Geochemical Insights Into Tropical Island Adaptations on Zanzibar Island

A new study reveals that the inhabitants of Kuumbi Cave in Zanzibar Island utilized forest dominated mosaic habitats that served as a refuge for foragers during glacial periods

Climate change played a significant role in shaping human-environment interactions in Africa during the late Pleistocene-Holocene period. However, while most studies in eastern Africa have focused on the dry interior, recent research has revealed that coastal and island settings have also played a crucial role in human cultural and economic change, as well as experiencing extinctions. Nonetheless, combined archaeological and palaeoenvironmental studies of these settings remain rare.

A new study in Frontiers in Environmental Archaeology, led by researchers from the Max Planck Institute of Geoanthropology, addresses this gap in research. Isotope analysis of human and animal teeth from Kuumbi Cave, Zanzibar Island, reveals that the site was consistently covered by mosaic habitats, dominated by forests and small patches of open woodland and grassland. The inhabitants of Kuumbi Cave utilized these diverse tropical habitats even after the arrival of agriculture in the region.

The authors of the study suggest that the stable mosaic of habitats served as a refuge for foragers during glacial periods, and that the Iron Age inhabitants of Kuumbi Cave were Indigenous foragers who incorporated or resisted the arrival of domesticated plants and animals into their existing tropical toolkit, rather than food producers migrating from the interior.