4000–3300 BCE: (The Route of Levantine Crops to the Horn of Africa: Lexical Evidence Showing That Wheat, Barley, and Chickpeas Reached the Ethiopian Highland…

4000–3300 BCE: (The Route of Levantine Crops to the Horn of Africa: Lexical Evidence Showing That Wheat, Barley, and Chickpeas Reached the Ethiopian Highlands from Egypt via the Red Sea Hills, Which Remained Marginally Arable Until Around 3300 BCE, the Cushitic-Speaking Peoples Adopting These Crops into Existing Agricultural Practices Centered on Finger Millet and Teff): The lexical evidence reveals a diffusion route that overturns the easy assumption of a direct Arabian connection. Levantine crops did not reach the Horn of Africa from across the Red Sea. They came apparently from Egypt, traveling via the Red Sea Hills, which in some locales were still marginally arable until around 3300 BCE. The Cushitic-speaking peoples of the Ethiopian highlands adopted these crops into their existing agricultural practices, which had centered previously around the cultivation of two indigenous highland grain crops: finger millet and teff. This is a crucial detail. The highland farmers were not blank slates awaiting foreign instruction. They were accomplished agriculturalists with their own crop complex, their own techniques, their own deep knowledge of highland ecology. What they did with barley and wheat was incorporation: they added Levantine crops to an already sophisticated farming system. The plow also arrived along with these Middle Eastern crops and in time became the primary implement of cultivation in the northern and central Ethiopian Highlands. But in the Sudan belt and farther south in East Africa, tropical warm-season rain regimes and different soil conditions limited the further spread of these various introductions. Ecology determined the boundaries of Levantine agriculture in Africa, a point that diffusionist narratives persistently refuse to grasp.