The Bacterial Flagellum, as an example of Irreducible Complexity, proves evolution unlikely.
Debate Rounds (3)
IRREDUCIBLE COMPLEXITY: The bacterial flagellum is irreducibly complex because it will not function AS A FLAGELLUM without all of the parts working together. Thus, if a part was removed, or all but one part were present, it would not function AS A FLAGELLUM.
My argument: No research has discovered a detailed evolutionary pathway showing how the flagellum could have been assembled in a stepwise, incremental process without the assistance of a designer.
I will gladly discuss this with you.
My argument will be that you suffer from a general misconception about the workings of evolution, leading you to a false conclusion.
I allow you the first argument, please prepare your initial statements properly.
This machine, like any machine we have experience with, is only functional when all parts are built and assembled in the final form. This is antithetical to any step-wise undirected process proposed by neo-darwinian evolutionary theory.
I challenge my opponent to cite research that has discovered one possible step-by-step pathway by which the flagellum could have been built without intelligent guidance.
Evolution is not a process of stepwise, incremental nature. The resolution about "irreducible complexity" is hence flawed to begin with.
Evolution consists of two major elements: random mutation on the one hand and selection by higher chances of procreation and survival (Darwin's famous "survival of the fittest"). It works the other way round, by eliminating mutations that do not prove persistent enough, not "fit" to their environment.
We have research to that end:
"The mechanisms of evolution—like natural selection and genetic drift—work with the random variation generated by mutation."
So how did the bacterial flagellum come into existence?
Studies have shown that the proteins forming the flagellum crystallize IN VITRO, so in the absence of life. It's a chemical process that has nothing to do with evolution at all:
"The process by which bacterial flagellar filaments are reconstituted from flagellin molecules in vitro is examined by physical measurements (flow birefringence, viscosity, sedimentation) and by electron microscopic analysis, using flagella isolated from a strain of Salmonella. It is shown to be essentially reversible and characteristic of crystallization. In the presence or absence of salt, the flagella are depolymerized into monomers by heat treatment. At neutral pH, the repoly-merization takes place only in the presence of salts."
This means that the flagellar filaments formed in sea water, possibly long before bacteria even existed. It's the natural state of these long-chained proteins in salt water.
This fact is commonly known and has found its way even to Wikipedia:
"Assembly. During flagellar assembly, components of the flagellum pass through the hollow cores of the basal body and the nascent filament. During assembly, protein components are added at the flagellar tip rather than at the base. In vitro, flagellar filaments assemble spontaneously in a solution containing purified flagellin as the sole protein." http://en.wikipedia.org...
As for the "irreducible complexity": "Integration of phylogenetic information with our interaction and phenotyping data reveals a conserved core of motility proteins, which appear to have recruited many additional species-specific components over time." http://www.ncbi.nlm.nih.gov...
This means that all flagella in existence each contain ADDITONAL, hence OPTIONAL, proteins and would work - and did work - well without them. So, elements could be taken away, or replaced by others, and mobility would still be there, making the point moot to begin with.
So what this come down to is this:
Evidence exists that the basic structure of the flagellum is very old, but it was a lifeless protein crystal then. Some mutated bacteria merged with this bit of organic crystal (yes, those exist, like sugar, for example, which is crystalline and organic, consisting of carbon, hydrogen and oxygen). Some of these mutations gained mobility by this, others did not. Those who gained mobility naturally moved around and thus reproduced faster than their static counterparts, which then became extinct.
Evidence also exists that later, some of these mobile bacteria mutated even further, diversifying and hence gaining parts for the flagellum that were not necessary for its function.
It's all there.
The described pathway clearly shows that a "designer" is not needed for any of this to work. The resolution is thus refuted beyond reasonable doubt, especially since only one source has been detailed by my opponent.
On a personal note: I believe in a creator god, but my opponent's argumentation just makes no sense to me.
"Evolution is not a process of stepwise, incremental nature. The resolution about "irreducible complexity" is hence flawed to begin with."
-Well, I certainly agree with you that the different forms of life did NOT come about by an incremental process, but I"m not the expert on current neoDarwinian evolutionary theories.
I do know, however, that that was once a necessary part of Darwin"s theory:
"If it could be demonstrated that any complex organ existed, which could not possibly have been formed by numerous, successive, slight modifications, my theory would absolutely break down."
R13; Charles Darwin, The Origin of Species
-What support does my opponent have to claim that this basic tenant is now gone from neo Darwinian evolutionary theory?
I agree with my opponent's definition of evolution. I refer to it as neo- Darwinian evolution, but we"re talking about the same thing. No need to quibble about definitions. Cheers :)
My opponent went on to describe the origin of the flagellum:
"So how did the bacterial flagellum come into existence?
[after citing and quoting an article]
""This means that the FLAGELLAR FILAMENTS formed in sea water, possibly long before bacteria even existed. It's the natural state of these long-chained proteins in salt water""
I thought my opponent had taken it for granted that I was talking about the ENTIRE FLAGELLUM ASSEMBLY rather than just the FLAGELLAR FILAMENTS. But I like to see him taking enough rope to hang himself :)
The above finding seems to show why these proteins would have been used by an intelligent designer - because they self-assemble easily, making it the perfect material to use on a "whip" of an electric motor, where it would need to be healed or replaced often.
