What are the ulltimate causes of the European conquest of the New World are, according to Guns, Germs, and Steel?
I understand that these causes stem from the Biophysical Environment, but I'd like a list of the ultimate factors and reasons why they led to the European Conquest of the New World. I believe that plant cultivation, animal domestication, and the east-west axis are ultimate causes, but please correct me if I'm wrong.
You are right that the east-west axis is an ultimate cause. On the other two, however, you should put the presence of many suitable wild species of plants and animals in Eurasia and the ability of those plants and animals to spread easily as the other two ultimate causes. You can see this in Figure 4.1 in the book.
The presence of many domesticable species allowed agriculture to start in Eurasia. The east-west axis allowed agriculture to spread. Agriculture, as Diamond explains throughout the book, is the key to creating large and complex civilizations. These civilizations allow “guns, germs, and steel” to arise or be invented.
So, the most ultimate causes are the fact that Eurasia had many domesticable plants and animals and the fact that its long east-west axis made it easy for those species to spread.