The Axis of a Continent

According to Jared Diamond, the picture below of some very basic geography explains nearly all of the "very differences experiences of Native Americans, Africans, and Eurasians." (176)  If one knows where a wide variety of domesticatable species are (Fertile Cresent) and the general terrain and weather of the general regions, you can follow and predict man's progress since our first steps out of Africa without being surprised by any twists or turns that this development takes.

If you were to remember one thing after reading Guns, Germs, and Steel, you would do well to remember this image.

Because climate (in general) varies depending of latitude (lines like the equator), crops that are domesticated at a certain latitude will be able to survive throughout that latitude.  The East-West axis of Eurasia meant that domesticated crops, animals, trade, art, and technology could be easily carried across the entire continent.  Breakthroughs in any of these developmentally-crucial areas would quickly and easily be adopted by all of the societies living there, which would accelerate them into discovering more things, etc...  Their East-West axis let the entire continent "brainstorm" and share advancements; this is why Europe and China were initially so advanced.

By comparison, the Americas (and to a lesser extent Africa) had a dominant North-South axis.  The climates along these axis differed very widely.  From the wide open plains of central North America, to the misty peaks of the Andes, to the lush Amazon Basin; the terrain varies almost like a spectrum as one travels from pole to pole.  The made the transmission of ideas, technology, livestock, and crops extremely difficult.  Entire civilizations, like the Incas, were seemingly "isolated" in their latitude.  Without the fast sharing of ideas, their development lagged behind that in Eurasia.

The effects of these very simple geographical differences decided the ENTIRE path of history.

Even though I normally do not like to accept anything as fate, this seems awfully hard to dispute.  If any of you reading this feel differently though, please share.