Rabbi Slifkin's Blind Watchmaker Thesis and the Panda's "Poorly Designed"
Extraordinarily Designed Thumb
In his book Challenge of Creation (2006), Rabbi
Slifkin asserts that there is convincing evidence that the marvels of life are
due to chance and naturalistic processes (such as random
mutation and natural selection).
Given that he accepts the billions of years of
naturalistic evolution, Rabbi Slifkin is forced
to deny the existence of the first man and women (Adam
and Chava), created on the sixth day in the image of God, as a
historical fact. Rather, he believes that the first three chapters of the Torah
is pretty much a total allegory. Thus there was no meta-natural
creation week as described in the first chapter of Genesis.
Following Darwin (and Ruse) he believes that man is a sort of
"modified monkey" evolved from hominid precursors. This is why Rabbi Slifkin
aligns himself with Darwinians who believe in vestigial organs, embryological
debris and poorly designed structures such as the Panda's thumb. While this type
of belief is supportive of atheism, Rabbi Slifkin believes that we can
nevertheless be "religious Darwinists". “Naturalistic Darwinian evolution is
fully compatible with religion” (Challenge p. 294). “The blind-watchmaker thesis
need not be incompatible with God” (Challenge p. 297).
Consider a section titled "Imperfect Design from a
Perfect Creator" in which Rabbi Slifkin writes
as follows:
Stephen Jay Gould [Harvard
University] has elaborated upon this argument in his work
The Panda's Thumb
[1980].
Pandas do not have an opposable thumb that is one of the five digits, as do
other animals with grasping hands. Instead, they have a modification of the
wrist bone, which serves to help grasp bamboo. Such a "thumb" makes sense in
light of Darwinian evolution; the thumb was already pressed into use as a
finger, leaving natural selection to operate with the wrist bone. But,
argues Gould, this is too inefficient a
limb to be the work of a wise Creator.
There are other features of organisms that not only appear
poorly designed,
but are even potentially detrimental. ... Evolutionists correctly argue that
these indicate descent from earlier species; atheist evolutionists
incorrectly argue that they disprove the existence of a wise Creator. ...
We can therefore plausibly contend
that He [the Creator] would use the simplest means to obtain the complex
goal of the world in which we live. It is a mark of genius to create a
system that can produce a panda from a non-panda (even
at the cost of having an inflexible thumb),
rather than having to design one from scratch. Far from being a menace to
religion, boundless Darwinian evolution assists in explaining an
age-old problem of why there existence no are so many features of living
things that seem poorly designed,
useless, or even harmful. [Challenge p. 303-304,
Emphasis added]
The main problem with this line of reasoning is that, even if
it true that the Panda's thumb is poorly designed, there are no detailed
testable Darwinian pathways that can explain wrist bones, thumbs, the muscle,
nerve and the brain mechanisms needed to run all this machinery (robots that
perform these functions are the product of advanced design techniques).
However, a 1999 study in Nature analyzed the giant panda's
thumb using computed tomography, magnetic resonance imaging (MRI) and related
techniques. Contrary to Rabbi Slifkin's and Gould "poorly designed" panda's
thumb, the study shows that the radial sesamoid bone (its "thumb") is "one of
the most extraordinary manipulation systems" among mammals.
The way in which the giant panda,
Ailuropoda melanoleuca, uses the radial sesamoid bone — its ‘pseudo-thumb’
— for grasping makes it one of the most extraordinary manipulation
systems in mammalian evolution. ...
The three-dimensional images we obtained indicate that the
radial sesamoid bone cannot move independently of its articulated bones, as
has been suggested, but rather acts as part of a functional unit of
manipulation. The radial sesamoid bone and the accessory carpal bone form a
double pincer-like apparatus in the medial and lateral sides of the hand,
respectively, enabling the panda to manipulate objects with great
dexterity. ...
We have shown that the hand of the giant panda has a much
more refined grasping mechanism than has been suggested in previous
morphological models.
