Nuclear gene trees and the phylogenetic relationships of the mangabeys (Primates: Papionini)

Phylogenetic relationships of mangabeys within the Old World monkey tribePapionini are inferred from analyses of nuclear DNA sequences from fiveunlinked loci. The following conclusions are strongly supported, based oncongruence among trees derived for the five separate gene regions: (1)mangabeys are polyphyletic within the Papionini; (2) Cercocebus is thesister taxon to the genus Mandrillus; and (3) Lophocebus belongs to a cladewith Papio and Theropithecus, with Papio as its most likely sister taxon.Morphologically based phylogenies positing mangabey monophyly wereevaluated by mapping the sequences for each locus on these trees. The dataseem to fit these trees poorly in both maximum-parsimony and likelihoodanalyses. Incongruence among nuclear gene trees occurred in theinterrelationships among Lophocebus, Papio, and Theropithecus. Severalfactors that may account for this incongruence are discussed, includingsampling error, random lineage sorting, and introgression.