[Taxacom] very nice opinion article in today's Zootaxa

[John Grehan]

-----Original Message-----
From: taxacom-bounces at mailman.nhm.ku.edu
[mailto:taxacom-bounces at mailman.nhm.ku.edu] On Behalf Of Kenneth Kinman
                
> Depending on the taxon involved, morphology may need to be weighed
more heavily than 
> molecular (especially in the interrim when molecular data is limited).
But as more whole
> genomes are added into the mix, molecular data will become more
important, but how to 
> weigh different subsets of molecular data will still be an issue. 

Whole genomes vs subsets is neither here nor there is the method is the
same. In the human-great ape case the molecular authorities already say
that the molecular evidence for the chimpanzee is "overwhelming" so no
more need be said or done - after all the molecular relationship has
established an evolutionary fact.

> I'm not saying that Richard Zander is guilty of this (sometimes
quantity can win out 
> beyond expectation), but I clearly do find John Grehan's number games
(based ONLY on
> morphology) extremely distressing.  

Distressing or not, it is at present the fact that there are at least 28
human-orangutan apomorphies vs maybe one or two chimp apomorphies. The
absence of molecular sequence support matters not a wit for the reasons
expounded in our papers.

> There is no balance at all when your database relies only on
morphology (dismissing the
> molecular data without offering any opposing molecular data that is
congruent with the 
> morphological data that is being given so much weight).  That is
quantity over quality in
> the extreme in my opinion.  

This view is based entirely on the assumption that molecular sequence
data must be able to render the correct result. For reasons expounded in
our papers I believe that the morphology is better quality, but of
course it is usually harder to find informative characters (the
human-orangutan case being quite exceptional I think).
        
> However, I must admit that the orangutan-hominid morpholiogical
similarities still makes 
> me seriously question the quality of the molecular data (thus far)
supposedly supporting
> an exclusive chimp-hominid clade. 

That is the very least one can hope for

> That's why I think an exclusive chimp-gorilla clade is a serious
alternative possibility
> (but which has only minor molecular support at present, at least the
way in which the 
> molecular data has been interpreted thus far).  

And it is strongly supported by morphology

> Homoplasy (molecular or morphological) is still a huge problem that is
still a huge 
> problem and will provide grist for continued debate for many years to
come.  

Homoplasy is not a problem because it is identified only after the
analysis. 

> My view is that:  Quantity only indicates quality when they are
consistently congruent 
>(both molecularly and morphologically).  Otherwise, more data is
needed. 

More data with the same methods, assumptions, concepts will solve
nothing.

John Grehan   
              -----------Ken Kinman
 
      



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