1. Department of Conservation Management, Nelson Mandela University , George Campus, Madiba Drive, George, Western Cape 6530 , South Africa
2. African Centre for Coastal Palaeoscience, Nelson Mandela University , PO Box 77000, Port Elizabeth, Eastern Cape 6031 , South Africa
3. Institute of Human Origins, School of Human Evolution and Social Change, PO Box 872402, Arizona State University , Tempe, AZ 85287-2402 , USA
4. Department of Anthropology, University of Colorado Springs , Colorado , USA
5. School of Complex Adaptive Systems, Arizona State University , 1031 S. Palm Walk, Tempe, AZ 85281-2701 , USA