What is the question that Jared Diamond is trying to answer through his research?
Jared Diamond set out to answer the question, "How did the world become so unequal?" In other words, he was trying to figure out what separates the “haves” from the “have nots.”
In order to do this, he develops a thesis that states that it all traces back to geography. Specifically, he claims that the people of Europe had a geographic advantage over the people of the rest of the world, thereby making them the more dominant "haves" that ruled over the subordinate "have nots" throughout history.
There are many pieces of evidence he uses to support this thesis. He starts by describing how the Europeans have 13 out of 14 domesticated animals, whereas South America only had 1, the llama, which was not suited to be a beast of burden. Additionally, geography led the Europeans to figure out how to make guns and gunpowder, the materials for which were readily available in Europe, and these ideas spread easily throughout the continent. Even if South America had figured out this technological advancement, its geography was not conducive to easy cultural diffusion.
Piggy-backing on the idea of cultural diffusion was Diamond's argument that Pizzaro had read of Cortes’ conquest of the Aztecs, giving him ideas and strategy when planning his invasion of the South American natives; South American geography, by contrast, had not enabled that news to spread throughout the continent. The natives were in the dark as to what had happened to their counterparts in the northern part of their continent. Therefore, the Europeans had an advantage over the natives when invading and conquering them.
Finally, Diamond claims that geography benefited the Europeans by exposing them to smallpox, allowing them to develop antibodies to the diesease after living in close proximity to domesticated animals for thousands of years. Conversely, South Americans did not have these antibodies so they fell to the disease very easily. These are some of the ways Diamond successfully demonstrates how geography is the driving factor in what established the "haves" and the "have nots."