Quote:the writer of the blog dishonestly represented the data. On the original paper, it doesn't say no homolog, it says "none yet known".
Isn't that the same as saying that AS OF TODAY, we don't know of any homologous proteins? So in essence, the conclusion that ~52% of the bacteria flagellum having no homologs is still a valid assertion given the data available now.
My problem with this is if that's the case, then the proposed evolutionary model for the bacteria flagellum still suffers from serious issues until the remainder, not necessarily 100%, of the proteins are shown to have homologs.
Quote:I assume he does this because most people do not have access to scientific papers? Have you tried to search google scholar for this? Or is it behind a paywall?
Yeah most papers are behind a paywall. A followup paper is Bacterial flagellar diversity and evolution: seek simplicity and distrust it?
Quote:Flagella are the chief organelles of motility in bacteria. In recent years, several new findings have illuminated the evolution of bacterial flagella, including cut-down versions of the organelle in Buchnera, a dispensable ATPase and structural evidence for homology between FliG (a component of the flagellar motor) and MgtE (a magnesium transporter). However, a fresh examination of the phylogenetic distribution of flagellar genes warns against a simplistic model of early flagellar evolution.
Interestingly, Behe DID read that paper! and even made an interesting post on it on UncommonDecent.
Behe concludes with:
Quote:Snyder et al (2009) think Buchnera’s derived structure “illuminates flagellar evolution by providing an example of what a simpler precursor of today’s flagellum might have looked like – a precursor dedicated solely to protein export rather than motility”. I think that simplicity should be distrusted. The activity of a protein export system has no obvious connection to the activity of a rotary motor propulsion system. Thus the difficulty of accounting for the propulsive function of the flagellum and its irreducible complexity remains unaddressed. In regard to the flagellum’s evolution, Snyder et al’s (2009) advice to distrust simplicity is sound and should be followed consistently.
So what I gather from all of this is that some advances have been made to illustrate possible pathways for the evolution of the bacteria flagellum. However, over half the flagellum proteins as of today have no known homologs. Furthermore, claims that protein export was a precursor to a flagellum rotary motor propulsion system cannot be made without showing at least the theoretical evolutionary pathway that led from the former to the latter.
I must say that this issue irks me and sometimes I wish I had a degree in biology to understand more!
