MOLECULAR AND MORPHOLOGICAL PHYLOGENIES OF MAMMALS - CONGRUENCE WITH STRATIGRAPHIC DATA

Tests of a sample of 206 cladograms of mammals show that morphological data seem to predict phylogenies that match the known fossil record b etter than molecular trees. Three metrics that assess the rank order o f branching points, the stratigraphic consistency of those nodes, and the ratio of ghost range to known range show a considerable diversity of values. Some published trees show excellent matching with fossil-re cord data; others show almost no correspondence whatsoever. Morphologi cal trees are nearly twice as good as molecular trees in terms of matc hing of the rank orders of nodes and oldest fossils, while morphologic al trees are 10% better than molecular in terms of stratigraphic consi stency of the nodes. The ratios of ghost range to known range are lowe r for molecular trees. Among the molecular trees, those based on gene data are considerably better than those based on protein sequences, at least in terms of the rank order of nodes and the stratigraphic consi stency of nodes. Protein trees, however, were best of all in terms of minimizing the proportion of ghost range. These findings probably indi cate real phenomena, but the match of molecular trees to the expectati ons of stratigraphy may improve as the study of molecular phylogeny ma tures. (C) 1998 Academic Press.