Did the eye evolve from a simple layer of photo-sensitive cells into the eyes that we have today? Darwin remarked that ...
"several facts make me suspect that any sensitive nerve may be rendered sensitive to light"
... but how do photo-sensitive cells work? Is the invertebrate eye really wired the wrong way round? Dr George Marshall an expert in anatomy, who specialised in the human eye for several years answers these questions and many more.
Edinburgh Creation Group is an active forum where scientifically minded people meet to discuss evidence supporting the biblical account of creation.
An Eye for Creation
An Interview with Eye-Disease Researcher Dr George Marshall, University of Glasgow, ScotlandCreation Magazine
September 1, 1996
Creation magazine [CM]: Dr Marshall, you wrote to us to comment on the article “Seeing back to front” which appeared in the March–May 1996 issue of Creation magazine. What was your comment?
Dr George Marshall [GM]: I pointed out that the principal reason as to why the eye cannot be regarded as being wired backward (as some evolutionists claim) was hidden in a footnote in your article.
Then what do you think of the idea that the eye is wired backward?
GM: The light-detecting structures within photoreceptor cells are located in the stack of discs. These discs are being continually replaced by the formation of new ones at the cell body end of the stack, thereby pushing older discs down the stack. Those discs at the other end of the stack are ‘swallowed’ by a single layer of retinal pigment epithelial (RPE) cells. RPE cells are highly active, and for this they need a very large blood supply—the choroid. Unlike the retina, which is virtually transparent, the choroid is virtually opaque, because of the vast numbers of red blood cells within it. For the retina to be wired the way that Professor Richard Dawkins suggested, would require the choroid to come between the photoreceptor cells and the light, for RPE cells must be kept in intimate contact with both the choroid and photoreceptor to perform their job. Anybody who has had the misfortune of a hemorrhage in front of the retina will testify as to how well red blood cells block out the light.
Dr George Marshall,eye-disease researcher
University of Glasgow, Scotland
The notion that the eye was wired backward occurred to me as a 13-year-old when studying eye anatomy in a school science class. It took me two years of lecturing on human eye anatomy to realize why the eye is wired the way it is. The idea that the eye is wired backward comes from a lack of knowledge of eye function and anatomy.How do you react to the notion that the human eye is the product of evolution?
The more I study the human eye, the harder it is to believe that it evolved. Most people see the miracle of sight. I see a miracle of complexity on viewing things at 100,000 times magnification. It is the perfection of this complexity that causes me to baulk at evolutionary theory.Can you give our readers some idea of just how complex the eye is?
The retina is probably the most complicated tissue in the whole body. Millions of nerve cells interconnect in a fantastic number of ways to form a miniature ‘brain’. Much of what the photoreceptors ‘see’ is interpreted and processed by the retina long before it enters the brain.A computer program has allegedly ‘imitated’ the evolution of an eye. Do you accept this?
Those who produced this model would acknowledge that the model is such a gross oversimplification that it cannot be cited as a proof. May I quote a colleague’s reaction [Dr John Hay, B.Sc.(Hons), Ph.D., M.Sc., C.Biol., F.I.Biol.]:What exactly does your work involve?
‘Computer simulation of evolutionary processes such as that described have three important flaws. First, the findings imply that the development which is being measured over so many generations is independent of development of other structures which are necessary for function. Second, the changes observed from the simulation are dependent on the original data input which clearly is consequent to human design of the sequences/regions to be worked on and also the program(s) which are used for the simulation. These are not, therefore, random. The third aspect of all this is that there is translation error in such simulations involving computer hardware/software. This can take the form of electronic error in single bits which are coding for a particular digit. Over many loops in this performance, intrinsic error can be magnified considerably. Was the simulation repeated using different PCs etc.? One feels that these three arguments are essential to any computer simulation package of evolutionary processes.
‘My first point indicated that even if there is an eye, it will be useless unless the organism has the neural and/or the mental processes to utilize information perceived by the eye. How can a chance mutation provide this complexity in several different structures? The argument has usually been that there is a plausible intermediate series of eye-designs in living animals, e.g. Euglena has an eyespot; other organisms have a “cup” which acts as a direction finder.
‘However, the organism which defies this evolution is Nautilus. It has a primitive eye with no lens, which is somewhat surprising considering that its close relative, the squid, has one. This organism has (apparently!) been around for millions of years but has never “evolved” a lens despite the fact that it has a retina which would benefit from this simple change.’
Lecturing to doctors in medicine who have specialized in ophthalmology and are attempting to gain fellowship with the Royal College of Ophthalmology (FRCOphth). However, my main remit is research into eye diseases using a combination of transmission electron microscopy and immunocytochemistry—a technique that uses antibodies to locate specific proteins such as enzymes.Do you believe that accepting creation as portrayed in Genesis is essential to your Christian faith?
Yes! On not literally accepting the Genesis account of creation one is left with a major problem—what Scriptures do you accept as true and what Scriptures do you reject as false? Only by accepting the whole of Scripture as the inspired Word of God does one avoid this dilemma. There are Scriptures that are a source of stumbling to the intellect. My practice is to ‘pigeon-hole’ them temporarily and never allow them to be a stumbling block to my faith. It’s amazing how many of these knotty problems have subsequently resolved themselves. Thus Genesis creation may initially appear to be hard to accept, but it strikes me that evolution is equally if not more problematic to believe.How useful do you find Creation magazine?
Its principal value is that it challenges what is uncritically accepted. Watch any TV program involving nature and you would think that evolution is an established fact. People get bombarded with this so often that they accept it without thinking. Creation magazine makes people realize that it is only a proposal and not fact. There are numerous places in my hospital where I can leave copies on coffee tables to get people to think for themselves.What advice would you have for Christian students, or for Christians in a science course or teaching situation?
First, recognize that science can become a ‘religion’ in its own right. Scientists say something, so the general public (the ‘worshippers’) accept it without question. Scientists are much more cautious about one another’s findings. Second, science is not static. The science of today is quite different in many ways from the science of yesterday, and will probably bear little resemblance to the science of tomorrow. People once believed in ‘spontaneous generation’ which could be ‘proved’ by putting an old sack and a few bits of cheese in a dark corner. Mice spontaneously generated out of the sack. We laugh at such notions, but I suspect that in a hundred years’ time people will laugh at some of our scientific notions. Third, one can still become an eminent scientist without accepting evolutionary dogma; the ability to produce sound science in the laboratory is not diminished by one’s stance on creation.Dr Marshall, thank you very much.