Flagellum Motor:Is this Scientific?
June 20, 2009 at 2:05 pm #11479
I believe it is scientific and not outside the empirical evidence to say the following:
THE BACTERIAL FLAGELLUM HAS THE MECHANICAL CHARACTERISTICS OF AN ELECTRIC MOTOR
1. There are 40 protein parts required to form a flagellum motor
2 These parts fit together to empirically function as the following:
b. stator–stator works with armature in electric motors to create a electromagnetic spinning force.
d. a drive shaft with bushings
3. There is of course a filament which functions as a propeller
Scott Minnich, Molecular Biologist, University of Idahoquote :
It is fueled by an acid flow. Michael Behe, Biochemist, Lehigh Universityquote :
Other notable features.quote :
Scientific Conclusion–Scientifically one can only say the given statement, that "the bacterial flagellum has the mechanical characteristics of an electric motor" with a filament for a propeller. The bacteria does not have and is not motive by "microscopic muscle," or general protoplasm. I think it is safe and scientific to call it a machine and a motor. To say this is not the case would be to say that a motor is not a motor.
Unscientific Conclusions–Now, to enter into the origin of this, whether it evolved, or whether it was by creative fiat is unprovable by the empirical evidence in the flagellum itself. Those who would argue otherwise are using inductive reasoning.
1. The bacterial flagellum has the mechanical characteristics of an electric motor.
2. It is NOT scientific to say "the BF is designed," but since an electric motor is designed one could say, "the BF has the mechanical characteristics of a designed electric motor."
3. Those who argue otherwise, must then argue that 1) An electirc motor is not designed and/or 2) the BF does not have the mechanical characteristics of a motor.
June 20, 2009 at 4:34 pm #91471MrMisteryParticipant
why must an electric motor be designed? This seems to me like a faulty logic: just because something in the natural world resembles a human-produced machine does not mean that that natural machine has to be created the same way as the artificial one.
From what I know (and I am not an evolutionary biologist) the current opinion is that the bacterial flagellum evolved from a secretory apparatus similar to the type III secretion system.
June 20, 2009 at 10:06 pm #91474
My 2nd statement is that it wouldn’t be scientific to say the flagellum is designed. The only scientific observation you can make is that they (BF and elec mot.) share a majority of common attributes, and that the empirical function (thank you Mr. Arastus)justifies calling it a motor. Whether it evolved or was by creative fiat is another issue. That’s the way I see it anyway, maybe most don’t share that point of view.
June 21, 2009 at 2:46 am #91479MrMisteryParticipant
Ok. then what exactly was the point of your post?
June 21, 2009 at 4:20 am #91483
Being truly scientific is my point. If we go too far beyond the actual observation, we can not claim authority on an issue. The subject is origins, which means many one time unrepeatable events happened up until the present. We have only the present by which to interpret the past. Therefore, on origins especially, we cannot use words like "this proves"–"this disproves". Refutation is different than disproving something. Giving inductive or circumstantial evidence is different than proving something.
Just one "for instance" on the subject of judging the past by the present. Slow and gradual is the pace set by evolution. Mountains move slowly and are measured by current movements–inches a year. Rivers cut out canyons–measured by today’s erosion rates–ignoring catastrophic power. But then at the same time the measurement of the sun, which currently is shrinking, is explained away as a cycle. This is obvious unscientific bias. You can’t just explain away things when it’s inconvenient data, but use a different standard of acceptance when it fits your model.
I could have taken the flagellum example and said "oh look, it’s designed, that proves there’s a Designer." I may be able to say that on personal level but not on a scientific plane. Neither do I think that an evolutionist should say "look, horizontal gene transfer, this proves evolution." He can say it on a personal level, but not on a scientific plane. HGT is scientific fact and observation, evolution is a theory.
June 21, 2009 at 11:29 pm #91496
I think I see your point, but you must understand that evolution is observable, and has been observed.
June 22, 2009 at 12:56 pm #91506
Here’s an example of evolution being observed: http://myxo.css.msu.edu/ecoli/ (Richard Lenski’s project on E. coli evolution)
Lenski has created some 45,000 generations of E. coli, and there are signs that the populations have started to evolve along different paths. For example, in 2008 one line of E. coli evolved to use citrate as a source of nutrients, and the citrate-utilizing organisms have "taken over" one of the lines, because the ability to use citrate has given them an edge in competition against the bacteria that cannot utilize citrate. Natural selection has favoured the cells containing genes to use citrate and they have now surpassed the bacteria lacking those genes.
The ability to utilize citrate hasn’t been just one random mutation, it has required several accumulated changes before the ability evolved.
There are also other signs of evolution that have been observed, you can find those out at Lenski’s home pages. It is also interesting to see whether the other lines eventually achieve the same or similar ability to utilize citrate, indicating that they are adapting for their environment.
