According to Jared Diamond, in Guns, Germs, and Steel, what are the three major elements that separate the world's haves from the have nots?

I am not certain how to identify exactly three factors that Diamond cites in Guns, Germs, and Steel that separated the world’s haves from the have-nots. If I had to identify exactly three, I would list them as the number of domesticable plant species in an area; the number of domesticable animal species; and the direction of the land mass’s axis.

Diamond does, of course, identify “guns, germs, and steel” as three factors that separated...

I am not certain how to identify exactly three factors that Diamond cites in Guns, Germs, and Steel that separated the world’s haves from the have-nots. If I had to identify exactly three, I would list them as the number of domesticable plant species in an area; the number of domesticable animal species; and the direction of the land mass’s axis.

Diamond does, of course, identify “guns, germs, and steel” as three factors that separated the world’s haves and have-nots.  However, these are only proximate factors.  It is too simple to say that the Europeans became the haves because they had guns, germs, and steel.  Instead, Diamond wants to know why the Europeans had these things.  He wants to know the ultimate causes behind the Europeans’ dominance.

In one sense, there is only one factor that explains the Europeans’ dominance. That is the fact that agriculture arose on their landmass before it arose anywhere else.  Diamond says that societies that got agriculture first became more technologically advanced than other societies and were therefore able to dominate those other societies. 

It is, however, possible to say that there are three factors that determine which places got agriculture first.  One factor is the number of plant species that could be domesticated. Diamond argues that an area with many plant species will be more likely to get agriculture simply because there are more plants that they might cultivate.  A second factor is the number of domesticable animals.  Animals can provide more protein for people’s diets, making them more likely to thrive.  They can provide fertilizer for plants and they can pull plows.  Thus, domesticable animals make it more likely that agriculture will arise in a given area.  Finally, there is the direction of the landmass’s axis.  If the landmass has a long east-west axis, it will be easier for crops to spread across the landmass.  This will mean that more places will get agriculture and, with it, civilization.

Thus, if I had to identify exactly three important factors from Guns, Germs, and Steel, I would say that they are the number of domesticable plant species, the number of domesticable animal species, and the direction of the axis of the landmass.