ASYMMETRY AND EXPLANATIONS

In Colless' (1995, Syst. Biol. 44, 102-108) results, cladograms for ra ndomly generated matrices were strongly asymmetrical, and he used this to maintain that real cladograms provide little evidence on asymmetry of phylogeny. His position, however, depended on retaining poorly sup ported groups as if they were well-supported. If poorly supported grou ps are removed, as with parsimony jackknifing, well-structured real da ta can still give strong asymmetry, while random matrices simply yield unresolved trees, obviating Colless' argument. (C) 1998 The Willi Hen nig Society.