I wasn’t going to hold forth any longer about evolution. No. I was going to live in peace, writing about race and sex, and watch the crowd that gathers on my front lawn with a rope. But the public is importunate. “Tell us more about point mutations and punctuated equilibrium,” say thousands of correspondents from everywhere. A heart-wrenching letter from Papua-New Guinea, written on a piece of bark, talks of people so fascinated that they can’t eat those big nasty grubs the tv crews give them when they’re doing specials. I’m not going to cause international starvation. So here it is.
The biggest problem with evolution is You Can’t Get There From Here. Lemme explain.
We’re supposed to think, almost required to think, that critters evolve by high-energy sunburn. They walk around munching on things until they get smacked in the germ plasm by a cosmic ray. It puts puts a crimp in their DNA, so they have weird offspring (which a lot of us manage without cosmic rays). These tads are occasionally an improvement on their parents, or in human experience at least think they are, and so they have lots of kids. So the race improves.
To believe this, you have to believe that you can improve a car engine by firing a rifle at it. And that teenagers are an improvement. On anything.
Well, here’s a question that occurred to me when I was about fifteen.
Suppose you have a giraffe or wombat or something that has black-and-white vision, and it decides to evolve color vision. Maybe it wants to watch movies.
Now, to watch color movies, it needs two things, aside from bad taste. First, it needs a whole potful (that’s evolving into a word) of complicated retinal chemistry to respond differently to different colors of light. I don’t know as how I can swallow the idea. A chemical engineer couldn’t make it work on purpose, much less by accident. You might as well believe that earthquakes build houses.
But let’s say it happened. So we’ve got a giraffe with color eyeballs.
Thing is, color eyeballs aren’t worth a good idea’s chance in Congress unless you have a bunch of complicated brain circuitry to interpret the retina’s output. Nerve impulses don’t come in colors. They’re just self-propagating depolarizations, sodium in potassium out, along a damp sticky fiber, that squirts polysyllabic glop like acetylcholine across synapses, blurt.
Now, the complicated retinal chemistry is perfectly useless unless you’ve already got the complicated brain circuitry — which is perfectly useless unless you’ve already got the complicated retinal chemistry. Which makes life difficult for the giraffe. For that tall spotted rascal to see color, he’s got to accidentally evolve, simultaneously, two phenomenally tricky systems that are independently of no value at all.
Only a Democrat could believe that. (They can believe anything. Look who they elected.)
Some time back, I ran into a book (Darwin’s Black Box, by Michael Behe. Amazon has it.) by one of these biochemist fellers who worry about things like phosphodiester bonds and replication forks and enzyme-catalyzed hooha. Biochemists probably have too much time on their hands.
He said the same thing I thought, so I knew he had to be on to something. What he called it was the Principle of Irreducible Complexity, which is a better phrase than I could come up with at fifteen. (If you’d seen the cheerleaders at King George High, you’d understand. I was trying to advance evolution by the only way I usually couldn’t.) Anyway, irreducible complexity says that sometimes you can’t get by gradual steps from A to B because the intermediate stages won’t do anything useful. You either get there all at once, or you don’t get there.
The example Behe uses is a mousetrap — the ordinary kind that has the cheese and trigger and wire thingy to crush the internal organs of cute furry rodents. (In the appendices he uses real stuff, like blood-clotting cascades.) For that sucker to work, you have to have all of it. Take away any part, and it doesn’t just work less well. It doesn’t work at all. Without the board it’s all stapled to, you have a handful of wire. Without the trigger plate, nothing will ever happen. Without the thumper thing, you’ve got a cheese tray. Every part is essential.
In short, some things need to have a certain level of complexity from the git-go. The point is crucial. It’s not implausible to imagine our giraffe slowly evolving a longer neck, because each time it accidentally got a little longer he’d be able to eat leaves the other giraffes couldn’t reach without ladders. Then he’d be tall and well-fed and good-looking and get all the girl giraffes and have lots of little tiny giraffe kids, who would grow up to have their daddy’s neck. That works logically. But getting color vision doesn’t. It appears that you either get it all at once, or you don’t get it.
(The best argument for evolution, I concede, is that the only way anything could look like a giraffe is accidentally.)
Now, if you question the theology of evolution, which is what it is, you get letters accusing you of being a low-down, no-’count, shiftless, obscurantist varmint who probably thinks God created the world out of nothing, the way the Big Bang did. The implication is that since God didn’t do it, evolution must have. In other words, if one theory is scientifically untenable, we must accept another, which is at best marginally better. Southern Baptists are the best thing that ever happened to the evolution lobby. They serve to divert attention from the wild inadequacies of Darwin, however amended. And from the curious truth that we don’t know where we came from.
There you have it — the last thing anyone will ever need to write on evolution. Papua-New Guineans can eat their grubs again. Doubtless the National Science Foundation will write me a letter of gratitude, and the Smithsonian will erect a statue of me on the Mall. I hope they’ll include my cowboy hat. It’s glorious.