[Frumious Bandersnatch]

Thanks for the article link. Just like to point out a few things:

Much of the author's posits are speculatory at best (and he is careful to note this). I note that he remarks that Ton B and Tol A share sequence similarities to Mot AB homologs. Therefore, he implies that the Mot AB homologs are just a mutant variation of Ton B and Tol A. While that could be, it is a bit speculative on his part to say this. However, he notes that the functions between these different proteins is similar, if not exactly the same.

As an aside I will admit, now that I've thought it over, that many parts have multiple functions (such as the human mouth used for both eating and talking). As an explanation, when I was talking of one part/one function, I was thinking in terms of parts which could not produce a function without each other (such as the heart and lungs - to use a crude example).

The author also talks of random mutations to achieve the flagellum without noting the enormous difficulties attached to this approach. His arguments could just as easily lead to the conclusion that the flagellum is grown on purpose by bacteria to escape population pressures. The assumption is also made that bacteria containing the new feature would retain it when it reproduces. If the flagellum is created by secretion (as emphasized by the author), the necessary changes to DNA to make the new structure heritable by succeeding generations would not necessarily be done.

But to get back to the original argument, the author provides a very nicely reasoned supposition that the motors in the flagellum already exist in another form in the bacteria. This may very well be true, but it still is supposition and needs to be confirmed. It doesn't explain at all how Tan A & Tan L become Mot A and Mot B. Also, the author's premise is that this is an evolutionary tactic. This could be so, but considering that the author implies that the proto flagellum could be created by a bacteria deliberately using secretions to do so, it highly likely that this is a random chance event.

I would have to say that a self-directed mutation (if mutation it is) may or may not be evolutionary in tone (it may just be a different breed of the same animal), but it is definately not Darwinistic is approach.

[js1138]

I see no evidence that evolution is ever deliberate. It may appear to be if you assume that things are what they are because of planning, but if evolution could plan, species would not go extinct.

[Diamond]

Matke's scenarios are analyized here: Evolving the Bacterial Flagellum Through Mutation and Cooption: Part VI by Mike Gene.

Cordially,