The Colonization of an Afro-Alpine Environment by Stone Age Hunter-Gatherers

Dr. Ralf Vogelsang | Institute of Prehistoric Archaeology, Palaeolithic Research Unit

Funded by the German Research Foundation (DFG), Research Unit FOR 2358

High-altitude mountain habitats are regarded as unfavorable regions for human colonization. Therefore, it seems reasonable that humans would only be pushed into such conditions by land scarcity in the lowlands following rapid population increase or ecological changes. On the other hand, tropical highlands in Africa have been mentioned time and again as potential refugia during times of environmental stress, such as the hyper-arid conditions in the Horn of Africa around 20,000 years ago when most parts of the region were uninhabitable.

A research unit approved by the DFG in 2016 is investigating this question in the Bale Mountains in Ethiopia, which are the largest alpine ecosystem on the African continent. Due to their remoteness, the mountains are classified as a natural environment with an abundance of endemic species. The research unit, however, is presenting the hypothesis that Stone Age hunter-gatherers developed the region into a cultural landscape with the use of fire. Academics from several German universities and Addis Ababa University in Ethiopia are examining this research question from the perspectives of different disciplines including geography, geology, biology und archaeology.

The archaeological project is investigating the earliest habitation of this tropical alpine landscape by excavating prehistoric settlement remains in rock shelters. Due to the harsh weather conditions, with strong winds, below freezing night temperatures and high solar radiation during the day, rock shelters must have been the preferred settlement sites. In Spring 2017, first excavations yielded settlement layers with small stone tools (microliths) that were used as arrowheads and are characteristic tool types of the African “Later Stone Age”. The bones of the game that were found and the types of firewood from the hearths not only indicate the subsistence strategies of the Stone Age people but also allow for a reconstruction of the environmental conditions at that time. In addition, the bone and charcoal can be used to date the layers using the radiocarbon method and to document that the highland area has been habitated for 4000 years. Further excavations will hopefully push this time frame back even further and provide an answer to the question of when and why the earliest settlement of the African highland region happened.

_{Text: Ralf Vogelsang}