African Pastoral: Archaeologists Rewrite History of Farming

http://www.nytimes.com/2004/07/27/science/27farm.html
A good article discussing the latest theories about the origins of agriculture. Agriculture appears to have been adopted in an entirely different way in Africa, and recent and ongoing genetic studies suggest that cattle were domesticated in Africa thousands of years before plants, in a pattern quite unlike that adopted by Europe and Asia. Egypt is the joker in the pack - it had both cattle (probably African varieties) and Near Eastern domesticates, although it adopted agriculture several hundred years after the Near East, in spite of its relatively close proximity. Quoting many scholars and their research, this article describes some of the most recent ideas.