[Taxacom] Propaganda (was: Molecules vs. Morphology)

[Dr. David Campbell]

> It clearly demonstrates that a sloppy extraction can lead to totally
> inaccurate results (make sure you aren't extracting genetic material
> from the stomach or intestines).

It's not just "sloppy" extractions; sometimes the organism (or sample, 
e.g. "it's already dead, so might as well try for DNA" with endangered 
species) makes it difficult for you, and there are also plenty of 
potential intermediate steps between tissue clip and extraction that 
can potentially cause trouble.  Possible contamination by bacteria is 
especially difficult to prevent, since they're pretty much everywhere 
that there are other organisms, plus places unsuitable for anything 
else.  

In general, more critical examination of molecular results would be 
advisable.  Not only are there the anomalies due to contamination, 
misidentification, etc., but also just because your latest analysis 
supports a clade does not mean that it is well-supported and the 
definitive final answer.  On the other hand, when a molecular clade is 
unexpected but well-supported, preferably using more than one 
analytical technique, it'd definitely worth going back and looking to 
see if there are morphological, geographical, or other correlates.   
              
-- 
Dr. David Campbell
425 Scientific Collections Building
Department of Biological Sciences
Biodiversity and Systematics
University of Alabama, Box 870345
Tuscaloosa AL 35487-0345  USA