1. Laboratory of Molecular Systematics and Evolution, University of Arizona, Tucson, Arizona 85721
2. Department of Human Genetics, South African Institute for Medical Research and the University of Witwatersrand, Johannesburg 2000, South Africa
3. Departimento di Biologia, Universita degli Studi “Tor Vergata”, Rome 00173, Italy
4. Department of Genetics and Human Variation, La Trobe University, Melbourne, Victoria 3038, Australia
5. Department of Human Genetics, National Institute of Genetics, Mishima 411, Japan
6. Department of Anthropology, University of Arizona, Tucson, Arizona 85721