[Taxacom] Paraphyly is INEVITABLE, so why fight it?
kennethkinman at webtv.net
Fri Dec 16 23:29:26 CST 2011
Well, I sort of took a step in that direction last April here
on Taxacom, by temporarily making the whole Gorilla-Pan-Hominid clade a
polytomy (which is coded by a series of repeated A's), which better
reflects the uncertainty whether the sister group to Hominidae is just a
chimp clade or a combined gorilla-chimp clade. See below.
John might argue that I should have included Pongo and
relatives in that polytomy as well, but the molecular data argues
against that (sorry John). Without molecular evidence to corroborate
his morphological evidence (of an orangutan-hominid clade), it just
reeks of plesiomorphy.
Anyway, Stephen, you obviously think that I should merge Pongidae
and Hominidae into one big family (Hominidae), which would eliminate the
paraphyly. However, at the risk of being anthropocentric, a more
traditional Family Hominidae (sensu stricto) better reflects that the
human lineage has raced ahead at an accelerated rate from their great
ape ancestors in a number of ways (anagenesis, if you will). This can
best be reflected by the traditional classification of a paraphyletic
Pongidae giving rise to the exgroup Hominidae. Whether to include
genera like Ardipithecus or Orrorin in Hominidae is debatable (but we
really need more complete material for them).
In the current climate, I guess it is natural to shy away from
paraphyly. The influence of strict cladists is such that paraphyly is a
"hot potato" that many prefer not to touch. But there are also a
growing number of us saying that paraphyly is INEVITABLE (always has
been), and totally avoiding it is totally nonsensical and renders
classifications less informative and less stable in the long run.
Therefore, it only makes sense to draw a line in the sand and say
"enough is enough", and there are certain traditional paraphyletic
groups that must be maintained and defended against the ignorance of a
simplistic strict cladism. Anyway, here is the revised classification I
proposed here in April 2011:
11 Pongidae% (sensu lato)
1 Australopithecus% (sensu lato)
P.S. Note that there are two different "incertae sedis" codings. The
series of A's within the "African" great ape clade show that the taxa
with that group cannot be further "claded" with any degree of certainty
(a polytomy). On the other hand, the ? shows that the position of
Ouranopithecus is even more uncertain (whether it clades with
Dryopithecus at all is uncertain).
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