[Taxacom] very nice opinion article in today's Zootaxa
stephen_thorpe at yahoo.co.nz
Thu Sep 15 20:47:56 CDT 2011
here is another current example of species based on molecular taxonomy: doi: 10.1016/j.ympev.2011.08.012
'The three south-eastern species R. eyrensis, R. angusta, and R. ormsbyi are morphologically very similar. The small morphological differences present among the three south-eastern taxa (see diagnosis for R. ormsbyi), apply to pooled population samples, and identifying an individual without locality data will be difficult without genotyping. Importantly, the three south-eastern species appear to be allopatric based on our extensive sampling and so geographic location will be essential in identification if a tissue sample (e.g. tail tip) is not available'
if the species are allopatric, and there are no ecological differences, then why the heck recognise them as full-species based just on molecular divergence?? I suspect that there used to be a tacit assumption that amount of morphological divergence correlated directly with time at the same rate across all taxa of organisms, but this is obviously false! Now, it appears to be replaced with the same assumption but for molecular divergence! But, probably, molecular divergence rates can vary widely, with two distinct species having very little divergence, or one species having much divergence between populations, as possibly in this case ...
From: John Shuey <jshuey at TNC.ORG>
To: taxacom at mailman.nhm.ku.edu
Cc: Karl Magnacca <kmagnacca at wesleyan.edu>
Sent: Friday, 16 September 2011 10:39 AM
Subject: Re: [Taxacom] very nice opinion article in today's Zootaxa
>I'm certainly not saying that Brower is in the right here, and I
>would not have done something like that, especially without
>contacting Janzen and Burns. That said, I'm reluctant to explicitly
>condemn it either, for the reasons I laid out previously - the bold
>claims that were made in the original 2004 paper and the repeated
>citation of provisional names, which does no good.
The point seems to be that there was "no proof of concept" after the ten in one paper for the bold claims. But that ignores papers like Venada - a monotypic genus that had 4 new highly cryptic species from ACG. Or Perichares - which I think had another 3 or 4 new cryptic taxa hidden under one presumably common, widespread name (exactly like Astraptes only fewer species involved). In both cases - bar codes separate out adults which are barely distinguishable. But the lineages all have ecologies and larval morphology that point to evolutionary lineages. And once you understand them, you can even sort out adults fairly reliably - some of the species are in fact quite obvious once you know them, others have phenotypes that are harder to pull out from mixed series. But the bottom line is that these are exactly the same traits covered in 10 in 1 for Astraptes, and which uphold the bold claims. And despite Brower's claims - NO ONE WAS DESCRIBING
SPECIES BASED SOLEY ON BARCODES (oddly that would be only him). The papers are all very traditional morphology based treatments - only with world class biology thrown in and barcodes as supplemental characters. The key point being that without all the detailed rearing and barcodes - no one would suspect that these cryptic taxa existed. That is exactly where the Astraptes work was headed as well (Sadly - I'm guessing that there is a strong chance that a decade of work will be tossed for more rewarding publications at this point in Burns' career).
The real issue is the classic "cherry picking" that the " gadfly and provocateur" career tract often has to follow in order to set up straw men to knock down. Rather than look at the accumulating evidence that was piling up with other papers by the group - data that supports the bold utility of barcoding - cherry pick the example you like in isolation, download a bunch of data off the web, and write a sarcastically flip paper (and hope you get some attention like this in the process). The Astraptes example happened to be the most exciting and complex (biologically and nomenclaturally) so it lagged - but anyone who has been at the USNM in recent years knew that work was continuing at a strong pace and that there was real anticipation about the final results.
So the question in my mind - why do people choose to ignore the accumulating evidence from other genera for the bold claims. Whatever happened to actually reading the literature to see how the issues are being resolved (almost everything in my previous email is available online)? More importantly, why would you step on a decade of the group's hard work rather than slide in as a collaborator to help explore sticky issues? I'm guessing because... , well actually I don't have a solid guess about anti-social behavior like this.
If you have never seen the Brower descriptions - well there really isn't a description for any taxa in here - just a diagnosis like the one below. The other nine are no more enlightening....
Astraptes fruticibus sp. nov.
Type locality. CostaRica, Alajuela Prov. Area de Conservacion
Guanacaste, Sector Santa Rosa, Area Administrativa,
10.838# N, 85.619# W, 295 m.
Diagnosis. The species may be differentiated from other
members of the Astraptes fulgerator complex by the following
combination of character states of the DNA barcode:
274T; 361T; 568T.
Holotype. Voucher 96-SRNP-10409, deposited at the University
Note: This species corresponds to the OTU ‘SENNOV’ of
Hebert et al. (2004).
Etymology. The name fruticibus means ‘from the bushes’,
referring to the fact that DNA barcodes from this species do
not form a distinct group in the cladistic analyses of Brower
Honest - that is it!
Please consider the environment before printing this email
John A Shuey, Ph.D.
Director of Conservation Science
jshuey at tnc.org
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