The following is part of a response to Jared Diamond’s Guns, Germs, and Steel.
Diamond’s most shocking point in the account of Pizarro’s victory at Cajamarca is the sheer magnitude of the advantage given by his steel weapons and armor, in addition to horses and occasional guns. It would be easy to attribute part of his victory to the shock and surprise which his attack had, but it would be difficult for surprise to allow 168 men to defeat 80,000. Indeed, the account of the slaughter describes the spaniards needing to kill wave upon wave of Incan lords before they were able to get to Atahuallpa. The advantage that the spanish weapons had against the incan armor, and vice versa, was completely overwhelming.
In his discussion of livestock, Diamond points out that they were not only advantageous as a form of food production, but as a Darwinian stimulus to evolve resistance to disease. Acting as sources of pathogens, humans who were in close contact with livestock would need to evolve ways to cope with the diseases they carried (and so pass on their genetics) or die (and so not likely be able to). Livestock thus acted as a catalyst for a disease-resistant population.
Diamond then brings these two ideas together, showing how they were not separate, but rather interconnected factors that allowed Eurasian cultures to take over the new world, rather than the other way around. The availability of large mammals for domestication in Eurasia created the possibility of densely settled societies where sedentary food surpluses could allow artisans to specialize in the innovation and creation of steel weapons. Add to that that the diseases themselves carried by Europeans often decimated New World populations, and the influence of livestock both in developing technology and in passing on pathogens is evident. In this way, the factors that gave eurasian societies an advantage over american ones should not be seen just as additive, but as multiplicative.
