There is no question that the effect of the trans-Saharan slave trade on sub-Saharan Africa was enormous. The trans-Saharan slave trade was initiated in the 7th Century by Arab traders who had spread throughout northern Africa, along the southern coast of the Mediterranean Sea and stretching from the Pacific Ocean to the Red Sea and Indian Ocean coasts. The effects of that expansion and of their expeditions into sub-Saharan Africa in search of slaves for the Near Eastern and European markets was to fundamentally transform the demographics of West and Central Africa.
As the slave trade expanded with the advent of European colonialism and competition among the British, Portuguese and Spanish for slaves, the effects on these regions grew. The genetic consequences themselves were profound, as African genes were intermingled with Arab and European genes, affecting the ethnic make-up of peoples in both regions. As one scientific examination of the genetic consequences of the trans-Saharan slave trade demonstrated, the movement of slaves by Berber and Arab traders was instrumental in transporting slaves from sub-Saharan Africa along six main routes running south to north, ending all-along the countries of northern Africa, including Morocco, Algeria, Libya and Egypt. [See “The trans-Saharan slave trade – clues from interpolation analyses and high-resolution characterization of mitochondrial DNA lineages,” BMC Evolutionary Biology, www.biomedcentral.com/content/pdf/1471-2148-10-138.pdf]
On a more generic level, the effects of the trans-Saharan slave trade on sub-Saharan Africa included the depopulation of much of West Africa, as the trade in slaves assumed enormous proportions, with most of the trans-Atlantic trade oriented to Brazil. Consequently, traders pushed further inland in search of “commodities.” Slave raids and violent conflicts over dwindling “resources” (i.e., potential slaves) among the European traders further inflicted permanent damage on the native populations of sub-Saharan Africa. Ancient African civilizations and kingdoms were decimated and entire tribes and clans eliminated. In addition, the higher value placed on male slaves as sources of labor skewed the demographics of surviving sub-Saharan African populations in such a way that the depopulation associated with the seizure of so many black Africans combined with the disproportionate decrease in one gender relative to the other exacerbated the long-term problem of ensuring the survival of individual tribes.
The scale of the impact of the trans-Saharan slave trade on sub-Saharan Africa has been debated by scholars, especially with respect to the demographic consequences. Clearly, the populations of West Africa suggest that they survived the effects of depopulation, especially in the most populous region of Nigeria. Time has enabled sub-Saharan Africa to undergo a period of renewal, interrupted by frequent wars and coups d’etat. Precisely what the effects of the depopulation and associated gender gap of the slave trade era remain are difficult to determine. It’s impossible to assess what Africa would look like today had the slave trade not occurred. It is, however, safe to say that the civilizations of sub-Saharan Africa suffered irreparable damage from centuries of violent exploitation, and that problems endemic to the region today can be traced to the European and Arab intrusions that were a fact of life.