1. Department of Biology, Stanford University, Gilbert Hall, Stanford, CA 94305-5020, USA
2. Department of Anthropology, University of Missouri, 210 Swallow Hall, Columbia, MO 65211, USA
3. Department of Anthropology, University of New Mexico, Albuquerque, NM 87131, USA
4. Department of Biology, University of New Mexico, Albuquerque, NM 87131, USA