Originally posted by Heffalump
Key factors, as summarized from the Pulitzer Prize winning 'Guns, Germs and Steel'. (A great read for anyone interested in this topic)
*Lack of domesticable animals
*Fewer domesticable plants than Eurasia slowed the growth of food production (i.e. farming)
*Geography. The north-south axis of Africa slowed the migration of domesticable crops due to differing climate patterns and temperatures.
*Geography. Even when cattle and horse made it to Africa they could not survive in the regions beyond equatorial Africa due to the tsete fly, which evidently carries infections lethal to them.
*Geograpy. The Sahara acted as a barrier, slowing the spread of ideas and knowledge from the north