For our odyssey we need a beginning point that is unambiguously on the biological side of the biological and cultural divide between non-human primates and ourselves. We also want the species making up the beginning point to be already part of the phylogenetic trend towards more complex cognitive capabilities and new forms of social organization and social structure that arose during the evolutionary trajectory leading to modern Homo sapiens. ¨e social systems for these species should be complex enough to contain evolutionary roots for the advanced cognitive abilities and complex forms of social organization that characterize our species. At the same time, the social systems should be in a position, phylogenetically speaking, where the relationship between the major features of social organization and social behaviors can still be explained by reference primarily to biological evolution driven by natural selection in its various forms (individual selection, sexual selection, and biological kin selection). Our beginning point should thus provide us with a baseline showing the level of complexity-and limitation-of social organization explicable by reference to natural selection as the primary driving force for evolutionary change within a species.