In his book
Darwin's Black Box, Michael Behe stresses that the
structure of the living cell and all other biochemical systems
were unknown "black boxes" for Darwin and his contemporaries.
Darwin assumed that these black boxes possessed very simple
structures and could have come about by chance. Now, however,
modern biochemistry has opened up these black boxes and revealed
the irreducibly complex structure of life. Behe states that
Darwin's comments on the emergence of the eye seemed convincing
because of the primitive level of nineteenth-century science:
Darwin persuaded much
of the world that a modern eye evolved gradually from a
simpler structure, but he did not even try to explain where
his starting point-the relatively simple light-sensitive
spot-came from. On the contrary, Darwin dismissed the question
of the eye's ultimate originÖ He had an excellent reason
for declining the question: it was completely beyond nineteenth-century
science. How the eye works-that is, what happens when a
photon of light first hits the retina-simply could not be
answered at that time.353
So, how does this system, which Darwin glossed
over as a simple structure, actually work? How do the cells
in the eye's retinal layer perceive the light rays that fall
The answer to that question is rather complicated.
When photons hit the cells of the retina they activate a chain
action, rather like a domino effect. The first of these domino
pieces is a molecule called "11-cis-retinal" that is sensitive
to photons. When struck by a photon, this molecule changes
shape, which in turn changes the shape of a protein called
"rhodopsin" to which it is tightly bound. Rhodopsin then takes
a form that enables it to stick to another resident protein
in the cell called "transducin."
Prior to reacting with rhodopsin, transducin
is bound to another molecule called GDP. When it connects
with rhodopsin, transducin releases the GDP molecule and is
linked to a new molecule called GTP. That is why the new complex
consisting of the two proteins (rhodopsin and transducin)
and a smaller molecule (GTP) is called "GTP-transducin-rhodopsin."
But the process has only just begun. The new
GTP-transducin-rhodopsin complex can now very quickly bind
to another protein resident in the cell called "phosphodiesterase."
This enables the phosphodiesterase protein to cut yet another
molecule resident in the cell, called cGMP. Since this process
takes place in the millions of proteins in the cell, the cGMP
concentration is suddenly decreased.
How does all this help with
sight? The last element of this chain reaction supplies the
answer. The fall in the cGMP amount affects the ion channels
in the cell. The so-called ion channel is a structure composed
of proteins that regulate the number of sodium ions within
the cell. Under normal conditions, the ion channel allows
sodium ions to flow into the cell while another molecule disposes
of the excess ions to maintain a balance. When the number
of cGMP molecules falls, so does the number of sodium ions.
This leads to an imbalance of charge across the membrane,
which stimulates the nerve cells connected to these cells,
forming what we refer to as an "electrical impulse." Nerves
carry the impulses to the brain and "seeing" happens there.354
In brief, a single photon hits a single cell,
and through a series of chain reactions the cell produces
an electrical impulse. This stimulus is modulated by the energy
of the photon-that is, the brightness of the light. Another
fascinating fact is that all of the processes described so
far happen in no more than one thousandth of a second. As
soon as this chain reaction is completed, other specialized
proteins within the cells convert elements such as 11-cis-retinal,
rhodopsin and transducin back to their original states. The
eye is under a constant shower of photons, and the chain reactions
within the eye's sensitive cells enable it to perceive each
one of these.
The process of sight is actually a great deal
more complicated than the outline presented here would indicate.
However, even this brief overview is sufficient to demonstrate
the extraordinary nature of the system. There is such a complicated,
finely calculated design inside the eye that it is nonsensical
to claim that this system could have come about by chance.
The system possesses a totally irreducibly complex structure.
If even one of the many molecular parts that enter into a
chain reaction with each other were missing, or did not possess
a suitable structure, then the system would not function at
It is clear that this system deals a heavy blow
to Darwin's explanation of life by "chance." Michael Behe
makes this comment on the chemistry of the eye and the theory
Now that the black box
of vision has been opened, it is no longer enough
for an evolutionary explanation of that power to consider
only the anatomical structures of whole eyes, as
Darwin did in the nineteenth century (and as popularizers
of evolution continue to do today). Each of the anatomical
steps and structures that Darwin thought were so simple
actually involves staggeringly complicated biochemical processes
that cannot be papered over with rhetoric.355
The irreducibly complex structure of the eye
not only definitively disproves the Darwinist theory, but
also shows that life was created with a superior design.
J. Behe, Darwin's Black Box, The Free Press, New
York, 1996, p. 18.
354 Michael J. Behe, Darwin's Black
Box, The Free Press, New York, 1996, pp. 18-21.
355 Michael J. Behe, Darwin's Black
Box, The Free Press, New York, 1996, p. 22. (emphasis