Human and ape phylogeny

[Ken Kinman]

John,
    Well to me distinguishing between phenetic and phenotypic is a sort of a
"semantic" splitting of hairs.  Perhaps all it will accomplish is making
boths sides feel like they have won in some way.  Biological "politics" (if
you will) which addresses minor points, but misses the bigger picture.  But
perhaps I have missed something and you can tell us "I told you so" down the
line.  Only time will tell.
      As for the orangutan-human data you have presented to some "pro-chimp"
systematists, it would be interesting to see how such data would hold up
presented to a wider audience (such as TAXACOM as a whole).
     And as for having investigated soft-tissue characters outside of the
great apes, the paper you cited DID analyze these characters with respect to
the lesser apes (Hylobates) as an outgroup.  And I would reiterate that
there is no strong reason to expect that a more distant outgroup (Old World
monkeys) would change the results (although as I stated before, one never
knows).
     In any case, I think it is indeed wise that you are bouncing all these
ideas off of TAXACOM before you present them to your more general public
audience.  I guess we will all learn something from this exercise, and it's
probably best we learn these lessons before subjecting the public to a
lesson that might well confuse them more than inform them.
      If so, perhaps the potential misrooting of molluscs might be a better
choice for your attempt to show science as a process in action.  We shall
see.  If the orangutan-human hypothesis really has some strong support, I
would be the first to admit it, and change sides in the debate.  But I still
haven't seen anything convincing up to this point.
       ------- Cheers,
                   Ken Kinman
*****************************************
>From: John grehan <jgrehan at TPBMAIL.NET>
>Reply-To: John grehan <jgrehan at TPBMAIL.NET>
>To: TAXACOM at USOBI.ORG
>Subject: Human and ape phylogeny
>Date: Fri, 4 Apr 2003 19:21:07 -03-30
>
>My thanks for the various feedback.
>
>My use of phenetic characters referred only to those characters that are
>not separated out into apomorphic and plesiomorphic states. Phenetic in my
>direct experience was never used to refer to phenotype. The term
>fphenotypic was used for that. But others obviously have a different
>experience.
>
>I seem to have some agreement that where in individual characters are not
>selected for analysis on the basis of their being already hypothesized
>apomorphies then the characters are phenetic. Some seem to indicate that if
>these phenetic characters are subjected to 'cladistic' analysis techniques,
>then the analysis is cladistic in these sense even though the characters
>are not. This seems to be the case for molecular phylogenies that are
>'cladistic' renditions of non-cladistic characters. In morphology the
>question is to what degree various characters used in cladistic analysis
>are themselves cladistic in being hypothesized apomorphies.
>
>When it comes to human-ape affinities there is no doubt that in terms of
>overall similarity of characters (not distinguishing between apomorphic and
>plesiomorphic states) humans have share the greatest similarity with chimps
>and gorilla. The same applies to the sequence data and perhaps the
>congruence of phenetic morphology and phenetic genetic sequences is not
>surprising.
>
>With respect to the conflicting sets of cladistic characters (orangutan vs
>chimp) the situation appears to be one of conflicting views about either
>the character itself (whether it stands up as a valid distinction), or
>whether the character is truly cladistic (i.e. is in actual fact unique to
>the taxa concerned). I have presented the orangutan data to a couple of the
>pro-chimp systematists and so far the orangutan data have held up. The main
>differences are either in one's personal opinion as to whether a character
>is realistic, or whether it is correctly interpreted. In the converse there
>appear to be some differences in whether many of the purported
>human-African characters are confined to those taxa. For these arrangements
>the strongest support has been for the human-chimp/gorilla node whereas the
>number of synapomorphies for either chimp or gorilla are comparatively
>weak.
>
>The paper on soft-tissue characters is problematic in that much of the
>information is distilled over a huge range of literature involving sources
>that are sometimes decades apart. Unless I missed something, the authors
>have not directly verified many if not most of the characters - but I could
>be wrong about that and will have to check. It is also uncertain to what
>extent the characters were investigated outside the great apes. More
>enquiries to be made.
>
>As this issue continues to unfold I will likely make further postings. My
>current feeling about this is that it might be premature to accept the
>human-chimp as an unproblematic given just because a majority say it is so.
>
>John Grehan


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