"As for the "irreducible complexity": "Integration of phylogenetic information with our interaction and phenotyping data reveals a conserved core of motility proteins, which appear to have recruited many additional species-specific components over time." http://www.ncbi.nlm.nih.gov...;
"This means that all flagella in existence each contain ADDITONAL, hence OPTIONAL, proteins and would work - and did work - well without them. So, elements could be taken away, or replaced by others, and mobility would still be there, making the point moot to begin with."
Wow, that"s a real leap of faith to go from the research described in that article and ANY solid conclusion.
I perused the article, cross-eyed most of the time, didn"t really understand their experiments, so had to go to the conclusion and discussion sections"
I understood this sentence" "A major goal of this study was to find novel flagellar components among the many proteins of still unknown function."
" i"m not sure what they mean by "among the many proteins"" but it"s saying that they"re trying to discover the FUNCTION of proteins (in the flagellar mechanism, or in the cell? I"m not sure what it"s referring to) whose functions haven"t yet been determined.
In the article cited above, there is the section: "The Evolution of the Flagellum". It starts with the sentence:
"Given the amazing complexity of the bacterial motility system, we wondered whether our interaction data and phenotypes can contribute to the understanding of its evolution."
Notice, the assumption is made at the oustet that the flagellum evolved. What follows in the article is no compelling reason to make such an assumption.
But it is quite interesting, so I"ll discuss the 3 points under the heading:
1. [something to do with a phylogenetic super tree that they made] shows that the flagellar system EVOLVED TOGETHER WITH OTHER CELLULAR SYSTEMS AND NOT INDEPENDENTLY."
I have no problem with that statement, but my opponent said the flagellar filament evolved before the first bacterium existed, so HE might have an issue to deal with. Let"s just leave that for later and go on to the next point:
2."Evolution of the flagellum is also consistent with the fact that neither any flagellar proteins nor any of their interactions is conserved"This indicates that protein interactions may be evolutionarily less conserved than generally believed."
-Intelligent Design is also consistent with this fact. For that matter, it shows that there are LESS chances for protein evolution than previously thought.
3."An evolutionary model also predicts that core proteins, which have been associated with the flagellum, should be tightly integrated""
-An Intelligent Design model also predicts that core proteins" should be tightly integrated.
-All that was said about evolution of the bacterial flagellum is window dressing that can be applied to support evolution and intelligent design equally.
Finally, about my opponent"s so-called account of how the evolution of the flagellum ACTUALLY HAPPENED:
-His own cited paper contradicted his claim that the flagellum developed before the bacterium cell.
-The rest is just more Darwinian story-telling. No details of HOW, just the blithe statement:
"SOME mutated bacteria merged with this bit of organic crystal...etc"
-HOW do you propose "some" mutated bacteria merged with the flagellum?
-What was the evolutionary PATHWAY? I know you EXPECT that story to be true, based on Evolutionary theory, but you haven"t cited any research that DEMONSTRATES this narrative to be true. Without it, you"re just begging the question.
My dear opponent has somehow lost track of what he wants to prove.
"I do know, however, that that was once a necessary part of Darwin"s theory:"
Irrelevant. Abandoned theories prove nothing and disprove nothing. My opponent demonstrates his misinformation about the subject. If we were to discuss anything on this level, we would have to discuss whether Earth is a disk, too. Obviously, any objection against Darwin's initial flaws in Evolution theory are not applicable to modern research, so I will not go into detail on this part any further, as it only distracts from the matter at hand: Has evolution been made UNLIKELY by the findings about the bacterial flagellum?
"I agree with my opponent's definition of evolution." So: conceded.
"I thought my opponent had taken it for granted that I was talking about the ENTIRE FLAGELLUM ASSEMBLY rather than just the FLAGELLAR FILAMENTS."
Oh, and I do. The filaments FORMED, they took the shape of the entire flagellum. I will turn to less complicated elaborations on the matter, so as not to overtax my opponent with scientific jargon again:
"The flagellar filament is the long helical screw that propels the bacterium ... the filament is made up of eleven protofilaments approximately parallel to the filament axis. Each protofilament is a series of tandem protein chains. ...
Assembly. During flagellar assembly, components of the flagellum pass through the hollow cores of the basal body and the nascent filament. During assembly, protein components are added at the flagellar tip rather than at the base." (from: http://en.wikipedia.org... ).
Allow me to explain: the flagellar filament IS the key part of the entire flagellum, it's a protein chain that forms into that exact shape CHEMICALLY as it crystallizes in salt water - as its natural chemical state. The filament takes the final shape of the flagellum regardless of cells. Further parts of the flagellum are added to that molecule, again without any LIFE (metabolism and/or cell division) involved. That's CHEMISTRY, not BIOLOGY. Nothing evolved here. Because nothing "mutated".
