[Dissertation] Bioarchaeology of Adaptation to Climate Change in Ancient Northwest China

Author:
Berger, Elizabeth S.

School: 
The University of North Carolina at Chapel Hill

Advisor: 
Dale Hutchinson

Defended:
2017

Abstract:

The 4000 BP climate event was a time of dramatic change, including a cooling and drying climate and the emergence of pastoral practices and a distinct cultural identity across northern Eurasia. However, the link between the climatic changes and the cultural changes has not yet been thoroughly explored. This dissertation therefore assesses human biological measures such as frailty, physiological stress, and nutritional status to ask whether late Holocene climate
change precipitated a crisis and collapse of subsistence practices, as has been claimed.

The dissertation employs the theoretical framework of the “adaptive cycle,” an understanding of complex systems that incorporates both change and continuity. The dissertation asks whether the Bronze Age transition, in which humans adapted to the arid climate of the second and first millennia BCE, constituted a “collapse” or “transformational adaptation,” in which the human-environment system changed categorically; or an “incremental adaptation,” in which defining system elements persisted with only peripheral changes. Skeletal samples from six populations (spanning 2600-221 BCE) were examined for bioarchaeological markers of oral health, nonspecific infectious lesions, trauma, stature, and fertility. There was broad continuity and some improvement in population health measures in the Bronze Age study populations, with a decline in health in the Iron Age groups. Bronze Age subsistence systems therefore seem to have been resilient enough to adapt to the new climate, while the sociopolitical conditions of the Iron Age led to poorer health outcomes.

The Bronze Age transition has often been described in terms of “collapse,” and by critically engaging with this narrative, the current project demonstrates that the transition in fact entailed an incremental adaptation, rather than a collapse. These findings also point to how sociocultural factors can serve as a buffer against environmental stressors in some groups, while themselves serving as stressors in others.

Table of Contents:

Chapter 1 Introduction and Background
Chapter 2 Theory and Method
Chapter 3 Qinghai Plateau: a mid-altitude temperate loess zone
Chapter 4 Hexi Corridor: a cold steppe and desert zone
Chapter 5 Loess plateau: a temperate loess zone
Chapter 6 Discussion and conclusions