Darwin has a much-quoted statement about the eye.
In his work On the Origin of Species, he wrote: ‘To suppose that the eye … could have been formed by natural selection seems, I freely confess, absurd in the highest degree’.1 He adds: ‘Yet reason tells me …’ that it must have happened by variations and natural selection. This was recently referred to again in an article in Scientific American by Trevor Lamb.2 He believes that he and his co-workers have solved this dilemma.
In contrast, Bible-believers would quote the Psalmist: ‘He who formed the eye, does he not see?’3 It is clear that this verse is stating that the eye is not the result of non-directional evolution, but the intention of our God.
Before examining Lamb’s article, we need to recognise that we all come to such material with a worldview. For Bible-believers, our worldview is governed by God’s revelation in Scripture (specifically, in this case, that everything in this world was the result of special creation as a result of God’s command, though it has been damaged because of man’s sin). For the non-believer, they will see the same world but seek to find a purely naturalistic explanation (origin by evolution).
Rod and cone photoreceptors
Dr. Lamb’s interest is in the rod and cone photoreceptors in the mammalian eye. These are the cells that receive light impulses and convert them to electrical signals which, in turn, are interpreted by the brain.
For a helpful review of the structure and function of the eye, the reader is recommended to read the monograph by Dr. Sylvia Baker, Seeing and Believing — Evolution, the Eye and Sight.4 The cones are for daylight vision (detecting colour) and the rods for night-time vision (light and darkness). Lamb’s purpose in the Scientific American article is to try and remove any implication of ‘intelligent design’ from the process of the formation of the eye and to demonstrate how it is probably the result of evolutionary processes. (Note the word ‘probably’. Lamb uses similar concepts throughout his paper.)
No fossils
The author acknowledges that his research is hampered by the fact that the eyes are generally not fossilised (being soft tissue) and so he has to look to the eyes (and their controlling genes) in modern creatures. This straight away poses a scientific problem: any relationship between modern creatures does not necessarily demonstrate an evolutionary history. He believes and argues that the primitive ‘eye’ was simply a simple light sensor that controlled circadian rhythms (that is, the cycle of biochemical, physiological, or behavioural processes throughout the day) and evolved into an ‘optically and neurologically sophisticated organ’. Of course, he cannot prove that this is what happened but seeks to present a ‘just so’ story that might explain such a transition.
Using the lamprey
It is not possible to reproduce Dr. Lamb’s arguments in full here. The Scientific American article is reasonably accessible to the non-specialist for anyone wishing to check out the detail. To interpret our supposed evolutionary history, Lamb, Pugh and Collin examined the living eel-like fish, the lamprey, a ‘more primitive jawless vertebrate’ with which, it is believed, we have a common ancestor. The eye of the lamprey is very similar to the mammalian eye (except that it lacks the rods). There is no living equivalent of the lamprey ancestor, but another eel-like creature, the hagfish, provides clues. The eyes of the hagfish are very different from ours (or even the lamprey’s) and it is similar to the pineal gland which modulates circadian rhythms. So, Lamb and his colleagues propose that the early eye was non-visual and later evolved into the true eye.
Embryology
The next stage in their research was to look at embryological development and they found that this appears to support their notion. (This will remind readers of the ‘embryological recapitulation’ approach which has been discredited in other areas.) They studied the lamprey development. In its larval stage, it is blind and the ‘eye’ resembles that of the hagfish. It undergoes metamorphosis and the full eye develops. So, they use this ‘with caution’ to reconstruct the evolutionary history of the eye.
As they say, ‘we postulate’ and ‘evolution probably proceeded in much the same way’. We give them credit for their cautious wording, but that will probably be overlooked by many readers. When listing the similarities between the lamprey eye and the mammalian one, Lamb comments that they are ‘too numerous to have arisen independently’. But God could have used the same blue print, couldn’t he?
Their scenario describes how the embryological eye develops by curvature from an essentially planar structure. They refer to the work of Nilsson & Pelger at Lund University5 as evidence that this could all occur in a relatively short evolutionary timescale. They note that Nilsson & Pelger ‘showed that the optical components of the eye could have easily evolved in a million years’.
Richard Dawkins has also referred to their work with approval: ‘[Darwin] felt faint every time he contemplated [the eye] … It is a very beautiful mechanism that depends on complicated optics … It’s very well adjusted for all sorts of aberrations … How could this come about by gradual natural selection? … Every gradual stage was a slight improvement on the one before … This is well understood and … has recently been improved on by computer modelling by two Swedes, Dan Nilsson and Susanne Pelger.’6
Work challenged
Their work has been challenged on a number of occasions but it certainly does not achieve the essential outcomes. For example, how did the lens and its accompanying systems arise?
In all these scenarios, the basic retinal structure and its activity are assumed and yet this is extremely complex and has to arise before the future changes can be explained. Again, the highly complex system of the chemical process of vision is overlooked7 as is the even more complex system of the brain’s interpretation of the signals into a visual image.
Inelegant traits?
Lamb’s final onslaught against any concept of a Creator’s involvement is his claim of ‘inelegant traits’ which no reasonable designer would incorporate. He only mentions two claims. Firstly, the mammalian eye retina is inside out and, as a result, it ‘degrades image quality’. This argument has been demonstrated as false repeatedly and ophthalmologists have argued that it is a position of ignorance.
In contrast to this, we would draw attention to the contrary discovery at Leipzig University of the ‘Mueller cells’8. These are cells that act like optical fibres enhancing the process of light transference across the retina to the photoreceptors. At the end, facing the light source, is a cone that guides the light into the cells and on to the receptors. One of the team commented: ‘Nature is so clever’! Labin and Ribak9 have shown that these Mueller cells improve the sharpness of the image and eliminate optical ‘noise’ due to internally reflected light. Their design overcomes chromatic aberration and they are ‘tuned’ to filter out radiation other than visible light.
The other ‘bad design’ is the so-called blind spot. But who is conscious of it? The eyes are so designed that the blind spots are positioned differently in each eye to compensate for their essential presence. The author throws in the comment that the ‘list goes on and on’, but he does not quantify these and so it is impossible to respond to the claim.
I could not help being amused by a footnote to the article which referred the reader to their website at www.ScientificAmerican.con (not .com).
References
1. On the Origin of Species, John Murray, London, 1859, p.186
2. Trevor D. Lamb, ‘Evolution of the Eye’, Scientific American, 2011, 305(1), July, 48-53
3. Psalm 94.9
4. Sylvia Baker, ‘Seeing and Believing — Evolution, the Eye and Sight’, The Genesis Agendum, 2004, Occasional Paper no.11
5. Dan-Erik Nilsson and Susanne Pelger, A Pessimistic Estimate of the Time Required for an Eye to Evolve, Proceedings of the Royal Society, London B, 1994, 256, 53-58
6. Richard Dawkins, The Daily Telegraph, April 12 1995
7. Michael J. Behe, Darwin’s Black Box, The Free Press, New York, 1996. pp.18-22
8. K. Franze et al, Müller Cells are Living Optical Fibers in the Vertebrate Retina, Proc. Natl. Acad. Sci., 2007 104, 8287
9. A.M. Labin and E.N. Ribak, Retinal Glial Cells Enhance Human Visual Acuity, Phys. Rev. Lett., 2010, 104(April 16), 158102
