My favorite part is the calories-invested vs. calories-returned analysis of different crops. Northern European societies struggled along for centuries trying to emulate the Romans' wheat-based economy. Wheat has a very poor calories-invested-vs.-returned profile in Northern locales, so Mediterranean climates enjoyed an advantage. Potatos have a much different profile, which favors the cooler environments of Northern Europe. When explorers brought potatos back from the New World, it introduced a shift in the Continental balance of caloric abundance. Of course this alone does not explain the course of European history. Still, it is intriguing to wonder what role North American foods may have played. Cultural, military, and technological achievements represent human activity, so are fueled by food calories. It is not clear how much credit Native Americans deserve for the caloric profile of the potato; surely "Mother Nature" deserves some credit. In that sense, the book may be somewhat misnamed, however other areas of the book hit on more direct contributions of Native Americans to the world as we now know it. Overall, this is a very interesting read.