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RE: Calm down!
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by TruthHater on March 18, 2009
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The point is, why split a demonstrably monophyletic group and describe a whole bunch of new genera? I don't think many people were unhappy with Crotalus as it is/was. Chucking in vast numbers of new names amidst a fanfare of publicity does little good, even if the groups, as defined, are monophyletic. If there weren't the long-standing precedent of Sistrurus being recognised as a separate genus, then I am sure most people would be happy with including these in Crotalus as well. The main reason that a proposal to do so found no resonance is because everyone is used to calling them Sistrurus. So, I guess history will tell, but I would put money that in 10 years time, everyone will still be talking about Crotalus atrox, Crotalus durissus, Crotalus ravus etc.
As to the python issue... sure, if you recognise every species (or every cluster of very closely related species) as a separate genus, then they are inevitably all monophyletic, and thus not "wrong" in a phylogenetic sense. However, as you split existing larger genera, you lose sight of the wood for the trees, and that is why most taxonomists and the general consensus of herpetology do not follow this approach.
Hoser revived and recognised the Wells & Wellington names, so while he may not have been behind the name, his recognition thereof was a decision that can be evaluated in the light of the present phylogeny.
Rawlings simply maintained the status quo of generally accepted classification that is consistent with their phylogeny. There is absolutely nothing in that tree that mandates recognition of Helionomus, Aspidoboa, Shireenhoserus, Australiasis, Nyctophilopython, Lenhoserus or Katrinus or the synonymy of Leiopython or Antaresia (on the other hand, the fact that carinata and viridis often do not group with other Morelia may warrant resurrection of the genus Chondropython for that group; however, the data don't provide strong evidence either way, so Rawlings et al. wisely left things as they were).
The ages of clades have never been the sole criterion for recognition (or otherwise) of genera. They may be a useful piece of the puzzle, but that's as far as it goes. This is historically inevitable, since until fairly recently we did not have access to that information anyway, except for the few geera with fossils.
The simple fact is that, at the end of the day, most biologists use nomenclature as an information retrieval system. Such systems work best if the labels stay stable - ask any librarian - unless they are actively misleading (in this case, unless they designate a non-monophyletic group). And what the rest of biology most wants is neither lumpers nor splitters, but what I choose to call "nomenclatural parsimonialists" - which loosely translates as "choose the option that *%$#s up the fewest names while remaining consistent with phylogenetic history".
So, to adjust Hoser's score sheet for pythons for these subtleties:
- Definitely mandated: 1 = 11% (Broghammerus)
- Biologically consistent but against normal taxonomic practice and consensus: 6 = 67% (recognition of Lenhoserus, Katrinus, Nyctophilopython, Australiasis, Helionomus and Aspiodoboa)
- Biologically wrong: 1 = 11% (assigning timorensis to Australiasis)
- Nomenclaturally wrong: 1 = 11% (Shireenhoserus as defined is a synonym of Enygrus)
And that's why Hoser's many new genera have generally been ignored by the rest of herpetology: even when they were consistent (in an atomising kind of way), they are simply out of step with how the rest of biology thinks.
Cheers,
Truth Hater
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RE: Calm down!
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by viper007 on March 18, 2009
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Thanks TH,
Your argument against Hoser’s recent nomenclature is actually a good one against almost any taxonomic name changes and could include recent breakups of the other viperids, colubrids and the like at generic level, when the species level taxa are well defined and known which would sit well with many.
It is also a good example for retaining python over broghammerus for the retics, even if the Hoser name makes sense in terms of defining phylogeny.
Getting to species level stuff where the definition seems to be more cut and dried, or at least it used to be, what’s your view on the Hoser and Schleip stoush on the northern white-lipped python.
Who is correct?
Is it one species as Hoser contends, or at least five as Schleip contends?
Without reference or comparison to Hoser’s descriptions of other snakes, do you think Schleip’s paper on it's own makes the case for a five way split?
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RE: Calm down!
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by TruthHater on March 18, 2009
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That's overstating it - nobody is opposed to ALL taxonomic changes - as I said, genera need changing if they are misleading, i.e., non-monophyletic. That's why Rawlings et al. recognised Broghammerus.
Some recent splits among viperids and colubrids were probably superfluous or premature.
As to Leiopython, I don't have time to go through the details, but Schleip's paper used advanced multivariate methods on a high percentage of the available museum material (that he examined himself in considerable detail - I believe he even flew to New York out of his own pocket to visit the AMNH and examine their crucial material) to demonstrate that there are well differentiated clusters of Leiopython scattered across New Guinea. The DNA evidence shows that at least some of these are definitely separate ancient lineages (and not even necessarily the most morphologically distinct ones), and his paper went through peer review by people who (hopefully) fully understand both the animals and the methods, so I would go with his version. The chapter Leiopython is not closed (following this up with DNA evidence when material becomes available will definitely be worthwhile), but the paper is based on real data, and thus evidence, and it is certainly a major contribution to our understanding of the genus that should stimulate further research.
Cheers,
TH
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RE: Calm down!
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by yoyoing on March 18, 2009
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Are viper 007 and TruthHater the same person arguing with themself, or two people staging the whole thing? It does sound good, but almost pre-planned. Take off the masks!
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RE: Calm down!
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by viper007 on March 22, 2009
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Were not the same, I can assure you.
What I do like is that we do have serious differences of opinion on some things and yet have managed to argue in a half civilized way instead of descending to flames.
I personally think Hoser's onto something when he pointed out that Schleip didn't have DNA evidence to back his claims as inferred at the start of his paper.
Truthhater runs with the multivariate analysis of Schleip, contending that's good enough and in fairness, the Schleip taxa wouldn't be the first described without DNA evidence.
I'd argue that those who reviwed Schleip's paper should have sought more evidence, but even without such evidence, his wouldn't be the first evidence light descriptions of taxa.
If I can take the liberty of changing the subject again, do you Truthhater or anyone else have an opinion on whether the genus Leiopython should be sunk in favour of Borthrochilus as done by various recent authors and likewise for the Hoser push to sink Apodora in favour of Liasis?
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RE: Calm down!
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by TruthHater on March 22, 2009
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Apodora: the Rawlings et al. paper recovered Apodora as grouping with Liasis olivaceus and other Liasis - but only with very weak support, so I'd consider the issue open. Rawlings et al. did not advocate synonymisation. Hoser's "push" consisted of the two sentences "Kluge (1993) split off papuana into it's own genus Apodora. I do not agree with this delineation and herein synonymise it with Liasis.". Without evidence to reject Kluge's phylogenetic analysis, I consider that statement scientifically irrelevant.
Re Bothrochilus and Leiopython, "nomenclatural parsimonialism" would suggest retention of Leiopython, especially since we now know that it is not monotypic.
Cheers,
Truth Hater
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RE: Calm down!
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by Cro on March 22, 2009
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"Are viper 007 and TruthHater the same person arguing with themself, or two people staging the whole thing? It does sound good, but almost pre-planned."
Two different people, in two different parts of the world. And what a great discussion. I hope it will continue. I find this very educational.
Best Regards
John Z
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RE: Calm down!
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by toddg on March 23, 2009
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I really love these WMMA style intellectual brawls. I haven’t seen one of these here since the infamous Wuster vs. Minton smack down regarding the validity of Crotalus horridus atricaudus!
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