Diversity of livelihoods is not only a characteristic of ancient African societies, but also a key to survival.
New research covering the millennium of African history shows that diversification of livelihoods has enabled ancient societies across the continent to adapt to major climate change. The results show that long-term resilience to climate change is not driven by unified solutions but by strategies based on ecological fitting, flexibility and local knowledge.
The study was published last week in the journal One Earth.
During the Holocene, major environmental changes occurred in Africa, which spanned approximately the last 11,000 years. For example, the wet period in Africa brought nearly 9,000 years of wet weather to most parts of the continent, followed by increasingly drought conditions. With ecosystems changing and food sources changing, societies have developed a gentle, locally adapted combination of grazing, agriculture, fishing and foraging that helped them navigate thousands of years of environmental turmoil. This self-sufficiency flexibility is a sign of Africa’s adaptation to changing conditions and is crucial for long-term resilience, the researchers say.
“What we see is not a linear story of progress, but a complex set of strategies that help people stay resilient. This is a real curriculum for today’s food systems,” said Leanne N. Phelps, the lead author of the study and the lead author of Lamont-Doherty Earth Observation and a postdoctoral researcher, part of the Columbia Climate School.
New lenses about ancient adaptations
To determine how ancient African communities adapt to the changing lifestyles of environmentally, researchers analyzed a recently published, comprehensive isotope dataset across the Holocene. When a person or animal eats a plant, isotopes are stored in their bones, teeth, and other tissues. By sampling and analyzing these tissues, researchers can identify the types of animals and plants that people eat and infer through extension how they get food.
Part of the analysis focused on the differences between C3 and C4 plants, which used different photosynthetic pathways. C3 plants (such as wheat and barley) thrives in colder, wettering environments, while C4 plants (such as millet, sorghum and tropical grass) prefer warm, dry conditions. These isotope differences can help researchers understand how communities combine ways to get food, as each method leaves unique patterns in human and animal remains.
The research team used a method called hierarchical clustering to classify similar isotope data into groups based on shared characteristics. Instead of starting with predefined categories, the algorithm looks for natural patterns in the data, grouping individuals with similar profiles into what they call “isotope-mural nikes.” Each niche reflects a unique combination of food consumption associated with one or more of the four core activities: grazing, farming, fishing and foraging.
To explain these profiles, the researchers reviewed archaeological records from all over Africa to identify types of livelihoods that may be implemented in different regions. They integrate modern climate and elevation data to reconstruct the environmental environment in which these strategies occur. This approach allows them to define 10 broad livelihood strategies and track how these strategies emerge, transfer and overlap in time and ecological regions.
For example, a niche is associated with C3-based agricultural systems in temperate regions, such as the Ethiopian Highlands and parts of North Africa. Other wall ni dependence on C4 plants and grazing animals in aquatic-based strategies near hayfields or lakes and rivers. Together, these models reveal the diversity, limitations and innovative ways in which African societies adapt their food sources to environmental changes.
The methodological approach is novel because it uses clustering techniques to detect statistically significant patterns in isotope data and pair them with archaeological records to determine how ancient communities make a living. Phelps said the approach could also help researchers in other fields understand large and complex data sets spanning long and wide areas.
Navigating lessons from climate change
Understanding how ancient societies adapt to climate and ecological changes provides a valuable framework for addressing climate challenges. This study contributes to the framework by demonstrating flexible, locally adapted strategies that support long-term human resilience in Africa. The authors emphasize that modern climate adaptation efforts should be similarly rooted, drawing on the types of diversified approaches that have maintained African communities for thousands of years.
“If we want to have climate solutions and global environmental change solutions work, it needs to be rooted in the understanding of how people use the resources available throughout the time,” Phelps said.
The study was conducted by Dylan S. Caroline Er Lehmann, University of Edinburgh; Jennifer C. Chen, Penn State; Shayla Monroe, Harvard University.
