There is a great answer to a similar question pasted in below. One of the most powerful changes that is pointed out, has to do with the changes in governmental structure that created legacies of ineptitude and even something called "kleptocracy," that became far too common on the African continent.
The way that the imperialist powers came in and superseded the natural progression of tribal cooperation and even at times tribal conflicts, created a situation where everyone quickly found it more profitable to ally themselves with the most powerful people in any situation, regardless of their trustworthiness or their ability to produce positive effects for the society, etc. This has been a constant factor in much of the horrible governance and the constant coups and other problems that have become a fixture in much of sub-saharan Africa.
Tribes started to distrust one another since certain cheifs were bribed by the Europeans to capture enemy tribesmen. Also many men were taken as slaves more so than women so that created a unbalance society. Long term once countries in Africa became independent there were struggles with governing since for generations they were under European rule. Today we see many nations that have recently declared independence going through corrupt governments, warlords, genocide, poverty, etc. The biggest "rape" of Africa is the over-using of resources, and stripping Africa of all its valuable sources to a point were there is hardly anything left.