Monday, December 26, 2011

ID and retinal design

The "poor design" of the retina has long been a standard objection to the efficiency of  the design of the eye. Here is an answer. Casey Luskin is an excellent scientist, and very generous in answering queries. 


http://www.discovery.org/a/18011


Eyeballing Design
"Biomimetics" Exposes Attacks on ID as Poorly Designed

By: Casey Luskin
Salvo Magazine
December 20, 2011


Link to Original Article
At least since the ancient Chinese tried to produce artificial silk, people have turned to biology for inspiration when designing technology. A 2009 article in the world's oldest science journal, Philosophical Transactions of the Royal Society of London, authored by Ohio State University nanotechnology engineer Bharat Bhushan, explains how this design process works:
The understanding of the functions provided by objects and processes found in nature can guide us to imitate and produce nanomaterials, nanodevices and processes. Biologically inspired design or adaptation or derivation from nature is referred to as "biomimetics." It means mimicking biology or nature.1
Perhaps the most familiar example of biomimetics is the body shape of birds serving as the inspiration for aircraft design. But the list of fascinating cases where engineers have mimicked nature to develop or improve human technology goes on and on:
• Faster Speedo swimsuits have been developed by studying the properties of sharkskin.
• Spiny hooks on plant seeds and fruits led to the development of Velcro.
• Better tire treads were created by understanding the shape of toe pads on tree frogs.
• Polar bear furs have inspired textiles and thermal collectors.
• Studying hippo sweat promises to lead to better sunscreen.
• Volvo has studied how locusts swarm without crashing into one another to develop an anti-collision system.
• Mimicking mechanisms of photosynthesis and chemical energy conversion might lead to the creation of cheaper solar cells.
• Copying the structure of sticky gecko feet could lead to the development of tape with cleaner and dryer super-adhesion.
• Color-changing cuttlefish have inspired television screens that use a fraction of the power of standard TVs.
• DNA might become a framework for building faster microchips.
• The ability of the human ear to pick up many frequencies of sound is being replicated to build better antennas.
• The Namibian fog-­basking beetle has inspired methods of desalinizing ocean water, growing crops, and producing electricity, all in one!
Disclaiming Design
The purpose of Dr. Bhushan's paper was to encourage engineers to study nature when creating technology. For some reason, however, he felt compelled to open his article with the following disclaimer:
Nature has gone through evolution over the 3.8 Gyr [Gigayear, equal to one billion years] since life is estimated to have appeared on the Earth. Nature has evolved objects with high performance using commonly found materials.
Why did Bhushan feel this was necessary?
The answer is hard to miss. The widespread practice and success of biomimetics among technology-creating engineers has powerful implications that point to intelligent design (ID). After all, if human technology is intelligently designed, and if biological systems inspire or outperform man-made systems, then we are confronted with the not-so-subtle inference that nature, too, might have been designed.

