And You Shall Know Us by the Trail of Our Dead: Detecting Signatures of Sublethal Warfare Through Healed Cranial Fractures in Baja California Hunter-Gatherers

Warfare results where environmental change confronts social complexity in hunter-gatherer groups. Lethal outcomes as a result of extragroup violence result. In this thesis, the links between warfare and environment are examined. Hunter-gatherer groups living under environmentally deprived conditions are more likely to engage in violent conflict as the result of competition between groups for resources. The use of violence within groups also adapts to environmental conditions by offering non-lethal outcomes. Where warfare is systemic and environmentally motivated, groups may turn to a regulated means of violent internal conflict resolution mitigating population destabilization. The Santa Barbara Chumash and the Las Palmas culture both reflect an opportunity for regulated conspecific violence to mitigate lethal outcomes through evidence of survived cranial trauma. This comparative study highlights similarities between Phillip Walker's previous study of the Santa Barbara Chumash in contrast with the Las Palmas culture of Baja California Sur. Both groups subsisted under marginal environmental regimes and encountered perennial warfare and violence as a result of perceived changes in their environment. Changes to their environment also acted as the impetus for culture change in both groups. A spectrum of violence that includes non-lethal outcomes can result through cultural perceptions of environmental deprivation. Sub-lethal outcomes improve group survival chances when posed with ongoing extragroup predation and unpredictable environmental changes.