New research published in the journal Proceedings of the National Academy of Sciences on August 13, 2012, produced a genetic confirmation of the earlier time frame of the divergence of humans from the great apes that is independent of the fossil record.
The researchers used genetic parentage information from 226 chimpanzees and 105 gorillas to establish an average generation time for great apes. The same genetic information was collected on 157 present day hunter-gatherer societies and 360 modern societies to establish an average generation time for humans.
Mutation rates in humans are well documented and the researchers made the assumption that the same or similar mutation rates occurred in the chimpanzee and gorilla populations over time.
The human great ape divergence time was calculated to be between seven and eight million years ago.
The human split from Neanderthal was calculated to be between 400,000 and 800,000 years ago.
The genetic research was done with no fossil record evidence.
The time frames produced agree with time frames for human divergence from the great apes and the split of humans from Neanderthal that have been derived from the fossil record.
This research is the first of its kind to develop a time frame for human evolution based solely on genetic information.
The researchers propose that similar techniques could enhance the future study of paleontology and anthropology not only for men and apes but for all species that have a present day relative from which sufficient genetic information and generation time data can be obtained.
Generation times in wild chimpanzees and gorillas suggest earlier divergence times in great ape and human evolution
Kevin E. Langergraber a,b,1 , Kay Prüfer c,1 , Carolyn Rowney b , Christophe Boesch b , Catherine Crockford d , Katie Fawcett e , Eiji Inoue f , Miho Inoue-Muruyama g , John C. Mitani h , Martin N. Muller i , Martha M. Robbins b , Grit Schubert b,2 , Tara S. Stoinski e , Bence Viola j , David Watts k , Roman M. Wittig b,d , Richard W. Wrangham l , Klaus Zuberbühler d , Svante Pääbo c,3 , and Linda Vigilant b,3
a Department of Anthropology, Boston University, Boston, MA 02215; b Primatology Department and c Genetics Department, Max Planck Institute for Evolutionary Anthropology, Leipzig 04103, Germany; d School of Psychology, University of St. Andrews, St. Andrews KY16 9JP, United Kingdom; e Dian Fossey Gorilla Fund International, Atlanta, GA 30315; f Graduate School of Science, Kyoto University, Kitashirakawa Oiwake-cho, Sakyo-ku, Kyoto 606-8502, Japan; g Wildlife Research Center, Kyoto University, Sakyo-ku, Kyoto 606-820, Japan; h Department of Anthropology, University of Michigan, Ann Arbor, MI 48109; i Department of Anthropology, University of New Mexico, Albuquerque, NM 87131; j Department of Human Evolution, Max Planck Institute for Evolutionary Anthropology, Leipzig 04103, Germany; k Department of Anthropology, Yale University, New Haven, CT 06511; and l Department of Human Evolutionary Biology, Peabody Museum, Harvard University, Cambridge, MA 02138