How did the rise of the Atlantic slave trade affect Africa, economically, politically, and demographically between 1450 and 1750?

There are bound to be profound impacts in anything that
involves a condition that involves about 9 to 12 million people.  This sheer volume of
slaves who were moved due to the Translantic Slave Trade makes it profound on all
scales, sadness present in every realm.  From an economic standpoint, I think that the
slave trade increased much in way of foreign capital in Africa and parts of the
continent where slaves were taken.  Local authorities, such as tribal chiefs or village
elders, were paid for their attempts in securing captured prisoners and numbers of their
own people for European slave dealers.  The demographic impact was broad and deep,
affecting populations and social development.  This capital was not invested or sought
to strengthen the continent, so individuals were being taken from it without much in way
of sustainable economic reality being fostered.  From a political point of view, the
slave trade made Africa dependent on the West.  Africa became the reservoir for the rest
of the world for its slave labor.  This helped to create a political condition that, to
a certain extent, lingers today in that Africa was not seen as able to maintain its own
viability without the influence of the West.  At the same time, it helped to make
colonization a reality that would soon emerge more easily.  In this, the political
condition whereby Africa would become victim to the West's continued exploitation was
enhanced to a large degree by the Atlantic slave trade.