[Taxacom] Blind-snakes Australia - 2-3 times as many as thought....

John Grehan calabar.john at gmail.com
Fri Jul 12 10:31:08 CDT 2013


>From my limited experience a genus is operationally  whatever someone
decides it will be, and whatever criteria are used there is no necessary
external objective standard by which anyone else will necessarily agree. In
the group I work with the practical expression has been a degree of
external visible difference by which a series of species are recognizably
different from others. This has sometimes preceded a phylogenetic analysis
supporting their monophyly, but either way the generic limits, as with just
about any other hierarchical level, come down to an assessment of
sufficient difference and similarity to draw a boundary and name. As
Raymond mentioned, some have used perspectives on the apparent age of
lineages to draw the boundaries, but again there is no necessity to do so
other than one's preference.

For applied purposes such as with biogeography the relationships (as Scott
pointed out) are more critical than the ranks (especially as there is so
much disagreement between morphological and molecular analyses - with the
latter often interspersing recognized or previously recognized groups among
different lineages [often genera broken up in the analyses I have been
looking at). I have a moth in hand that is 'extremely' different in some
respects from others in its family, and even has a wing pattern unique
among all Lepidoptera, that I intend labeling as a distinct genus. At this
time I have not been able to confirm its phylogenetic placement on
morphogenetic evidence, but in the future it is always possible to find
that this species is subsumed within some other genus.

So there are no 'good' or 'bad' genera in any objective sense as far as I
an see - in my subjective and therefore uninformative opinion. Hmm -
perhaps I have just wasted some perfectly good minutes on this posting -
and that of everyone else time who reads it. Blame it on a nice morning
cuppa tea.
John Grehan


On Fri, Jul 12, 2013 at 10:43 AM, Scott Thomson
<scott.thomson321 at gmail.com>wrote:

