The Case for a Creator - Lee Strobel [110]
“How does it work?” I asked.
“Extremely efficiently,” he said. “Just picture an outboard motor on a boat and you get a pretty good idea of how the flagellum functions, only the flagellum is far more incredible. The flagellum’s propeller is long and whiplike, made out of a protein called flagellin. This is attached to a drive shaft by hook protein, which acts as a universal joint, allowing the propeller and drive shaft to rotate freely. Several types of proteins act as bushing material to allow the drive shaft to penetrate the bacterial wall and attach to the rotary motor.” 8
“Where does it get its energy?” I asked.
“That’s an interesting phenomenon,” he replied. “Some other biological systems that generate movement, like muscles, use energy that has been stored in what’s called a ‘carrier molecule.’ But the flagellum uses another system—energy generated by a flow of acid through the bacterial membrane. This is a complex process that scientists are still studying and trying to understand. The whole system works really well—the flagellum’s propeller can spin at ten thousand revolutions per minute.”
As a car aficionado, I was staggered by that statistic! A friend had recently given me a ride in his exotic high-performance sports car, and I knew it wasn’t capable of generating that many rpms. Even the notoriously high-revving Honda S2000, with a state-of-the-art, four-cylinder, two-liter, dual-overhead-cam aluminum block engine, featuring four valves per cylinder and variable intake and exhaust valve timing, has a redline of only nine thousand rpms. 9
“Not only that,” Behe continued, “but the propeller can stop spinning within a quarter turn and instantly start spinning the other way at ten thousand rpms. Howard Berg of Harvard University called it the most efficient motor in the universe. It’s way beyond anything we can make, especially when you consider its size.”
“How small is it?”
“A flagellum is on the order of a couple of microns. A micron is about 1/20,000 of an inch. Most of its length is the propeller. The motor itself would be maybe 1/100,000ths of an inch. Even with all of our technology, we can’t even begin to create something like this. Sometimes in my lectures I show a drawing of the flagellum from a biochemistry textbook, and people say it looks like something from NASA. If you think about it, we’ve discovered machines inside ourselves. On Star Trek they had a creature called the Borg, which has tiny machines inside. Well, it turns out everybody does!”
Drawings of the flagellum are, indeed, very impressive, since they look uncannily like a machine that human beings would construct. I remember a scientist telling me about his father, an accomplished engineer who was highly skeptical about claims of intelligent design. The dad could never understand why his son was so convinced that the world had been designed by an intelligent agent. One day the scientist put a drawing of the bacterial flagellum in front of him. Fascinated, the engineer studied it silently for a while, then looked up and said to his son with a sense of wonder: “Oh, now I get what you’ve been saying.”
“Think of this too,” Behe continued. “Imagine a boat with its motor running. Uh-oh! Nobody’s steering it. It goes out and crashes—boom! Well, who’s steering the bacterial cell? It turns out it has sensory systems that feed into the bacteria flagellum and tell it when to turn on and when to turn off, so that it guides it to food, light, or whatever it’s seeking. In a sense, it’s like those smart missiles that have guidance systems to help them find their target, except there’s no explosion at the end!”
“And the flagellum is irreducibly complex?”
“That’s right,” he said. “Genetic studies have shown that between thirty and thirty-five proteins are needed to create a functional flagellum. I haven’t even begun to describe all of its complexities; we don’t