1. Max Planck-Institute for Evolutionary Anthropology, Deutscher Platz 6, D-04103 Leipzig, Germany.
2. United States Department of Agriculture/Agricultural Research Service and Department of Genetics, North Carolina State University, Raleigh, NC 27695, USA.
3. Archaeobiology Program, Department of Anthropology, National Museum of Natural History, Smithsonian Institution, Washington, DC 20560, USA.
4. Henry Wellcome Ancient Biomolecules Centre, Department of Zoology, University of Oxford, Oxford OX1 3PS, UK.
5. Laboratory of Genetics, University of Wisconsin, Madison, WI 53706, USA.