[Taxacom] Describing genera without molecular phyolgies

[Scott Thomson]

I think answers to this will also be affected by the evolutionary theories
being applied.

However that aside. I agree about looking for gaps. Mayr used the term
decided gap. My own view is genera can be defined by character sweeps. That
is interrelated characters, must be multiple, all connected to a unique
functional change. For example the sweep of characters used to make strike
and gape predation possible. Any underlying all this I think these days the
genetics is also necessary. Though I consider both mt DNA and nu DNA. I
prefer a total evidence approach I guess.

Cheers Scott

On Mon, May 25, 2020, 8:43 PM Richard Zander via Taxacom <
taxacom at mailman.nhm.ku.edu> wrote:

> I appreciate the comments of Lynn Raw and Richard Pyle. They mention
> important concerns.
>
> Richard Pyle wrote:
> I consider myself a classical taxonomist, and I'm not worried.  Who is
> worried?  Are you worried?
>
> Well, yes, I am worried.
>
>  For two reasons: (1). Biodiversity analysis requires decent
> classifications. Nowadays, environmental protection of molecularly cryptic
> species gets more attention in the news than protection of whole
> ecosystems. Following strict phylogenetic monophyly, species, genera, and
> even families are commonly either sunk to synonymy or invented without
> reasonable evolutionary evaluation. Making predictions for the expected
> vast changes in floral and faunal composition is now difficult because of
> the sea of rapidly changing nomenclature that lumps disparate taxa or
> splits taxa into unmanageable units.
>
> And (2): Systematics is supposed to be a science. But it has always been
> vulnerable because mathematics and statistics are not reputed to be a
> strength of taxonomists. I think "innumerate" is the term often used for
> us. Phylogenetics is replete with bad statistics. Sampling is a joke, with
> say 5 or 10 exemplars of a species being considered a lot. Evolutionary
> scenarios from different data sets (morphology and DNA) are compared with
> Bayes Formula, instead of Bayes Factors. Accuracy is rejected in favor of
> precision. Dichotomous trees of cluster analysis are accepted as models for
> analysis. Molecular studies substitute clades of molecular strains of
> species for actual species, when (or perhaps because)  the last might
> require much additional sampling, assuming many information-bearing strains
> are not extinct. "Shared ancestors" are considered by some cladists to be
> interspersed in a cladogram without actually modeling these (e.g. where are
> their autapomorphies? Do they reverse and disappear?).
>
> I am worried for biodiversity analysis in an era of climate crisis and for
> any remaining respect for systematics as a science. I do not say that
> phylogenetics is a shuck and a scam, or that it is a 30-year Lysenko-level
> perversion of science. If true, then that would be more than just worrisome.
>
> Richard Zander
>
> -----Original Message-----
> From: Richard Pyle <deepreef at bishopmuseum.org>
> Sent: Saturday, May 23, 2020 7:44 PM
> To: Richard Zander <Richard.Zander at mobot.org>; 'JF Mate' <
> aphodiinaemate at gmail.com>
> Cc: 'Taxacom' <taxacom at mailman.nhm.ku.edu>
> Subject: RE: [Taxacom] Describing genera without molecular phyolgies
>
> Hi Richard,
>
> > Richard Pyle wrote "modern technology and biological insights have
> > dramatically improved our ability to infer phylogenetic relationships
> > of organisms; and one could also (rightly) argue that this leads to
> legitimate rejiggering of prior classifications."
> > Not so. Modern classification should reflect evolutionary relationships.
> > Phylogenetics does not model evolution."
>
> So, your primary point of disagreement is that I used the expression
> "phylogenetic relationships", instead of "phylogenies"???  If so, then sure
> -- consider my sentence amended to:
>
> "modern technology and biological insights have dramatically improved our
> ability to infer phylogenies of organisms"
>
> Note that I never said or even intended to imply that we're in any way
> closer to inferring evolutionary relationships.  Although I think a pretty
> powerful case can be made for that assertion as well.
>
> I'm pretty-much in agreement with everything else you wrote.  I just tend
> to be a little less grumpy (and less self-confident) about it.
>
> > I am sorry to see classical taxonomists still worrying over the
> > ascendancy and hegemony of phylogenetics.
>
> I consider myself a classical taxonomist, and I'm not worried.  Who is
> worried?  Are you worried?
>
> Aloha,
> Rich
>
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