[Taxacom] DNA only descriptions

[Bob Mesibov]

Hi, Jason.

You wrote:

'I think it would be better to argue that without morphological descriptions and background, the new species cannot be integrated into the existing body of work or be useful to those without the necessary facilities.'

Surely this is the point at issue, not whether DNA is good or bad for diagnosis. The only way a DNA-only taxon can be integrated into an existing body of work is if *all* related taxa have had their homologous sequences done. In the few instances where this is true, we would then have two parallel taxonomies, molecular and morphological. Do we want that?

I note that other Taxacomers are interpreting 'useful to those without the necessary facilities' as field-guide users. You'd probably agree with me that we're also thinking of taxonomists without sequencing facilities, or the money to pay to get sequences done. DNA-only taxonomy splits the taxonomic community along another line, dividing haves from have-nots.

A very weak counter to this argument is that the latter divide already exists, that not everyone has access to high-quality microscopes or SEMs or other tools required for diagnosis. But most of the Earth's described flora and fauna was named by people with simple equipment. That's more than 1.5 million species. Are the remaining X million to be discovered and documented in some way qualitatively different, so that sequences are *required* to distinguish them?

Note that I'm not thinking of cryptic species. The authors of that Invertebrate Systematics article are arguing for DNA-only taxonomy *in principle*, i.e. biota-wide.

Regards,
Bob
-- 
Dr Robert Mesibov
Honorary Research Associate
Queen Victoria Museum and Art Gallery, and
School of Zoology, University of Tasmania
Home contact: PO Box 101, Penguin, Tasmania, Australia 7316
03 64371195; 61 3 64371195
Webpage: http://www.qvmag.tas.gov.au/?articleID=570