On 2/20/07, Bill Whan <[log in to unmask] > wrote: > > A recent discussion on the Frontiers of Identification list is of > interest: http://birdingonthe.net/mailinglists/FRID.html . > A technical paper "Comprehensive DNA barcode coverage of North > American > birds" has attracted wide attention because it suggests more splits > might be made in the N. American bird species list. I, too, have been following this discussion, and I believe that the spectre of fifteen or more cryptic species has been accorded more ink than it deserves. DISCLAIMER: THE WRITER DISCLAIMS ALL KNOWLEDGE OF GENETICS! All I know about genetics I absorbed by osmosis from my step-daughter, who is a genuine expert on beetle genetics. With that caveat in place, this is what I have gleaned from reading the paper. DNA barcoding is a search for quick and dirty ways of making identification to species of organisms in the laboratory using clusters of base pairs on a very limited number of base pairs. The referenced article is a test of that approach on a well worked-out taxon: namely, North American birds. The authors were very pleased to report that 94% of all North American birds could be identified using a string of only 648 base pairs on a single mitochondrial DNA gene. The comments about the possibility of cryptic species and the possibility that all the white-headed gulls are actually one species (which would surprise no one) were merely specualtions on why the technique failed in some cases. The following is a quote from the introduction to the full paper: "DNA barcoding translates expert taxonomic knowledge of diagnostic morphologic characters into a widely accessible format, DNA sequences, enabling more people to identify specimens. In addition to assigning specimens to known species, DNA barcoding can speed the discovery of new species, as large sequence differences in animal mtDNA generally signal species status." The first sentence says that the taxonomy comes first, then the barcode. The second sentence says that the barcoding MAY facilitate the discovery of new species in the future. This is a speculation and it remains to be seen whether it is very useful. I have some further ruminations on this topic that I will save for the Forum. Cheers, Bob -- Robert D Powell Wilmington, OH, USA [log in to unmask] Nulla dies sine linea ______________________________________________________________________ Ohio-birds mailing list, a service of the Ohio Ornithological Society. Our thanks to Miami University for hosting this mailing list. Additional discussions can be found in our forums, at www.ohiobirds.org/forum/. You can join or leave the list, or change your options, at: http://listserv.muohio.edu/scripts/wa.exe?LIST=OHIO-BIRDS Send questions or comments about the list to: [log in to unmask]