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Re: Afrotheria revisited



I've looked at the Tabuce et al. article and there is something methodologically eyecatching about it (attention Micky Mortimer). (I'm afraid the methodology is the only connection this letter has to dinosaurs.)
There are two cladograms described as the strict consensus trees on the basis of 52 character traits. One is said to be the consensus of 105 equally parsimonious trees, of length 225, and is pretty much phylogenetic grass. On the same page there is another tree, the strict consensus of 4 equally parsimonious trees of length 214: a remarkable improvement, since it is almost totally resolved (3 trichotomies, as opposed to the "16-otomy" in the first). No comment is made about the difference between the two, and it took a minute of looking-- and counting the taxa covered in the two analyses-- to figure out what the difference was: the 52 traits gave grass for 23 taxa, but almost perfect resolution for 22.
The procedure may well be legitimate (the taxon dropped is Arsinotherium, and I can imagine it being autapomorphic enough to confuse an analysis of the others), but it FEELS like throwing out inconvenient data and I'd have preferred some discussion.
DISCLAIMER: This isn't really my area of expertise, I'm an amateur, and if people who really know about how to do phylogenetic analyses tell me it's o.k. I'll just have to believe them.
--
Allen Hazen
Philosophy Department
University of Melbourne