Ecological flexibility and adaptation to past climate change in the Middle Nile Valley: A multiproxy investigation of dietary shifts between the Neolithic and Kerma periods at Kadruka 1 and Kadruka 21.

Human responses to climate change have long been at the heart of discussions of past economic, social, and political change in the Nile Valley of northeastern Africa. Following the arrival of Neolithic groups in the 6th millennium BCE, the Northern Dongola Reach of Upper Nubia witnessed a cultural florescence manifested through elaborate funerary traditions. However, despite the wealth of archaeological data available from funerary contexts, including evidence for domesticated animals and plants as grave goods, the paucity of stratified habitation contexts hinders interpretation of local subsistence trajectories. While it is recognised archaeologically that, against the backdrop of increasing environmental deterioration, the importance of agriculture based on Southwest Asian winter cereals increased throughout the Kerma period (2500-1450 BCE), the contribution of domesticated cereals to earlier Neolithic herding economies remains unclear. This paper presents direct dietary data from a total of 55 Middle Neolithic and Kerma period individuals from Kadruka 21 and Kadruka 1. Microbotanical data obtained from human dental calculus and grave sediments are integrated with human and faunal stable isotopes to explore changes in dietary breadth over time. The combined results demonstrate the consumption of wild plant species, including C4 wetland adapted grasses, by Middle Neolithic individuals at Kadruka 1. Despite existing evidence for domesticated barley in associated graves, the results obtained in this study provide no clear evidence for the routine consumption of domesticated cereals by Middle Neolithic individuals. Rather, direct microparticle evidence for the consumption of Triticeae cereals is only associated with a single Kerma period individual and corresponds with an isotopic shift indicating a greater contribution of C3-derived resources to diet. These results provide evidence for Neolithic dietary flexibility in Upper Nubia through the persistence of foraging activities and support existing evidence linking increased agricultural reliance to the development of the Kerma culture.