184 Appendix II 



of the invariable outgroup (A) must always be considered plesiomorphic. However, 

 resolution of relationships within one or more of the variable outgroups may necessitate 

 that either the alternative condition be considered plesiomorphic or that the polarity be 

 considered equivocal. 



Case VII (A/A,B/A,B/B): In this case, polarities are always equivocal and can only be 

 determined by the resolution of relationships within one or more of the variable outgroups. 

 Of course, polarities are always equivocal in the case in which all outgroups exhibit both 

 states (A,B/A,B/A,B/A,B). 



To summarize, In cases I and II (Table 11), either the more common state must be 

 considered plesiomorphic or the situation is equivocal; the interpretation that the less 

 common state is plesiomorphic will never be favored. In the remaining five cases there will 

 be at least some situations in which the less common state either may or must be considered 

 to be plesiomorphic. Therefore, I have considered the more common state to be 

 plesiomorphic for characters with case I and II distributions, but have withheld polarity 

 decisions on characters with case III, IV, V, VI, and VII distributions, using them only at 

 lower hierarchical levels when certain ingroup taxa can serve as functional outgroups 

 (Watrous and Wheeler, 1981). 



Of course, not all characters fit into the cases mentioned above. For example, there are 

 some characters with more than two states in the ingroup, and some in which one or more 

 states found in an outgroup are not comparable to any of those seen in the ingroup. In this 

 study, such cases are relatively rare and are discussed individually. 



