Seeing is not believing Terry Byland's remarkable bionic eye illuminates the great fallacy of ID: nature is often neither intelligent nor well-designed.
James Randerson Articles List of 2 items Latest Show all list end Profile Webfeed All James Randerson articles About Webfeeds February 20, 2007 8:30 PM | Printable version " Aged 37, the last thing you want to hear is that you are going blind - and that there's nothing they can do." From the day in 1985 when Terry Byland was diagnosed with retinitis pigmentosa, it took seven and a half years for the rare condition to rob him of his sight. But in 2004 he was given hope. Prof Mark Humayun at the Doheny Eye Institute at the University of Southern California selected him as the sixth patient in a trial of a rudimentary " bionic eye". The device relays visual cues from a tiny camera in a pair of glasses worn by the patient to a surgical implant connected to their retina. Consisting of a four-by-four grid of electrical signals, it is hardly a return to full vision, but by giving back some visual sense it has transformed the lives of Prof Humayun's patients. This is a truly stunning piece of medical engineering. But what struck me as I listened to Prof Humayun describe his 16-pixel eye at the American Association for the Advancement of Science's annual meeting in San Francisco last week was that it is the most effective counter I know to one of the central arguments of intelligent design (ID). Proponents of the creationist alternative to Darwin's theory of evolution by natural selection look at a complex biological structures like the eye and ask, "what use is half an eye?". The human body's elegant machines are so wonderfully crafted, so irreducibly complex they say, that it is impossible to imagine them having been built up piece by piece by an accumulation of random mutations. All the bits have to fit together - so half an eye, or half a heart, or half of the metabolic pathway that extracts energy from sugar is no use at all. Try telling that to Terry Byland. A 16-pixel monochrome eye is about as basic a form of vision as you could imagine, and yet he can tell the difference between a plate and a knife, perceive the direction that objects in front of him are moving and find the door of a room. It has revolutionised his life. Prof Humayun is about to begin trials of a 64-pixel eye which he predicts will allow patients at the very least to do the same tasks, but much more quickly. When he gets to 1000 pixels, he reckons his test subjects will be able to recognise faces. If his bionic eye were subject to mutation and natural selection, it is easy to imagine the step-by-step process leading from the 16-pixel stage to a fully-formed eye. In Darwin's day, the eye was a great battleground in the evolution debate. These days the ID crowd tends to steer clear of it, though. It smacks too much of traditional fusty Victorian zoology, and besides, biologists have done a comprehensive job of documenting every conceivable step along the gradual road from a single light sensing cell to binocular, colour vision. But the same principle applies to the sexy molecular machines the IDers now prefer to cite as unevolvable. The spinning tail that a bacterium uses to swim may look so exquisitely put together that half a tail would be useless. But Prof Humayun's 16-pixel eye teaches us to be wary of the lazy assumption that having only part of a complex biological structure confers no benefit at all. Part of the reason that ID is such a seductive argument is the way that adaptation is often referred to in popular culture. No natural history documentary script would be complete without a description of the polar bear as "perfectly adapted" to its habitat or a eulogy to the "exquisite camouflage" of the arctic fox. But nature is much more interesting than the Discovery Channel would have us believe. Look closely and much of it wouldn't be winning any design awards. Rabbits, for example, have an inefficient and frankly gross way of digesting their food. Your furry pet has a side branch to its gut that is full of enzymes and bacteria. By munching on half-digested morsels from this side branch that have passed out of its backside the rabbit's stomach and intestines have a second go at extracting nutrients. It works, but from a design point of view it is crazy. Despite looking pretty impressive, the human eye itself is put together in a way that a fairly unintelligent designer could improve on. The rod and cone cells that gather light and convert it into electrical impulses destined for the brain are wired up "back to front". So light hitting the retina has to pass through a maze of wiring before it reaches the light-gathering rods and cones. And anyone with a bad back could be forgiven for cursing our knuckle-dragging ancestors who gave us a spine that is not well designed for upright support. The point is, though, that all of these bad designs, with their echoes of ancestors long since gone, are good enough. Which brings us back to Terry Byland. His bionic eye is nowhere near perfect, but it has changed his life. And if he were trying to avoid nature's crimson teeth and claws, he would have a considerable advantage over his sightless competitors. In the world of the blind, the 16-pixel eyed man is king. ____________________________________________________________________________________ Expecting? Get great news right away with email Auto-Check. Try the Yahoo! Mail Beta. http://advision.webevents.yahoo.com/mailbeta/newmail_tools.html To unsubscribe send a message to [EMAIL PROTECTED] with the subject unsubscribe. 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