title: Human and ape molecular clocks and constraints on paleontological hypotheses.
abstract: Although the relationships of the living hominoid primates (humans and apes) are well known, the relationships of the fossil species, times of divergence of both living and fossil species, and the biogeographic history of hominoids are not well established. Divergence times of living species, estimated from molecular clocks, have the potential to constrain hypotheses of the relationships of fossil species. In this study, new DNA sequences from nine protein-coding nuclear genes in great apes are added to existing datasets to increase the precision of molecular time estimates bearing on the evolutionary history of apes and humans. The divergence of Old World monkeys and hominoids at the Oligocene-Miocene boundary (approximately 23 million years ago) provides the best primate calibration point and yields a time and 95% confidence interval of 5.4 +/- 1.1 million years ago (36 nuclear genes) for the human-chimpanzee divergence. Older splitting events are estimated as 6.4 +/- 1.5 million years ago (gorilla, 31 genes), 11.3 +/- 1.3 million years ago (orangutan, 33 genes), and 14.9 +/- 2.0 million years ago (gibbon, 27 genes). Based on these molecular constraints, we find that several proposed phylogenies of fossil hominoid taxa are unlikely to be correct.
authors.affiliation: Department of Biology and Institute of Molecular Evolutionary Genetics, Pennsylvania State University, University Park, PA 16802, USA.
authors.forename: R L
authors.initials: RL
authors.lastname: Stauffer
authors.forename: A
authors.initials: A
authors.lastname: Walker
authors.forename: O A
authors.initials: OA
authors.lastname: Ryder
authors.forename: M
authors.initials: M
authors.lastname: Lyons-Weiler
authors.forename: S B
authors.initials: SB
authors.lastname: Hedges
mesh_terms: D000818:Animals; D019143:Evolution, Molecular; D005580:Fossils; D015186:Hominidae / Q000235:genetics*; D006801:Humans; D009687:Nuclear Proteins / Q000235:genetics*; D010802:Phylogeny; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA
chemical_list: D009687:Nuclear Proteins