Slightly off topic but, I thoroughly enjoyed Jared Diamond's Gun's Germs and Steel[1]. Though his argument has some weaknesses, it makes an interesting case for why racial inequalities exist in the fashion that they do.
It's a great read, although as you say there are plenty of weaknesses. One of the theories this paper looks at is the impact on historical land distribution inequalities to the situation today, and that feels like a very Diamondesque argument.
[1] http://en.wikipedia.org/wiki/Guns,_Germs,_and_Steel