Just finished "Guns, Germs and Steel" by Jared Diamond. It was pretty good. His main point was coming up with a reason that "civilization as we know it" developed first in asia minor and then took off in china and europe, and the reason that europeans invaded america instead of the other way around. His proposal is that it had to do with (a) what wild plants and especially animals were available in different areas (eurasia had lots of good domesticatable animals, and high-protein cereals and pulses) and (b) which continents had long east-west axes vs. long north-south axes for the diffusion of culture, agriculture, and inventions (the same crops can be grown in china as spain, and so all the cultures along that axis eventually benefit from tje same agricultural innovations anywhere along it, while the use of the llama as a pack animal never made it north across central america, nor did the wheel ever come south across it: thus no llama-drawn plow!) I'm not sure I totally buy all his argumentation, but it makes a good story.