GUNS, GERMS AND STEEL - Cloverport Independent Schools

HEMISPHERES COLLIDING • 3 6 3
the Americas. Chiefdoms are inferred from archaeological evidence, such as ranked burials,
architecture, and settlement patterns. The table greatly simplifies a complex mass of historical
facts: see the text for some of the many important caveats.
another such society than for nomadic hunter-gatherers to "borrow" food
production from sedentary farmers (or to be replaced by the farmers).
WHY WERE THE trajectories of all key developments shifted to later
dates in the Americas than in Eurasia? Four groups of reasons suggest
themselves: the later start, more limited suite of wild animals and plants
available for domestication, greater barriers to diffusion, and possibly
smaller or more isolated areas of dense human populations in the Americas
than in Eurasia.
As for Eurasia's head start, humans have occupied Eurasia for about a
million years, far longer than they have lived in the Americas. According
to the archaeological evidence discussed in Chapter 1, humans entered the
Americas at Alaska only around 12,000 B.C., spread south of the Canadian
ice sheets as Clovis hunters a few centuries before 11,000 B.C., and
reached the southern tip of South America by 10,000 B.C. Even if the dis-