Illegal Alien

"Your Honor," said Dale, "Ms. Ziegler has put much emphasis on the missing parts of Dr. Calhoun’s body. Surely we’re entitled to explore whatever reasons there might be for those particular parts to be taken."

"I’m inclined to grant some latitude," said Pringle, "but don’t let this go on too long, Mr. Rice."

"I shall be the very soul of brevity, Your Honor," said Dale, with a small bow. "Now, Dr. Smathers, you heard the reverend’s contention that the eye could not possibly have evolved in stages. I can have the court reporter read back the exact quote, if you like, but I believe the gist of it was, ‘What good is half an eye? What good is a quarter of an eye?’ Do you agree with that?"

Smathers smiled and spread his hands. "Today, we consider a one-eyed man to be at least partially disabled: he has a drastically reduced field of view including no peripheral vision on one side of his body, and, of course, he has no depth perception, since depth perception is a function of stereoscopic vision — which requires two simultaneous views of the same scene from slightly different angles."

Smathers paused, and took a drink of water from the glass on the witness stand. "Well, there’s an old saying, sir. In the country of the blind, the one-eyed man is king. If nobody else had two eyes, one eye would be a spectacular improvement over no eyes. You wouldn’t be considered disabled; rather, you’d be considered incredibly advantaged."

"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.