3-AREA STATEMENTS - STANDARD ASSUMPTIONS FOR BIOGEOGRAPHIC ANALYSIS

An implementation is explored for standard assumptions (zero and one) for historical biogeographic analysis based on three-area statements specified by widespread taxa and nodes of taxon cladograms. Analysis of simple examples suggests that three-area statements permit a better measure of fit between an area cladogram and data on area relationship than do existing implementations of assumption zero, such as Brooks parsimony analysis, or existing implementations of assumption one, such as that of Nelson and Platnick (1981, Systematics and biogeography: Cladistics and vicariance, Columbia Univ. Press, New York, London), which proves defective in its oversensitivity to information specified by widespread taxa. Aspects of assumptions one and zero are adapted for evaluation of alternative assumption-two cladograms, first with data for nodes and then with data for widespread taxa.