Essay by Jeff Lindsay, Design Flaws versus Intelligent Design: The Perspective of an Engineer and Inventor
http://www.jefflindsay.com/DesignFlaws.shtml
In my current work, I often work on inventions that become patents. Those who invent know that many of the most clever inventions are non-intuitive. Inventions often come when the inventor encounters a problem with the "obvious" way of doing things, and then finds an alternative that violates old assumptions. Those who are ignorant may look at the invention and dismiss it as fundamentally flawed for its failure to conform to simple paradigms of the past - but what at first looks like a design flaw may hold a brilliant breakthrough.
This argument is based on the assumption that the human eye does not see well compared to an octopus. Is there any evidence that our sight is suboptimal relative to the octopus? The argument is based on a simple-minded assumption and ignorance of what the retina actually does. Do we really understand the complexities of the retina enough to address this issue?
Lindsay cites research on the retina by Helga Kolb, “How the Retina Works”
http://www.americanscientist.org/issues/num2/2003/1/how-the-retina-works/1
The above broad sketch of retinal circuitry suggests that the retina is remarkably complex. As vision research advances, the retina seems to take on an increasingly active role in perception. Although we do not fully understand the neural code that the ganglion-cell axons send as trains of spikes into the brain, we are coming close to understanding how ensembles of ganglion cells respond differently to aspects of the visual scene and how fields of influence on particular ganglion cells are constructed. Much of the construction of the visual images does seem to take place in the retina itself, although the final perception of sight is indisputably done in the brain….
The most recent surprise has been that a previously unknown ganglion cell type appears to function as a giant photoreceptor itself, without needing input from rods or cones. This ganglion's cell membrane contains light-reactive molecules known as melanopsins. Given such unexpected findings, it appears that there may still be much more to learn about how the retina works.
Lindsay writes that this discovery “points to at least one obvious function that could not be achieved with nerves behind the photoreceptors.”
He then lays down this challenge to those who think the vertebrate eye is flawed in design:
- How do you know that you would see better if your eye was rewired according to the design you think is more logical?
- Can you provide the image processing functions of the neural circuitry in front of the photoreceptors by moving the nerves to some other place?
- Can you provide the benefits of photoreceptive ganglion cells by moving them elsewhere?
- What problems are associated with rerouting the nerves?
Lindsay also cites a discussion by Arthur Chadwick comparing the design benefits of the human eye versus the cephalopod (eg. squid and octopus) eye:
http://origins.swau.edu/q_and_a/evol/questions/q6.html
Which design is best? This is not an easy question to answer. In the vertebrate eye, the photoreceptor cells lie in contact with the opaque pigment epithelium. This tissue prevents the transmission of light past the eye, and also is involved in the critical process of recycling exposed photopigments, a critical process for eyes of animals that are very active, since it allows for tight packing of photoreceptor cells and rapid recycling of used photopigments. The invertebrate eye, that lacks this feature, may have to sacrifice the ability to keep up a sustained high level of visual acuity for the possible gain in visual acuity, but this is only speculation. In any case it is far premature to conclude that one design or the other is inferior without having physiological bases for such statements.
As research on the functionality of the eye continues, we learn more of its fantastic ability to receive and process signals. The more we learn, the more we are convinced that no plausible mechanism in evolution can produce such a structure with the properties it possesses. This trend, and past experience assure us that when we have a fuller knowledge of the functional properties of the vertebrate eye, we will understand why the retina is designed the way it is. Recent developments along this line include an article in Nature by M.J. Berry II, I.H.Brivanlou , T.A. Jordan and M. Meister, entitled "Anticipation of moving stimuli by the retina," (398:334-338). In this article the authors explore one of the most phenomenal feats of optical response ever discovered: the ability to precisely anticipate the position of a moving object at the level of the retina. Gegenfurtner, in an article in the same issue ("Neurobiology: The eyes have it!" 398), summarizing the paper by Berry, et.al, states:
"But the visual system can circumvent such delays [between detection and response to a moving object] by anticipating the path of moving stimuli. Such motion anticipation was assumed to be controlled by high-level motion areas of the visual cortex. Now, very much to our surprise, Berry et al. (page 334 of this issue) report that motion anticipation is already accomplished to a large extent in the retina, by neural circuits that were discovered long ago." Barry, et.al. in the article demonstrate how the eye performs calculus in order to solve the problems of the future location of a moving object, for example, a baseball batter responding to a fastball:"In a stunning surprise, Berry et al. now show that motion anticipation not only starts at the retina, the first stage of processing in the visual system, but that it also follows from current models of retinal processing. The basic ingredients are all well studied and common to many stages of processing in the visual system. So how do these ingredients work to produce motion anticipation? The most important part of the process is actually the simplest -namely that retinal ganglion cells pool their inputs over large regions of the visual scene (their receptive fields)." (p291).
"In this scenario, the retina integrates the light stimulus over space and time, with a weighting function k(x,t) given by the ganglion cell's receptive field, and the resulting signal determines the neuron's firing rate." This amazing new understanding of how the "backward" retina can perform calculations of a very high order is no deterrent to evolutionists, who quickly integrate evolution into our understanding of the process. To explain the existence of this phenomenal ability in the retina, Gegenfurtner suggests:
"If, for example, we assume a processing delay of about 100 ms [the time necessary for processing an impulse in the visual cortex of the brain], an animal (or a car nowadays) moving at a speed of 40 km per hour would be seen more than one metre behind its actual position. To overcome this potentially lethal problem, evolution has selected(emphasis added) mechanisms that anticipate the path of motion." (Gegenfurtner, p291). That statement illustrates the expectations of evolution and flies in the face of the assertions of Gould and Dawkins that evolution is a science of mistakes and wrong pathways. In fact, evolution appears to be defined in a circular manner, as the science of what is. When a marvelous organ such as the eye that is infathomably complex is encountered, evolutionists apparently feel the need to find some flaw in it that can be used to distract attention from the problem the existence of such complexity presents for evolution.
The eye remains one of the most intractible arguments for a Designer in nature, and suggestions to the contrary are without scientific merit. Those who protest thst the eye is poorly designed are being challenged to design a better one, or to show how it might be improved. Until they convincingly do so, this argument cannot be taken seriously.