[Endo, H., Yamagiwa,
D., Hayashi, Y. H., Koie, H., Yamaya, Y., and Kimura, J. 1999. Nature
397: 309-310. Emphasis added]
Evolutionists such as Gould say that the design of the
Panda's thumb is poor compared to that of the primate opposable thumb. However,
the opposable thumb is not designed for continuous grasping (and may even result
in carpal tunnel syndrome). The Giant Panda is a herbivore that spends nearly
all of its waking hours eating by collecting bamboo leaves (by grasping) and
stripping leaves from the stalks. The Panda's hand, with its "thumb" directly
bound to the metacarpals, is a much stronger design able to withstand continuous
use. Here is the relevant quote from Gould.
The panda's thumb provides an elegant zoological
counterpart to Darwin's orchids. An engineer' best solution is debarred
by history. The panda' true thumb is committed to another role, too
specialized for a different function to become an opposable,
manipulating digit. So the panda must use parts on hand and
settle for an enlarged wrist bone and a somewhat clumsy, but
quite workable, solution. The sesamoid thumb wins no prize in an
engineer's derby. It is, to use Michael Ghiselin's phrase - a
contraption; not a lovely contrivance. ...
Darwin's metaphor for organic form reflects his sense of wonder
that evolution can fashion such a world of diversity and adequate design
with such limited raw material: "Although an organ may not have been
originally formed for some special purpose, if it now serves for this
end we are justified in saying that it is specially contrived for it. On
the same principle, if a man were to make a machine for some special
purpose, but were to use old wheels, springs, and pulleys, only slightly
altered, the whole machine, with all its parts, might be said to be
specially contrived for that purpose. Thus throughout nature almost
every part of each living being has probably served, in a slightly
modified condition, for diverse purposes, and has acted in the living
machinery of many ancient and distinct specific forms."
We may not be flattered by the metaphor of refurbished wheels and
pulleys, but consider how well we work. Nature is, in
biologist Francois Jacob's words, an excellent tinkerer,
not a divine artificer. And who shall sit in judgment between these
exemplary skills? [ Stephen Jay Gould, The Panda's Thumb:
More Reflections in Natural History, W. W. Norton & Company, 1980 ]
Gould had already started arguing in 1971 that
Darwin's mechanism was insufficient to account for what he calls
"nature’s irreducible complexity". In 1971, he and Eldredge introduced a
new naturalistic mechanism called "punctutated equilibrium intended to
answer the question as to why the fossil record is so anti-Darwinian. In
the Prologue to Panda's Thumb, Gould writes:
"Yet, while Darwinian
theory extends its domain, some of its cherished postulates are
slipping, or at least losing their generality. The "modern
synthesis," the contemporary version of Darwinism that has reigned for
thirty years, took the model of adaptive gene substitution within local
populations as an adequate account, by accumulation and extension, of
life's entire history. The model may work well in its empirical domain
of minor, local, adaptive adjustment; populations of the moth Biston
betularia did turn black, by substitution of a single gene, as a
selected response for decreased visibility on trees that had been
blackened by industrial soot [note to reader: subsequent to Gould
writing this the evolutionary icon of the peppered moth has been
debunked]. But is the origin of a new species simply this process
extended to more genes and greater effect? Are larger evolutionary
trends within major lineages just a further accumulation of sequential
adaptive changes?
Many evolutionists (myself included) are beginning to
challenge this synthesis and to assert that the hierarchical view that
different levels of evolutionary change often reflect different kinds of
causes. ...
But we must reckon with a multiplicity of
mechanisms that preclude the explanation of higher level
phenomena by the model of adaptive gene substitution favored for the
lowest level.
