Alliances were formed between polities and hierarchical relationships developed between centers were more frequent during the Late Classic (Marcus, 1993, Martin and Grube, 1995 and Martin

and Grube, 2000), but these larger polities were highly unstable. One potential explanation for political collapse was the failure of leaders to find creative ways to maintain network stability either through hierarchical integration or cooperation (Cioffi-Revilla and Landman, 1999). Instead, kings of the largest polities succumbed to immediate self-interest and attempted to obtain greater hegemonic Fulvestrant concentration control (Scarborough and Burnside, 2010). Polities defeated in war went into decline and less effort was invested in maintaining economic and political networks. The frequency and magnitude of war served to destabilize the sociopolitical and economic fabric of the Maya world and, along with environmental degradation and drought, further undermined the institution of kingship. Finally, we return to the concept of rigidity from resilience theory and the character of the classic Maya collapse. Hegmon et al. (2008) compared three societal transformations in the American Southwest (Mimbres, Hohokam, Mesa Verde) using this concept and with Perifosine mouse respect to the scale of demographic change and population

displacement, degree of cultural change, and physical suffering. They used rigidity measures of integration, hierarchy and conformity and found that more rigidly organized societies were more prone to severe transformations that involved human suffering, population decline and displacement, and major cultural changes BCKDHA (evident in both Mesa Verde and Hohokam cases).

Data from the Maya region are consistent with these observations. The Maya collapse was far more severe when compared with these examples from the American Southwest. Many more people were involved and there is evidence for sustained conflict and war over several centuries. Evidence for declining health in the skeletal record is consistent with human suffering and the collapse of each polity was associated ultimately with population decline and dispersal. In the Maya case the rigidity trap was imposed largely by the hierarchical structure of Maya society that was amplified as the landscape was transformed and impacted during the Classic Period (Scarborough and Burnside, 2010). This came at a time when environmental shocks in the form of decadal-scale droughts became more frequent and severe (Kennett et al., 2012). Even in the face of these changes the culturally conservative institution of kingship persisted for centuries, and its rigidity likely contributed to the suppression of innovation in the face of environmental change and instability. Archeologists and earth scientists provide a unique perspective on the cumulative history of anthropogenic environmental change and its potential for destabilizing our society.