> If I may add in here I wrote a paper on the topic of the genus once,
> defining it.
>
> To me I felt that a genus was a monophyletic group of species that shared a
> character sweep that represented an innovation within the family in
> question. By that I mean they shared multiple characters that were all
> involved in a function of some type. For example in turtles the characters
> that are all a part in being a strike and gape piscivore; ie long neck,
> flat head, wide mouth etc. This of course is a morphological and a
> functional approach to this question, which is what I was doing and is not
> a particularly useful definition to geneticists. However it gave me the
> advantage of having a line in the sand I could draw on the issue. It
> requires a deep understanding of not only the characters of a species, but
> what they are actually used for.
>
> I think it was Stephen who said something about taxonomists should not just
> split but be willing to lump, I totally agree with this. If you constantly
> split you are going to end up with a whole bunch of OTU's grouped by what
> are really monotypic genera, this is really a loss of information not a
> gain. We gain information by being able to infer relationship from
> phylogeny.
>
> Cheers, Scott
>
>
> On Fri, Jul 12, 2013 at 4:23 AM, Raymond Hoser - The Snakeman <
> viper007 at live.com.au> wrote:
>
> > Stephen you wrote:
> >
> > "Your comments do bring up an interesting question at the heart of
> > systematics, which has never been resolved to my satisfaction, namely:
> what
> > is a genus?"
> >
> > And I agree wholeheartedly.
> >
> > Much of the bickering among taxonomists would be resolved (at this level
> > at least) with a better definition to work with!
> >
> > Getting there won't be easy however as molecular biologists will probably
> > want to ignore such things are morphology and vice versa for some of the
> > more traditional taxonomists, who probably treat molecular phylogenies
> with
> > a strong element of suspicion.
> >
> > I prefer to work using both and find that they do tend to work hand in
> > hand, and also with primitive groups draw the line further back in time
> in
> > terms of divergences.  Subjective to an extent I agree.
> >
> > All the best
> >
> >
> >
> >
> > Snakebustersâ - Australia's best reptilesâ
> >
> > The only hands-on reptilesâ shows that lets people hold the animalsâ.
> >
> > Reptile partiesâ, events, courses
> > Phones: 9812 3322
> >
> > 0412 777 211
> >
> >
> > Date: Thu, 11 Jul 2013 17:16:56 -0700
> > From: stephen_thorpe at yahoo.co.nz
> > Subject: Re: [Taxacom] Blind-snakes Australia - 2-3 times as many as
> > thought....
> > To: viper007 at live.com.au; taxacom at mailman.nhm.ku.edu
> >
> > Hi Raymond,
> > Your comments do bring up an interesting question at the heart of
> > systematics, which has never been resolved to my satisfaction, namely:
> what
> > is a genus? I would say that divergence times are irrelevant. My own view
> > is that a genus is just a convenient monophyletic grouping of species,
> i.e.
> > not too big, not too small, and easily recognisable. Others may disagree
> ...
> > Cheers,
> > Stephen
> >
> >
> >
> >
> > From: Raymond Hoser - The Snakeman <viper007 at live.com.au>
> > To: Stephen Thorpe <stephen_thorpe at yahoo.co.nz>; "rwrossco at gmail.com" <
> > rwrossco at gmail.com>; "envirodata at hotmail.com" <envirodata at hotmail.com>;
> "
> > taxacom at mailman.nhm.ku.edu" <taxacom at mailman.nhm.ku.edu>
> > Sent: Friday, 12 July 2013 12:01 PM
> > Subject: RE: [Taxacom] Blind-snakes Australia - 2-3 times as many as
> > thought....
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> > Thanks for the kind comments Stephen.
> >
> > Oversplitting of genera is a matter of opinion.
> >
> > There was a time when pretty much every snake on earth was placed in the
> > genus “Coluber”, but thankfully those days have now passed.
> >
> > For the Blindsnakes, until 2012, pretty much all were placed in the
> genera
> > Typhlops and Ramphotyphlops even though there were clades with
> divergences
> > measuring over 60 million years and with the same genus name, which if
> they
> > were mammals, would be placed in different families.
> >
> > I thought I was conservative for busting up just to the genus level and
> if
> > you cared to read the paper in question, my splits were generally of
> clades
> > divided at least 30 MYA which is perfectly reasonable for a genus-level
> > split in vertebrates (in my humble opinion).
> >
> > But by all means, if you want to keep calling every blindsnake in
> > Australia Ramphotyphlops, we will have to agree to disagree, but for what
> > it’s worth you are entitled to do so and I won’t stop you.
> >
> > All the best
> >
> >
> > Snakebustersâ - Australia's best reptilesâ
> > The only hands-on reptilesâ shows that lets people hold the animalsâ.
> > Reptile partiesâ, events, courses
> > Phones: 9812 3322
> > 0412 777 211
> >
> >
> >
> >
> > Date: Thu, 11 Jul 2013 00:26:41 -0700
> > From: stephen_thorpe at yahoo.co.nz
> > Subject: Re: [Taxacom] Blind-snakes Australia - 2-3 times as many as
> > thought....
> > To: viper007 at live.com.au; rwrossco at gmail.com; envirodata at hotmail.com;
> > taxacom at mailman.nhm.ku.edu
> >
> >
> >
> > Dear Gents, Ladies, Dimwits and Raymond, but particularly Raymond:
> >
> > The reference of which you speak (but don't cite!) is presumably this:
> > Marin, J. et al. (Early View, 2013): Hidden species diversity of
> Australian
> > burrowing snakes (Ramphotyphlops). Biological journal of the Linnean
> > Society, doi: 10.1111/bij.12132
> >
> > A search in the PDF for the name Hoser turns up nothing. Actually, I find
> > the above article to be somewhat vague in terms of taxonomy/nomenclature,
> > but at least they don't oversplit genera, like this fellow did in 2012:
> > Hoser, R. 2012: A review of the extant Scolecophidians (“Blindsnakes”)
> > including the formal naming and diagnosis of new tribes, genera,
> subgenera,
> > species and subspecies for divergent taxa. Australasian journal of
> > herpetology, (15): 1-64.
> >
> > I think many people here would say that if you name enough taxa willy
> > nilly, a few names are bound to stick purely by chance ... so I wouldn't
> > crow too loudly about it if I were you ... just a bit of friendly free
> > advice ...
> >
> > Stephen
> >
> >
> >
> >
> >
> > From: Raymond Hoser - The Snakeman <viper007 at live.com.au>
> > To: "rwrossco at gmail.com" <rwrossco at gmail.com>; "envirodata at hotmail.com"
> <
> > envirodata at hotmail.com>; "taxacom at mailman.nhm.ku.edu" <
> > taxacom at mailman.nhm.ku.edu>
> > Sent: Thursday, 11 July 2013 6:17 PM
> > Subject: [Taxacom] Blind-snakes Australia - 2-3 times as many as
> > thought....
> >
> >
> > Gents and ladies, did you see the latest from Marin, Donnellan, Vidal,
> > Aplin and the rest this week.
> >
> > They say there are about 2-3 times the known number of blindsnake species
> > in Australia
> > with a series of phylogenies that upheld the species I recently named.
> > - Bad news is they put them all in Ramphotyphlops .... (dimwits!).
> >
> > PS - Those who reckon everything is already named are dreaming!
> > All the best
> >
> > Snakebustersâ - Australia's best reptilesâ
> >
> > The only hands-on reptilesâ shows that lets people hold the animalsâ.
> >
> > Reptile partiesâ, events, courses
> > Phones: 9812 3322
> >
> > 0412 777 211
> >
> >
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>
> --
> Scott Thomson
> 29400 Rt 6
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> The Taxacom Archive back to 1992 may be searched with either of these
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>
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>
> (2) a Google search specified as:  site:
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> Celebrating 26 years of Taxacom in 2013.
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