The Flagellum is Not a Motor?



That has a lot to do with it. We are trying to limit the wear and tear on our palms and face.

They conclude that all motors are designed, and they also use it as a premise. It’s an open and shut case for begging the question. There doesn’t seem to be any way around this. What we seem to disagree on is the power of language and its ability to create evidence by merely uttering a word. If I call a tree a duck, will it suddenly become a duck? According to ID supporters, they seem to think that this can happen.

(Herculean Skeptic) #22

And let me (possibly) close by saying, I worked with, installed, repaired and sold pumps and motors for nearly 20 years. I read the article linked above, and the closest analogy, based upon my experience, is that it is not most like a motor, but rather it is most like a pump, which has a motor affixed to it. A motor merely turns a shaft at a particular rate, direction and force. A pump also has an impeller and a shaft seal to keep the fluid out. These all seem to be present here. So, judging from my professional experience (first time I’ve said that here…) the bacterial flagella is not a motor, but is, instead, a pump. How it got there, I have no idea… but it is not (just) a motor. It’s a pump.


I used to drive a Mazda RX-7. It had a rotary motor. The RX-7 rotary motor. There, I just said the Mazda RX-7 is a rotary motor. Yes, it’s absurd.

As long as you continue to read people in the most unflattering light possible you will not be exhibiting the stated goals and intentions of this site.

@swamidass why don’t you just ask @bjmiller if he meant to say that the bacterial flagellum is a rotary motor?

(S. Joshua Swamidass) #24

@Michael_Callen, to give you the most important distinction, this is wroth considering.

Perhaps one of the most important distinctions between a flagellum and a rotary engine is that a rotary engine is far more complex than a flagellum, with far more different types of parts. The flagellum is far more like a mousetrap (with just 3 different parts) than any human designed rotary motor.

There are about 22 different proteins in the flagellum. Interestingly enough, most these proteins are very similar to one another. It is as if there are, maybe, 4 different parts, each with 5 variations, that are put together to make a flagellum, which looks superficially like a human rotary engine, but is actually working by totally different physical principles. The early flagellum might have had just 4 types of parts or even fewer. That is why it is far more similar in complexity to a simple mousetrap than a complex rotary engine.

Of course, by calling it a “motor” that is not the image in your head. You imagine something profoundly complex when the flagellum is not nearly as complex by any objective measure as a motor.

(Herculean Skeptic) #25

I get it! I’m sorry to add to the suffering. Really…

I understand and appreciate this too. It seems, though, that this argument was really an unreasonable response to the word “motor”… and rather a nod to a war over design, that’s all. It is very confusing to those of us who are on the fence when we see rabid arguments over “motors” and “ducks” as labels. I’m just making that point and no other. The freakin’ thing looks like a motor. I know motors. But if it evolved, so be it. If it was designed, prove it… changing the name isn’t going to win the battle or even make the battle lines more clear.

(S. Joshua Swamidass) #26

It is not absurd to call the Mazda RX-7’s motor a rotary motor. It is a rotary motor.

I did ask @bjmiller, and we are waiting for him to respond. @mung, why don’t you ask him to respond? He could clear it up whenever he likes. I asked him to explain where the analogy breaks down. He disappeared. No one banned him. He has full access to post on this thread.

(S. Joshua Swamidass) #27

It does not, however, look like a motor. It is almost nothing like the motors you know.

(S. Joshua Swamidass) #28

@Michael_Callen, Jonathan Wells argued that this structure looks like a “turbine” engine, and must be spinning around like a motor. He even postulated that it must be the cause of cancer, when it spun in the wrong way. Does it look like a turbine to you?

Centriole? Huh?
(Herculean Skeptic) #29

I don’t know how you know what’s in my head, exactly, but I’m frightened for you to be in there. Especially now.

