Appendix IV 

 Polarity Reevaluation for Lower Level Analysis 



Using Brachylophus and Dipsosaurus as outgroups to a subset of iguanines permits 

 determination of polarities for certain characters whose polarities were undeterminable at 

 the level of all iguanines. However, it also requires that the polarities of other characters be 

 reassessed, since character polarities for the less inclusive group may not be identical to 

 those for the more inclusive group. The procedure used for reassessment is similar to that 

 used for assessing the polarities of characters whose polarities were not initially 

 determinable (Appendix III), but differs in that a more distant outgroup must be considered 

 (Fig. 64A,B). This more distant outgroup is actually the outgroup node from the analysis 

 of polarities for Iguaninae as a whole. It must be considered because, unlike the case for 

 characters whose polarities were undeterminable at the level of all iguanines, it has been 

 assigned a character state. This additional branch also has the effect of rendering the two 

 rerooted cladograms (Fig. 64C,D) nonequivalent. 



FIG. 64. All possible cladogram topologies for two unspecified near outgroups, one more remote 

 outgroup, and an ingroup (inverted triangle), before (A and B) and after (C and D) rerooting at the outgroup 

 node. 



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