DNA barcodes catalogue animals

Nathan Schiff nschiff at asrr.arsusda.gov
Thu May 15 15:19:49 EDT 2003


Doug, you don't mention how they are going to identify the species so
they know what they are sequencing once they have it.  I think that will
take more than the time and money allotted alone.  Nathan

On Thu, 15 May 2003, Doug Yanega wrote:

> >"It's an exciting tool - thus far I've been impressed by the 
> >results," says museum entomologist Scott Miller. Members of museum 
> >staff are discussing whether to launch a large-scale barcoding 
> >effort for the museum's collections. Barcoding can work with small 
> >fragments, such as an insect's leg, and on specimens collected 
> >decades ago.
> 
> But note that he also said
> -----
> But it won't replace the traditional methods of identifying and 
> classifying species by their appearance, he says: "It's one more tool 
> in the box, but we will always need backup."
> ------
> Hebert's claim that this appraoch would enable us to catalogue all 
> life on earth in 20 years for $2 billion is the biggest crock of pure 
> bull I've ever heard, and a horrendous slap in the face to the 
> generations of taxonomists who've been laboring for over 200 years to 
> get a handle on extant biodiversity. Just consider the implication: 
> he's saying that in a 20-year interval, people could collect fresh 
> material (or find fresh enough material in museums that is still 
> sequenceable - when they say "decades" it means no more than 30 years 
> old, and even then only if killed and preserved in a certain way) of 
> every species from every habitat during every season in every country 
> in the world. Yeah, right. All those hundreds of thousands of taxa 
> known only from single specimens, or only from material too old or 
> too improperly preserved to retain adequate DNA, could be re-captured 
> with a trivial amount of collecting effort - and, on top of that, 
> every species that has NEVER been collected before would also 
> magically be caught and sequenced in the process. Is there a single 
> person here who believes this?
> 
> And just look at the dollar amount: if a *whopping* 20% of the 2 
> billion budget was earmarked for labor (as opposed to sequencing, 
> databasing, cataloguing, collecting trips, and every other expense), 
> at an average of, say $30 per hour (enough to pay a $60K annual 
> salary), that would only give about 6K person/years of labor, meaning 
> the equivalent of about 300 full-time researchers over that 20-year 
> interval. He's expecting the task of collecting and sequencing 100 
> million species to be performed with a total investment of labor 
> equivalent to about 300 researchers' worth? Even if it was done by 
> full-time researchers, each researcher is supposed to collect and 
> sequence 333,000 species, with no duplication of effort? That's 
> 16,000 species a year, per researcher, or 333 unique species each 
> week (and don't forget that someone has to sort them out and identify 
> them *before* sequencing). He can't possibly have the slightest idea 
> what he's talking about.
> 
> Moreover, genetic barcoding is completely divorced from any 
> biologically meaningful concept of species; it is pure phenetics, and 
> can yield identical results for different species, and - even more 
> commonly - different results within a species, just depending on 
> whether the chunk of DNA sequenced happens to have variability or 
> not. It is not a panacea, not some miracle that will give us a 
> complete tree of life - it's simply another set of data, and cannot 
> be used to unambiguously declare the taxonomic status of any 
> organism, let alone build a phylogenetic classification. We've long 
> been aware of the increasing trend to marginalize morphological 
> taxonomists, and now this trend has found a new and outspoken 
> champion, Paul Hebert, to announce to the world that we've all been 
> wasting our time, that only DNA holds the key, and that relying on 
> DNA is cheap and easy. Excuse me if I publicly berate this as idiocy.
> 
> FWIW, portions of the above tirade are based on *other* articles 
> detailing Hebert's explicit comments on how traditional taxonomy has 
> utterly failed us, which the article cited by Olle did not get into.
> 
> Argh,
> -- 
> 
> Doug Yanega        Dept. of Entomology         Entomology Research Museum
> Univ. of California - Riverside, Riverside, CA 92521
> phone: (909) 787-4315 (standard disclaimer: opinions are mine, not UCR's)
>               http://cache.ucr.edu/~heraty/yanega.html
>    "There are some enterprises in which a careful disorderliness
>          is the true method" - Herman Melville, Moby Dick, Chap. 82


 
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