirical detectability of intelligent causes
renders intelligent design a fully scientific theory," its
proponents invest most of their efforts in swaying politicians and
the public, not the scientific community. |
The leading ID organization
is the Center for the Renewal of Science and Culture (CRSC).
|
Launched by Phillip E. Johnson's book Darwin on Trial (1991),
the intelligent-design movement crystallized in 1996 as the Center
for the Renewal of Science and Culture (CRSC), sponsored by the
Discovery Institute, a conservative Seattle think tank. Johnson, a
law professor whose religious conversion catalyzed his antievolution
efforts, assembled a group of supporters who promote design theory
through their writings, financed by CRSC fellowships. According to
an early mission statement, the CRSC seeks "nothing less than the
overthrow of materialism and its damning cultural legacies." |
The CRSC calls its strategy
the "Wedge," because it wants to liberate science from "atheistic
naturalism."
|
Johnson refers to the CRSC members and their strategy as the Wedge,
analogous to a wedge that splits a log -- meaning that intelligent
design will liberate science from the grip of "atheistic
naturalism." Ten years of Wedge history reveal its most salient
features: Wedge scientists have no empirical research program and,
consequently, have published no data in peer-reviewed journals (or
elsewhere) to support their intelligent-design claims. But they do
have an aggressive public relations program, which includes
conferences that they or their supporters organize, popular books
and articles, recruitment of students through university lectures
sponsored by campus ministries, and cultivation of alliances with
conservative Christians and influential political figures. |
|
Philip E. Johnson: "This
isn't really, and never has been, a debate about science. It's about
religion and philosophy." |
The Wedge aims to "renew" American culture by grounding society's
major institutions, especially education, in evangelical religion.
In 1996, Johnson declared: "This isn't really, and never has been, a
debate about science. It's about religion and philosophy." According
to Dembski, intelligent design "is just the Logos of John's Gospel
restated in the idiom of information theory." Wedge strategists seek
to unify Christians through a shared belief in "mere" creation,
aiming -- in Dembski's words -- "at defeating naturalism and its
consequences." This enables intelligent-design proponents to coexist
in a big tent with other creationists who explicitly base their
beliefs on a literal interpretation of Genesis. |
At heart, ID proponents are
not motivated to improve science but to transform it into a theistic
enterprise.
|
"As Christians," writes Dembski, "we know naturalism is false.
Nature is not self-sufficient. … Nonetheless neither theology nor
philosophy can answer the evidential question whether God's
interaction with the world is empirically detectable. To answer this
question we must look to science." Jonathan Wells, a biologist, and
Michael J. Behe, a biochemist, seem just the CRSC fellows to give
intelligent design the ticket to credibility. Yet neither has
actually done research to test the theory, much less produced data
that challenges the massive evidence accumulated by biologists,
geologists, and other evolutionary scientists. Wells, influenced in
part by Unification Church leader Sun Myung Moon, earned Ph.D.'s in
religious studies and biology specifically "to devote my life to
destroying Darwinism." Behe sees the relevant question as whether
"science can make room for religion." At heart, proponents of
intelligent design are not motivated to improve science but to
transform it into a theistic enterprise that supports religious
faith. |
|
The ID movement is advancing
its strategy but its tactics are no substitute for real science.
|
Wedge supporters are at present trying to insert intelligent design
into Ohio public-school science standards through state legislation.
Earlier the CRSC advertised its science education site by assuring
teachers that its "Web curriculum can be appropriated without
textbook adoption wars" -- in effect encouraging teachers to do an
end run around standard procedures. Anticipating a test case, the
Wedge published in the Utah Law Review a legal strategy for
winning judicial sanction. Recently the group almost succeeded in
inserting into the federal No Child Left Behind Act of 2001 a "sense
of the Senate" that supported the teaching of intelligent design. So
the movement is advancing, but its tactics are no substitute for
real science. |
|
Brian's comments will be in upper case
CAPITAL LETTERS to give you more to think about.
|
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