It’s a mystery why humans didn’t learn to produce food in areas of the globe that are, in theory, very suitable for food production. Indigenous people in California, Argentina, and Australia never developed agriculture even though the land has been put to good agricultural use later on.
One major obstacle to the theory of geographic determinism is the question of why societies that theoretically could have established agriculture did not—although Diamond will address this question somewhat later on.
Diamond briefly explains how archaeologists get information about the past. Archaeologists can identify ancient civilizations that had agriculture by carbon dating the ruins of these civilizations and determining their ages. Communities that once had farms and domesticated animals will have the remains of plant and animal matter from the same periods when those communities were thriving, often in the form of charcoal from a fire. One problem with tracing agriculture through ancient civilizations is that it’s sometimes hard to tell if certain plants and animals were actually domesticated in the area, or only brought in from other places through trade.
This is an important passage because it shows where Diamond gets his data from—and what the limits of his data are. Evidence of agricultural practices is spotty, since much of the evidence is thousands and thousands of years old, and the evidence that does survive is often unclear and fragmented (for example, remains of animal life in a fire).
Using carbon dating, archaeologists have identified areas where agriculture and the domestication of animals arose thousands of years ago: Mesopotamia, China, Mesoamerica, the Andes, and the Eastern United States. Of these, Mesopotamia has the earliest records of both agriculture and animal domestication, about 8500 B.C. There are also regions where agriculture arose somewhat later, perhaps between 6000 and 3500 B.C., including the Indus River Valley in present-day Pakistan and India. It is likely that these regions adopted agriculture after a single agricultural product entered the region through trade. Then there are regions like California and Australia where agriculture began abruptly with the arrival (or invasion) of European explorers.
The “original” centers of agriculture in the world were in Mesopotamia, China, and Central America. But the majority of societies in which agriculture flourishes did not discover agriculture independently; they acquired it from communication or trade with neighboring societies. Often, when colonists and explorers explored new regions, they brought agriculture with them, perhaps suggesting their awareness of agriculture’s importance in establishing an organized society.
In short, only a few areas of the world really developed agriculture independently—the other regions adopted it after communicating and trading with neighboring regions. The regions that developed agriculture earliest then had a head start toward guns, germs, and steel.
As the book goes on, Diamond clarifies what a “head start” truly means for a society. The societies that developed agriculture earliest (rather than acquiring it through trade) experimented with crop techniques before other societies did, meaning that they made important advances in technology first.