How did Jared Diamond advance his argument in Part Three of Guns, Germs, and Steel?

In Part Three, Diamond attempts to describe how societies
that got agriculture first used that advantage to also get "guns, germs, and steel."  In
other words, he describes how the development of agriculture led to the development of
technology and of infectious diseases.  He also links agriculture to the development of
centralized governments.  All of these things allowed such societies to dominate other
societies.

Diamond advances his argument by making these
connections.  He shows how the presence of livestock in human communities led to the
evolution of infectious diseases.  He shows how agriculture led to larger populations
and, in turn, to technology.  He shows how these larger populations led to the need for
centralized government.

Diamond advances his argument,
then, by showing how the development of agriculture leads to the development of the more
proximate causes of European dominance.