[Taxacom] Cyanoprokaryota help
dlahr at ib.usp.br
Wed Mar 20 06:47:11 CDT 2013
My apologies Richard, but I do not see how your commentary relates to this
thread. I mean this comment literally, as in, you will have to explain it
a bit further.
We never discussed molecular vs morphological, I do not understand how that
is relevant here. We are also not discussing species relationships, but
deep lineages. Additionally, I do not see a connection between your
interpretations of ancestor-descendant relationship scenarios and
phylogenetic resolution. In my view, both cases you have pointed out only
indicate error in the initial naming, ie, if a genus nests within another,
this means renaming is necessary. This does not indicate a general flaw
with the reconstruction method.
On Mon, Mar 18, 2013 at 7:39 PM, Richard Zander <Richard.Zander at mobot.org>wrote:
> Not objective? The fundamental phylogenetic presupposition that of any
> three species two are more closely related fails totally in two cases:
> 1) paraphyly, including nesting of genera among species of other genera.
> 2) when any one generalist, wide-ranging extant species can be easily
> hypothesized as ancestral to one or more derived, highly specialized,
> and possibly evolutionarily dead-end descendant species.
> Both cases are common. Ergo phylogenetic resolution of branch order is
> commonly random in both morphological and molecular analyses. This is
> not even subjective much less objective.
> Richard H. Zander
> Missouri Botanical Garden, PO Box 299, St. Louis, MO 63166-0299 USA
> Web sites: http://www.mobot.org/plantscience/resbot/ and
> Modern Evolutionary Systematics Web site:
> UPS and FedExpr - MBG, 4344 Shaw Blvd, St. Louis 63110 USA
> -----Original Message-----
> From: taxacom-bounces at mailman.nhm.ku.edu
> [mailto:taxacom-bounces at mailman.nhm.ku.edu] On Behalf Of Dan Lahr
> Sent: Monday, March 18, 2013 4:22 PM
> To: Ken Kinman
> Cc: taxacom at mailman.nhm.ku.edu
> Subject: Re: [Taxacom] Cyanoprokaryota help
> Hi Ken,
> I am familiar with your views on strictly monophyletic classifications.
> I personally find the discussion constructive for science. However, I
> have not been convinced that allowing paraphyletic classifications is a
> good solution, but this is not the place to go into the gritty details.
> Therefore, I stick to the general convention of naming exclusively
> monophyletic entities.
> Dividing life into Prokaryota and Eukaryota is unsatisfactory, because
> these are grades and do not lead to any objectivity, and do not reflect
> things we know about the true nature of the critters.
> There may surely be a possibility that the root of life is within
> bacteria, which would make eukaryotes and archaea simply branches on the
> bacterial tree. If so, then a lot of bacterial groups would need to be
> renamed, because our understanding of the true diversity will remain
> restrictive and flawed if we do not change the names.
> The system allows relabeling when relabeling is needed. The Woesian
> revolution has shown that relabeling was needed, and relabeling ensued.
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Daniel J. G. Lahr, PhD
Assist. Prof., Dept of Zoology,
Univ. of Sao Paulo, Brazil
+ 55 (11) 3091 0948
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