[Mesquitelist] Pairwise comparisons
michel.laurin at upmc.fr
Tue Apr 10 02:35:41 PDT 2012
I am using Mesquite to perform pairwise comparisons, a test described by:
Maddison WP (2000) Testing character correlation using pairwise
comparisons on a phylogeny. J theor Biol 202: 195-204
However, I have some trouble interpreting the output. Among the
statistics are the following:
Selector: Most Pairs
I understand this as specifying the way pairs are selected (most pairs
gives the highest number of pairs, no matter the state in the terminal
180 pairs are made (logical given that the tree has 361 terminal taxa).
However, when I try to follow the pairs, I find much more than 13 in
which both taxa are scored for both characters. Hence, I am puzzled by
the 167 "Reminder", which I thought were the pairs for which at least
one of the characters was not documented in at least one of the two
compared taxa. Is it possible that polymorphism also results in these
pairs being lumped in "remainder"?
I assume that "Positive" means that both characters covary in the same
direction; "Negative", that one increases when the other decreases, and
"Neutral" is when at least one of the characters does not vary.
Any information on this would be helpful.
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