Introduction

Standing on top of a hill and overlooking the surrounding valleys and streams, a small group of Cro-Magnon humans are planning tomorrow’s hunt. Their concern is to determine when and where to attack the herd, and the solution to this problem will require some behavioral knowledge. Where would these animals be tomorrow? Can they be better approached at night? Which ones are the most vulnerable? Although imaginary, scenarios such as this one must have been common throughout much of the evolutionary history of humans, unprotected and unequipped by means other than their intelligence and social organization to face environmental challenge.