According to Guns, Germs, and Steel, why did Native American societies lag so far behind Eurasian societies in things like germs, technology, and...

The answer to this, as with almost everything else in this
book, has to do with geography and food
production.

According to Diamond, things like germs and
technology come to those who get food production earliest.  They are able to build large
societies and develop technology and political organizations and such.  Diamond argues
that the Americas were not a great place for food production.  There were few
domesticable plant species and essentially no large domesticable animals.  In addition,
the long north-south axis and the many barriers to movement (deserts, mountains,
jungles) along that axis made diffusion
difficult.

Geography, then, made it difficult for Native
Americans to develop food production and it made it difficult for crops and other
technologies to diffuse.  This meant that American societies had a harder time becoming
as developed and advanced as Eurasian societies became.