Phylogenetic Systematics oflguanine Lizards 107 



among the basic taxa. Because of character incongruence, the interpretation of these 

 characters as synapomorphies is not always straightforward, and a reasonable 

 interpretation of any one character must take the others into consideration. Some of the 

 similarities are undoubtedly homoplastic and must ultimately be interpreted as more 

 than one synapomorphy. 



IV. Characters of undeterminable polarity (characters 43, 44, 55, 56, 57, 59, 60, 61, 

 63, 65, 71, 73, 79, 80, 84, 85, 88, 90, 94, 95). These characters are too variable 

 either within or among the outgroups, or both, for any reasonable inference to be made 

 about their polarity. Therefore, these characters cannot be used as evidence for 

 phylogenetic relationships within Iguaninae until either the relationships of the 

 outgroups to iguanines are determined (Maddison et al., 1984) or some phylogenetic 

 structure within iguanines is established so that some iguanines can serve as outgroups 

 to others in an analysis of a less inclusive group (Watrous and Wheeler, 1981). 



