[1] Univ Calgary, Cell Biol & Anat, Calgary, AB, Canada
[2] Univ Calif Davis, Dept Anthropol, Davis, CA 95616 USA
[3] Univ Cape Town, Dept Archaeol, Rondebosch, South Africa
[4] Univ Cape Town, Human Evolut Res Inst, Rondebosch, South Africa
[5] Univ Calif Berkeley, Integrat Biol, Berkeley, CA 94720 USA
[6] Arizona State Univ, Sch Math & Nat Sci, Tempe, AZ 85287 USA