Today, Guillermo Zorrilla Revilla has passed the viva voce for his Phd dissertation, which was supervised by Ana Mateos and Jesús Rodríguez, researchers at the Centro Nacional de Investigación sobre la Evolución Humana (CENIEH), and centers on studying energy expenditure in children and adolescents to explain human conduct in societies based on subsistence economies, such as among modern and past hunter-gatherer groups.

This thesis, entitled “Energy demands of subsistence activities in subadult individuals. Contributions to the Ecology of Human Behavior”, assesses whether learning tasks by sex, which is widely employed in these groups, is due to some energy advantage (or disadvantage) already manifest at these ages. It also looks at whether, at these stages of immaturity, subadult individuals are capable of covering the energy cost of certain activities. Finally, it analyzes whether the speed and energy cost of locomotion in subadult individuals could affect the mobility of a hunter-gatherer group.

The results show that neither the energy expended nor the efficiency of a productive activity explain the division of labor between the sexes, and that neither the speed nor the energy employed in walking by subadult individuals would constrain the mobility of a group of adult hunter-gatherers.

The jury, chaired by Esther M. Rebato Ochoa (Universidad del País Vasco/Euskal Herriko Unibertsitatea), and also made up of Andreu Ollé Cañellas (IPHES/Universitat Rovira i Virgili), Karen Leslie Kramer (University of Utah), Maria Ines Oliveira Varela da Silva (Loughborough University - SSEH), and Diana Marre Cifola (Universitat Autònoma de Barcelona), awarded the new Universidad de Burgos doctor the mark of 'cum laude'.