[Taxacom] Vouchering and CBOL

Richard Zander Richard.Zander at mobot.org
Tue May 29 12:34:12 CDT 2007


Although it is preferable to voucher barcoded specimens, since all data
is valuable, the amount of data involved only indicate, in most cases,
the bare possibility that a specimen may represent a new taxon. Which in
its own right, is a good idea. But . . . 

There is generally not enough information to support the assertion
either that (1) the specimen's barcode DNA characteristics are not to be
expected by chance alone, or that (2) that one specimen represents the
taxon since most barcode loci are haplotypes and only represent the
matrilineal pedigree or genealogy of that one specimen (or patrilineal
in case of Y chromostome). The specimen's haplotype DNA does not
represent a population, much less a species. The jump from exemplar to
taxon is not a justified cerebration.

Thus, using barcodes, in most cases only morphological and biosystematic
study of a range of specimens will determine status as a new taxon. The
much-cited Two-barred Skipper study is an example of a good barcoding
study, with barcode sifting followed by intensive biosytematic study,
but the taxonomy is supported statistically only by the biosystematic
study, which presents results for which alternative hypotheses are
doubtful. 

Barcoding only supports a morphological determination of taxonomic
distinction if the results are not expected by chance alone at some
level of significance. This is generally not presented in presented
studies.

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Richard H. Zander 
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Missouri Botanical Garden
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richard.zander at mobot.org
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