Human Adaptation to High Altitude Environments

Regents Of The University Of Michigan - Ann Arbor, Ann Arbor MI

Investigators

Abstract

Humans are the only species to colonize the entire globe and inhabit such a vast array of habitats, including challenging environments like high mountain systems. Researchers strive to understand the process by which Homo sapiens developed the unique, culturally-mediated aptitude for living and thriving in arduous settings. Archaeology is ideally suited to exploring this issue because it allows one to trace over deep time the innovations and successes - but also, of course, the mistakes and failures - that constituted the adaptive process of human behavioral evolution. Previous scholarship into mountain adaptations has focused on the permanent colonization of the world's few expanses of contiguous high elevation terrain - the so-called high plateaus - which occurred late in human evolutionary history. In contrast, the longer-term processes by which people engaged with high altitudes before permanently mastering them remain unexplored. Where and when did humans first seek dizzying new heights and what encouraged them to do so? Africa contains some of the world's very earliest evidence for a human presence in such environments, yet the continent's high mountain systems are sorely under-investigated. This project will remedy this by investigating when, why and how early humans first inhabited and ultimately settled southern Africa's highest mountain system, the Maloti-Drakensberg Mountains of highland Lesotho. By charting the deep-time development of human-highland dynamics in this region, the project will yield insights into our species' profound capacity for behavioral flexibility that forms the core of who we are today. The project will produce a range of pedagogical and developmental outcomes, including training and research opportunities for undergraduate and graduate students, the further professionalization of Lesotho's first generation of archaeologists, and heritage awareness and empowerment through public open-days, school site-visits, consultations with local chiefs and other stakeholders, and extensive dissemination of findings. Led by Dr. Brian Stewart of the University of Michigan, the project will reconstruct patterns of human dispersal, landscape learning and survival strategies necessary for living in highland Lesotho during the climatically volatile past two glacial cycles. Dr. Stewart and a multidisciplinary research team will conduct an integrated program of cave excavation, landscape survey and environmental sampling targeting the highlands' unusually dense prehistoric archaeological record and ancient sedimentary exposures. These datasets will allow them to construct a detailed picture of highland adaptations and settlement dynamics anchored to high-resolution records of local environmental and hydrological change. Specifically, they will examine whether and to what extent survival strategies documented for recent montane hunter-gatherers can be extended into earlier stages of our species' evolution. Longer-term fluctuations in regional demography will also be explored to test hypotheses regarding Lesotho's possible role as a dry-phase human refugium, with related implications for population packing, high rates of cultural innovation, and viewing Africa's montane zones as epicenters of human behavioral and genetic change.