[Taxacom] DNA only descriptions

[Stephen Thorpe]

DNA would I think be great for associating life stages, males and females of 
dimorphic species, etc., but very little of that seems to go on. Instead we just 
get all this cryptic species rubbish and DNA touted as "the lazy 
taxonomist's" substitute for morphology ...




________________________________
From: Jason Mate <jfmate at hotmail.com>
To: Taxacom <taxacom at mailman.nhm.ku.edu>
Sent: Tue, 17 August, 2010 8:34:20 AM
Subject: Re: [Taxacom] DNA only descriptions


Whee bit delayed but I am trying to keep with the spirit of one-a-day.

I actually made it quite clear that congruence of several datasources is to be 
prefered but it seems that simply by not attacking molecular data I have become 
the de facto devil´s advocate. So be it. In response to Tom, traits such as 
singing come to mind as non-morphological. Not very useful with museum specimens 
either. And anybody who has to routinely identify insects knows the limits of 
morphology. Often females are impossible to identify except by association or 
specimens must be compared to reliably identified material (chicken and egg 
problem). Also dissecting the genitalia is unavoidable (try doing that in the 
field). Any wonder only butterfly watching has taken-off! My point is that 
morphological differences are important to us but not necessarily to the 
organism. I always get a chuckle reading Mayr´s example of PNG natives 
recognising the same species of birds as ornithologists. Humans, are humans and 
they break the world down not at its joints but according to the patterns they 
see. 


Ken, naming a subspecies or a species makes no difference really: you are 
stating a hypothesis, which you support with data (traditionally morphology, 
later eco/ethological traits and lately molecular data). A cryptic species is 
not a cheap species. Accepting that morphology may not pick-up all of 
biodiversity is not a surrender. And species (the philosophical concept) only 
exist until the next revision... our very own uncertainty principle. I agree 
however in your assertion that molecular data is best suited to split these 
cases. It is a point-less exercise to use it when a cursory visual examination 
will give you the I.D. (sorry Kim, tricorders are expensive flights of the 
imagination). 


Stephen, you are the exact opposite of Lyn Cook. Morphology only and then we´ll 
see if we need DNA. I repeat, all available data must be used in the 
description. That said, a taxon may have "identical" morphology to another 
(kudos to Aurelien for bringing this up) and still be a good species and 
described based on other data, whatever that may be. Karyotypic species have 
been around for decades and not everybody has access to the facilities to carry 
out this sort of work. Also as  much as I would like to dedicate my life to the 
study of mites, I kinda like beetles so if some are cryptic, I´ll stick with 
them and still consider my output as important.

Bob, yes, my point all along is how to integrate the new data with the existing 
database. In particular Richard´s nicely put biodiversity ´´dark matter´´. Not 
just the weird and wonderful but the species which are hidden in plain site 
(cryptic species). Like the microscope, karyology and other tools, DNA offers 
another view. All previous ones have added, not supplanted data and molecular 
data is no different. I agree that Lyn Cook´s premise is weak, but the fallacy 
of her position lies in the essence of what science is. Data is data and Ms 
Cook´s attitude is to purposefully ignore data (Kim, sorry to say this but yours 
too). This is contrary to science. Alas, arguing that DNA data is somewhat 
tainted and should be ignored, downgraded or what have you is just daft.


Best

Jason
                        
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