[aruanan]

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.

No and no. Those who moved to less hospitable climes had the occasion to modify their environment to suit their human needs by using an inventiveness they already possessed. It also doesn't follow that those who employ more technology are "more evolved" than those who employ less technology for at least two reasons: "more evolved" is a bucket word into which can be dumped all sorts of meanings, "more evolved" presumes a sense of further progression toward some ideal, which is part of the intellectual baggage carried from an earlier age in which "more highly evolved" connoted something good and "less highly evolved" connoted something bad or inferior.

[trubolotta]

That’s a decent explanation but I like the old standby, necessity is the mother of invention.