"Wacky Waving Inflatable Arm Flailing Tube Man" by m01229 @flickr (CC BY 2.0)
Icons of Evolution Home of Biologist and Iconoclast Jonathan Wells

Flailing Blindly


I did not watch the sixth episode of Cosmos on April 13, but I’m told that it included animations to illustrate the molecular workings of a chloroplast — the organelle that carries out photosynthesis in a plant cell. In a review of the episode posted on the blog of the censor-everything-but-Darwinism National Center for Science Education, Josh Rosenau called the animations “cartoonish industrial machinery, rather than the messy complexity of the real molecular workhorses within a cell.”


Rosenau cited an April 14 piece in the New York Times by Carl Zimmer, who wrote that a widely used 2006 animation titled “The Inner Life of a Cell” was “a piece of art. The scientists and animators made choices about what to show, and how to show it. For one thing, they left out just about all the proteins, giving the cell the look of a nearly empty ocean.” It shows proteins (in Zimmer’s words) “moving with stately grace.” It also shows a molecular machine called kinesin placing one microscopic “foot” in front of the other as it slowly hauls a large vesicle along a microtubule.

Kinesin (pictured above) is considerably more energy efficient than man-made machines. It has been called “a stunning example of cellular nanotechnology” and “positive evidence for design.”

As Zimmer pointed out, however, the cytoplasm of a real cell is quite crowded, and real proteins “are perpetually quivering” because of Brownian motion. (These are not new observations: Cytoplasmic crowding has been known for over thirty years, and Brownian motion was identified almost two hundred years ago.) So the same groups that collaborated on the 2006 animation recently produced a new one titled “Protein Packing.” As Zimmer put it, “they wanted to cram a virtual cell with proteins at a more realistic density, and then have them jitter and collide.”

The new animation (like the old) also includes a kinesin molecule hauling a vesicle, but this time the kinesin’s movements are characterized (in Zimmer’s words) by

barely constrained randomness. Every now and then, a tiny molecule loaded with fuel binds to one of the kinesin “feet.” It delivers a jolt of energy, causing that foot to leap off the molecular cable and flail wildly, pulling hard on the foot that’s still anchored. Eventually, the gyrating foot stumbles into contact again with the cable, locking on once more — and advancing the vesicle a tiny step forward. This updated movie offers a better way to picture our most intricate inner workings…. In the 2006 version, we can’t help seeing intention in the smooth movements of the molecules; it’s as if they’re trying to get from one place to another. In reality, however, the parts of our cells don’t operate with the precise movements of the springs and gears of a clock. They flail blindly in the crowd.

But that’s not what the biological evidence shows. In fact, kinesin moves quickly, with precise movements, to get from one place to another. A kinesin molecule takes one 8-nanometer “step” along a microtubule for every high-energy ATP molecule it uses, and it uses about 80 ATPs per second. On the scale of a living cell, this movement is very fast. To visualize it on a macroscopic scale, imagine a microtubule as a one-lane road and the kinesin molecule as an automobile. The kinesin would be traveling over 200 miles per hour!

The fact that the cell’s cytoplasm is quite crowded makes this even more remarkable — like an automobile going 200 miles per hour through a traffic jam. So on what basis (other than the new animation) does Zimmer claim that kinesin molecules “flail blindly” with “barely constrained randomness”?

Perhaps it’s because Zimmer, like Rosenau, is an apologist for Darwinism. (In 2001, Zimmer wrote the glossy coffee-table book that accompanied PBS’s propaganda series Evolution.) For Zimmer and Rosenau, regardless of what the evidence shows, “barely constrained randomness” is what characterizes evolution, so it has to be a fact — and intelligent design has to be false.

Not just false. In his review of the Cosmos episode, Rosenau wrote that creationism (which for him includes intelligent design) is pseudoscience, and one hallmark of pseudoscience is to “keep repeating claims long after they’ve been tested and found to be untrue.” According to Rosenau, one such claim is that cells contain “molecular machines.” So for him the difference between moving precisely and flailing blindly “isn’t trivial.”

Yet according to publicly accessible scientific evidence such as that cited above, the claim that kinesin molecules “flail blindly” with “barely unconstrained randomness” has been tested and found to be untrue. Indeed, they are remarkably good molecular machines.

So, who are the pseudoscientists?