1. Department of Human Evolutionary Biology, Peabody Museum, Harvard University, 11 Divinity Avenue, Cambridge, MA 02138, USA
2. Bioinformatics Group, Department of Computer Science and Interdisciplinary Center for Bioinformatics, University of Leipzig, Härtelstraße 16-18, 04107 Leipzig, Germany
3. Department of Anthropology, University of California, Davis, CA 95616-8522, USA