At the basis of all this ferment lies
nature’s irreducible complexity. Organisms are not
billiard balls, propelled by simple and measurable external forces to
predictable new positions on life’s pool table. Sufficiently complex
systems have greater richness. Organisms have a history that constrains
their future in myriad, subtle ways (see essays of section I). Their
complexity of form entails a host of functions incidental to whatever
pressures of natural selection superintended the initial construction
(see essay 4). Their intricate and largely
unknown pathways of embryonic development guarantee that simple
inputs (minor changes in timing, for example) may be translated into
marked and surprising changes in output (the adult organism, see essay
18). [Emphasis added, p15-6].
Thus Gould's argument from the Panda's thumb was not
an argument about mechanism (neo-Darwinian or punctuated equilibrium),
but an attempt to "prove" the so-called "fact" of evolution (common
descent). Gould writes:
"I have tried to weld these essays into an integrated
whole by organizing them into eight sections. The first on
pandas, turtles and anglerfish, illustrates why we can
be confident that evolution occurred. The argument embodies an
paradox: the proof of evolution lies in imperfections
that reveal history. [Prologue to "Panda's Thumb", page 12-13].
Gould was here attempting to show that nature is an
"an excellent tinkerer, not a divine artificer", i.e. he was trying to
show that nature has the power to create contrivances such as the
Panda's Thumb without the need for the Creator. It's a pity that the
late Steven J. Gould (both Jewish and a kohen) could be so
profoundly wrong.
A vitriolic and (in-)famous anti-ID blog calls itself
"The Panda's Thumb". Their posted mission statement asserts that the "The
Panda's Thumb is many things. First, it is an example of
jury-rigged evolutionary adaptation made famous by the late Stephen Jay
Gould in an essay of the same name." The Panda's thumb is a a site that
is highly recommended by the anti-creation site talk.origins.
The main page of the site
invites us to visit the Pandas's Thumb as follows:
Visit the Panda's Thumb. The Panda's
Thumb is dedicated to explaining the theory of evolution, critiquing the
claims of the anti-evolution movement, and defending the integrity of
science and science education in America and around the world.
(talk.orgins, accessed Nov. 24, 2006)
No blog has been so poorly named given that scientists
now believe that the Panda's thumb is an "extraordinary manipulation
system".
The opposition blog is a pro-ID blog called "Uncommon
Descent". A recent remark on this blog by Paul Nelson is interesting.
Paul Nelson (Ph.D. from the University of Chicago in Philosophy 1998) is
a fellow at the Discovery Intelligent Design think tank, where he
specializes in the philosophy of biology. He writes:
It’s one of the great urban myths of
evolutionary biology that there is actual evidence showing the
suboptimality of the panda’s pseudothumb. There is none. When
(in March 1990) I asked Stephen Gould himself for the evidence,
one-on-one in his office at the Museum of Comparative Zoology at
Harvard, he replied that the pseudothumb’s suboptimality was simply
obvious. (Gould did not at that meeting, or in any subsequent
communications, provide me with any data supporting his opinion. I’ve
looked through the literature, and indeed there is none.) It was
“obvious” to my wife’s grandmother that our first child would be a boy.
“The baby is all in front,” she said, putting her hands on my wife’s
tummy late in pregnancy. “A boy, clearly.” On March 16, 1992, Hannah
Rachel was born. Comment by Paul
Nelson — August 29, 2006 @ 10:06 am
Visit
to the Zoo (August 2006)
http://www.uncommondescent.com/index.php/archives/1526 (September
19, 2005)
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Figure 1 (from the 1999 Nature article)
Schematic drawings of the grasping mechanism of the giant panda
(medial view of right hand, with the proximal direction at the
bottom). . a, Hand open. b, Hand open but with the
phalanges flexed. c, The grasping action (from a small
palmar angle). The radial sesamoid and accessory carpal bones do
not move independently of their articulated bones in the
grasping action, but constitute two functional units: the RRM
complex (see text) in the medial part of the hand, and the AU
complex (see text) in the lateral part. Pincer-like structures
are made by the phalanges and the RRM complex in the medial
part, and by the phalanges and the AU complex in the lateral
part. d, As c, but showing the muscles in the
pincer-like structures on both sides of the grasped hand
(arrows). |
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