When we look at the diversity of animals found in the world, from deep sea to land and air, we find a vast number of species that seem to possess consciousness. Is there something all these species have in common? Are neurons and ganglia required, or can evolution generate consciousness in different ways? What can the study of evolutionary biology tell us about the nature of the mind? Josh and Ray sail away with Peter Godfrey-Smith from the University of Sydney, author of Metazoa: Animal Life and the Birth of the Mind. Sunday 6/04 at 11 am.