No, I’m not imagining something more complex than it is. I’m totally aware of every part needed to operate an electric motor. What we have here is, as you say, abundantly more simple in terms of number of parts, but it is due to the elegance of the motor and its design in terms of performing the functions similar to that of an electric motor, even more simply. But, at the end of the day, it performs like a motor, turning a shaft in a certain direction, at a certain speed, delivering torque to do work. That’s why it is worthy of the label “motor.” It doesn’t mean it was designed…

(S. Joshua Swamidass) #30

I’m fine with this. However, that undermines entirely the claim that it is “too complex” to have evolved. The flagellum is actually surprisingly simple.

(Herculean Skeptic) #31

Yes, it looks like a turbine to me. At least a water wheel. And it appears to be made of pasta, which I can no longer eat… because I’m on Keto… and that makes me very sad.

(Herculean Skeptic) #32

That’s funny, I shuddered for a second when you used the “complexity” word… I said to myself, now, don’t go there Joshua!! We’ll end up with a new thread… :slight_smile:

(EDIT: I have to run out for a few hours… I really appreciate your responses and patience with me!)

(S. Joshua Swamidass) #33

Yup, and is also associated with the movement of chromosomes during division. It looks like a turbine, but it is nothing of the sort. It neither spins, nor is required for the movement of chromosomes. It, interestingly enough, can be composed into a flagellum though, and is composed into flagellum within some eukaryotic cells, but not the way you might think! The molecular world just works totally different than our intuitions would tell us.

So is calling it “like” a tubine valid? Yes, as long as we understand the many ways it fails. In this case, there are better analogies. The centriole (which is what this is) is much more like a spandrel than a flagellum.

(Dale Cutler) #34

•Does the bacterial flagellum have a power source. ✓
•Does the bacterial flagellum have a shaft. ✓
•Does the bacterial flagellum move in a rotary fashion. ✓
•Does what drives the bacterial flagellum produce torque. ✓
•Does the bacterial flagellum have a stationary part that pushes against it, causing it to move (i.e., a ‘stator’). ✓
•Does the the bacterial flagellum have a stationary component within which it turns (i.e., a ‘bearing’ or ‘bushing’). ✓

What about the bacterial flagellum disqualifies it from being called a motor?

(Herculean Skeptic) #35

And it looks like some yummy pasta, too… However, with the motor, “looks” are not what was being described in terms of the bacterial flagellar motor… what was being described was the function of the motor (or whatever you want to call it.) It so happens that it looks very similar (reminds one of) a pump with a motor attached.

That’s exactly why I always refer to it as a Cocker Spandrel. (Really leaving now… :slight_smile: )

(Herculean Skeptic) #36

I think that’s the point of this part of the conversation. It’s not unfair to refer to it as a motor… it’s only unfair (philosophically speaking) to assume that because it functions like a motor and has parts that are similar in function to that of an electric motor (or a pump) that it is intelligently designed.

EDIT: And that should be fine, right? Similarly, because I have a hammer, anvil and a stirrup in my ear, I cannot state unequivocally that they, too, were designed.

(Dale Cutler) #37

Actually, the drivers of the bacterial flagellum ‘motor’ are more like fantastic kinetic sculptures, doing their thing by conformational changes and electrostatics, arguably more complex than a simple DC motor.

(Herculean Skeptic) #38

Right, but complexity is subjective… or at least relative. I think that, in terms of a pump, the design of the bacterial flagellum is fantastic–however it got here. If it was created, it’s genius. If it evolved, kudos to physical processes in coming up with a winner! That speed, efficiency, and ability to signal and change direction is utterly amazing. But, remember, a stator is not a single part… it is a variety of layers folded (rolled?) together, so a stator in a motor is much more complex than it seems. Then there are (often) start circuits, switches, capacitors (start and run), governors, etc. There are many more parts in a standard motor than what is shown above in the simple one. Add to that the mechanical shaft seal and impeller too… I think that there are many ways to look at the same thing.


But he said flagellum. It’s right there for everyone to see!


ok, sure. I’d agree with you. Common ground. Now where did @bjmiller write that “the flagellum is a rotary engine”? I can’t find it.