There’s also a related paper about the topic: "Parallel changes in gene expression after 20,000 generations of evolution in Escherichia coli" by Cooper et al. (PNAS, 2002)
June 22, 2009 at 6:54 pm #91511
I was thinking about that one, but couldn’t find the link. Thanks for posting it, biohazard. I would especially like to hear what AFJ thinks about it.
June 22, 2009 at 8:59 pm #91517AstusAleatorParticipant
"BF is irreducibly complex" — unscientific
"BF may have been created." — unscientific
"BF is created/designed." — unscientific
"BF may have been designed." — scientific (but with little/no supporting evidence)
"BF may have evolved." — scientific
"BF definitely evolved." — unscientific as a conclusion, but used as a scientific assumption because it is currently the best scientific explanation.
June 24, 2009 at 7:23 am #91546Jesse2504Participant
They say theres more than one way to skin a cat, when it comes to basic principles of movement there isn’t such great diversity.
Everything that moves follows the same similar function and movements to achieve its movement in the matter around it. These are based on Newtons laws of motion.
Its not logical to say that because something in bacteria resembles the same METHOD of movement as something we designed that it too had to of been designed. Its more to the point that the movements we associate with propeller motion are seen in both artificial and biological entities.
A more extreme example of this would be to say that any biological entity which makes use of friction is a tread, which is every single thing in existence. We designed a tread off the principle of equal and opposite force, which gives rise to friction providing a way to move relative to other matter.
Yes we can say it is like a propeller and yes it is a biological motor. It was created evolutionarily speaking by mutation or chance coupled with natural selection to resemble today probably the most effective form of movement for these bacteria.
June 28, 2009 at 6:17 am #91607quote :
My first question is what kind of trade offs did this alleged evolution incur which is apparent in research such as this? Kind of like –did you know the fastest horse is also deaf?
I did read one of the papers on the above site. Here is an excerpt:quote :
In other words, they gained and lost–physiological trade offs. And what was good for one environment wasn’t for another–ecological specialization.
I had read an article before on these trade offs by Kevin L. Anderson Ph.D. and Georgia Purdom Ph. D.quote :
This would tend to neutralize NS in theory–a trade off good in one environment and bad in another. So what happens when the environment changes or they move to a different environment?
The earth is not a laboratory with intelligent scientists controlling a system en vitro. It is an open system with changing environments.
These bacteria are still bacteria. Lets see if after another 40000 generations they will still be bacteria. On the other hand, wouldn’t a wise creator make such a small creature which is responsible for the decay process on a molecular level so adaptive to different lacks and shortages of chemicals in the environment? If they were extinct can you imagine the problems it would cause!
June 29, 2009 at 5:46 am #91618quote AFJ:
This is exactly what natural selection is all about. An organism cannot have all the possible traits and characteristics there are available, so it is very often a trade off: you give away a trait that might’ve been very useful, but is not any more as important in the new environment, in order to save energy, time and room to build some other structure that helps in the new situation. Of course, if the environment reverts back to the old situation, the organism is in major trouble.
Natural selection cannot predict environmental changes, so there is always a certain degree of lag and always a chance that the new ability turns out to be disadvantageous on the long run. It also rarely manages to produce flawless designs, because no environment is stable enough long enough to hone these things into perfection. It is usually enough that the current design is better than its competitors and good enough to survive in general.
July 1, 2009 at 2:03 am #91691
Yes, biohazard. I agree with you. it’s like looking at the weather in 2D when it is a 3D system. But the point I see here, that you may not agree with, is that NS is not directional, but evolution is supposed to be. To say that NS is directional is to say that the proper sequence of environments just so happened to keep things in direction from less to more complex life. Even though I personally see the "least" complex life as too complex for us–that is we can’t figure out how to make it ourselves, though we’ve tried.
July 1, 2009 at 2:21 am #91693canalonParticipant
No AFJ, NS is certainly not directional. It seems to go toward mor complexity, but it is in fact a simple artifact. Were you to look at the distribution of complexity (measured one way or another) vs number of organisms (or even species or OTU) you would see a distribution extremely skewed to the left. Because life entails a minimum complexity below which it cannot maintain it self (at least in today’s conditions), but no maximum for complexity. So there are tons of bacteria and relatively much less tetrapods.
Many parasites are showing that selection can also go toward less complexity in the right conditions with the loss of multiple functions provided by their hosts.
July 1, 2009 at 3:42 am #91696quote AFJ:
Neither NS nor evolution are directional. Organisms adapt to survive in whatever environment they happen to be at the moment; they are not concerned with what "direction" they are heading as long as they can survive and reproduce.
July 1, 2009 at 6:53 am #91707quote canalon:
That parasites part was an excellent example about the bi-directional nature of evolution and NS. It is also interesting to think whether (some?) viruses have also evolved in a similar manner: they were originally more complex, but they’ve given up every part from their structure whose function the target cell can replace, and eventually only nucleic acids and some accessory structures remain nowadays.
If that was true, natural selection would’ve made something that was living essentially dead but still functional 🙂
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