Olga Soffer is Professor Emerita at the Department of Anthropology, University of Illinois Urbana-Champaign, USA. Her primary areas of research interest combine anthropology, archaeology, and palaeontology.

Clive Gamble is Emeritus Professor of Archaeology at the University of Southampton, UK. Gamble's main research interests are the archaeology of human origins, the social life of the earliest humans and the timing of their global colonisation.