Everybody knows about Michael Behe. Not only is he a Discovery Institute Senior Fellow, he was the Discoveroids’ star witness in the Kitzmiller case — see Kitzmiller v. Dover: Michael Behe’s Testimony.
Behe is best known for his argument in Darwin’s Black Box that the presence of “irreducible complexity” in many biochemical systems indicates that they must be the result of intelligent design rather than evolutionary processes. His most famous example is the bacterial flagellum. Behe’s colleagues at Lehigh University are so impressed by his brilliance that they publicly disassociated themselves from him by issuing this statement: Department Position on Evolution and “Intelligent Design”.
We found a great refutation of Behe’s argument at the website of ABC Science, a division of the Australian Broadcasting Corporation: The bacterial flagellar motor: brilliant evolution or intelligent design? That website has a comments section (with no comments so far).
You already know what to think of Behe and his magic flagellum, but it’s good to have a single source to which one can point. It was written by Matt Baker of the Victor Chang Cardiac Research Institute. Here are some excerpts from Baker’s article, with bold font added by us:
In terms of speed and agility, flagella-powered bacteria would leave Olympic swimmers for dead. They swim hundreds of body lengths in a second, and can change direction in a fraction of that time. The source of this incredible mobility is the microscopic equivalent of an outboard motor — the bacterial flagellar motor. At one millionth of the size of a grain of sand, this motor rotates up to five times faster than a Formula1 engine, spinning the whip-like flagella and driving the bacterium forward.
It starts out like a rapturous Discoveroid article. If it were one of theirs, it would end up declaring that the only possible conclusion is Oogity Boogity! But this article isn’t from the Discoveroids. Baker says:
It is perhaps not surprising then that such complexity and technology has been hijacked for use as proof, via intelligent design, of the existence of a creator. Intelligent design is a theory advocated by the new-wave of creationists that are primarily located in the US. It holds that some aspects of life are so complex that they cannot have evolved through a series of steps via natural selection, and therefore must have been designed in one go.
Baker clearly understands the adversary. Let’s read on:
A central tenet of this theory is the notion of ‘irreducible complexity’. This asserts that some biological machines — like the flagellar motor — must be the product of design, because if you were to remove one or two components from the motor it would not function properly, or at all. The logic being, this motor was designed as a whole construction — it didn’t evolve through a series of steps, so the individual parts of the motor would serve no purpose on their own.
The Discoveroids are always complaining that their critics are ignorant of intelligent design. But it’s clear that Baker knows what he’s talking about. He continues:
So the creationist argument relies on us finding no evidence of individual parts of the motor having a role outside of bacterial flagella. Luckily, individual components of the bacterial flagellar motor have indeed been found elsewhere. And they work. So the motor is ‘reducible’, and certainly not ‘irreducibly complex’.
How embarrassing for Behe! Here’s more:
Proof of the flagellar motor’s ‘reducibility’ — that it’s component parts can function elsewhere — comes in the form of the injectisome; another fabulous molecular machine found in bacteria. This needle-like complex is used by disease-causing bacteria to punch holes in the host’s target cells.
The protein machinery used to assemble the proteins that make up the punching needle is identical to that used to assemble the ‘propeller’ part of the flagellar motor — the filament and hook of the motor. In addition, nine core proteins of the flagellar motor share common ancestry with injectisome proteins — the genes that code for them are so similar they have clearly come from the same genetic ancestor.
Gasp! What will Behe do now? But wait, this gets even better:
In fact, the flagellar motor contains a wealth of other evidence pointing not to intelligent design, but to its evolutionary origins. Bacteria swim in many different ways, and the motors that drive their swimming are widely varied, implying an adaptive response to an environment — a hallmark of evolution. So while the flagellar motor of freshwater Salmonella is powered by protons (hydrogen ions, H+), motors of other bacteria that live in salt water environments, like Vibrio alginolyticus are powered by sodium ions (Na+) from the salty environs.
There’s also considerable variety in propeller shape across different bacterial species — propellers can be straight or curly, left- or right-handed, and more or less rigid. In fact, genetic sequencing of the proteins that make up the propellers has shown that there must be thousands of different bacterial flagellar systems.
That’s not all — Baker has even more to say:
Recent work on flagellar motors in species other than bacteria, such as single-celled archaea, show they also swim by a rotary motor, but one that is completely unrelated to the bacterial motors. The archaeal motors sometimes use a completely different power source (ATP hydrolysis), and their propeller grows from the base, instead of from the tip. This indicates that convergent evolution has taken place: two completely separate evolutionary paths have converged towards rotary powered swimming.
This must be very humiliating for the Discoveroids. What will they do? Ah, we know — they’ll have Casey refute Baker’s science. Then they’ll assign Klinghoffer to the task he does best — slashing away at Discoveroid detractors. That should do the job. But Baker understands the opposition. He says:
While all this may seem relatively harmless, the intelligent design movement is well funded, slickly presented, and actively challenges educational curricula in many countries. It is a dangerously well-articulated distraction from the large body of evidence supporting evolutionary theory. Scientists studying the flagellar motor can contribute by demonstrating that it is clearly not a smoking gun that proves intelligent design.
Typically, intelligent design proponents persevere despite this evidence. They simply adjust their goal posts by selecting other systems to act as poster boys for irreducible complexity. It is difficult to respond to these movable challenges. But as we learn more about the origins of these and other complex systems, we can at least reduce the number of available candidates used to prop up the theory of intelligent design.
Okay, now let’s sit back and wait for the inevitable Discoveroid response. You know they can’t ignore this.
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