Does DNA bar coding in butterflies really work

[nomad]

Is DNA barcoding a really good method of determining closely related species, without using others methods .... morphology, genitalia differences,  geographical isolation etc 

Yes. DNA barcodes help solve butterfly classification conundrums. Florida Museum article

www.floridamuseum.ufl.edu/science/dna-barcodes-help-solve-butterfly-classification-conundrums/

No. Lots of pitfalls. Butterflies poke holes in DNA barcodes from Nature International journal of science

www.nature.com/news/2006/060227/full/060227-1.html

What do you think.

[Adam Cotton]

Barcodes by themselves, particularly just a single short sequence of the COI mitochondrial DNA gene, may be prone to tree topography errors (estimated at up to 30% in some cases), but modern NGS (next generation sequencing) techniques which sequence the whole genome are much more accurate.

At least when using barcode only sequencing it should be combined with morphological characters to support (or not) the results.

Adam.

[jshuey]

My take is that bar-codes really work for differentiating evolutionary lineages.  The Karner Blue example is a great case study, where hybridization indicates that the two subspecies involved have not quite separated yet (they may never separate or in a few hundred thousand years - you may see complete divergence).  Who knows?  But right now, the subspecies exchange mRNA regularly enough to blur the distinctiveness of each lineage.


Bar-codes are simply a tool, to be used just like morphology.  In the case of skippers from Belize, they seem really powerful for differentiating cryptic species.   I use Bar-codes regularly and I find them very useful for this work.

Here is the original reference for this type question - the now famous "10 species in one" paper -  www.pnas.org/content/101/41/14812.  In this case, species which can not be distinguished morphologically, have very distinct bar-codes (and different hostplants and larval morphology as well).

The same research group threw out a cautionary tale where really distinct species hardly differed in "short bar-code" readings at - biodiversitygenomics.net/site/wp-content/uploads/2016/01/2007%20-%20Burns%20-%20DNA%20Barcodes%20of%20closely%20related%20spcies%20of%20skipper%20butterflies.pdf. 


John

[jhyatt]

Yes - Shuey is right on the money. Barcodes are just another character to consider, and not the last word, in systematics. Sometimes they're very helpful, sometimes not.
I think of barcodes as usually being in the "necessary, but not sufficient", category.
jh