[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]

Re: Re: pterosaurian monophyly



>In a message dated 95-09-19 12:43:16 EDT, rowe@lepomis.psych.upenn.edu
>(Mickey Rowe) writes (quoting Kevin Padian):
>
>>One of the tenets of phylogenetic systematics is that you can't
>>  assert convergence, you have to demonstrate it by showing that
>>  another phylogeny is better supported.  And that means a full
>>  cladistic analysis with all the characters. 
>
>All too true. But what does "better supported" mean? Victorious in
>synapomorphy wars? 
>I have 50 characters to your 32? Suppose the "true phylogeny" is riddled with
>convergences and homoplasy; how could analysis ferret this out? It's time to

The ways the analysis can ferret this out:

A new analysis is conducted, including ALL the proposed characters (the 50
and the 32).  Additional characters can be added.  Character states which
were improperly coded are corrected.  New taxa may be added.

This will produce a better supported tree (even if it does show an increase
in homoplasy).


Thomas R. Holtz, Jr.
Vertebrate Paleontologist
Dept. of Geology
University of Maryland
College Park, MD  20742
Email:Thomas_R_HOLTZ@umail.umd.edu (th81)
Fax: 301-314-9661
Phone:301-405-4084