"mutation is a change of the nucleotide sequence of the genome of an organism, virus, or extrachromosomal genetic element. Mutations result from unrepaired damage to DNA or to RNA genomes (typically caused by radiation or chemical mutagens), errors in the process of replication, or from the insertion or deletion of segments of DNA by mobile genetic elements." (from: http://en.wikipedia.org... ).
The filaments and other (additional) proteins constituting the flagellum do not have a DNA, they do not have a genome of any other kind, either. They are just lifeless molecules, crystals. So the construction of the flagellum does not contain any indication of evolution.
My opponent agreed that evolution involves mutation and selection. The entire flagellum is formed from components that cannot mutate, as it constitutes out of crystalline proteins combining themselves to the filament, as quoted above. So research makes it no less likely that a fully functional flagellum completely formed before any metabolical processes and hence evolution were involved. This means that the complexity of the flagellum does not contribute to any answer about EVOLUTION at all. It can easily have formed before, by purely chemical processes. Later on, when life emerged, the flagella became subject of evolution and were slightly changed for different species, adding additional proteins along the way.
"Ideas About The Earliest Membranes
Several hypotheses of the origin of cellular membranes exist:
As you can see, the forming of membranes PREDATES "life" and hence EVOLUTION. ABIOGENICALLY formed molecules like the flagellum were chemically bound to proto-membranes, just like a dust particle might stick to the surface of a drop of oil, forming proto-cells. Evolution started with the first cellular reproduction, so when the first DNA strand duplicated itself inside a cell, which must have been later as it requires a formed cell.
All this is scientific fact to our best current knowledge.
Any conclusion the quoted researchers DRAW from their facts is of no consequence here. We're not discussing their conclusions, we're discussing their FINDINGS, and in the course of a debate arrive at our own conclusions.
If I wanted to simply quote conclusions, I would just quote from http://en.wikipedia.org... and be done with it.
"Wow, that"s a real leap of faith to go from the research described in that article and ANY solid conclusion."
I counter with a source more apt to the level of scientific knowledge my opponent will be able to understand:
"Evolution. The evolution of bacterial flagella has been used as an argument against evolution by creationists. They argue that complex structures like flagella cannot evolve from simple structures. In other words, flagella are "irreducibly complex" and need all of their protein components to function. However, it has been shown by numerous studies that a large number of proteins can be deleted without (complete) loss of function."
I was under the impression that someone asking for scientific proof would have the basic knowledge to UNDERSTAND the answer.
My opponent admits that he does not understand the sources I present, and chooses to IGNORE them and skip the relevant part of the article, thus changing the topic at hand. As stated above, I'm discussing experimental findings. By his decision to omit this, my point is basically conceded.
Now for his quotes from my sources:
"Given the amazing complexity of the bacterial motility system, we wondered whether our interaction data and phenotypes can contribute to the understanding of its evolution."
So? The answer is "no" as the flagellum is a protein complex and the term "evolution" is not applicable as we already agreed: Evolution = mutation + selection; Mutation = change in DNA; flagellum does not contain DNA; ergo flagellum does not evolve.
It can thus not be used as an argument against evolution.
"shows that the flagellar system EVOLVED TOGETHER WITH OTHER CELLULAR SYSTEMS AND NOT INDEPENDENTLY."
My opponent clearly states: "I have no problem with that statement"
This is the final concession of my point, as my opponent completely abandons his resolution: "The Bacterial Flagellum, as an example of Irreducible Complexity, proves evolution unlikely."
So he has no problem with evolution ("EVOLVED TOGETHER WITH OTHER CELLULAR SYSTEMS"), but finds evolution unlikely at the same time? This is a clear contradiction, and my opponent has just disproved himself.
Further: "Intelligent Design is also consistent with this fact."
"ALSO" means that evolution POSSIBLY accounts for the findings, TOO, making evolution NOT "unlikely" as demanded by the resolution. My opponent has thus admitted that evolution is a possible and thus admissible explanation! This is a clear contradiction, again.
"All that was said about evolution of the bacterial flagellum is window dressing that can be applied to support evolution and intelligent design equally."
Exactly. Hence both are EQUALLY LIKELY. I consider this point conceded.
"but you haven"t cited any research that DEMONSTRATES this narrative to be true."
And I didn't have to. The resolution clearly demands only that I show evolution to NOT BE UNLIKELY to make my point.
And that I did.
I have shown that the flagellum can have formed chemically, not disproving evolution.
My opponent accepted that the flagellum evolved. Then so be it.
Thanks for this, best of luck!
1 votes has been placed for this debate.
Vote Placed by bladerunner060 3 years ago
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Reasons for voting decision: Pro basically conceded the debate in his final round, as Con pointed out. Pro needs to craft his resolutions more carefully, methinks--he appeared to want to shift to arguing that ID was compatible with the evidence, too, which did nothing to support the resolution. Arguments to Con. Sourcing was about equal--neither side sourced overmuch (I don't fault Con for his wikipedia usage, but all the sources were really just for basic backgorund). Conduct was about equal. S&G was equal enough for government work. As always, happy to clarify this RFD.
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