Why Humans Became Food Producers 235instability and seasonal dryness were annuals, including
wild cereal grains and legumes (such as peas, lentils, and
chickpeas). Because they complete their life cycle in a sin-
gle year, annuals can evolve very quickly under unstable
conditions. Moreover, they store their reproductive abili-
ties for the next wet season in abundant seeds, which can
remain dormant for prolonged periods.
The Natufians, who lived where these conditions were
especially severe, adapted by modifying their subsistence
practices in two ways. First, they probably burned the
landscape regularly to promote browsing by red deer and
grazing by gazelles, the main focus of their hunting activi-
ties. Second, they placed greater emphasis on the collec-
tion of wild seeds from the annual plants that could be
effectively stored to see people through the dry season.
The importance of stored foods, coupled with the scar-
city of reliable water sources, promoted more sedentary
living patterns, reflected in the substantial villages of late
Natufian times. The reliance upon seeds in Natufian sub-
sistence was made possible by the fact that they already
possessed sickles (originally used to cut reeds and sedges
for baskets) for harvesting grain and grinding stones for
processing a variety of wild foods.^11
The use of sickles to harvest grain turned out to have
important consequences, again unexpected, for the Natu-
fians. In the course of harvesting, it was inevitable that
many easily dispersed seeds would be lost at the harvest
site, whereas those from plants that did not readily scatter
their seeds would be mostly carried back to where people
processed and stored them.^12
The periodic burning of vegetation carried out to
promote the deer and gazelle herds may have also af-
fected the development of new genetic variation. Heat
is known to affect mutation rates. Also, fire removes in-
dividuals from a population, which changes the genetic
structure of a population drastically and quickly. With
seeds for nondispersing variants being carried back to
settlements, it was inevitable that some lost seeds would
germinate and grow there on dump heaps and other dis-
turbed sites (latrines, areas cleared of trees, or burned-
over terrain).
Many of the plants that became domesticated were
“colonizers,” variants that do particularly well in dis-
turbed habitats. Moreover, with people becoming in-
creasingly sedentary, disturbed habitats became more
extensive as resources closer to settlements were depleted
over time. Thus, variants of plants particularly suscep-
tible to human manipulation had more opportunities toEventually they began to cultivate various plants to provide
enough food for the community. According to this theory,
animal domestication began because the oases attracted
hungry animals, such as wild goats, sheep, and also cattle,
which came to graze on the stubble of the grain fields and to
drink. Finding that these animals were often too thin to kill
for food, people began to fatten them up.
Although Childe’s oasis theory can be critiqued on a
number of grounds and many other theories have been
proposed to account for the shift to domestication, it re-
mains historically significant as the first scientifically
testable explanation for the origins of food production.
Childe’s theory set the stage for the development of archae-
ology as a science. Later theories developed by archaeolo-
gists built on Childe’s ideas and took into account the role
of chance environmental circumstances of the specific
region along with other specific cultural factors that may
have driven change.
The Fertile Crescent
Present evidence indicates that the earliest plant domes-
tication took place gradually in the Fertile Crescent, the
long arc-shaped sweep of river valleys and coastal plains
extending from the Upper Nile (Sudan) to the Lower Ti-
gris (Iraq). Archaeological data suggest the domestica-
tion of rye as early as 13,000 years ago by people living
at a site (Abu Hureyra) east of Aleppo, Syria, although
wild plants and animals continued to be their major
food sources. Over the next several millennia they be-
came full-fledged farmers, cultivating rye and wheat.^9
By 10,300 years ago, others in the region were also grow-
ing crops.
This domestication process may have been the conse-
quence of a chance convergence of independent natural
events and other cultural developments.^10 The Natufians,
whose culture we looked at earlier in this chapter, illustrate
this process. These people lived at a time of dramatically
changing climates in Southwest Asia. With the end of the
last glaciation, temperatures became not only significantly
warmer but markedly seasonal as well. Between 6,000 and
12,000 years ago, the region experienced the most extreme
seasonality in its history, with dry summers significantly
longer and hotter than today. As a consequence of in-
creased evaporation, many shallow lakes dried up, leaving
just three in the Jordan River Valley.
At the same time, the region’s plant cover changed
dramatically. Those plants best adapted to environmental
(^9) Pringle, H. (1998). The slow birth of agriculture. Science 282, 1449.
(^10) McCorriston, J., & Hole, F. (1991). The ecology of seasonal stress and the
origins of agriculture in the Near East. American Anthropologist 93, 46–69.
(^11) Olszewki, D. I. (1991). Comment. Current Anthropology 32, 43.
(^12) Blumer, M. A., & Byrne, R. (1991). The ecological genetics and domesti-
cation and the origins of agriculture. Current Anthropology 32, 30.