Evolution is a Fact #38 - The Origin of Complex Cells

by cofty 71 Replies latest watchtower beliefs

  • Vidqun

    Last, but not least, this is how it looks in real life.

  • Ucantnome

    I thought the orangey picture was a mistake it looks like a man's nose

  • shepherdless

    Oh no! Not the flagella motor!

    Years ago, my wife and my mother in law sat me down and made me watch an hour long video by the "Discovery Institute" (a group that, according to Wikipedia is "best known for its advocacy of the pseudoscientific principle of intelligent design"). The video gave 3 arguments for intelligent design, the best of them being that flagella motor. All arguments could have been comprehensively covered in 5 mins, but it was stretched to an hour with lots of cartoon graphics and repeated explanations.

    That was one hour of my life I can never get back. Of course you can easily go on the Internet and find articles debunking the whole issue within seconds, but I could not get my wife or m.i.l. to even look at them.

  • cofty

    Vidqun it is bad form to go off on a tangent while we are still discussing the original topic.

    This thread is about the origin of the complex cell through endosymbiosis. I will be responding in detail to your last post on that topic later.

    If you want to talk about the bacterial flagellum start another thread and I will explain why you are also wrong about irreducible complexity. You don't get to decide the topic on my thread. Your desperation is showing.

    As somebody once said debating a creationist is like challenging them to smash up your room for 10 minutes and then you have 10 minutes to repair it or else you lose.

  • cantleave

    Throwing irreducible complexity into the argument proves to me you either not a microbiologist or so influenced by cognitive dissonance that you shouldn't be.

  • Vidqun

    Shepherdless, debunking indeed! This is how it usually goes: "Bacterial flagella have functions and mechanisms that have differentiated during evolution." In the same breath one then says: "However, the evolutionary history and relationships of these functions and mechanisms remain unclear." See no. 6 above.

    Cofty, as you might have noticed, Shepherdless had a problem with my argument of complexity. This drives the point home. And it’s not completely out of context, seeing that it is part and parcel of various bacteria, which are included in our discussion.

    While on the subject, I see a third flagellar motor has been discovered. Absolutely brilliant, i.e., the design of the motor and the way it was discovered. Howard Berg's latest paper in Current Biology announces an exciting find: another rotary motor has been discovered in a bacterial cell. The Harvard expert on the bacterial flagellum (see him speaking about the "Marvels of Bacterial Behavior" above), along with two colleagues, describes a new kind of rotating motor in a bacterium, separate and distinct from ATP synthase and the kind of flagella found in E. coli. The short title of the paper is dramatic: "A Rotary Motor Drives Flavobacterium Gliding."

    Cells of Flavobacterium johnsoniae, a rod-shaped bacterium devoid of pili or flagella, glide over glass at speeds of 2-4 ?m/s. Gliding is powered by a protonmotive force, but the machinery required for this motion is not known. Usually, cells move along straight paths, but sometimes they exhibit a reciprocal motion, attach near one pole and flip end over end, or rotate. This behavior is similar to that of a Cytophaga species described earlier.... To learn more about the gliding motor, we sheared cells to reduce the number and size of SprB filaments and tethered cells to glass by adding anti-SprB antibody. Cells spun about fixed points, mostly counterclockwise, rotating at speeds of 1 Hz or more. The torques required to sustain such speeds were large, comparable to those generated by the flagellar rotary motor. However, we found that a gliding motor runs at constant speed rather than at constant torque. Now, there are three rotary motors powered by protonmotive force: the bacterial flagellar motor, the Fo ATP synthase, and the gliding motor.

    What this implies is even more irreducible complexity for the bacterial flagellum. Without the flagellum+T3SS working cooperatively, the flagellum will not work, because T3SS is "required for secretion of axial components" of the flagellum. This suggests that both the T3SS and the flagellum had to exist simultaneously for the flagellum to assemble properly and function.

    The article concludes: "That's a suggestion that will surely be debated between evolutionists and design advocates. What's clear at this point is that another irreducibly complex, functional system for motility has been revealed, based on a rotary engine driven by proton-motive force. Harvard's announcement will certainly stimulate further research into this gliding motor and how it works. Not surprisingly, they feigned no hypothesis about how this system might have evolved." This is certainly music to my ears.

  • WhatshallIcallmyself

    Vidqun -


    A simple explanation why your latest post's conclusions are wrong. Please read it!

    Your position is wrong because there are pathways for the flagellum to evolve. We don't need to know how it did it exactly... You, on the other hand have to show there isn't a path way which would involve you knowing everything so as you could be sure that you haven't missed anything; yes that's impossible which is why arguments such as the one you are making are wrong.

  • Island Man
    Island Man

    Flagellum smagellum! I find it odd that a microbiologist would bring up an argument that was brought up and soundly refuted at the Dover trial. You need to update your knowledge, Vidqun. Bacterial flaggellum is not irreducibly complex. It is the imagination and knowledge of creationists that is irreducibly simple.


  • Vidqun

    WhatshallIcallmyself, I thank you for your educated opinion of right and wrong. I am following the current evidence, which points me to ID. Be assured, when your pathways are discovered, then I will reconsider my position. Until then, I will be led by logic, which I have been trying to explain all this time. I am sorry for those that missed it. That means my teaching ability stinks, so I apologize for that and only that.

  • cofty

    Vidqun this is my thread and the topic is the origin of complex cells via endosymbiosis.

    Stick to the topic. This is number 38 in a series and every one is very specific for a reason.

    It is obvious to anybody who has the patience to read your contributions that you are floundering on this topic despite your claim to be a professional microbiologist.

    I will responding to your last post on endosymbiosis later. If you want to talk about the bacterial flagellum start your own topic.

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