THE STATISTICAL RELIABILITY OF SYNAPOMORPHIC ANALYSES

A statistical test has been developed to ascertain whether a given num ber of presumptive synapomorphies between one pair of taxa is signific antly greater than the number between another pair of taxa. This is sh own to be a form of testing the significance of a difference between t wo proportions. It is necessary first to adjust for common patterns of synapomorphy that raise or lower both numbers. The method has been ch ecked by simulation, and is illustrated by data on the relationships o f tetrapods. It proves that Hennigian cladistics has statistical const raints. (C) 1996 The Linnean Society of London