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RE: Erketu ellisoni online free access



I quoted him accurately, Mickey. Yes, he did write adding 50 characters
rather than removing them, but the point remains the same: that at the
92% missing data for Erketu cannot possibly be meaningful since so much
about the animal is unknown.
Ken


Kenneth Carpenter, Ph.D.
Curator of Lower Vertebrate Paleontology/
Chief Preparator
Department of Earth Sciences
Denver Museum of Nature & Science
2001 Colorado Blvd.
Denver, CO 80205
 
Phone: 303-370-6392
Fax: 303-331-6492

for PDFs of some of my publications, as well as information of the Cedar
Mountain Project: 
https://scientists.dmns.org/sites/kencarpenter/default.aspx
++++++++++++++++++

-----Original Message-----
From: owner-dinosaur@usc.edu [mailto:owner-dinosaur@usc.edu] On Behalf
Of Michael Mortimer
Sent: Tuesday, March 21, 2006 4:42 PM
To: dinosaur@usc.edu
Subject: RE: Erketu ellisoni online free access

Ken Carpenter wrote-

>I was referring to Weims 2006. In this paper, he offers more 
>hypothetical results rather than real evidence of having tested his 
>statements. No data matrices are presented, nor resultant analyses (he 
>does refer to a paper "in press"). He writes (p40): "I tested the 
>effects of adding 50 incomplete characters to a set of 50 characters in

>the 16-taxon case using parsimony...adding the set of incomplete 
>characters generally INCREASES phylogenetic accuracy relative to 
>excluding them." Hell, in that case, let's just cut 50% from all the 
>characters of Wilson 2002 and call the results more accurate than 
>Wilson 2002.

Er, you misunderstand.  Wiens meant if you have a 16 taxon, 50 character
matrix with no missing data, adding another 50 characters with missing
data generally increases the accuracy of the results (as long as the
missing data is 75% or less).  Adding another 50 characters with no
missing data would result in even more accuracy, of course (Wiens,
1998).  "Adding the set of incomplete characters generally increases
phylogenetic accuracy relative to excluding them", not relative to
leaving those characters complete.

Mickey Mortimer