IUBio GIL .. BIOSCI/Bionet News .. Biosequences .. Software .. FTP


Tue Jun 21 14:46:35 EST 1994

Mark, You say:

>In fact, the term monophyly was defined by Haekel and his usage can be show
>be identical to that of Hennig's, which was NOT at all vague.


>I agree to an extent, however, the term monophyly DID have a singular
>meaning until Ashlock........

I would greatly appreciate the references which prove these points as it seems
 to be one which is central to the debate-- that is, whether or not monophyly
 was generally used by systematists to mean holophyletic exclusively or
 holo+paraphyletic PRIOR to Ashlock and Hennig.  I believe that the latter
 option is true, but I will be convinced with specific references to general use
of the Hennig-type definition prior to Hennig or Ashlock.

>If you want to keep archaic classification schemes that are not
>phylogenetic by allowing paraphyly for the naming of higher taxa, then
>just say so and forget the now-dead semantic argument for holophyly.
>And forget trying to legimitimize it.

The recognition of paraphyletic groups allows one to imply 
phenetic change.  Phenetic is not mutually exclusive with phylogenetic.  
A classification which includes paraphyletic groups can recognize 
both phenetic and phylogenetic data.  See Ashlock's figure 2!

You seem to be arguing two things: 
1) that the argument is simply semantic and we should, therefore, give in to
 the most popular usage of the term 
2) the term with historical priority should be used.

I agree that the argument is purely semantic and therefore there is no 
empirical evidence which could be used to justify one usage over the
other.  However, I don't know if you could prove that your usage is more
common than the Ashlockian alternative.  Even if you could, I'm not sure we
should give into trends.  I agree more with your second point...with an
 additional recommendation.  We should find out which usage has historical
priority and should embrace it IF the terms are logically and usefully named.
I previously gave what I thought was logical about the Ashlock definitions
and illogical about the Hennig definitions.  I'm still waiting to see that
Hennig's usage was the common usage from Haeckel's times onward.

Andrew Roger
aroger at ac.dal.ca
Dept. of Biochem
Dalhousie University
Halifax, N.S.

More information about the Protista mailing list

Send comments to us at archive@iubioarchive.bio.net