Preface, Lee Freese; the last ancestor - an ecological network model on the origins of human sociality, Alexandra Maryanski; the evolution of macrosociety - why are large societies rare?, Richard Machalek; separation versus unification in sociological human ecology, William R. Catton Jr; the natural ecology of human ecology, Jeffrey S. Wicken; between the atom and the void - hierarchy in human ecology, Gerald L. Young; from entropy to economy - a thorny path, C. Dyke; the ethical foundations of sustainable economic development, R. Kerry Turner and David W. Pearce; the energy consumption turnaround and socioeconomic well-being in industrial societies in the 1980s, Marvin E. Olsen.