To prevent ID-oriented thoughts from entering the minds of readers, materialists writing about biomimetics have long upheld a tradition of including superfluous praise of the amazing power of Darwinian evolution.
For example, when explaining how the unique bumpy shape of whale flippers has been mimicked to improve wind turbine design, a ScienceDaily article reminded readers that "sea creatures have evolved over millions of years to maximise efficiency of movement through water."2
Similarly, in 2008, Business Week carried a piece on biomimetics noting that "ultra-strong, biodegradable glues" have been developed "by analyzing how mussels cling to rocks under water," and that bullet-trains could be made more aerodynamic if given "a distinctly bird-like nose." But the story couldn't help but point out that these biological templates weren't designed, but rather "evolved in the natural world over billions of years."3
It's uncanny how predictable this theme has become. In another instance, MSNBC explained how "armor" on fish might be copied to improve battle ware for soldiers. Yet the article included the obligatory subheading instructing readers that "millions of years of evolution could provide exactly what we need today."4
Well, aren't we lucky?
Better Keep the Disclaimers
Dr. Bhushan was wise to include his disclaimer promoting unguided evolution: From an ID-based view, it's unsurprising that designers of human technology would find so many solutions to problems within the biosphere. ID-friendly implications permeate the field of biomimetics, and they are dangerous to materialism.
Evolutionary thinkers, of course, will assert that these finely tuned biological systems evolved by blind natural selection preserving random mutations. Over billions of years, they imagine, this unguided process perfected these systems, ultimately besting the inventions of our top engineering minds.
Such deeply held convictions might be hard to unseat from the minds of materialists. But consider this: When human engineers want to create technology, do they use unguided processes of random mutation and natural selection? No. They use intelligent design.
In fact, whenever we understand the origin of a piece of technology, we see that intelligent design was always required to generate the system. How then, is Dr. Bhushan so confident that the elegant systems in nature that surpass human designs—including multi-component machines—­resulted from unguided evolutionary processes?
Poorly Designed Objections
Some materialists attack design arguments not by alleging that biological systems lack high levels of specified complexity, but by alleging that they are full of "flaws." Yet anyone who has used Microsoft Windows is painfully aware that flawed designs are still designed. But theistic evolutionist biologist Kenneth Miller argues that evolution would naturally lead us to expect the biological world to be full of "cobbled together" kluges that reflect the clumsy, undirected Darwinian process.5
For example, Miller maintains that the vertebrate eye was not intelligently designed because the optic nerve extends over the retina instead of going out the back of the eye—an alleged design flaw. According to Miller, "visual quality is degraded because light scatters as it passes through several layers of cellular wiring before reaching the retina."
Similarly, Richard Dawkins contends that the retina is "wired in backwards" because light-sensitive cells face away from the incoming light, which is partly blocked by the optic nerve. In Dawkins's ever-humble opinion, the vertebrate eye is "the design of a complete idiot."6
A closer examination shows that the design of the vertebrate eye works far better than Dawkins and Miller let on.
Dawkins concedes that the optic nerve's impact on vision is "probably not much," but the negative effect is even less than he admits. Only if you cover one eye and stare directly at a fixed point does a tiny "blind spot" appear in your peripheral vision as a result of the optic nerve covering the retina. When both eyes are functional, the brain compensates for the blind spot by meshing the visual fields of both eyes. Under normal circumstances, the nerves' wiring does nothing to hinder vision.
Nonetheless, Dawkins argues that even if the design works, it would "offend any tidy-minded engineer." But the overall design of the eye actually optimizes visual acuity.
To achieve the high-quality vision that vertebrates need, retinal cells require a large blood supply. By facing the photoreceptor cells toward the back of the retina, and extending the optic nerve out over them, the cells are able to plug directly into the blood vessels that feed the eye, maximizing access to blood.
Pro-ID biologist George Ayoub suggests a thought experiment where the optic nerve goes out the back of the retina, the way Miller and Dawkins claim it ought to be wired. Ayoub finds that this design would interfere with blood supply, as the nerve would crowd out blood vessels. In this case, the only means of restoring blood supply would be to place capillaries over the retina—but this change would block even more light than the optic nerve does under the actual design.
Ayoub concludes: "In trying to eliminate the blind spot, we have generated a host of new and more severe functional problems to solve."7
In 2010, two eye specialists made a remarkable discovery that showed the elegant mechanism found in vertebrate eyes to solve the problem of any blockage of light due to the position of the optic nerve. Special "glial cells" sit over the retina and act like fiber-optic cables to channel light through the optic nerve wires directly onto the photoreceptor cells. According to New Scientist, these funnel-shaped cells prevent scattering of light and "act as light filters, keeping images clear."8
Ken Miller acknowledges that an intelligent designer "would choose the orientation that produces the highest degree of visual quality." Yet that seems to be exactly what we find in the vertebrate eye. In fact, the team of scientists who determined the function of glial cells concluded that the "retina is revealed as an optimal structure designed for improving the sharpness of images."
ID-theorist William Dembski has observed that "no one has demonstrated how the eye's function might be improved without diminishing its visual speed, sensitivity, and resolution."9 It's therefore unsurprising that optics engineers study the eye to improve camera technology. According to another tech article:
Borrowing one of nature's best designs, U.S. scientists have built an eye-shaped camera using standard sensor materials and say it could improve the performance of digital cameras and enhance imaging of the human body.
The article reported that the "digital camera has the size, shape and layout of a human eye" because "the curved shape greatly improves the field of vision, bringing the whole picture into focus."10
It seems that human eyes are so poorly designed that engineers regularly mimic them.
Repeat After Me . . .
Bhushan ends his article on biomimetics by paying more lip service to evolution, declaring that "nature has evolved and optimized a large number of materials and structured surfaces with rather unique characteristics." His chosen blindness to the pro-ID implications of biomimetics does not negate the fact that, intriguingly, nature routinely inspires and outperforms the best human ­technology.
Biologists and engineers who still want to believe that life's elegant complexity results from neo-Darwinian processes may find that the only way to do so is to keep repeating Francis Crick's mantra—"Biologists must constantly keep in mind that what they see was not designed, but rather evolved"—over and over to themselves. •
Endnotes 1. Bharat Bhushan, "Biomimetics: lessons from nature—an overview," Philosophical Transactions of the Royal Society of London A, vol. 367 (2009), pp. 1445–1486.
2. "Whales and Dolphins Influence New Wind Turbine Design" ScienceDaily (July 7, 2008): www.sciencedaily.com/releases/2008/07/080707222315.htm.
3. Matt Vella, "Using Nature as a Design Guide," Bloomberg Businessweek (February 11, 2008):www.businessweek.com/innovate/content/feb2008/id20080211_074559.htm.
4. Jeanna Bryner, "Incredible fish armor could suit soldiers" (July 28, 2008):www.msnbc.msn.com/id/25886406.
5. Kenneth R. Miller, "Life's Grand Design," Technology Review (February/March 1994), pp. 25–32.
6. Richard Dawkins, The Greatest Show on Earth: The Evidence for Evolution (Free Press, 2009), p. 354.
7. George Ayoub, "On the Design of the Vertebrate Retina," Origins & Design, vol. 17:1 (Winter 1996): www.arn.org/docs/odesign/od171/retina171.htm.
8. Kate McAlpine, "Evolution gave flawed eye better vision," New Scientist (May 6, 2010):www.newscientist.com/article/mg20627594.000-evolution-gave-flawed-eye-better-vision.html.
9. William Dembski & Sean McDowell, Understanding Intelligent Design: Everything You Need to Know in Plain Language (Harvest House, 2008), p. 53.
10. Julie Steenhuysen, "Eye spy: U.S. scientists develop eye-shaped camera," Reuters (August 6, 2008): www.reuters.com/article/2008/08/06/us-camera-eye-idUSN0647922920080806.