Wednesday, May 12, 2010

Backwards Reasoning

One of the arguments against the idea of an intelligent designer, going back at least to David Hume, is that if such a designer exists it must be incompetent given all the "bad" designs found in nature. One of the prized exhibits in this argument has for years been the "backwards" design of the retina, but, unfortunately for many authors who've hitched their Darwinian wagon to it, this old horse appears headed for the glue factory.

An article in New Scientist explains why:

It looks wrong, but the strange, "backwards" structure of the vertebrate retina actually improves vision. Certain cells act as optical fibres, and rather than being just a workaround to make up for the eye's peculiarities, they help filter and focus light, making images clearer and keeping colours sharp.

Although rods and cones are responsible for capturing light, they are in a curious position. Hidden at the base of the retina, they are covered by several layers of cells as well as the bed of nerves that carries visual information to the brain. One result is a blind spot in our visual field, leading the vertebrate retina to be listed among evolution's biggest "mistakes".

Light clearly gets through, however, and in 2007 researchers analysing the retinas of guinea pigs reported that the glial cells which nourish and physically support the bed of neurons also act as optical fibres for the rods and cones. These M�ller cells are funnel-shaped, with wide tops that cover the surface of the retina and a long slender body that guides light to the receptors below.

Now Amichai Labin and Erez Ribak of the Technion-Israel Institute of Technology in Haifa have used data from human eye cells to model the workings of the retina. Their findings suggest that sending light via the M�ller cells offers several advantages.

The rest of the article gives a very interesting explanation of the two advantages these researchers have discovered. Besides these there are other excellent reasons for wiring the retina the way it is that have been understood for some time and which are discussed in this article.

One might think that theists would be heartened by such findings since they seem to support the idea that a designer played some role in the creation. Not so Ken Miller, however. Miller is a theistic evolutionist whose career is heavily invested in persuading people that there's absolutely no evidence for intelligent design in biology, particularly in the human eye, and he's adamant that we not draw any inferences from the research cited by New Scientist that would support ID:

However, Kenneth Miller, a biologist at Brown University in Providence, Rhode Island cautions that this doesn't mean that the backwards retina itself helps us to see. Rather, it emphasises the extent to which evolution has coped with the flawed layout. "The shape, orientation and structure of the M�ller cells help the retina to overcome one of the principal shortcomings of its inside-out wiring," says Miller.

Well, this is certainly an odd take on the research. One might think that the backwards wiring of the retina is only backwards if it impedes vision, but this system actually aids vision. Nevertheless, Miller assumes it's still backwards, apparently because it's not how he would have designed it, and then marvels at how evolution has compensated for the engineering error.

I think probably the retina is less backwards than is Miller's reasoning. If Professor Miller wants my advice it would be to stop digging, throw down his shovel, and pretend that he never heard of the retina.


Values Clarification

Thomas Sowell reflects upon his childhood and suggests that the moral distance we've traveled in the last seventy years or so is inversely correlated to how educated we've become. Here's his lede:

One of the many fashionable notions that have caught on among some of the intelligentsia is that old people have "a duty to die," rather than become a burden to others.

This is more than just an idea discussed around a seminar table. Already the government-run medical system in Britain is restricting what medications or treatments it will authorize for the elderly. Moreover, it seems almost certain that similar attempts to contain runaway costs will lead to similar policies when American medical care is taken over by the government.

Make no mistake about it, letting old people die is a lot cheaper than spending the kind of money required to keep them alive and well. If a government-run medical system is going to save any serious amount of money, it is almost certain to do so by sacrificing the elderly.

There was a time-- fortunately, now long past-- when some desperately poor societies had to abandon old people to their fate, because there was just not enough margin for everyone to survive. Sometimes the elderly themselves would simply go off from their family and community to face their fate alone.

But is that where we are today?

Sowell goes on to illustrate with a poignant anecdote how we have shifted from a focus on helping others to focussing on living for ourselves. Check it out.

It's a modern conceit that somehow education and technology have, in ways that matter, made us superior to our forebears. This attitude is a naive bit of chauvinistic self-congratulation. Knowing more about physics makes us neither wiser nor more ethical than those who lived prior to the knowledge explosion. Indeed, more people can read today than at any time in history, we can enjoy films, we can surf the web, we can drive cars, but how do we use these wonderful gifts? Much of what we read and watch is junk. For all of our knowledge, wealth, and technology we're certainly no happier than were our grandparents, our families are less stable, and our mental health much more precarious.

Why is that? Perhaps it's because our grandparents knew something that many moderns don't: Happiness is not something that one can obtain through deliberate pursuit. It's not a drug, nor is it the result of the accumulation of knowledge or goods. It is, rather, a by-product of living a life of virtue, meaning, and caring for others.

Modernity, however, scoffs at this. Moderns believe that we should look out for #1 and that when other people stand in the way of our well-being they need to be shoved out of the way. That's why the abortion industry is so lucrative and why there's political presure to limit the care we provide to the elderly. Moderns also deny that there's any such thing as virtue and they hold that meaning can be injected into life by gratifying one's desires, whether sensual or material.

Unfortunately, there's not much evidence to support these beliefs. Surely Shakespeare was correct that, if death is the end of our existence, life is simply "a tale told by an idiot, full of sound and fury, signifying nothing."

Sowell thinks the modern world has lost something crucially important to human flourishing. I think he's right.