How does the role of germs figure in answering Yali's question?
Yali's question is" Why is it that you white people developed so much cargo and brought it to New Guinea, but we black people have little cargo of our own?"
Diamond presents the argument that once societies began to evolve from hunters and gathers to food producers and farmers the paradigm shifted. People began to build homes to live in that were permanent. The areas were food production was cultivated became more dense in population. The societies then began to domesticate animals to be used in moving their cargo, plowing their fields and doing the heavy work.
The animals carried bacteria and germs which were passed on to people. The people became ill from these germs and the weaker people died while the stronger people developed an immunity to the germs. This concept of germs is what directly affected the development of stronger societies and wiped out weaker societies. Thus, the Natives were completely decimated by the Spanish explorers bringing their germs (Small Pox)to the Americas when they landed in Panama and Colombia.
"This (Small Pox) had killed the Inca emperor Huaqyna Capac and most of his court around 1526, and then immediately killed his designated heir, Ninan Cuyuchi. Those deaths precipitated a contest for the throne between Atahuallpa and his half brother Huascar. If it had not been for the epidemic, the Spaniards would have faced a united empire."
The Eurasians became the stronger race and colonized more land and gained more "cargo" partly because of the role of germs in our world history.