New NAS Document <i>Science, Evolution, and Creationism</i> Misrepresents the Flagellum - Evolution News & Views

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New NAS Document Science, Evolution, and Creationism Misrepresents the Flagellum

One could write many pages correcting the inaccurate information in the National Academy of Science's (NAS) new version of Science, Evolution and Creationism. One of its most egregious errors is that it blatantly misrepresents the flagellum. It states, "For example, in the case of the bacterial flagellum, there is no single, uniform structure that is found in all flagellar bacteria." (pg. 40) While technically this statement may be true if one looks at the fine-grain of the amino-acid sequence of every single protein among flagellum-bearing bacteria, there most certainly are highly conserved flagellar parts. In this regard, this statement is extremely misleading and inaccurate. Consider the conclusions, directly to the contrary of the NAS, of Mark J. Pallen et al.'s 2005 article in Trends in Microbiology, "Bacterial flagellar diversity in the post-genomic era":

The E. coli/S. enterica paradigm emerges remarkably intact from our survey of flagellar diversity in the postgenomic era and appears to provide a perfect example of Darwin's epithet: 'prodigal in variation but niggard in innovation' [37]. We have been able to provide functional assignments to many conserved, but previously unrecognized, flagellar genes in diverse systems, emphasizing the continuity of flagellar structure and function. These observations will provide a firm foundation for future experimental studies, enabling conserved (and therefore presumably important) domains and residues to be identified. Surprisingly, we have determined the conservation of some regulatory components of the flagellar apparatus; for example, the FliA--FlgM system is common to flagellar systems spanning four bacterial phyla (proteobacteria, spirochaetes, firmicutes and thermotogales).

(Mark J. Pallen, Charles W. Penn, and Roy R. Chaudhuri, "Bacterial flagellar diversity in the post-genomic era," Trends in Microbiology, Volume 13, Issue 4, April 2005, Pages 143-149)

Indeed, in 2006 Pallen even wrote with Nick Matzke, "Despite this diversity, it is clear that all (bacterial) flagella share a conserved core set of proteins." Pallen and Matzke identify a core set of structural components "at the heart of the bacterial flagellum":
Three modular molecular devices are at the heart of the bacterial flagellum: the rotorstator that powers flagellar rotation, the chemotaxis apparatus that mediates changes in the direction of motion and the T3SS that mediates export of the axial components of the flagellum.

(Mark J. Pallen and Nicholas J. Matzke, "From The Origin of Species to the origin of bacterial flagella," Nature Reviews Microbiology, AOP, published online 5 September 2006.)

By claiming "there is no single, uniform structure that is found in all flagellar bacteria," it seems that the NAS is promoting misinformation about the actual flagellar structure.


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