semi-holophyly clarified (was "generic oversplitting")

Ken Kinman kinman at HOTMAIL.COM
Wed Jul 18 13:00:13 CDT 2001

     The point is that I don't practice traditional paraphyly EITHER (for
many of the same reasons that you don't).  The {{markers}} for outgroups
effectively transform such traditional paraphyletic groups into
semi-holophyletic groups (with all the information contained in strictly
holophyletic groups).
      I even started calling them semi-holophyletic (instead of the equally
accurate semi-paraphyletic) to make this clearer and try to get strict
cladists to take a closer look.  My classifications **ARE** continuously
nested, but still allow an occasional semi-paraphyletic break in the tree of
life at carefully selected major nodes (which usually precede very poorly
understood sections of the tree).  The markers are cross-referenced in both
directions to clearly and explicitly show this continuity.  I am not asking
strict cladists to abandon any of their principles, but do ask that they
reexamine their belief that absolutely pure holophyly is the ONLY way to
achieve their goals.
     A modified system makes it possible to incorporate both branching and
divergence into a single classification, and at the same time provides much
greater nomenclatural stability in poorly understood parts of the tree of
life.   And it also sweeps away the perceived need to eliminate ranks or the
notion that the whole Linnean System isn't worth the bother (it is not a
dead or dying system if I have anything to say about it).  I understand the
fundamental principles and goals of both sides, and believe that it is
mainly stubbornness, inertia, and indifference which are standing in the way
of bridging the differences.
      A middle ground approach is possible (and if anyone says this is like
being half-pregnant, I think I might tear my hair out).  A cladisto-eclectic
system will almost certainly be widely adopted sooner or later, once the
advantages become apparent to enough people (and it will probably snowball
from there).  Until then, things will just slowly deterioriate.  In the
meantime, I will continue to plant my hybrid seeds and explain their
advantages to anyone who will listen.
                 Rant over,  Ken
>From: Thomas DiBenedetto <tdibenedetto at>
>To: 'Ken Kinman' <kinman at HOTMAIL.COM>, TAXACOM at USOBI.ORG
>Subject: RE: generic oversplitting (heart of the problem)
>Date: Wed, 18 Jul 2001 11:39:28 -0400
>-----Original Message-----
>From: Ken Kinman [mailto:kinman at HOTMAIL.COM]
>An Ashlockian approach, coupled with my simple convention for exgroups, is
>almost certainly where we are going to end up eventually, so why put it off
>and go through even more turmoil?
>I have never found the argument, that one's own particular point of view is
>certain to win out in the end, to be very compelling (even when I find
>myself resorting to it). I see no reason whatsoever to think that this will
>be the case in this particular instance. The reason is rather simple. The
>cladist's disdain for paraphyly is fundamental to the cladistic point of
>view. This perspective is based on the goal of structuring our scientific
>classification in such a manner that it mirrors what we accept as the
>historical pattern of taxic divergence. It accepts that the historical
>process has yielded higher groups that divide to form lower groups, forming
>a contiuous inter-nested hierarchy. The notion of taking (e.g.) one group
>the descendants of the ancestral reptile, and removing it from the natural
>group formed by the all of the divergences of that ancestral reptile and
>descendants, is an absurdity within the cladistic perspective. It runs
>directly counter to the fundamental goal of cladistics, which is to
>in accordance with the historical pattern of lineage divergences.
>I think that by now you should recognize that there is no compromise
>available for this dispute. Either one accepts the principle that the
>classifcation mirror the historical divergence pattern, or one doesn't.
>appeal to a "reasonable compromise" rings hollow for it is in fact nothing
>but an appeal for your own perspective. Eclectic classifications do not
>out holophyletic groups, so your perpsective offers the virtues of
>and inclusiveness. In fact though, it simply asks cladists to abandon their
>fundamental principle and goal. That is not going to happen.
>I suggest that any further argument on this point be focussed on the very
>simple question that is truly at issue. Should the scientific
>be aligned with our conclusions regarding how lineages have diverged, or
>should our classification be only partly reflective of that pattern,
>modified by other criterea as well. That has always been the real issue
>between cladists and "darwinians". Paraphyly is a deriviative issue in this
>dispute. Paraphyletic groups are an absurdity in the first perspective, and
>they are probably a necessary feature of the second. It is a distraction to
>argue about them when the real issue is even more fundamental.
>Tom DiBenedetto
Get your FREE download of MSN Explorer at

More information about the Taxacom mailing list