Cladistics and "Eclecticism"

Tom Wendt twendt at MAIL.UTEXAS.EDU
Thu Feb 7 15:17:52 CST 2002


Richard Jensen says:

>And, ecological versus systematic usages are not the issue here (it seems to me
>you keep throwing this in as a red herring).  Species do exist as ecological
>entities, but I am using my concept of species in a strictly systematic context
>for this discussion.

Ah, but Richard, don't you see, that IS the issue.  To many systematists
(plant systematists at least) trained about 20-30 and more years ago, the
"species problem" was absolutely central to how we approached systematics.
We spent a lot of time trying to define and understand species on
biological (including ecological) grounds, and on trying to understand the
variations in how species are organized.  Species were (are) a very real
thing to us.  Higher levels were based on relationships (internal and
external), but species were based on their intrinsic qualities; there was
no real definition of a genus or family, but the species existed and could,
with sufficient work, be understood and defined in a very real way in a
given group of plants.  However, the sudden symbiosis between molecular
systematics and cladistics led to a very new way of working.  Everything
became top-down (or bottom-up, depending on how you look at it--but I mean,
from base of the cladagram towards the tips), partly because back then, the
new molecular techniques worked much better (and gave "sexier" results) at
the broader levels (phylogeny of the angiosperms, etc.)  The species became
nothing more than (and defined as) the branch tip (that's very clear from
Tom DiB.'s postings) and no different in that sense from any other level of
organization in the tree--defined entirely by relationship to other
branches.  The "species" became an entirely new concept, and systematics
became, for many cladists, the study of phylogeny, period.  [And this also
leads to some of the great controversy over Phylocode (I'm NOT trying to
start a new thread here)--For phylocoders, the problems being "solved" by
phylocode are above the species level and the species is an afterthought;
while for many against it, it is the effect on the species level
nomenclature that really riles them up.]  You and Tom DiB. are arguing
right past each other, because to you (and me), the species is real; to Tom
DiB., it is a relationship.
Tom Wendt




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