[Taxacom] Methodological plurality [was cladistic analysis for morphological characters -- UPGMA is not cladistics]
Richard.Zander at mobot.org
Mon Nov 19 11:28:25 CST 2012
I've always wanted to introduce the Lost Continent of Lemuria into a
Taxacom discussion. I appreciate the opportunity!
Opinions on these matters? Lack of a common vocabulary? Confabulate?
I happen to have struggled with the topic of a plurality of methods for
quite a while, and am familiar with the argot of phylogenetics. I think
"congruence of what?" if a fine question to help initiate a thread on
possible justification for a plurality of methods.
I think a plurality of methods is important to integrate all data (total
evidence) in that different methods are needed to deal with different
data. Classical taxonomy deals with all data informally, but does not
ignore look-and-feel, autapomorphies, and biosystematic/biogeographic
information. Morphological cladistics uses only information reflective
of sister group order. Molecular systematics (with a multiplicity of
methods itself, NJ, Bayes', ML) deals with information in DNA on
sister-group branch order and continuity. The only way to conjoin and
integrate the results of all three approaches is to translate all
results into serial macromolecular transformations of taxa, as best
possible, then see what lineages are congruent, and use Bayes' empiric
priors to calculate support for transformations of taxa.
THEN if you want, transform this information on evolution of taxa (from
one another) into sister group cladograms, if you really must, by
deleting the names of nodes in the evolutionary tree.
The Hennigian cladistic explanation of sister groups as generated by an
unnamed, unobserved and superfluous invented shared ancestor seems to me
similar to explaining distribution of species between North America and
Europe by an intermediate continent of Atlantis (and its more recent
remnant Poseidonis) as a stepping stone. Or by floristic and faunistic
similarities around the Indian Ocean by the past existence of the Lost
Continent of Lemuria. Such is superfluous and unnecessary.
Those who are interested in this aspect of biogeography might check out
Scott-Elliot, W. 1925. The Story of Atlantis and The Lost Lemuria, with
Six Maps. Theosophical Publishing House, London. (Available in the book
bins of thrift stores near you.)
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
On 11/17/2012 9:30 AM, Richard Zander wrote:
> Congruence of what?
Tree topology or more specifically sister-group relationships between
OTUs. Viewed as a Venn or Euler diagrams it can also be thought of a
pattern of nesting or hierarchy.
Nesting? Nesting is not a process in nature, it is a
> feature of the method. Of course nesting will be different when
> different methods are used since serial macroevolutionary
> transformations of taxa are interprested (as nesting) in different
I made no claim that "nesting" was a process. Most list readers will be
familiar with your opinions on these matters and won't be surprised we
have trouble finding a common vocabulary. One needs to be careful not to
confabulate patterns, processes, diachronic and synchronic context of
My post was was intended to open a discussion on the use of a plurality
of methods and what, if any justification for this common practice
Kipling W. Will
Associate Professor/Insect Systematist
Associate Director,Essig Museum of Entomology
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