Like any identification
system there are do’s and don’ts. For DNA barcoding there are seven major
don’ts or as the paper calls them “seven deadly sins”. The sins are as follows failure to test clear hypotheses,
inadequate a priori identification of specimens, the use of the term ‘species
identification, inappropriate use of neighbor-joining trees, inappropriate use
of bootstrap resampling, inappropriate use of fixed distance thresholds, and
the one that I will be discussing today incorrectly interpreting the barcoding
gap. The paper states that incorrectly interpreting the barcoding gap has “two
distinct scenarios”, the first being for specimen identification and the second
being species discovery.
The first scenario just means that the organism is so close to
another organism in its species that t is identified incorrectly as the other
organism. The second scenario means that a new species could be incorrectly
identified as a pre-existing species. I feel like all the sins listed above
could be easily avoided just by being careful when examining the species. But I
think instead of having a system that relies on the barcoding “sequence” of one
gene, have a system that if questions or errors like this are possible add an
extra position that is barcoded on that gene.
Here is the link to the article:
What exactly is DNA barcoding?
ReplyDeleteExcellent question, Lauren. See: Jake's prevoius post.
ReplyDeleteSeems like there is a chicken and egg problem. If one wants to use barcoding to identify a specimen, it would seem that proper a priori identification would make using a barcode unnecessary. I suspect that I'm missing some nuance here.
Is there not another gene they could use instead of 648 base pair of the cytochrome c oxidase, or maybe they could use both that gene along with another one.
ReplyDeleteIs there not another gene they could use instead of 648 base pair of the cytochrome c oxidase, or maybe they could use both that gene along with another one.
ReplyDelete