NUCLEAR GENE TREES AND THE PHYLOGENETIC-RELATIONSHIPS OF THE MANGABEYS (PRIMATES, PAPIONINI)

Phylogenetic relationships of mangabeys within the Old World monkey tr ibe Papionini are inferred from analyses of nuclear DNA sequences from five unlinked loci. The following conclusions are strongly supported, based on congruence among trees derived for the five separate gene re gions: (1) mangabeys are polyphyletic within the Papionini; (2) Cercoc ebus is the sister taxon to the genus Mandrillus; and (3) Lophocebus b elongs to a clade with Papio and Theropithecus, with Papio as its most likely sister taxon. Morphologically based phylogenies positing manga bey monophyly were evaluated by mapping the sequences for each locus o n these trees. The data seem to fit these trees poorly in both maximum -parsimony and likelihood analyses. Incongruence among nuclear gene tr ees occurred in the interrelationships among Lophocebus, Papio, and Th eropithecus. Several factors that may account for this incongruence ar e discussed, including sampling error, random lineage sorting, and int rogression.