Intelligent design isn’t intelligent
Tuesday’s Op-Ed presented Michael Behe’s “Facts on Intelligent Design”. Behe’s ideas on this subject keenly illustrate one of the strengths of science, namely that anyone can give an alternate explanation for literally anything we think we know. What makes science so useful and progress so quickly is the tradition of critically analyzing these alternatives from individuals. Let’s examine some of Dr. Behe’s “facts”.
Behe says that the complex machines found in living organisms couldn’t possibly have evolved via Darwin’s evolutionary mechanisms, because simpler forms of these machines (those with parts removed) would not be functional. Behe
calls these systems “irreducibly complex”. He believes that because of this irreducible complexity, that the machines must have been consciously engineered by an “Intelligent Designer”. A close look at his writings brings to light problems with his “Facts on intelligent design”.
No one I know, not even Behe, would argue that a non-functional trait can convey any advantage to an organism that possesses it. Nonfunctional traits certainly cannot evolve into more complex structures. There is no disagreement between the experts and Behe on this point. Where most biologists disagree with him is in the logic of his next step. Behe argues that if you make such a system simpler (move it backwards in time on its evolutionary journey), then the system must become nonfunctional. This is the faulty assumption that leads Behe to believe that an “Intelligent Designer” be the behind-the-scenes Engineer. Many biologists strongly disagree with this inference, because we can directly observe many systems that show us exactly the opposite of what Behe wants us to believe. These systems retain their functionality from the most complex, modern versions back to the simplest, most ancient versions.
Take the complex, lens-containing eye of the human. Nearly 150 years ago Charles Darwin wrote, “reason tells me, that if numerous gradations from a perfect and complex eye to one very imperfect and simple … can be shown to exist, … then the difficulty of believing that a perfect and complex eye could be formed by natural selection … can hardly be considered a real [difficulty].” In the next 600 words, I can take you on Charles Darwin’s journey through the eyes of the simplest single-celled organisms, to simple animals like flatworms, all the way through to the most complex eyes on the planet to illustrate why the logic behind Behe’s irreducible complexity fails to stand up to real, observable facts.
One of the simpler forms of life is a single-celled organism called euglena that has a structure inside it called an eyespot. The eyespot is a patch of protein that is sensitive to light. The system allows euglena determine the direction of the light and to move toward it. This simplest of eyes, smaller even than a single cell, is invaluable since euglena (like plants) relies on sunlight for its food. A close cousin called a dinoflagellates (also a single-celled creature) actually has a clear material on its surface that focuses the light onto the eyespot. These simplest of eyes in single-celled life forms already exhibit step-wise improvements and modifications that add complexity to the machine. It is not hard to see how a clear patch on the one cell’s surface could indeed be advantageous. Function has not been lost. Complexity has evolved.
The next variation is made up of specialized cells that possess an expanded sensor. These cells grow in a flat patch on the surface of simple animals like flatworms. The cells that make up these patches are analogous to euglena. The increase in complexity from euglena to the flatworm is a simple step from single-celled sensors to multi-celled versions. There is no magic necessary. Function is not lost; complexity has evolved.
A modification of the flat patch that improves it markedly is the cupped patch found in invertebrate marine worms (annelids) and the simpler mollusks. This modification is much better at determining the direction of the light, since a shadow will form on one side of the cup when light impacts the other side. No great change here – just cup the patch. The deeper the cup, the better the information the animal receives. Deeper and deeper cupped patches evolved, because as they did so, they became more and more useful. The cupped eye reached its peak in the abalone and Nautilus. Here the cup is so deep and the opening so small, that the eye functions like a pinhole camera.
The evolution of a complex eye containing a lens (like ours) is best taught to us by the chicken. There is a protein in chickens (and in humans) that takes care of acids that build up when muscles run out of oxygen. The same acid is the chemical that burns in our thighs when we run too far too fast. An enzyme made of protein recycles the acid and eventually takes the burn out of your legs. If you put enough of this protein in the right place, it will form beautiful, colorless, clear crystals all by itself. In the chicken, this same protein is secreted into the front of a cupped eye, where it crystallizes to form the lens. The very protein that takes care of our legs when we have to run too far forms the lens of the chicken’s eye! A very old protein that has not even been modified, but nevertheless has learned a new trick. No function has been lost. Complexity has evolved.
Do we know every single transitional form between eyespot and human eye? Of course we do not. But objective facts indicate that the eye evolved exactly the way Charles Darwin speculated some 150 years ago: from simplest to most complex with many functional transitions in between!
Another problem for Dr. Behe: Shouldn’t an Intelligent Designer make intelligent designs? If Behe is correct that an Intelligent Designer actually designed these eyes, wouldn’t you expect that humans (arguably the most complex creatures on the planet) would have “intelligently designed” eyes? The simple fact of the matter is that we do not! The lobster actually has much more logically “designed” eyes than we do! The cells that detect the light in the human eye are fed by blood vessels that lay on the surface of the light sensing layer inside the eye. These vessels block a lot of the light that enters the eye. There are diseases of the human eye where the vessels block nearly all the light and cause blindness. The lobster, on the other hand, has its vessels underneath the light absorbing cells; an intelligent choice, if one were to invoke an Intelligent Chooser.
So what’s the deal with our eyes? Did the Designer mess up? Of course not; our eyes are the product of evolution. Evolution does not look forward at some final design. It takes what is at hand and modifies it. Eyes that were better than the previous iteration become more successful. Lobster eyes simply had a different starting point than human eyes and ended up being a superior “design”.
Can we prove that an Intelligent Designer did not create the perfect design for a complex eye and, in a snap of supernatural fingers, deliver them to the human head, complete with their “design errors”? Of course we cannot. Did the Intelligent Designer also include the evidence for their evolutionary ancestry as some kind of “deception”? Of course not. Science cannot by definition prove the existence or non-existence of God.
What we can say is that the rules of physics, chemistry and biology are sufficient for the evolution of simple to complex eyes, and for the evolution of all of the unbelievably beautiful and varied forms of life on this planet. Is there a place in my world view for a Cre
ator of the Universe? You bet there is. I just don’t need an Intelligent Designer to give me the flawed, works-in-progress “designs” that I possess. The laws of nature and the mechanisms of natural selection work just fine to take care of those details.
