CHARACTER POLARITIES AND THE 

 PHYLOGENETIC INFORMATION CONTENT 



OF CHARACTERS 



Character- State distributions for the 95 characters among the four outgroups and the 

 polarities inferred from these distributions are summarized in Table 5. Distributions of the 

 characters among the basic taxa (genera) of iguanines are given in Table 6. Not 

 surprisingly, the number of characters that exhibit variation within a basic taxon is 

 correlated with the number of recognized species in the taxon. 



Each character can be placed in one of four categories depending on its phylogenetic 

 information content: 



I. Unambiguous synapomorphies of basic taxa (characters 1, 2, 3, 4, 6, 9, 11, 12, 14, 

 15, 16, 17-2, 20, 22, 26, 27, 29, 30, 31, 32, 33, 34, 35, 36-2, 38, 41, 42, 46-3, 47, 

 49-2, 58, 64, 67, 72, 74, 75, 76, 81, 86, 87, 89, 91, 93). The derived condition of 

 each of these characters is found in only one of the basic taxa and is characteristic of the 

 taxon in which it is found. These characters support the monophyly of particular 

 iguanine genera but provide no information about relationships among them. 



II. Ambiguous synapomorphies of basic taxa (characters 10, 13-2, 24, 28-2, 53, 78, 

 82, 92). The derived condition of each of these characters is characteristic of one of the 

 basic taxa but is also variably present in one or more other basic taxa. These characters 

 are either (1) synapomorphies of one basic taxon that have arisen convergently in part 

 of another one; (2) synapomorphies of one entire basic taxon plus part of another one 

 that are indicative of the paraphyletic status of the latter; or (3) synapomorphies of a 

 clade consisting of two or more basic taxa that have subsequently reversed within some 

 of them. These characters may or may not provide information about relationships 

 among basic taxa. 



III. Derived characters shared by two or more basic taxa (characters 5, 7, 8, 13, 17, 

 18, 19, 21, 23, 25, 28, 36, 37, 39, 40, 45, 46, 46-2, 48, 50, 51, 52, 54, 62, 66, 68, 

 69, 70, 77, 83). The derived condition of each of these characters is characteristic of 

 more than one of the basic taxa and may or may not occur variably in one or more of 

 the others. These characters are the primary data relevant to an analysis of relationships 



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