Letter to the Editor
Response to Lahti's
an Inverted Retina
Jerry Bergman, ASA Fellow
From: PSCF 53 (June 2001): 139-141
In reference to David Lahti's comments on my retina paper (PSCF 52 [March 2000]: 18-30), I cited only a few of the many reasons why the inverted retina is a superior design compared to the verted retina. Many other examples exist, which space limitations prohibited discussing. Furthermore, the literature clearly shows that Lahti's argument that the existing retina is not the optimal design is incorrect from a theoretical standpoint; in fact, it is the optimal design, both in theory and in fact, given the needs of humans.
To prove that humans do not have an intelligent creator, prominent scientists like Dawkins, Williams, and Diamond use a reverse theological design argument to argue that the verted eye is an excellent example of poor design. Dawkins1 states that "evidence of telling imperfections" (p. 91) in design is important evidence that no designer (God) exists. His examples include the inverted retina and others such as the flatfish. He concludes that "no sensible designer would have conceived [them]" and that "Octopus eyes are ... more 'sensibly' designed" (pp. 92, 95). Intelligent design theorists use examples of excellent design to prove a designer. Theorists, such as Dawkins, use what they consider poor design to suggest that there could not be an intelligent designer.
The neurologists, ophthalmology researchers, and others that I consulted all mentioned that they thought that the arguments used by Dawkins, Williams, et al. were based on an appalling lack of knowledge about how the human eye functions. I was not able to locate a single qualified retina neurologist who agreed with the claims of poor design--all such statements were made only by evolutionary biologists in an effort to defend their "blind watchmaker" argument.
Lahti's argument that "no one has postulated that eye functionality would improve" if the human eye was verted is not true. Claims made by evolutionary biologists on this matter are not ambiguous. Dawkins et al. have postulated that the inverted retina is inferior, and if it were verted, it would be superior because the putative problems that he has elucidated would not exist. In contrast, it is clear from what is known now that if we had evolved a verted eye, our vision would not be more efficient but less so, as is apparent when the literature on pigment epithelium is reviewed.
As to Lahti's claim that Darwinists "claim that the natural world was designed," design in the common use refers to intelligent design. Of course, Darwinists believe the Earth was "designed" by natural selection, selecting the mutations and genetic variety that maximize survival and reproduction success. Actually, to use the expression natural selection "designed" is like calling the wind blowing around paint an "artist." The phrase "the world was designed by mutations (copying errors )" includes a number of contradictory ideas. Also, contrary to Lahti's statement, biologists have said much about both the purpose and the agent of this design in a metaphysical sense.
I have located hundreds of quotes by prominent evolutionists that make it quite clear that they believe evolution has proved that the Universe has no ultimate purpose, is pointless, and were evolution to occur a thousand times again, it likely never would produce anything like humans or dinosaurs. Furthermore, the agent of this "design" is clearly mutations coupled with natural selection, proving that an intelligent designer does not exist. In my thirty years of reading thousands of books and articles by various evolutionists, I have found that their beliefs and conclusions vary widely, but many, and especially the most prominent evolutionists, quite clearly teach that life has no ultimate purpose except survival and reproduction success.
Although, as Lahti notes, Darwinists generally believe that the extant organisms are the tips of long branches and that no morphological structure on one tip is inherited from that of another, transitional forms would be expected to connect the organisms located on the lower parts of the tree. Furthermore, the primary information we have of what these transition forms might be like comes from extant organisms. As Lahti correctly notes, we have no evidence that the inverted retina evolved from the verted retina, but we also have no evidence that the retina evolved from any other type of eye or pre-eye structure. In spite of this fact, the many types of eyes that now exist--from the eye spot to the human eye--are lined up hierarchically to support some hypothetical eye evolution (such as that proposed by Dawkins).1
Relative to Lahti's claim that the eye evolved numerous times, it often is suggested by evolutionists that the eye evolved approximately thirty separate times--an idea which, although widely held, has faced serious problems as a result of the discovery that the genes coding for the structures that allegedly evolved separately often have an extremely high level of homology, thus creating in the minds of some researchers problems with the idea of convergent evolution of the eye and its various structures.
Lahti's statement that "there is absolutely no disagreement in evolutionary biology about these particulars" is quickly shown to be false under the weight of extensive reading. There exists enormous disagreement over most of the central ideas in Darwinism. It is therefore difficult to make statements about what "evolutionists believe," because so much disagreement exists among them over even the basic ideas of Darwinism.2
1Richard Dawkins, The Blind Watchmaker (New York: Norton, 1986).
2Kim Sterelny, Dawkins vs. Gould: Survival of the Fittest (New York: Totem Books, 2001).