Quote:The point of the precursor system being mentioned is that it shows that a system -like this one- is functional, if not for motility.
I understand that. Structures that were used for different purposes can be utilized in a different manner. In the case of flagellum, the proteins in the flagellum should be traced back to precursors that were providing a different functionality in the precursor bacteria. In order to prove that, you need to show that the flagellum proteins have homologs. If only 50% have homologs, what is your explanation for the other 50%? So the question is, how did those proteins evolve? How were they incorporated into the flagellum?
