Total evidence, consensus, and bat phylogeny: A distance-based approach

Resolution of the total evidence (i.e., character congruence) versus consen sus (i.e., taxonomic congruence) debate has been impeded by (1) a failure t o employ validation methods consistently across both tree-building and cons ensus analyses, (2) the incomparability of methods for constructing as oppo sed to those for combining trees, and (3) indifference to aspects of trees other than their topologies. We demonstrate a uniform, distance-based appro ach which allows for comparability among the results of character-and taxon omic-congruence studies, whether or not an identical suite of taxa has been included in all contributing data sets. Our results indicate that total-ev idence and consensus trees differ little in topology if branch lengths are taken into account when combining two or more trees. In addition, when char acter-state data are converted to distances, our method permits their combi nation with information produced by techniques which generate distances dir ectly. Moreover, treating all data sets or trees as distance matrices avoid s the problem that different numbers of characters in contributing studies may confound the conclusions of a total-evidence or consensus analysis. Our protocol is illustrated with an example involving bats, in which the three component studies based on serology, DNA hybridization, and anatomy imply distinct phylogenies. However, the total-evidence and consensus trees suppo rt a fourth, somewhat different, topology resolved at all but one node and which conforms closely to the currently accepted higher category classifica tion of Chiroptera. (C) 1999 Academic Press.