[Taxacom] DNA only descriptions

[Stephen Thorpe]

[to Robin] steady on old man! :)

I think the DNA boys and girls have two thoughts stuck in their minds, which 
seem sensible enough on the face of it, but deeper down lack substance ...

(1) it would be good for identification to be automated, and this would probably 
have to be done by DNA analysis

(2) if you describe a species without DNA, then you run the risk of your new 
taxon actually being a complex of cryptic species

Let me discuss each in turn:

(1) good for whom? Good for some, certainly. How much effort should go in to 
trying to make this a reality? Does this mean we should all stop descriptive 
taxonomy and work on developing this idea instead until it is a reality? What if 
it can't be done after all? Might not this idea just rip the guts out of 
taxonomy, leaving an empty and uninteresting shell? What if you enjoy trying to 
identify things? What if it really does require a spark of talent that can't be 
automated?

(2) IN THEORY this is true, but:
(2a) this is no argument for not also describing the morphology; and
(2b) "cryptic species" seem a bit dodgy to me - maybe you can find as many of 
them as you look for? Maybe these genetic lineages are not what we mean by 
species, anyway? I bet most good morphospecies are a single species, and that 
problem cases are relatively few and far between...

Stephen




________________________________
From: Robin Leech <releech at telusplanet.net>
To: Kim van der Linde <kim at kimvdlinde.com>; Stephen Thorpe 
<stephen_thorpe at yahoo.co.nz>
Cc: taxacom at mailman.nhm.ku.edu; Kenneth Kinman <kennethkinman at webtv.net>
Sent: Sat, 21 August, 2010 1:26:35 PM
Subject: Re: [Taxacom] DNA only descriptions

No, Kim, that is NOT what you do.  You are using all the base
morphology information to give you a very select set of specimens
to examine for their DNA.

All the data referring to all the rest of the hierarchy (Phylum down
to genus) and relationships has been given to you on a platter.

And even more, all the other species in the genus, which are known
morphologically, have already been separated away from the select
set of specimens on which you are going to perform your DNA testing.
These specimens are, apparently, morphologically indestinguishable.

Now, having run your DNA test, let us say that you find what amounts
to 3 distinct species.

This is where I would like to come in and as a morphological taxonomist,
examine separately the 3 species, to look for morphological features missed
previously.

I feel that this is where the DNA boys have a distinct role to play, and one
that dovetails into the morphology.  When I find the morphological features -
and trust me, I will - you and I will then describe 3 species.  We will use
all the morphological features to do this, but we will also mention the DNA
as part of the process.  The DNA analysis is not the process in and of itself.
It is but a wee step.

Robin

----- Original Message ----- From: "Kim van der Linde" <kim at kimvdlinde.com>
To: "Stephen Thorpe" <stephen_thorpe at yahoo.co.nz>
Cc: <taxacom at mailman.nhm.ku.edu>; "Kenneth Kinman" <kennethkinman at webtv.net>
Sent: Friday, August 20, 2010 5:58 PM
Subject: Re: [Taxacom] DNA only descriptions


> 
> 
> On 8/20/2010 7:35 PM, Stephen Thorpe wrote:
>>> In my opinion, the crucial aspect we should not forget is that we use 
>>>morphology
>>> as a proxy for genetic differences
>> 
>> IT DEPENDS WHAT ONE IS DOING! Descriptive taxonomy, or "systematics"?
>> Descriptive taxonomists would still describe morphology even if systematists
>> knew EVERYTHING about the genetics ...
> 
> Sorry, no, you can describe a species using DNA only. It is desirable,
> no, but we could do it. And with cryptic species, that is exactly what
> we do.
> 
> Kim
> -- http://www.kimvdlinde.com
> 
> _______________________________________________
> 
> Taxacom Mailing List
> Taxacom at mailman.nhm.ku.edu
> http://mailman.nhm.ku.edu/mailman/listinfo/taxacom
> 
> The Taxacom archive going back to 1992 may be searched with either of these 
>methods:
> 
> (1) http://taxacom.markmail.org
> 
> Or (2) a Google search specified as: site:mailman.nhm.ku.edu/pipermail/taxacom  
>your search terms here
>