[aruanan]

The ability to make the most of their environment? Since Africa is the richest continent in terms of resources, why aren’t they the most developed?

Because it's also a cesspool of disease? Because the technological development and widespread use in Northern Europe of mechanical devices known to Southern Europe and Greece for over a thousand years mostly as curiosities came as a consequence of the confluence of a number of different factors, among them being the Judeo-Christian belief that if God looked at the work of his hands and saw it was good, getting one's hands dirty in labor was not a bad thing for someone created in the image of God, the relative loss to the north of the older belief prevalent throughout the Roman and Greek world that the truly educated man didn't labor or engage in business but had others do his work for him (still seen in places in Latin America)? Because a less hospitable climate required more effort, planning, and inventiveness to survive and prosper than a more tropical one?

Besides, just having resources available doesn't mean that anything is going to be done with them. A resource only has meaning in the context of a technology that has defined it as a resource. Outside of that, for instance, flint is just another rock and a petroleum seep is just a pool of stinky black crap.

[abclily]

“Because a less hospitable climate required more effort, planning, and inventiveness to survive and prosper than a more tropical one?”

So, you’re saying that those who moved north needed to develop more inventiveness than those who stayed in Africa? Of course, what follows from your assumption is the notion that those who moved north are more evolved than than those who stayed in Africa.