New evidence reveals dispersal of pearl millet from West Africa to South Asia by 2500 BCE

Pearl millet (Pennisetum glaucum (L.) R. Br. syn. Cenchrus americanus (L.) Morrone) is the most widely cultivated millet in the world. It is a major source of food and fodder in Africa and South Asia, where it has been grown since prehistoric times. Genetic studies trace the domestication of this important crop to the western Sahel in Africa by 2800 BCE, although the earliest evidence of domestication traits have been dated to c. 2500 BCE in pottery temper. In South Asia, securely dated finds appear around 1900 BCE. Here, we report two absolute dates of pearl millet caryopses to 2578–2358 and 2576–2356 cal BCE from Bhando Qubo, an archaeological site in the lower Indus Valley (Sindh, Pakistan). These caryopses have proven to be contemporary to the oldest evidence of domesticated pearl millet in Africa and represent the earliest Pennisetum glaucum grains directly dated by 14C AMS worldwide. This discovery indicates that pearl millet expanded into South Asia at least five centuries earlier than previously thought and highlights the Indus Valley as a crucial corridor for prehistoric crop diffusion.