the required work load pushed the limits of the tribe's carrying capacity, in which case the slaughter began. Rappaport showed that this ritual served several important purposes, such as restoring the ratio of pigs to humans, supplying the local communities with pork, and preventing land degradation. Rappaport found that a shrub called rumbim, was used to mark the beginning and ends of periods of warfare. The victorious Maring tribe would plant it on a designated area to mark the end of fighting, and the beginning of the slaughter. The shrub remained until the next slaughter was initiated, once the pig to human ratio became overwhelming due to competition for resources. His studies in Papua New Guinea allowed him to calculate the energy exchanges within the community, neighboring tribes, and their environment. In contrast to studying how culture and ritual could be adaptive, Rappaport also studied how the use of culture and ritual could be maladaptive or potentially harmful to ecological systems (Hoey, 590). He argued that cultures sometimes serves their own components, such as economic or political institutions, at the expense of men and ecosystems [such that].... Cultural adaptations, like all adaptations, can perhaps and usually do become maladaptive" (Hoey, 590). Throughout his work, Rappaport tends to stress unity and try to avoid potential problems in the social system. He often said, "I've tried for unification with everything from weighing sweet potatoes to God Almighty.... That's what I'm interested in." (Hoey, 581). Years of study on ritual and religion, along with the addition of interests in environmental issues, led to later works, such as Ritual and Religion in the Making of Humanity. In this ambitious book, Rappaport addresses the history of humanity as part of the evolution of life as a whole. Ritual, which he defines as "the performance of more or less invariant sequences of formal acts and utterances not encoded by the performers", lays the framework for the creation and formulation of religion (Wolf, 1999, 21). A key theme is that language could not arise until some means had been established to guarantee the reliability of words. Words are cheap, intrinsically unreliable and might always deceive. Costly and repetitive ritual action - the invariance of liturgy - emerged during human evolution as the means by which communities coped with such threats, guaranteeing the reliability of words uttered by ritual performers (cf. Knight 1998, 1999). When persons take part