Instead, what cries out for explanation is the failure of food production to appear, until modern times, in some ecologically very suitable areas that are among the world’s richest centers of agriculture and herding today.
Why did food production develop first in these seemingly rather marginal lands, and only later in today’s most fertile farmlands and pastures?
There are only five such areas for which the evidence is at present detailed and compelling: Southwest Asia, also known as the Near East or Fertile Crescent; China; Mesoamerica (the term applied to central and southern Mexico and adjacent areas of Central America); the Andes of South America, and possibly the adjacent Amazon Basin as well; and the eastern United States (Figure 5.1).
One factor is the decline in the availability of wild foods.