SEJ>It is a commonplace in Darwinist anti-design polemics that
SEJ>the vertebrate eye is badly designed, being allegedly
SEJ>`wired backwards' with optic nerve ganglions getting in
SEJ>the way of incoming light to the retina. For example,
SEJ>Dawkins writes:
SEJ>"Any engineer would naturally assume that the photocells
SEJ>would point towards the light, with their wires leading
SEJ>backwards towards the brain. He would laugh at any
SEJ>suggestion that the photocells might point away from the
SEJ>light, with their wires departing on the side nearest the
SEJ>light. Yet this is exactly what happens in all vertebrate
SEJ>retinas. Each photocell is, in effect, wired in backwards,
SEJ>with its wire sticking out on the side nearest the light.
SEJ>The wire has to travel over the surface of the retina, to
SEJ>a point where it dives through a hole in the retina (the
SEJ>so-called 'blind spot') to join the optic nerve. This
SEJ>means that the light, instead of being granted an
SEJ>unrestricted passage to the photocells, has to pass
SEJ>through a forest of connecting wires, presumably suffering
SEJ>at least some attenuation and distortion (actually
SEJ>probably not much but, still, it is the principle of the
SEJ>thing that would offend any tidy-minded engineer!)."
SEJ>(Dawkins R., "The Blind Watchmaker," 1991, reprint, p93).
SEJ>In fact leading Darwinist theoretician George C. Williams
SEJ>says that the vertebrate eye is "stupidly designed"
SEJ>("Natural Selection: Domains, Levels, and Challenges,"
SEJ>1992, pp72-73), because of this inversion, and
SEJ>anthropologist Jared Diamond claims that "A camera
SEJ>designer who committed such a blunder would be fired
SEJ>immediately." ("Voyage of the Overloaded Ark," Discover,
SEJ>June 1985, pp82-92).
SEJ>This "God-wouldn't-do-it-that-way" argument has been
SEJ>answered satisfactorily by design theorists, for example
SEJ>see George Ayoub's "On the Design of the Vertebrate
SEJ>Retina," Origins & Design 17:1, Winter 1996, at:
SEJ>http://www.arn.org/docs/odesign/od171/retina171.htm
Heh. A bunch of hand-waving and missing-the-point. rather
than addressing optimality, Ayoub airily dismisses any
consideration of the issue. Ayoub does no *comparative*
histology, which would be critical to making a point.
SEJ>(click on Figure 2 for a nice diagram of these ganglions),
SEJ>and Paul Nelson's "Jettison the Arguments, or the Rule?:
SEJ>The Place of Darwinian Theological Themata in Evolutionary
SEJ>Reasoning," at:
SEJ>http://www.arn.org/docs/nelson/pn_jettison.htm
I've responded to this one before. Nelson's statements that
no valid equation concerning suboptimal design can be
formulated is quite simply false.
See <http://x1.dejanews.com/getdoc.xp?AN=224001175>.
SEJ>But here is a BBC Sci-Tech article that cites a recent
SEJ>Harvard study which found that those self-same ganglions
SEJ>are part of an early-warning system that enables the human
SEJ>eye to detect and "calculate the future position of a
SEJ>moving object" and then to "fire off an alert message to
SEJ>the brain thousandths of a second before the object
SEJ>actually arrives in that place":
SEJ>http://news.bbc.co.uk/hi/english/sci/tech/newsid_305000/305411.stm
SEJ>This enables "tennis players and
SEJ>cricketers..[to]... routinely react to balls travelling at
SEJ>up to 100mph, when technically their brains should not be
SEJ>able to register them before they are gone."
SEJ>So it seems that this alleged `bug' is actually a feature!
SEJ>If this holds up, then not only has the human eye the
SEJ>normal visual circuitry, but it even has additional
SEJ>pre-processing circuitry, the like of which has only
SEJ>become possible in human computer technology in the
SEJ>mid-20th century!
This self-congratulatory text is about a completely orthogonal
issue. Whether one has local processing in the ganglion cells
(the fact of which has been known for quite some time -- the
"news" here is about the "predictive" information) or not does
not bear upon the problem of the blind spot that vertebrate
histology guarantees for our eyes.
SEJ>As Denton points out, it is only as our technology
SEJ>develops that we can begin to appreciate the incredible
SEJ>ingenuity of the advanced technology in the living world:
SEJ>"But it is not just the complexity of living systems which
SEJ>is so profoundly challenging, there is also the incredible
SEJ>ingenuity that is so often manifest in their
SEJ>design. Ingenuity in biological design is particularly
SEJ>striking when it is manifest in solutions to problems
SEJ>analogous to those met in our own technology. Without the
SEJ>existence of the camera and the telescope, much of the
SEJ>ingenuity in the design of the eye would not have been
SEJ>perceived. Although the anatomical components of the eye
SEJ>were well known by scientists in the fifteenth century,
SEJ>the ingenuity of its design was not appreciated until the
SEJ>seventeenth century when the basic optics of image
SEJ>formation were first clearly expressed by Kepler and later
SEJ>by Descartes. However, it was only in the eighteenth and
SEJ>nineteenth centuries, as the construction of optical
SEJ>instruments became more complicated, utilizing a movable
SEJ>iris, a focusing device, and corrections for spherical and
SEJ>chromatic aberration, all features which have their
SEJ>analogue in the eye, that the ingenuity of the optical
SEJ>system could at last be appreciated fully by Darwin and
SEJ>his contemporaries." (Denton M.J., "Evolution: A Theory
SEJ>in Crisis," 1985, p332).
Speaking of things that hinder progress, let me point out the
principle that humans were gifted with omni-competent senses.
This view caused most people to reject Spallanzani's
suggestion that bats utilized sounds that humans were
incapable of hearing for the purpose of navigation.
Spallanzani's elegant experiments were completed ignored. It
wasn't until the late 1930's when Donald Griffin demonstrated
production of ultrasound by bats that Spallanzani's hypotheses
could once again be entertained, a time gap of well over a
century.
SEJ>If the human eye indeed has additional pre-processing
SEJ>visual circuitry then it is even better designed than
SEJ>design theorists had imagined. And the Darwinist problem
SEJ>of explaining away the ingenious design of the eye has
SEJ>just become even *more* "absurd in the highest degree":
Pre-processing circuitry is standard equipment on many eyes,
not just humans. The new article is about a specific type
of pre-processing, not just the usual on-center-off-surround,
off-center-on-surround, and lateral inhibition edge-sharpening
type processing.
SEJ>"To suppose that the eye with all its inimitable
SEJ>contrivances for adjusting the focus to different
SEJ>distances, for admitting different amounts of light, and
SEJ>for the correction of spherical and chromatic aberration,
SEJ>could have been formed by natural selection, seems, I
SEJ>freely confess, absurd in the highest degree." (Darwin C.,
SEJ>"The Origin of Species," 6th Edition, 1928, reprint,
SEJ>p167).
And, of course, the following pages that explain how the
absurdity is imagined rather than real are conveniently
ignored.
Wesley