Robert Sawyer - Illegal Alien

“But, still,” said Dale, “that one eye is a miraculous creation, no?”

“Not really. A human eye consists of a lens for focusing light; a retina, which is a delicate, light-sensitive membrane at the back of the eye—sort of like the eye’s ‘film’; and the optic nerve for transferring information to the brain. The reverend is right, of course, that three such complex structures couldn’t simultaneously appear as the result of a single mutation. The eye, evolutionarily, started out as light-sensitive tissue—which had the ability to distinguish light from shadow. Now, that’s not half an eye. That’s not a quarter of an eye. It’s the tiniest, least significant fraction of an eye. There’s nothing miraculous about light-sensitive cells. Our skin is full of their precursors; you tan because of exposure to ultraviolet light, after all. Well, not you, sir, but—”

“Go on, Doctor.”

“Well, this tiny, barest fraction of an eye is enough to make you king if everyone else is totally blind. What good is a partial eye? If it lets you detect that some creature is coming toward you—a creature that might eat you—if it lets you sense that, even as an indistinct shadow, so that you can get away before it’s upon you, well, yes, that’s an advantage, and yes, evolution would select for it.

“And as time goes by, if a transparent membrane developed over those light-sensitive cells, to protect them from damage, well, if that membrane lets you keep your light-sensitive cells when others are losing theirs, then, yes, that’s an advantage, and evolution would select for it.

“And if that transparent membrane became thicker in the middle by random chance, and that thickness had the effect of focusing the light somewhat, giving you a slightly sharper view of whatever was approaching, then, yes, that’s an advantage, and evolution would select for it, too.

“Bit by bit, tiny change by tiny change, you do go from no vision at all to a highly sophisticated eye, like the one we possess. In fact, in Earth’s fossil record, it seems that vision didn’t evolve once—it appears that it evolved as many as sixty different times. It takes all sorts of forms: our single-lens eyes, the compound eyes of insects, the lensless pinhole-camera eyes of nautiluses. Yes, the eye evolved, on its own, unguided, unplanned, through natural selection.”

“But the eye is so refined, Doctor, so sophisticated. Do you really believe it isn’t the handiwork of God?”

Smathers looked out at the courtroom. “About half the people I see here today are wearing glasses; I’ll bet of the remaining half, a goodly number are wearing contact lenses. Now, it may be a miracle that LensCrafters can make glasses in about an hour, but I’d have actually expected an omnipotent God to have designed eyes that focused properly on their own, without mechanical aids.

“Of course, one could argue that God never intended us to watch TV all night long, or to read so much, or to sit in front of computers, or to do delicate work with our hands. But poor eyesight is not just a modern ailment. The ancient Indians of North America used to have their own eye tests. The second-last star in the handle of the Big Dipper is actually a double star. On a clear night, a person with normal vision should be able to easily see a second, fainter star very close to the main one; that’s the test the Indians used.

“And the ancient Greeks used the Seven Sisters of the Pleiades star cluster in Taurus the Bull as an eye test—could you see all seven? Well, today, even with normal vision, only six are clearly visible—one of the Pleiades stars has dimmed over the millennia. But the fact that ancient peoples had eye tests proves that poor vision is hardly something new.”

Dale glanced at the jury, then looked back at the Canadian scientist. “Still, Dr. Smathers, surely the question of focus is a minor one. Surely, in its overall design, the perfection of the eye demonstrates the existence of a divine creator?”

“No, it does not,” said Smathers. “The eye, in fact, is incompetently designed. No engineer would ever do it that way. Remember I mentioned three fundamental components—the lens, the retina, and the optic nerve? Well, a sensible design would have the retina connected to the optic nerve at the back—so that the optic nerve doesn’t obscure the light coming from the lens to the retina.

“But our eye is wired up ass-backward—forgive me, Your Honor—with the optic nerve connecting to the retina in the front. Our vision would be sharper if the light coming through the lens didn’t have to pass through layers of neural tissue before reaching the retina. It’s degraded further by the fact that there’s also a network of blood vessels on top of the retina to service that neural tissue.

“And, if all that weren’t bad enough, the nerve tissue has to make a channel through the retina to come out at the back of the eye and head on to the brain. That channel causes a blind spot in each eye. We’re not normally aware of it, because our brain fills in the missing visual information with an extrapolated picture, but I’m sure many people in this court have done the easy experiments that let you demonstrate that you do have a blind spot in your vision. The loss of image quality I mentioned earlier and the blind spot simply would not be necessary if our eyes had been designed logically, with the neural wiring behind, rather than in front, of the retina.”

Ziegler rose again. “Really, Your Honor, I must renew my objection. Where is all this going?”

“The Court is baffled, Mr. Rice,” said Pringle.

“I need but a moment more to finish with this witness, Your Honor.”

“Very well, Mr. Rice. But no more than that.”

“Thank you.” Dale looked at Smathers. “You were talking about the loss of image quality due to the backward wiring of the human eye. But surely, Professor, what you’re really saying is simply that you haven’t perceived the wisdom of God’s design. We can’t build an artificial eye yet, after all. Perhaps there’s something fundamental that we’re unaware of that requires the apparently incompetent design you’ve mentioned.”

“No, there’s not. It’s true that we can’t build eyes yet, but nature builds them all the time. And because nature operates by trial and error through evolution, sometimes she gets it wrong, as in our eyes, but other times she gets it right. It’s often said that octopuses and squids have eyes very similar to human eyes, and they do. But theirs evolved independently of ours, and are wired properly, with all the neural tissue behind the retina. Neither an octopus nor a squid has blood vessels or neural tissue diffusing the light falling on its retina, and neither of them has blind spots. Far from being proof of divine creation, Mr. Rice, the human eye is one of the best proofs of the fact of evolution.”

“On the record now, in California v. Hask . The jury is not present. All right, Mr. Rice, you may proceed.”

“Your Honor, I’d like to speak in support of the two defense motions Ms. Katayama filed yesterday.”

“Go ahead.”

“First, on the matter of our new witness—”

“I don’t like new witnesses this late in the game, counselor,” said Pringle.

“Nor do I. But this is a special instance. The witness is Dr. Carla Hernandez, who assisted in the surgery on Hask. Obviously, she had no involvement with Hask until he was shot, so there was no way she could have been deposed earlier.”

“Your Honor,” said Linda Ziegler, “this case is about the murder of Cletus Calhoun. Anything that might have happened after that murder is irrelevant to the proceedings at hand.”

“Dr. Hernandez’s testimony does relate to matters that occurred before the murder,” said Dale.