<P> On the African continent, three areas have been identified as independently developing agriculture: the Ethiopian highlands, the Sahel and West Africa . By contrast, Agriculture in the Nile River Valley is thought to have developed from the original Neolithic Revolution in the Fertile Crescent . Many grinding stones are found with the early Egyptian Sebilian and Mechian cultures and evidence has been found of a neolithic domesticated crop - based economy dating around 7,000 BP . Unlike the Middle East, this evidence appears as a "false dawn" to agriculture, as the sites were later abandoned, and permanent farming then was delayed until 6,500 BP with the Tasian and Badarian cultures and the arrival of crops and animals from the Near East . </P> <P> Bananas and plantains, which were first domesticated in Southeast Asia, most likely Papua New Guinea, were re-domesticated in Africa possibly as early as 5,000 years ago . Asian yams and taro were also cultivated in Africa . </P> <P> The most famous crop domesticated in the Ethiopian highlands is coffee . In addition, khat, ensete, noog, teff and finger millet were also domesticated in the Ethiopian highlands . Crops domesticated in the Sahel region include sorghum and pearl millet . The kola nut was first domesticated in West Africa . Other crops domesticated in West Africa include African rice, yams and the oil palm . </P> <P> Agriculture spread to Central and Southern Africa in the Bantu expansion during the 1st millennium BC to 1st millennium AD . </P>

What was the central aspect of the neolithic revolution